QWidget(3qt)QWidget(3qt)NAME
QWidget - The base class of all user interface objects
SYNOPSIS
#include <qwidget.h>
Inherits QObject and QPaintDevice.
Inherited by QAxWidget, QButton, QFrame, QDialog, QComboBox,
QDataBrowser, QDataView, QDateTimeEditBase, QDateTimeEdit,
QDesktopWidget, QDial, QDockArea, QGLWidget, QHeader, QMainWindow,
QMotifWidget, QNPWidget, QScrollBar, QSizeGrip, QSlider, QSpinBox,
QSplashScreen, QStatusBar, QTabBar, QTabWidget, QWorkspace, and
QXtWidget.
Public Members
explicit QWidget ( QWidget * parent = 0, const char * name = 0, WFlags
f = 0 )
~QWidget ()
WId winId () const
QStyle & style () const
void setStyle ( QStyle * style )
QStyle * setStyle ( const QString & style )
bool isTopLevel () const
bool isDialog () const
bool isPopup () const
bool isDesktop () const
bool isModal () const
bool isEnabled () const
bool isEnabledTo ( QWidget * ancestor ) const
bool isEnabledToTLW () const (obsolete)
QRect frameGeometry () const
const QRect & geometry () const
int x () const
int y () const
QPoint pos () const
QSize frameSize () const
QSize size () const
int width () const
int height () const
QRect rect () const
QRect childrenRect () const
QRegion childrenRegion () const
QSize minimumSize () const
QSize maximumSize () const
int minimumWidth () const
int minimumHeight () const
int maximumWidth () const
int maximumHeight () const
void setMinimumSize ( const QSize & )
virtual void setMinimumSize ( int minw, int minh )
void setMaximumSize ( const QSize & )
virtual void setMaximumSize ( int maxw, int maxh )
void setMinimumWidth ( int minw )
void setMinimumHeight ( int minh )
void setMaximumWidth ( int maxw )
void setMaximumHeight ( int maxh )
QSize sizeIncrement () const
void setSizeIncrement ( const QSize & )
virtual void setSizeIncrement ( int w, int h )
QSize baseSize () const
void setBaseSize ( const QSize & )
void setBaseSize ( int basew, int baseh )
void setFixedSize ( const QSize & s )
void setFixedSize ( int w, int h )
void setFixedWidth ( int w )
void setFixedHeight ( int h )
QPoint mapToGlobal ( const QPoint & pos ) const
QPoint mapFromGlobal ( const QPoint & pos ) const
QPoint mapToParent ( const QPoint & pos ) const
QPoint mapFromParent ( const QPoint & pos ) const
QPoint mapTo ( QWidget * parent, const QPoint & pos ) const
QPoint mapFrom ( QWidget * parent, const QPoint & pos ) const
QWidget * topLevelWidget () const
BackgroundMode backgroundMode () const
virtual void setBackgroundMode ( BackgroundMode )
void setBackgroundMode ( BackgroundMode m, BackgroundMode visual )
const QColor & foregroundColor () const
const QColor & eraseColor () const
virtual void setEraseColor ( const QColor & color )
const QPixmap * erasePixmap () const
virtual void setErasePixmap ( const QPixmap & pixmap )
const QColorGroup & colorGroup () const
const QPalette & palette () const
bool ownPalette () const
virtual void setPalette ( const QPalette & )
void unsetPalette ()
const QColor & paletteForegroundColor () const
void setPaletteForegroundColor ( const QColor & )
const QColor & paletteBackgroundColor () const
virtual void setPaletteBackgroundColor ( const QColor & )
const QPixmap * paletteBackgroundPixmap () const
virtual void setPaletteBackgroundPixmap ( const QPixmap & )
const QBrush & backgroundBrush () const
QFont font () const
bool ownFont () const
virtual void setFont ( const QFont & )
void unsetFont ()
QFontMetrics fontMetrics () const
QFontInfo fontInfo () const
const QCursor & cursor () const
bool ownCursor () const
virtual void setCursor ( const QCursor & )
virtual void unsetCursor ()
QString caption () const
const QPixmap * icon () const
QString iconText () const
bool hasMouseTracking () const
bool hasMouse () const
virtual void setMask ( const QBitmap & bitmap )
virtual void setMask ( const QRegion & region )
void clearMask ()
const QColor & backgroundColor () const (obsolete)
virtual void setBackgroundColor ( const QColor & c ) (obsolete)
const QPixmap * backgroundPixmap () const (obsolete)
virtual void setBackgroundPixmap ( const QPixmap & pm ) (obsolete)
enum FocusPolicy { NoFocus = 0, TabFocus = 0x1, ClickFocus = 0x2,
StrongFocus = TabFocus | ClickFocus | 0x8, WheelFocus = StrongFocus
| 0x4 }
bool isActiveWindow () const
virtual void setActiveWindow ()
bool isFocusEnabled () const
FocusPolicy focusPolicy () const
virtual void setFocusPolicy ( FocusPolicy )
bool hasFocus () const
virtual void setFocusProxy ( QWidget * w )
QWidget * focusProxy () const
void setInputMethodEnabled ( bool b )
bool isInputMethodEnabled () const
void grabMouse ()
void grabMouse ( const QCursor & cursor )
void releaseMouse ()
void grabKeyboard ()
void releaseKeyboard ()
bool isUpdatesEnabled () const
virtual bool close ( bool alsoDelete )
bool isVisible () const
bool isVisibleTo ( QWidget * ancestor ) const
bool isVisibleToTLW () const (obsolete)
QRect visibleRect () const (obsolete)
bool isHidden () const
bool isShown () const
bool isMinimized () const
bool isMaximized () const
bool isFullScreen () const
uint windowState () const
void setWindowState ( uint windowState )
virtual QSize sizeHint () const
virtual QSize minimumSizeHint () const
virtual QSizePolicy sizePolicy () const
virtual void setSizePolicy ( QSizePolicy )
void setSizePolicy ( QSizePolicy::SizeType hor, QSizePolicy::SizeType
ver, bool hfw = FALSE )
virtual int heightForWidth ( int w ) const
QRegion clipRegion () const
QLayout * layout () const
void updateGeometry ()
virtual void reparent ( QWidget * parent, WFlags f, const QPoint & p,
bool showIt = FALSE )
void reparent ( QWidget * parent, const QPoint & p, bool showIt = FALSE
)
void recreate ( QWidget * parent, WFlags f, const QPoint & p, bool
showIt = FALSE ) (obsolete)
void erase ()
void erase ( int x, int y, int w, int h )
void erase ( const QRect & r )
void erase ( const QRegion & reg )
void scroll ( int dx, int dy )
void scroll ( int dx, int dy, const QRect & r )
void drawText ( int x, int y, const QString & str )
void drawText ( const QPoint & pos, const QString & str )
QWidget * focusWidget () const
QRect microFocusHint () const
bool acceptDrops () const
virtual void setAcceptDrops ( bool on )
virtual void setAutoMask ( bool )
bool autoMask () const
enum BackgroundOrigin { WidgetOrigin, ParentOrigin, WindowOrigin,
AncestorOrigin }
virtual void setBackgroundOrigin ( BackgroundOrigin )
BackgroundOrigin backgroundOrigin () const
virtual bool customWhatsThis () const
QWidget * parentWidget ( bool sameWindow = FALSE ) const
WFlags testWFlags ( WFlags f ) const
QWidget * childAt ( int x, int y, bool includeThis = FALSE ) const
QWidget * childAt ( const QPoint & p, bool includeThis = FALSE ) const
void setWindowOpacity ( double level )
double windowOpacity () const
void setPalette ( const QPalette & p, bool ) (obsolete)
void setFont ( const QFont & f, bool ) (obsolete)
Public Slots
virtual void setEnabled ( bool )
void setDisabled ( bool disable )
virtual void setCaption ( const QString & )
virtual void setIcon ( const QPixmap & )
virtual void setIconText ( const QString & )
virtual void setMouseTracking ( bool enable )
virtual void setFocus ()
void clearFocus ()
virtual void setUpdatesEnabled ( bool enable )
void update ()
void update ( int x, int y, int w, int h )
void update ( const QRect & r )
void repaint ()
void repaint ( bool erase )
void repaint ( int x, int y, int w, int h, bool erase = TRUE )
void repaint ( const QRect & r, bool erase = TRUE )
void repaint ( const QRegion & reg, bool erase = TRUE )
virtual void show ()
virtual void hide ()
void setShown ( bool show )
void setHidden ( bool hide )
void iconify () (obsolete)
virtual void showMinimized ()
virtual void showMaximized ()
void showFullScreen ()
virtual void showNormal ()
virtual void polish ()
void constPolish () const
bool close ()
void raise ()
void lower ()
void stackUnder ( QWidget * w )
virtual void move ( int x, int y )
void move ( const QPoint & )
virtual void resize ( int w, int h )
void resize ( const QSize & )
virtual void setGeometry ( int x, int y, int w, int h )
virtual void setGeometry ( const QRect & )
virtual void adjustSize ()
Static Public Members
void setTabOrder ( QWidget * first, QWidget * second )
QWidget * mouseGrabber ()
QWidget * keyboardGrabber ()
QWidget * find ( WId id )
Properties
bool acceptDrops - whether drop events are enabled for this widget
bool autoMask - whether the auto mask feature is enabled for the widget
QBrush backgroundBrush - the widget's background brush (read only)
BackgroundMode backgroundMode - the color role used for painting the
background of the widget
BackgroundOrigin backgroundOrigin - the origin of the widget's
background
QSize baseSize - the base size of the widget
QString caption - the window caption (title)
QRect childrenRect - the bounding rectangle of the widget's children
(read only)
QRegion childrenRegion - the combined region occupied by the widget's
children (read only)
QColorGroup colorGroup - the current color group of the widget palette
(read only)
QCursor cursor - the cursor shape for this widget
bool customWhatsThis - whether the widget wants to handle What's This
help manually (read only)
bool enabled - whether the widget is enabled
bool focus - whether this widget (or its focus proxy) has the keyboard
input focus (read only)
bool focusEnabled - whether the widget accepts keyboard focus (read
only)
FocusPolicy focusPolicy - the way the widget accepts keyboard focus
QFont font - the font currently set for the widget
QRect frameGeometry - geometry of the widget relative to its parent
including any window frame (read only)
QSize frameSize - the size of the widget including any window frame
(read only)
bool fullScreen - whether the widget is full screen (read only)
QRect geometry - the geometry of the widget relative to its parent and
excluding the window frame
int height - the height of the widget excluding any window frame (read
only)
bool hidden - whether the widget is explicitly hidden
QPixmap icon - the widget's icon
QString iconText - the widget's icon text
bool inputMethodEnabled - enables or disables the use of input methods
for this widget
bool isActiveWindow - whether this widget is the active window (read
only)
bool isDesktop - whether the widget is a desktop widget, i.e.
represents the desktop (read only)
bool isDialog - whether the widget is a dialog widget (read only)
bool isModal - whether the widget is a modal widget (read only)
bool isPopup - whether the widget is a popup widget (read only)
bool isTopLevel - whether the widget is a top-level widget (read only)
bool maximized - whether this widget is maximized (read only)
int maximumHeight - the widget's maximum height
QSize maximumSize - the widget's maximum size
int maximumWidth - the widget's maximum width
QRect microFocusHint - the currently set micro focus hint for this
widget (read only)
bool minimized - whether this widget is minimized (iconified) (read
only)
int minimumHeight - the widget's minimum height
QSize minimumSize - the widget's minimum size
QSize minimumSizeHint - the recommended minimum size for the widget
(read only)
int minimumWidth - the widget's minimum width
bool mouseTracking - whether mouse tracking is enabled for the widget
bool ownCursor - whether the widget uses its own cursor (read only)
bool ownFont - whether the widget uses its own font (read only)
bool ownPalette - whether the widget uses its own palette (read only)
QPalette palette - the widget's palette
QColor paletteBackgroundColor - the background color of the widget
QPixmap paletteBackgroundPixmap - the background pixmap of the widget
QColor paletteForegroundColor - the foreground color of the widget
QPoint pos - the position of the widget within its parent widget
QRect rect - the internal geometry of the widget excluding any window
frame (read only)
bool shown - whether the widget is shown
QSize size - the size of the widget excluding any window frame
QSize sizeHint - the recommended size for the widget (read only)
QSize sizeIncrement - the size increment of the widget
QSizePolicy sizePolicy - the default layout behavior of the widget
bool underMouse - whether the widget is under the mouse cursor (read
only)
bool updatesEnabled - whether updates are enabled
bool visible - whether the widget is visible (read only)
QRect visibleRect - the visible rectangle (read only) (obsolete)
int width - the width of the widget excluding any window frame (read
only)
double windowOpacity - the level of opacity for the window
int x - the x coordinate of the widget relative to its parent including
any window frame (read only)
int y - the y coordinate of the widget relative to its parent and
including any window frame (read only)
Protected Members
virtual bool event ( QEvent * e )
virtual void mousePressEvent ( QMouseEvent * e )
virtual void mouseReleaseEvent ( QMouseEvent * e )
virtual void mouseDoubleClickEvent ( QMouseEvent * e )
virtual void mouseMoveEvent ( QMouseEvent * e )
virtual void wheelEvent ( QWheelEvent * e )
virtual void keyPressEvent ( QKeyEvent * e )
virtual void keyReleaseEvent ( QKeyEvent * e )
virtual void focusInEvent ( QFocusEvent * )
virtual void focusOutEvent ( QFocusEvent * )
virtual void enterEvent ( QEvent * )
virtual void leaveEvent ( QEvent * )
virtual void paintEvent ( QPaintEvent * )
virtual void moveEvent ( QMoveEvent * )
virtual void resizeEvent ( QResizeEvent * )
virtual void closeEvent ( QCloseEvent * e )
virtual void contextMenuEvent ( QContextMenuEvent * e )
virtual void imStartEvent ( QIMEvent * e )
virtual void imComposeEvent ( QIMEvent * e )
virtual void imEndEvent ( QIMEvent * e )
virtual void tabletEvent ( QTabletEvent * e )
virtual void dragEnterEvent ( QDragEnterEvent * )
virtual void dragMoveEvent ( QDragMoveEvent * )
virtual void dragLeaveEvent ( QDragLeaveEvent * )
virtual void dropEvent ( QDropEvent * )
virtual void showEvent ( QShowEvent * )
virtual void hideEvent ( QHideEvent * )
virtual bool macEvent ( MSG * )
virtual bool winEvent ( MSG * )
virtual bool x11Event ( XEvent * )
virtual bool qwsEvent ( QWSEvent * )
virtual void updateMask ()
virtual void styleChange ( QStyle & oldStyle )
virtual void enabledChange ( bool oldEnabled )
virtual void paletteChange ( const QPalette & oldPalette )
virtual void fontChange ( const QFont & oldFont )
virtual void windowActivationChange ( bool oldActive )
virtual int metric ( int m ) const
void resetInputContext ()
virtual void create ( WId window = 0, bool initializeWindow = TRUE,
bool destroyOldWindow = TRUE )
virtual void destroy ( bool destroyWindow = TRUE, bool
destroySubWindows = TRUE )
WFlags getWFlags () const
virtual void setWFlags ( WFlags f )
void clearWFlags ( WFlags f )
virtual bool focusNextPrevChild ( bool next )
QFocusData * focusData ()
virtual void setKeyCompression ( bool compress )
virtual void setMicroFocusHint ( int x, int y, int width, int height,
bool text = TRUE, QFont * f = 0 )
DESCRIPTION
The QWidget class is the base class of all user interface objects.
The widget is the atom of the user interface: it receives mouse,
keyboard and other events from the window system, and paints a
representation of itself on the screen. Every widget is rectangular,
and they are sorted in a Z-order. A widget is clipped by its parent and
by the widgets in front of it.
A widget that isn't embedded in a parent widget is called a top-level
widget. Usually, top-level widgets are windows with a frame and a title
bar (although it is also possible to create top-level widgets without
such decoration if suitable widget flags are used). In Qt, QMainWindow
and the various subclasses of QDialog are the most common top-level
windows.
A widget without a parent widget is always a top-level widget.
Non-top-level widgets are child widgets. These are child windows in
their parent widgets. You cannot usually distinguish a child widget
from its parent visually. Most other widgets in Qt are useful only as
child widgets. (It is possible to make, say, a button into a top-level
widget, but most people prefer to put their buttons inside other
widgets, e.g. QDialog.)
If you want to use a QWidget to hold child widgets you will probably
want to add a layout to the parent QWidget. (See Layouts.)
QWidget has many member functions, but some of them have little direct
functionality: for example, QWidget has a font property, but never uses
this itself. There are many subclasses which provide real
functionality, such as QPushButton, QListBox and QTabDialog, etc.
Groups of functions:
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</center>
Every widget's constructor accepts two or three standard arguments: <ol
type=1>
1 QWidget *parent = 0 is the parent of the new widget. If it is 0
(the default), the new widget will be a top-level window. If
not, it will be a child of parent, and be constrained by
parent's geometry (unless you specify WType_TopLevel as widget
flag).
2 const char *name = 0 is the widget name of the new widget. You
can access it using name(). The widget name is little used by
programmers but is quite useful with GUI builders such as Qt
Designer (you can name a widget in Qt Designer, and connect() to
it using the name in your code). The dumpObjectTree() debugging
function also uses it.
3 WFlags f = 0 (where available) sets the widget flags; the
default is suitable for almost all widgets, but to get, for
example, a top-level widget without a window system frame, you
must use special flags.
The tictac/tictac.cpp example program is good example of a simple
widget. It contains a few event handlers (as all widgets must), a few
custom routines that are specific to it (as all useful widgets do), and
has a few children and connections. Everything it does is done in
response to an event: this is by far the most common way to design GUI
applications.
You will need to supply the content for your widgets yourself, but here
is a brief run-down of the events, starting with the most common ones:
paintEvent() - called whenever the widget needs to be repainted. Every
widget which displays output must implement it, and it is wise not to
paint on the screen outside paintEvent().
resizeEvent() - called when the widget has been resized.
mousePressEvent() - called when a mouse button is pressed. There are
six mouse-related events, but the mouse press and mouse release events
are by far the most important. A widget receives mouse press events
when the mouse is inside it, or when it has grabbed the mouse using
grabMouse().
mouseReleaseEvent() - called when a mouse button is released. A widget
receives mouse release events when it has received the corresponding
mouse press event. This means that if the user presses the mouse inside
your widget, then drags the mouse to somewhere else, then releases,
your widget receives the release event. There is one exception: if a
popup menu appears while the mouse button is held down, this popup
immediately steals the mouse events.
mouseDoubleClickEvent() - not quite as obvious as it might seem. If the
user double-clicks, the widget receives a mouse press event (perhaps a
mouse move event or two if they don't hold the mouse quite steady), a
mouse release event and finally this event. It is not possible to
distinguish a click from a double click until you've seen whether the
second click arrives. (This is one reason why most GUI books recommend
that double clicks be an extension of single clicks, rather than
trigger a different action.)
If your widget only contains child widgets, you probably do not need to
implement any event handlers. If you want to detect a mouse click in a
child widget call the child's hasMouse() function inside the parent
widget's mousePressEvent().
Widgets that accept keyboard input need to reimplement a few more event
handlers:
keyPressEvent() - called whenever a key is pressed, and again when a
key has been held down long enough for it to auto-repeat. Note that the
Tab and Shift+Tab keys are only passed to the widget if they are not
used by the focus-change mechanisms. To force those keys to be
processed by your widget, you must reimplement QWidget::event().
focusInEvent() - called when the widget gains keyboard focus (assuming
you have called setFocusPolicy()). Well written widgets indicate that
they own the keyboard focus in a clear but discreet way.
focusOutEvent() - called when the widget loses keyboard focus.
Some widgets will also need to reimplement some of the less common
event handlers:
mouseMoveEvent() - called whenever the mouse moves while a button is
held down. This is useful for, for example, dragging. If you call
setMouseTracking(TRUE), you get mouse move events even when no buttons
are held down. (Note that applications which make use of mouse tracking
are often not very useful on low-bandwidth X connections.) (See also
the drag and drop information.)
keyReleaseEvent() - called whenever a key is released, and also while
it is held down if the key is auto-repeating. In that case the widget
receives a key release event and immediately a key press event for
every repeat. Note that the Tab and Shift+Tab keys are only passed to
the widget if they are not used by the focus-change mechanisms. To
force those keys to be processed by your widget, you must reimplement
QWidget::event().
wheelEvent()-- called whenever the user turns the mouse wheel while
the widget has the focus.
enterEvent() - called when the mouse enters the widget's screen space.
(This excludes screen space owned by any children of the widget.)
leaveEvent() - called when the mouse leaves the widget's screen space.
moveEvent() - called when the widget has been moved relative to its
parent.
closeEvent() - called when the user closes the widget (or when close()
is called).
There are also some rather obscure events. They are listed in qevent.h
and you need to reimplement event() to handle them. The default
implementation of event() handles Tab and Shift+Tab (to move the
keyboard focus), and passes on most other events to one of the more
specialized handlers above.
When implementing a widget, there are a few more things to consider.
In the constructor, be sure to set up your member variables early on,
before there's any chance that you might receive an event.
It is almost always useful to reimplement sizeHint() and to set the
correct size policy with setSizePolicy(), so users of your class can
set up layout management more easily. A size policy lets you supply
good defaults for the layout management handling, so that other widgets
can contain and manage yours easily. sizeHint() indicates a "good" size
for the widget.
If your widget is a top-level window, setCaption() and setIcon() set
the title bar and icon respectively.
See also QEvent, QPainter, QGridLayout, QBoxLayout, and Abstract Widget
Classes.
Member Type Documentation
QWidget::BackgroundOrigin
This enum defines the origin used to draw a widget's background pixmap.
The pixmap is drawn using the:
QWidget::WidgetOrigin - widget's coordinate system.
QWidget::ParentOrigin - parent's coordinate system.
QWidget::WindowOrigin - top-level window's coordinate system.
QWidget::AncestorOrigin - same origin as the parent uses.
QWidget::FocusPolicy
This enum type defines the various policies a widget can have with
respect to acquiring keyboard focus.
QWidget::TabFocus - the widget accepts focus by tabbing.
QWidget::ClickFocus - the widget accepts focus by clicking.
QWidget::StrongFocus - the widget accepts focus by both tabbing and
clicking. On Mac OS X this will also be indicate that the widget
accepts tab focus when in 'Text/List focus mode'.
QWidget::WheelFocus - like StrongFocus plus the widget accepts focus by
using the mouse wheel.
QWidget::NoFocus - the widget does not accept focus.
MEMBER FUNCTION DOCUMENTATIONexplicit QWidget::QWidget ( QWidget * parent = 0, const char * name = 0,
WFlags f = 0 )
Constructs a widget which is a child of parent, with the name name and
widget flags set to f.
If parent is 0, the new widget becomes a top-level window. If parent is
another widget, this widget becomes a child window inside parent. The
new widget is deleted when its parent is deleted.
The name is sent to the QObject constructor.
The widget flags argument, f, is normally 0, but it can be set to
customize the window frame of a top-level widget (i.e. parent must be
0). To customize the frame, set the WStyle_Customize flag OR'ed with
any of the Qt::WidgetFlags.
If you add a child widget to an already visible widget you must
explicitly show the child to make it visible.
Note that the X11 version of Qt may not be able to deliver all
combinations of style flags on all systems. This is because on X11, Qt
can only ask the window manager, and the window manager can override
the application's settings. On Windows, Qt can set whatever flags you
want.
Example:
QLabel *splashScreen = new QLabel( 0, "mySplashScreen",
WStyle_Customize | WStyle_Splash );
QWidget::~QWidget ()
Destroys the widget.
All this widget's children are deleted first. The application exits if
this widget is the main widget.
bool QWidget::acceptDrops () const
Returns TRUE if drop events are enabled for this widget; otherwise
returns FALSE. See the "acceptDrops" property for details.
void QWidget::adjustSize () [virtual slot]
Adjusts the size of the widget to fit the contents.
Uses sizeHint() if valid (i.e if the size hint's width and height are
>= 0), otherwise sets the size to the children rectangle (the union of
all child widget geometries).
See also sizeHint and childrenRect.
Example: xform/xform.cpp.
Reimplemented in QMessageBox.
bool QWidget::autoMask () const
Returns TRUE if the auto mask feature is enabled for the widget;
otherwise returns FALSE. See the "autoMask" property for details.
const QBrush & QWidget::backgroundBrush () const
Returns the widget's background brush. See the "backgroundBrush"
property for details.
const QColor & QWidget::backgroundColor () const
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code. Use
paletteBackgroundColor() or eraseColor() instead.
BackgroundMode QWidget::backgroundMode () const
Returns the color role used for painting the background of the widget.
See the "backgroundMode" property for details.
BackgroundOrigin QWidget::backgroundOrigin () const
Returns the origin of the widget's background. See the
"backgroundOrigin" property for details.
const QPixmap * QWidget::backgroundPixmap () const
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code. Use
paletteBackgroundPixmap() or erasePixmap() instead.
Examples:
QSize QWidget::baseSize () const
Returns the base size of the widget. See the "baseSize" property for
details.
QString QWidget::caption () const
Returns the window caption (title). See the "caption" property for
details.
QWidget * QWidget::childAt ( int x, int y, bool includeThis = FALSE ) const
Returns the visible child widget at pixel position (x, y) in the
widget's own coordinate system.
If includeThis is TRUE, and there is no child visible at (x, y), the
widget itself is returned.
QWidget * QWidget::childAt ( const QPoint & p, bool includeThis = FALSE )
const
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Returns the visible child widget at point p in the widget's own
coordinate system.
If includeThis is TRUE, and there is no child visible at p, the widget
itself is returned.
QRect QWidget::childrenRect () const
Returns the bounding rectangle of the widget's children. See the
"childrenRect" property for details.
QRegion QWidget::childrenRegion () const
Returns the combined region occupied by the widget's children. See the
"childrenRegion" property for details.
void QWidget::clearFocus () [slot]
Takes keyboard input focus from the widget.
If the widget has active focus, a focus out event is sent to this
widget to tell it that it is about to lose the focus.
This widget must enable focus setting in order to get the keyboard
input focus, i.e. it must call setFocusPolicy().
See also focus, setFocus(), focusInEvent(), focusOutEvent(),
focusPolicy, and QApplication::focusWidget().
void QWidget::clearMask ()
Removes any mask set by setMask().
See also setMask().
void QWidget::clearWFlags ( WFlags f ) [protected]
Clears the widget flags f.
Widget flags are a combination of Qt::WidgetFlags.
See also testWFlags(), getWFlags(), and setWFlags().
QRegion QWidget::clipRegion () const
Returns the unobscured region where paint events can occur.
For visible widgets, this is an approximation of the area not covered
by other widgets; otherwise, this is an empty region.
The repaint() function calls this function if necessary, so in general
you do not need to call it.
bool QWidget::close () [slot]
Closes this widget. Returns TRUE if the widget was closed; otherwise
returns FALSE.
First it sends the widget a QCloseEvent. The widget is hidden if it
accepts the close event. The default implementation of
QWidget::closeEvent() accepts the close event.
The QApplication::lastWindowClosed() signal is emitted when the last
visible top level widget is closed.
Examples:
bool QWidget::close ( bool alsoDelete ) [virtual]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Closes this widget. Returns TRUE if the widget was closed; otherwise
returns FALSE.
If alsoDelete is TRUE or the widget has the WDestructiveClose widget
flag, the widget is also deleted. The widget can prevent itself from
being closed by rejecting the QCloseEvent it gets. A close events is
delivered to the widget no matter if the widget is visible or not.
The QApplication::lastWindowClosed() signal is emitted when the last
visible top level widget is closed.
Note that closing the QApplication::mainWidget() terminates the
application.
See also closeEvent(), QCloseEvent, hide(), QApplication::quit(),
QApplication::setMainWidget(), and QApplication::lastWindowClosed().
void QWidget::closeEvent ( QCloseEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive widget close events.
The default implementation calls e->accept(), which hides this widget.
See the QCloseEvent documentation for more details.
See also event(), hide(), close(), and QCloseEvent.
Examples:
const QColorGroup & QWidget::colorGroup () const
Returns the current color group of the widget palette. See the
"colorGroup" property for details.
void QWidget::constPolish () const [slot]
Ensures that the widget is properly initialized by calling polish().
Call constPolish() from functions like sizeHint() that depends on the
widget being initialized, and that may be called before show().
Warning: Do not call constPolish() on a widget from inside that
widget's constructor.
See also polish().
void QWidget::contextMenuEvent ( QContextMenuEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive widget context menu events.
The default implementation calls e->ignore(), which rejects the context
event. See the QContextMenuEvent documentation for more details.
See also event() and QContextMenuEvent.
Example: menu/menu.cpp.
void QWidget::create ( WId window = 0, bool initializeWindow = TRUE, bool
destroyOldWindow = TRUE ) [virtual protected]
Creates a new widget window if window is 0, otherwise sets the widget's
window to window.
Initializes the window (sets the geometry etc.) if initializeWindow is
TRUE. If initializeWindow is FALSE, no initialization is performed.
This parameter only makes sense if window is a valid window.
Destroys the old window if destroyOldWindow is TRUE. If
destroyOldWindow is FALSE, you are responsible for destroying the
window yourself (using platform native code).
The QWidget constructor calls create(0,TRUE,TRUE) to create a window
for this widget.
const QCursor & QWidget::cursor () const
Returns the cursor shape for this widget. See the "cursor" property for
details.
bool QWidget::customWhatsThis () const [virtual]
Returns TRUE if the widget wants to handle What's This help manually;
otherwise returns FALSE. See the "customWhatsThis" property for
details.
void QWidget::destroy ( bool destroyWindow = TRUE, bool destroySubWindows =
TRUE ) [virtual protected]
Frees up window system resources. Destroys the widget window if
destroyWindow is TRUE.
destroy() calls itself recursively for all the child widgets, passing
destroySubWindows for the destroyWindow parameter. To have more control
over destruction of subwidgets, destroy subwidgets selectively first.
This function is usually called from the QWidget destructor.
void QWidget::dragEnterEvent ( QDragEnterEvent * ) [virtual protected]
This event handler is called when a drag is in progress and the mouse
enters this widget.
See the Drag-and-drop documentation for an overview of how to provide
drag-and-drop in your application.
See also QTextDrag, QImageDrag, and QDragEnterEvent.
Example: iconview/simple_dd/main.cpp.
void QWidget::dragLeaveEvent ( QDragLeaveEvent * ) [virtual protected]
This event handler is called when a drag is in progress and the mouse
leaves this widget.
See the Drag-and-drop documentation for an overview of how to provide
drag-and-drop in your application.
See also QTextDrag, QImageDrag, and QDragLeaveEvent.
void QWidget::dragMoveEvent ( QDragMoveEvent * ) [virtual protected]
This event handler is called when a drag is in progress and the mouse
enters this widget, and whenever it moves within the widget.
See the Drag-and-drop documentation for an overview of how to provide
drag-and-drop in your application.
See also QTextDrag, QImageDrag, and QDragMoveEvent.
void QWidget::drawText ( int x, int y, const QString & str )
Draws the string str at position (x, y).
The y position is the base line position of the text. The text is drawn
using the default font and the default foreground color.
This function is provided for convenience. You will generally get more
flexible results and often higher speed by using a a painter instead.
See also font, foregroundColor(), and QPainter::drawText().
void QWidget::drawText ( const QPoint & pos, const QString & str )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Draws the string str at position pos.
void QWidget::dropEvent ( QDropEvent * ) [virtual protected]
This event handler is called when the drag is dropped on this widget.
See the Drag-and-drop documentation for an overview of how to provide
drag-and-drop in your application.
See also QTextDrag, QImageDrag, and QDropEvent.
Example: iconview/simple_dd/main.cpp.
void QWidget::enabledChange ( bool oldEnabled ) [virtual protected]
This virtual function is called from setEnabled(). oldEnabled is the
previous setting; you can get the new setting from isEnabled().
Reimplement this function if your widget needs to know when it becomes
enabled or disabled. You will almost certainly need to update the
widget using update().
The default implementation repaints the visible part of the widget.
See also enabled, enabled, repaint(), update(), and clipRegion().
void QWidget::enterEvent ( QEvent * ) [virtual protected]
This event handler can be reimplemented in a subclass to receive widget
enter events.
An event is sent to the widget when the mouse cursor enters the widget.
See also leaveEvent(), mouseMoveEvent(), and event().
void QWidget::erase ( int x, int y, int w, int h )
Erases the specified area (x, y, w, h) in the widget without generating
a paint event.
If w is negative, it is replaced with width() - x. If h is negative, it
is replaced width height() - y.
Child widgets are not affected.
See also repaint().
void QWidget::erase ()
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This version erases the entire widget.
void QWidget::erase ( const QRect & r )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Erases the specified area r in the widget without generating a paint
event.
void QWidget::erase ( const QRegion & reg )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Erases the area defined by reg, without generating a paint event.
Child widgets are not affected.
const QColor & QWidget::eraseColor () const
Returns the erase color of the widget.
See also setEraseColor(), setErasePixmap(), and backgroundColor().
const QPixmap * QWidget::erasePixmap () const
Returns the widget's erase pixmap.
See also setErasePixmap() and eraseColor().
bool QWidget::event ( QEvent * e ) [virtual protected]
This is the main event handler; it handles event e. You can reimplement
this function in a subclass, but we recommend using one of the
specialized event handlers instead.
The main event handler first passes an event through all event filters
that have been installed. If none of the filters intercept the event,
it calls one of the specialized event handlers.
Key press and release events are treated differently from other events.
event() checks for Tab and Shift+Tab and tries to move the focus
appropriately. If there is no widget to move the focus to (or the key
press is not Tab or Shift+Tab), event() calls keyPressEvent().
This function returns TRUE if it is able to pass the event over to
someone (i.e. someone wanted the event); otherwise returns FALSE.
See also closeEvent(), focusInEvent(), focusOutEvent(), enterEvent(),
keyPressEvent(), keyReleaseEvent(), leaveEvent(),
mouseDoubleClickEvent(), mouseMoveEvent(), mousePressEvent(),
mouseReleaseEvent(), moveEvent(), paintEvent(), resizeEvent(),
QObject::event(), and QObject::timerEvent().
Reimplemented from QObject.
QWidget * QWidget::find ( WId id ) [static]
Returns a pointer to the widget with window identifer/handle id.
The window identifier type depends on the underlying window system, see
qwindowdefs.h for the actual definition. If there is no widget with
this identifier, 0 is returned.
QFocusData * QWidget::focusData () [protected]
Returns the focus data for this widget's top-level widget.
Focus data always belongs to the top-level widget. The focus data list
contains all the widgets in this top-level widget that can accept
focus, in tab order. An iterator points to the current focus widget
(focusWidget() returns a pointer to this widget).
This information is useful for implementing advanced versions of
focusNextPrevChild().
void QWidget::focusInEvent ( QFocusEvent * ) [virtual protected]
This event handler can be reimplemented in a subclass to receive
keyboard focus events (focus received) for the widget.
A widget normally must setFocusPolicy() to something other than NoFocus
in order to receive focus events. (Note that the application programmer
can call setFocus() on any widget, even those that do not normally
accept focus.)
The default implementation updates the widget (except for toplevel
widgets that do not specify a focusPolicy() ). It also calls
setMicroFocusHint(), hinting any system-specific input tools about the
focus of the user's attention.
See also focusOutEvent(), focusPolicy, keyPressEvent(),
keyReleaseEvent(), event(), and QFocusEvent.
bool QWidget::focusNextPrevChild ( bool next ) [virtual protected]
Finds a new widget to give the keyboard focus to, as appropriate for
Tab and Shift+Tab, and returns TRUE if is can find a new widget and
FALSE if it can't,
If next is TRUE, this function searches "forwards", if next is FALSE,
it searches "backwards".
Sometimes, you will want to reimplement this function. For example, a
web browser might reimplement it to move its "current active link"
forwards or backwards, and call QWidget::focusNextPrevChild() only when
it reaches the last or first link on the "page".
Child widgets call focusNextPrevChild() on their parent widgets, but
only the top-level widget decides where to redirect focus. By
overriding this method for an object, you thus gain control of focus
traversal for all child widgets.
Warning: QScrollView uses it own logic for this function, which does
the right thing in most cases. But if you are using a QScrollView and
want complete control of the focus chain you'll need to override
QScrollView::focusNextPrevChild() and your top-level widgets'
focusNextPrevChild() functions.
See also focusData().
void QWidget::focusOutEvent ( QFocusEvent * ) [virtual protected]
This event handler can be reimplemented in a subclass to receive
keyboard focus events (focus lost) for the widget.
A widget normally must setFocusPolicy() to something other than NoFocus
in order to receive focus events. (Note that the application programmer
can call setFocus() on any widget, even those that do not normally
accept focus.)
The default implementation updates the widget (except for toplevel
widgets that do not specify a focusPolicy() ). It also calls
setMicroFocusHint(), hinting any system-specific input tools about the
focus of the user's attention.
See also focusInEvent(), focusPolicy, keyPressEvent(),
keyReleaseEvent(), event(), and QFocusEvent.
Example: qmag/qmag.cpp.
FocusPolicy QWidget::focusPolicy () const
Returns the way the widget accepts keyboard focus. See the
"focusPolicy" property for details.
QWidget * QWidget::focusProxy () const
Returns the focus proxy, or 0 if there is no focus proxy.
See also setFocusProxy().
QWidget * QWidget::focusWidget () const
Returns the focus widget in this widget's window. This is not the same
as QApplication::focusWidget(), which returns the focus widget in the
currently active window.
QFont QWidget::font () const
Returns the font currently set for the widget. See the "font" property
for details.
void QWidget::fontChange ( const QFont & oldFont ) [virtual protected]
This virtual function is called from setFont(). oldFont is the previous
font; you can get the new font from font().
Reimplement this function if your widget needs to know when its font
changes. You will almost certainly need to update the widget using
update().
The default implementation updates the widget including its geometry.
See also font, font, update(), and updateGeometry().
QFontInfo QWidget::fontInfo () const
Returns the font info for the widget's current font. Equivalent to
QFontInto(widget->font()).
See also font, fontMetrics(), and font.
QFontMetrics QWidget::fontMetrics () const
Returns the font metrics for the widget's current font. Equivalent to
QFontMetrics(widget->font()).
See also font, fontInfo(), and font.
Examples:
const QColor & QWidget::foregroundColor () const
Same as paletteForegroundColor()QRect QWidget::frameGeometry () const
Returns geometry of the widget relative to its parent including any
window frame. See the "frameGeometry" property for details.
QSize QWidget::frameSize () const
Returns the size of the widget including any window frame. See the
"frameSize" property for details.
const QRect & QWidget::geometry () const
Returns the geometry of the widget relative to its parent and excluding
the window frame. See the "geometry" property for details.
WFlags QWidget::getWFlags () const [protected]
Returns the widget flags for this this widget.
Widget flags are a combination of Qt::WidgetFlags.
See also testWFlags(), setWFlags(), and clearWFlags().
void QWidget::grabKeyboard ()
Grabs the keyboard input.
This widget reveives all keyboard events until releaseKeyboard() is
called; other widgets get no keyboard events at all. Mouse events are
not affected. Use grabMouse() if you want to grab that.
The focus widget is not affected, except that it doesn't receive any
keyboard events. setFocus() moves the focus as usual, but the new focus
widget receives keyboard events only after releaseKeyboard() is called.
If a different widget is currently grabbing keyboard input, that
widget's grab is released first.
See also releaseKeyboard(), grabMouse(), releaseMouse(), and
focusWidget().
void QWidget::grabMouse ()
Grabs the mouse input.
This widget receives all mouse events until releaseMouse() is called;
other widgets get no mouse events at all. Keyboard events are not
affected. Use grabKeyboard() if you want to grab that.
Warning: Bugs in mouse-grabbing applications very often lock the
terminal. Use this function with extreme caution, and consider using
the -nograb command line option while debugging.
It is almost never necessary to grab the mouse when using Qt, as Qt
grabs and releases it sensibly. In particular, Qt grabs the mouse when
a mouse button is pressed and keeps it until the last button is
released.
Note that only visible widgets can grab mouse input. If isVisible()
returns FALSE for a widget, that widget cannot call grabMouse().
See also releaseMouse(), grabKeyboard(), releaseKeyboard(),
grabKeyboard(), and focusWidget().
void QWidget::grabMouse ( const QCursor & cursor )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Grabs the mouse input and changes the cursor shape.
The cursor will assume shape cursor (for as long as the mouse focus is
grabbed) and this widget will be the only one to receive mouse events
until releaseMouse() is called().
Warning: Grabbing the mouse might lock the terminal.
See also releaseMouse(), grabKeyboard(), releaseKeyboard(), and cursor.
bool QWidget::hasFocus () const
Returns TRUE if this widget (or its focus proxy) has the keyboard input
focus; otherwise returns FALSE. See the "focus" property for details.
bool QWidget::hasMouse () const
Returns TRUE if the widget is under the mouse cursor; otherwise returns
FALSE. See the "underMouse" property for details.
bool QWidget::hasMouseTracking () const
Returns TRUE if mouse tracking is enabled for the widget; otherwise
returns FALSE. See the "mouseTracking" property for details.
int QWidget::height () const
Returns the height of the widget excluding any window frame. See the
"height" property for details.
int QWidget::heightForWidth ( int w ) const [virtual]
Returns the preferred height for this widget, given the width w. The
default implementation returns 0, indicating that the preferred height
does not depend on the width.
Warning: Does not look at the widget's layout.
Reimplemented in QMenuBar and QTextEdit.
void QWidget::hide () [virtual slot]
Hides the widget.
You almost never have to reimplement this function. If you need to do
something after a widget is hidden, use hideEvent() instead.
See also hideEvent(), hidden, show(), showMinimized(), visible, and
close().
Examples:
Reimplemented in QMenuBar.
void QWidget::hideEvent ( QHideEvent * ) [virtual protected]
This event handler can be reimplemented in a subclass to receive widget
hide events.
Hide events are sent to widgets immediately after they have been
hidden.
See also event() and QHideEvent.
Reimplemented in QScrollBar.
const QPixmap * QWidget::icon () const
Returns the widget's icon. See the "icon" property for details.
QString QWidget::iconText () const
Returns the widget's icon text. See the "iconText" property for
details.
void QWidget::iconify () [slot]
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
void QWidget::imComposeEvent ( QIMEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive Input Method composition events. This handler is called when
the user has entered some text using an Input Method.
The default implementation calls e->ignore(), which rejects the Input
Method event. See the QIMEvent documentation for more details.
See also event() and QIMEvent.
void QWidget::imEndEvent ( QIMEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive Input Method composition events. This handler is called when
the user has finished inputting text via an Input Method.
The default implementation calls e->ignore(), which rejects the Input
Method event. See the QIMEvent documentation for more details.
See also event() and QIMEvent.
void QWidget::imStartEvent ( QIMEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive Input Method composition events. This handler is called when
the user begins entering text using an Input Method.
The default implementation calls e->ignore(), which rejects the Input
Method event. See the QIMEvent documentation for more details.
See also event() and QIMEvent.
bool QWidget::isActiveWindow () const
Returns TRUE if this widget is the active window; otherwise returns
FALSE. See the "isActiveWindow" property for details.
bool QWidget::isDesktop () const
Returns TRUE if the widget is a desktop widget, i.e. represents the
desktop; otherwise returns FALSE. See the "isDesktop" property for
details.
bool QWidget::isDialog () const
Returns TRUE if the widget is a dialog widget; otherwise returns FALSE.
See the "isDialog" property for details.
bool QWidget::isEnabled () const
Returns TRUE if the widget is enabled; otherwise returns FALSE. See the
"enabled" property for details.
bool QWidget::isEnabledTo ( QWidget * ancestor ) const
Returns TRUE if this widget would become enabled if ancestor is
enabled; otherwise returns FALSE.
This is the case if neither the widget itself nor every parent up to
but excluding ancestor has been explicitly disabled.
isEnabledTo(0) is equivalent to isEnabled().
See also enabled and enabled.
bool QWidget::isEnabledToTLW () const
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
This function is deprecated. It is equivalent to isEnabled()bool QWidget::isFocusEnabled () const
Returns TRUE if the widget accepts keyboard focus; otherwise returns
FALSE. See the "focusEnabled" property for details.
bool QWidget::isFullScreen () const
Returns TRUE if the widget is full screen; otherwise returns FALSE. See
the "fullScreen" property for details.
bool QWidget::isHidden () const
Returns TRUE if the widget is explicitly hidden; otherwise returns
FALSE. See the "hidden" property for details.
bool QWidget::isInputMethodEnabled () const
Returns enables or disables the use of input methods for this widget.
See the "inputMethodEnabled" property for details.
bool QWidget::isMaximized () const
Returns TRUE if this widget is maximized; otherwise returns FALSE. See
the "maximized" property for details.
bool QWidget::isMinimized () const
Returns TRUE if this widget is minimized (iconified); otherwise returns
FALSE. See the "minimized" property for details.
bool QWidget::isModal () const
Returns TRUE if the widget is a modal widget; otherwise returns FALSE.
See the "isModal" property for details.
bool QWidget::isPopup () const
Returns TRUE if the widget is a popup widget; otherwise returns FALSE.
See the "isPopup" property for details.
bool QWidget::isShown () const
Returns TRUE if the widget is shown; otherwise returns FALSE. See the
"shown" property for details.
bool QWidget::isTopLevel () const
Returns TRUE if the widget is a top-level widget; otherwise returns
FALSE. See the "isTopLevel" property for details.
bool QWidget::isUpdatesEnabled () const
Returns TRUE if updates are enabled; otherwise returns FALSE. See the
"updatesEnabled" property for details.
bool QWidget::isVisible () const
Returns TRUE if the widget is visible; otherwise returns FALSE. See the
"visible" property for details.
bool QWidget::isVisibleTo ( QWidget * ancestor ) const
Returns TRUE if this widget would become visible if ancestor is shown;
otherwise returns FALSE.
The TRUE case occurs if neither the widget itself nor any parent up to
but excluding ancestor has been explicitly hidden.
This function will still return TRUE if the widget is obscured by other
windows on the screen, but could be physically visible if it or they
were to be moved.
isVisibleTo(0) is identical to isVisible().
See also show(), hide(), and visible.
bool QWidget::isVisibleToTLW () const
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
This function is deprecated. It is equivalent to isVisible()void QWidget::keyPressEvent ( QKeyEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive key press events for the widget.
A widget must call setFocusPolicy() to accept focus initially and have
focus in order to receive a key press event.
If you reimplement this handler, it is very important that you
explicitly ignore the event if you do not understand it, so that the
widget's parent can interpret it; otherwise, the event will be
implicitly accepted. Although top-level widgets are able to choose
whether to accept or ignore unknown events because they have no parent
widgets that could otherwise handle them, it is good practice to
explicitly ignore events to make widgets as reusable as possible.
The default implementation closes popup widgets if the user presses
Esc. Otherwise the event is ignored.
See also keyReleaseEvent(), QKeyEvent::ignore(), focusPolicy,
focusInEvent(), focusOutEvent(), event(), and QKeyEvent.
Example: picture/picture.cpp.
Reimplemented in QLineEdit and QTextEdit.
void QWidget::keyReleaseEvent ( QKeyEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive key release events for the widget.
A widget must accept focus initially and have focus in order to receive
a key release event.
If you reimplement this handler, it is very important that you ignore()
the release if you do not understand it, so that the widget's parent
can interpret it.
The default implementation ignores the event.
See also keyPressEvent(), QKeyEvent::ignore(), focusPolicy,
focusInEvent(), focusOutEvent(), event(), and QKeyEvent.
QWidget * QWidget::keyboardGrabber () [static]
Returns the widget that is currently grabbing the keyboard input.
If no widget in this application is currently grabbing the keyboard, 0
is returned.
See also grabMouse() and mouseGrabber().
QLayout * QWidget::layout () const
Returns the layout engine that manages the geometry of this widget's
children.
If the widget does not have a layout, layout() returns 0.
See also sizePolicy.
Examples:
void QWidget::leaveEvent ( QEvent * ) [virtual protected]
This event handler can be reimplemented in a subclass to receive widget
leave events.
A leave event is sent to the widget when the mouse cursor leaves the
widget.
See also enterEvent(), mouseMoveEvent(), and event().
void QWidget::lower () [slot]
Lowers the widget to the bottom of the parent widget's stack.
After this call the widget will be visually behind (and therefore
obscured by) any overlapping sibling widgets.
See also raise() and stackUnder().
bool QWidget::macEvent ( MSG * ) [virtual protected]
This special event handler can be reimplemented in a subclass to
receive native Macintosh events.
In your reimplementation of this function, if you want to stop the
event being handled by Qt, return TRUE. If you return FALSE, this
native event is passed back to Qt, which translates the event into a Qt
event and sends it to the widget.
Warning: This function is not portable.
See also QApplication::macEventFilter().
QPoint QWidget::mapFrom ( QWidget * parent, const QPoint & pos ) const
Translates the widget coordinate pos from the coordinate system of
parent to this widget's coordinate system. The parent must not be 0 and
must be a parent of the calling widget.
See also mapTo(), mapFromParent(), mapFromGlobal(), and underMouse.
QPoint QWidget::mapFromGlobal ( const QPoint & pos ) const
Translates the global screen coordinate pos to widget coordinates.
See also mapToGlobal(), mapFrom(), and mapFromParent().
QPoint QWidget::mapFromParent ( const QPoint & pos ) const
Translates the parent widget coordinate pos to widget coordinates.
Same as mapFromGlobal() if the widget has no parent.
See also mapToParent(), mapFrom(), mapFromGlobal(), and underMouse.
QPoint QWidget::mapTo ( QWidget * parent, const QPoint & pos ) const
Translates the widget coordinate pos to the coordinate system of
parent. The parent must not be 0 and must be a parent of the calling
widget.
See also mapFrom(), mapToParent(), mapToGlobal(), and underMouse.
QPoint QWidget::mapToGlobal ( const QPoint & pos ) const
Translates the widget coordinate pos to global screen coordinates. For
example, mapToGlobal(QPoint(0,0)) would give the global coordinates of
the top-left pixel of the widget.
See also mapFromGlobal(), mapTo(), and mapToParent().
Example: scribble/scribble.cpp.
QPoint QWidget::mapToParent ( const QPoint & pos ) const
Translates the widget coordinate pos to a coordinate in the parent
widget.
Same as mapToGlobal() if the widget has no parent.
See also mapFromParent(), mapTo(), mapToGlobal(), and underMouse.
int QWidget::maximumHeight () const
Returns the widget's maximum height. See the "maximumHeight" property
for details.
QSize QWidget::maximumSize () const
Returns the widget's maximum size. See the "maximumSize" property for
details.
int QWidget::maximumWidth () const
Returns the widget's maximum width. See the "maximumWidth" property for
details.
int QWidget::metric ( int m ) const [virtual protected]
Internal implementation of the virtual QPaintDevice::metric() function.
Use the QPaintDeviceMetrics class instead.
m is the metric to get.
QRect QWidget::microFocusHint () const
Returns the currently set micro focus hint for this widget. See the
"microFocusHint" property for details.
int QWidget::minimumHeight () const
Returns the widget's minimum height. See the "minimumHeight" property
for details.
QSize QWidget::minimumSize () const
Returns the widget's minimum size. See the "minimumSize" property for
details.
QSize QWidget::minimumSizeHint () const [virtual]
Returns the recommended minimum size for the widget. See the
"minimumSizeHint" property for details.
Reimplemented in QLineEdit.
int QWidget::minimumWidth () const
Returns the widget's minimum width. See the "minimumWidth" property for
details.
void QWidget::mouseDoubleClickEvent ( QMouseEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive mouse double click events for the widget.
The default implementation generates a normal mouse press event.
Note that the widgets gets a mousePressEvent() and a
mouseReleaseEvent() before the mouseDoubleClickEvent().
See also mousePressEvent(), mouseReleaseEvent(), mouseMoveEvent(),
event(), and QMouseEvent.
QWidget * QWidget::mouseGrabber () [static]
Returns the widget that is currently grabbing the mouse input.
If no widget in this application is currently grabbing the mouse, 0 is
returned.
See also grabMouse() and keyboardGrabber().
void QWidget::mouseMoveEvent ( QMouseEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive mouse move events for the widget.
If mouse tracking is switched off, mouse move events only occur if a
mouse button is pressed while the mouse is being moved. If mouse
tracking is switched on, mouse move events occur even if no mouse
button is pressed.
QMouseEvent::pos() reports the position of the mouse cursor, relative
to this widget. For press and release events, the position is usually
the same as the position of the last mouse move event, but it might be
different if the user's hand shakes. This is a feature of the
underlying window system, not Qt.
See also mouseTracking, mousePressEvent(), mouseReleaseEvent(),
mouseDoubleClickEvent(), event(), and QMouseEvent.
Examples:
Reimplemented in QSizeGrip.
void QWidget::mousePressEvent ( QMouseEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive mouse press events for the widget.
If you create new widgets in the mousePressEvent() the
mouseReleaseEvent() may not end up where you expect, depending on the
underlying window system (or X11 window manager), the widgets' location
and maybe more.
The default implementation implements the closing of popup widgets when
you click outside the window. For other widget types it does nothing.
See also mouseReleaseEvent(), mouseDoubleClickEvent(),
mouseMoveEvent(), event(), and QMouseEvent.
Examples:
Reimplemented in QSizeGrip.
void QWidget::mouseReleaseEvent ( QMouseEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive mouse release events for the widget.
See also mouseDoubleClickEvent(), mouseMoveEvent(), event(), and
QMouseEvent.
Examples:
void QWidget::move ( const QPoint & ) [slot]
Sets the position of the widget within its parent widget. See the "pos"
property for details.
void QWidget::move ( int x, int y ) [virtual slot]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This corresponds to move( QPoint(x, y) ).
void QWidget::moveEvent ( QMoveEvent * ) [virtual protected]
This event handler can be reimplemented in a subclass to receive widget
move events. When the widget receives this event, it is already at the
new position.
The old position is accessible through QMoveEvent::oldPos().
See also resizeEvent(), event(), pos, and QMoveEvent.
bool QWidget::ownCursor () const
Returns TRUE if the widget uses its own cursor; otherwise returns
FALSE. See the "ownCursor" property for details.
bool QWidget::ownFont () const
Returns TRUE if the widget uses its own font; otherwise returns FALSE.
See the "ownFont" property for details.
bool QWidget::ownPalette () const
Returns TRUE if the widget uses its own palette; otherwise returns
FALSE. See the "ownPalette" property for details.
void QWidget::paintEvent ( QPaintEvent * ) [virtual protected]
This event handler can be reimplemented in a subclass to receive paint
events.
A paint event is a request to repaint all or part of the widget. It can
happen as a result of repaint() or update(), or because the widget was
obscured and has now been uncovered, or for many other reasons.
Many widgets can simply repaint their entire surface when asked to, but
some slow widgets need to optimize by painting only the requested
region: QPaintEvent::region(). This speed optimization does not change
the result, as painting is clipped to that region during event
processing. QListView and QCanvas do this, for example.
Qt also tries to speed up painting by merging multiple paint events
into one. When update() is called several times or the window system
sends several paint events, Qt merges these events into one event with
a larger region (see QRegion::unite()). repaint() does not permit this
optimization, so we suggest using update() when possible.
When the paint event occurs, the update region has normally been
erased, so that you're painting on the widget's background. There are a
couple of exceptions and QPaintEvent::erased() tells you whether the
widget has been erased or not.
The background can be set using setBackgroundMode(),
setPaletteBackgroundColor() or setBackgroundPixmap(). The documentation
for setBackgroundMode() elaborates on the background; we recommend
reading it.
See also event(), repaint(), update(), QPainter, QPixmap, and
QPaintEvent.
Examples:
Reimplemented in QButton, QFrame, QGLWidget, QSizeGrip, QStatusBar, and
QTabBar.
const QPalette & QWidget::palette () const
Returns the widget's palette. See the "palette" property for details.
const QColor & QWidget::paletteBackgroundColor () const
Returns the background color of the widget. See the
"paletteBackgroundColor" property for details.
const QPixmap * QWidget::paletteBackgroundPixmap () const
Returns the background pixmap of the widget. See the
"paletteBackgroundPixmap" property for details.
void QWidget::paletteChange ( const QPalette & oldPalette ) [virtual
protected]
This virtual function is called from setPalette(). oldPalette is the
previous palette; you can get the new palette from palette().
Reimplement this function if your widget needs to know when its palette
changes.
See also palette and palette.
const QColor & QWidget::paletteForegroundColor () const
Returns the foreground color of the widget. See the
"paletteForegroundColor" property for details.
QWidget * QWidget::parentWidget ( bool sameWindow = FALSE ) const
Returns the parent of this widget, or 0 if it does not have any parent
widget. If sameWindow is TRUE and the widget is top level returns 0;
otherwise returns the widget's parent.
Example: mdi/application.cpp.
void QWidget::polish () [virtual slot]
Delayed initialization of a widget.
This function will be called after a widget has been fully created and
before it is shown the very first time.
Polishing is useful for final initialization which depends on having an
instantiated widget. This is something a constructor cannot guarantee
since the initialization of the subclasses might not be finished.
After this function, the widget has a proper font and palette and
QApplication::polish() has been called.
Remember to call QWidget's implementation first when reimplementing
this function to ensure that your program does not end up in infinite
recursion.
See also constPolish() and QApplication::polish().
Example: menu/menu.cpp.
QPoint QWidget::pos () const
Returns the position of the widget within its parent widget. See the
"pos" property for details.
bool QWidget::qwsEvent ( QWSEvent * ) [virtual protected]
This special event handler can be reimplemented in a subclass to
receive native Qt/Embedded events.
In your reimplementation of this function, if you want to stop the
event being handled by Qt, return TRUE. If you return FALSE, this
native event is passed back to Qt, which translates the event into a Qt
event and sends it to the widget.
Warning: This function is not portable.
See also QApplication::qwsEventFilter().
void QWidget::raise () [slot]
Raises this widget to the top of the parent widget's stack.
After this call the widget will be visually in front of any overlapping
sibling widgets.
See also lower() and stackUnder().
Example: showimg/showimg.cpp.
void QWidget::recreate ( QWidget * parent, WFlags f, const QPoint & p, bool
showIt = FALSE )
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
This method is provided to aid porting from Qt 1.0 to 2.0. It has been
renamed reparent() in Qt 2.0.
QRect QWidget::rect () const
Returns the internal geometry of the widget excluding any window frame.
See the "rect" property for details.
void QWidget::releaseKeyboard ()
Releases the keyboard grab.
See also grabKeyboard(), grabMouse(), and releaseMouse().
void QWidget::releaseMouse ()
Releases the mouse grab.
See also grabMouse(), grabKeyboard(), and releaseKeyboard().
void QWidget::repaint ( int x, int y, int w, int h, bool erase = TRUE ) [slot]
Repaints the widget directly by calling paintEvent() immediately,
unless updates are disabled or the widget is hidden.
If erase is TRUE, Qt erases the area (x, y, w, h) before the
paintEvent() call.
If w is negative, it is replaced with width() - x, and if h is
negative, it is replaced width height() - y.
We suggest only using repaint() if you need an immediate repaint, for
example during animation. In almost all circumstances update() is
better, as it permits Qt to optimize for speed and minimize flicker.
Warning: If you call repaint() in a function which may itself be called
from paintEvent(), you may get infinite recursion. The update()
function never causes recursion.
See also update(), paintEvent(), updatesEnabled, and erase().
Example: qwerty/qwerty.cpp.
void QWidget::repaint () [slot]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This version erases and repaints the entire widget.
void QWidget::repaint ( bool erase ) [slot]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This version repaints the entire widget.
void QWidget::repaint ( const QRect & r, bool erase = TRUE ) [slot]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Repaints the widget directly by calling paintEvent() directly, unless
updates are disabled or the widget is hidden.
Erases the widget region r if erase is TRUE.
void QWidget::repaint ( const QRegion & reg, bool erase = TRUE ) [slot]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Repaints the widget directly by calling paintEvent() directly, unless
updates are disabled or the widget is hidden.
Erases the widget region reg if erase is TRUE.
Only use repaint if your widget needs to be repainted immediately, for
example when doing some animation. In all other cases, use update().
Calling update() many times in a row will generate a single paint
event.
Warning: If you call repaint() in a function which may itself be called
from paintEvent(), you may get infinite recursion. The update()
function never causes recursion.
See also update(), paintEvent(), updatesEnabled, and erase().
void QWidget::reparent ( QWidget * parent, WFlags f, const QPoint & p, bool
showIt = FALSE ) [virtual]
Reparents the widget. The widget gets a new parent, new widget flags
(f, but as usual, use 0) at a new position in its new parent (p).
If showIt is TRUE, show() is called once the widget has been
reparented.
If the new parent widget is in a different top-level widget, the
reparented widget and its children are appended to the end of the tab
chain of the new parent widget, in the same internal order as before.
If one of the moved widgets had keyboard focus, reparent() calls
clearFocus() for that widget.
If the new parent widget is in the same top-level widget as the old
parent, reparent doesn't change the tab order or keyboard focus.
Warning: It is extremely unlikely that you will ever need this
function. If you have a widget that changes its content dynamically, it
is far easier to use QWidgetStack or QWizard.
See also getWFlags().
Example: toplevel/options.ui.h.
void QWidget::reparent ( QWidget * parent, const QPoint & p, bool showIt =
FALSE )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
A convenience version of reparent that does not take widget flags as
argument.
Calls reparent(parent, getWFlags() & ~WType_Mask, p, showIt).
void QWidget::resetInputContext () [protected]
This function is called when the user finishes input composition, e.g.
changes focus to another widget, moves the cursor, etc.
void QWidget::resize ( const QSize & ) [slot]
Sets the size of the widget excluding any window frame. See the "size"
property for details.
void QWidget::resize ( int w, int h ) [virtual slot]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This corresponds to resize( QSize(w, h) ).
void QWidget::resizeEvent ( QResizeEvent * ) [virtual protected]
This event handler can be reimplemented in a subclass to receive widget
resize events. When resizeEvent() is called, the widget already has its
new geometry. The old size is accessible through
QResizeEvent::oldSize().
The widget will be erased and receive a paint event immediately after
processing the resize event. No drawing need be (or should be) done
inside this handler.
Widgets that have been created with the WNoAutoErase flag will not be
erased. Nevertheless, they will receive a paint event for their entire
area afterwards. Again, no drawing needs to be done inside this
handler.
The default implementation calls updateMask() if the widget has
automatic masking enabled.
See also moveEvent(), event(), size, QResizeEvent, and paintEvent().
Examples:
Reimplemented in QFrame and QGLWidget.
void QWidget::scroll ( int dx, int dy )
Scrolls the widget including its children dx pixels to the right and dy
downwards. Both dx and dy may be negative.
After scrolling, scroll() sends a paint event for the the part that is
read but not written. For example, when scrolling 10 pixels rightwards,
the leftmost ten pixels of the widget need repainting. The paint event
may be delivered immediately or later, depending on some heuristics
(note that you might have to force processing of paint events using
QApplication::sendPostedEvents() when using scroll() and move() in
combination).
See also QScrollView, erase(), and bitBlt().
void QWidget::scroll ( int dx, int dy, const QRect & r )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This version only scrolls r and does not move the children of the
widget.
If r is empty or invalid, the result is undefined.
See also QScrollView, erase(), and bitBlt().
void QWidget::setAcceptDrops ( bool on ) [virtual]
Sets whether drop events are enabled for this widget to on. See the
"acceptDrops" property for details.
void QWidget::setActiveWindow () [virtual]
Sets the top-level widget containing this widget to be the active
window.
An active window is a visible top-level window that has the keyboard
input focus.
This function performs the same operation as clicking the mouse on the
title bar of a top-level window. On X11, the result depends on the
Window Manager. If you want to ensure that the window is stacked on top
as well you should also call raise(). Note that the window must be
visible, otherwise setActiveWindow() has no effect.
On Windows, if you are calling this when the application is not
currently the active one then it will not make it the active window. It
will flash the task bar entry blue to indicate that the window has done
something. This is because Microsoft do not allow an application to
interrupt what the user is currently doing in another application.
See also isActiveWindow, topLevelWidget(), and show().
Reimplemented in QXtWidget.
void QWidget::setAutoMask ( bool ) [virtual]
Sets whether the auto mask feature is enabled for the widget. See the
"autoMask" property for details.
void QWidget::setBackgroundColor ( const QColor & c ) [virtual]
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code. Use
setPaletteBackgroundColor() or setEraseColor() instead.
Examples:
void QWidget::setBackgroundMode ( BackgroundMode ) [virtual]
Sets the color role used for painting the background of the widget. See
the "backgroundMode" property for details.
void QWidget::setBackgroundMode ( BackgroundMode m, BackgroundMode visual )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Sets the widget's own background mode to m and the visual background
mode to visual. The visual background mode is used with the designable
properties backgroundColor, foregroundColor and backgroundPixmap.
For complex controls, the logical background mode sometimes differs
from a widget's own background mode. A spinbox for example has
PaletteBackground as background mode (typically dark gray), while it's
embedded lineedit control uses PaletteBase (typically white). Since the
lineedit covers most of the visual area of a spinbox, it defines
PaletteBase to be its visual background mode. Changing the
backgroundColor property thus changes the lineedit control's
background, which is exactly what the user expects in Qt Designer.
void QWidget::setBackgroundOrigin ( BackgroundOrigin ) [virtual]
Sets the origin of the widget's background. See the "backgroundOrigin"
property for details.
void QWidget::setBackgroundPixmap ( const QPixmap & pm ) [virtual]
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code. Use
setPaletteBackgroundPixmap() or setErasePixmap() instead.
Example: desktop/desktop.cpp.
void QWidget::setBaseSize ( const QSize & )
Sets the base size of the widget. See the "baseSize" property for
details.
void QWidget::setBaseSize ( int basew, int baseh )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This corresponds to setBaseSize( QSize(basew, baseh) ). Sets the
widgets base size to width basew and height baseh.
void QWidget::setCaption ( const QString & ) [virtual slot]
Sets the window caption (title). See the "caption" property for
details.
void QWidget::setCursor ( const QCursor & ) [virtual]
Sets the cursor shape for this widget. See the "cursor" property for
details.
void QWidget::setDisabled ( bool disable ) [slot]
Disables widget input events if disable is TRUE; otherwise enables
input events.
See the enabled documentation for more information.
See also isEnabledTo(), QKeyEvent, QMouseEvent, and enabledChange().
void QWidget::setEnabled ( bool ) [virtual slot]
Sets whether the widget is enabled. See the "enabled" property for
details.
void QWidget::setEraseColor ( const QColor & color ) [virtual]
Sets the erase color of the widget to color.
The erase color is the color the widget is to be cleared to before
paintEvent() is called. If there is an erase pixmap (set using
setErasePixmap()), then this property has an indeterminate value.
See also erasePixmap(), backgroundColor(), backgroundMode, and palette.
void QWidget::setErasePixmap ( const QPixmap & pixmap ) [virtual]
Sets the widget's erase pixmap to pixmap.
This pixmap is used to clear the widget before paintEvent() is called.
void QWidget::setFixedHeight ( int h )
Sets both the minimum and maximum heights of the widget to h without
changing the widths. Provided for convenience.
See also sizeHint, minimumSize, maximumSize, and setFixedSize().
Examples:
void QWidget::setFixedSize ( const QSize & s )
Sets both the minimum and maximum sizes of the widget to s, thereby
preventing it from ever growing or shrinking.
See also maximumSize and minimumSize.
void QWidget::setFixedSize ( int w, int h )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Sets the width of the widget to w and the height to h.
void QWidget::setFixedWidth ( int w )
Sets both the minimum and maximum width of the widget to w without
changing the heights. Provided for convenience.
See also sizeHint, minimumSize, maximumSize, and setFixedSize().
Examples:
void QWidget::setFocus () [virtual slot]
Gives the keyboard input focus to this widget (or its focus proxy) if
this widget or one of its parents is the active window.
First, a focus out event is sent to the focus widget (if any) to tell
it that it is about to lose the focus. Then a focus in event is sent to
this widget to tell it that it just received the focus. (Nothing
happens if the focus in and focus out widgets are the same.)
setFocus() gives focus to a widget regardless of its focus policy, but
does not clear any keyboard grab (see grabKeyboard()).
Be aware that if the widget is hidden, it will not accept focus.
Warning: If you call setFocus() in a function which may itself be
called from focusOutEvent() or focusInEvent(), you may get an infinite
recursion.
See also focus, clearFocus(), focusInEvent(), focusOutEvent(),
focusPolicy, QApplication::focusWidget(), grabKeyboard(), and
grabMouse().
Examples:
void QWidget::setFocusPolicy ( FocusPolicy ) [virtual]
Sets the way the widget accepts keyboard focus. See the "focusPolicy"
property for details.
void QWidget::setFocusProxy ( QWidget * w ) [virtual]
Sets the widget's focus proxy to widget w. If w is 0, the function
resets this widget to have no focus proxy.
Some widgets, such as QComboBox, can "have focus", but create a child
widget to actually handle the focus. QComboBox, for example, creates a
QLineEdit which handles the focus.
setFocusProxy() sets the widget which will actually get focus when"
this widget" gets it. If there is a focus proxy, focusPolicy(),
setFocusPolicy(), setFocus() and hasFocus() all operate on the focus
proxy.
See also focusProxy().
void QWidget::setFont ( const QFont & ) [virtual]
Sets the font currently set for the widget. See the "font" property for
details.
Reimplemented in QComboBox, QLabel, and QTabDialog.
void QWidget::setFont ( const QFont & f, bool )
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
Use setFont(const QFont& font) instead.
void QWidget::setGeometry ( const QRect & ) [virtual slot]
Sets the geometry of the widget relative to its parent and excluding
the window frame. See the "geometry" property for details.
void QWidget::setGeometry ( int x, int y, int w, int h ) [virtual slot]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This corresponds to setGeometry( QRect(x, y, w, h) ).
void QWidget::setHidden ( bool hide ) [slot]
Sets whether the widget is explicitly hidden to hide. See the "hidden"
property for details.
void QWidget::setIcon ( const QPixmap & ) [virtual slot]
Sets the widget's icon. See the "icon" property for details.
void QWidget::setIconText ( const QString & ) [virtual slot]
Sets the widget's icon text. See the "iconText" property for details.
void QWidget::setInputMethodEnabled ( bool b )
Sets enables or disables the use of input methods for this widget to b.
See the "inputMethodEnabled" property for details.
void QWidget::setKeyCompression ( bool compress ) [virtual protected]
Enables key event compression, if compress is TRUE, and disables it if
compress is FALSE.
Key compression is off by default (except for QLineEdit and QTextEdit),
so widgets receive one key press event for each key press (or more,
since autorepeat is usually on). If you turn it on and your program
doesn't keep up with key input, Qt may try to compress key events so
that more than one character can be processed in each event.
For example, a word processor widget might receive 2, 3 or more
characters in each QKeyEvent::text(), if the layout recalculation takes
too long for the CPU.
If a widget supports multiple character unicode input, it is always
safe to turn the compression on.
Qt performs key event compression only for printable characters.
Modifier keys, cursor movement keys, function keys and miscellaneous
action keys (e.g. Escape, Enter, Backspace, PrintScreen) will stop key
event compression, even if there are more compressible key events
available.
Not all platforms support this compression, in which case turning it on
will have no effect.
See also QKeyEvent::text().
void QWidget::setMask ( const QBitmap & bitmap ) [virtual]
Causes only the pixels of the widget for which bitmap has a
corresponding 1 bit to be visible. Use Qt::color0 to draw transparent
regions and Qt::color1 to draw opaque regions of the bitmap.
If the region includes pixels outside the rect() of the widget, window
system controls in that area may or may not be visible, depending on
the platform.
Note that this effect can be slow if the region is particularly
complex.
See examples/tux for an example of masking for transparency.
See also clearMask().
void QWidget::setMask ( const QRegion & region ) [virtual]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Causes only the parts of the widget which overlap region to be visible.
If the region includes pixels outside the rect() of the widget, window
system controls in that area may or may not be visible, depending on
the platform.
Note that this effect can be slow if the region is particularly
complex.
See also clearMask().
void QWidget::setMaximumHeight ( int maxh )
Sets the widget's maximum height to maxh. See the "maximumHeight"
property for details.
void QWidget::setMaximumSize ( const QSize & )
Sets the widget's maximum size. See the "maximumSize" property for
details.
void QWidget::setMaximumSize ( int maxw, int maxh ) [virtual]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This function corresponds to setMaximumSize( QSize(maxw, maxh) ). Sets
the maximum width to maxw and the maximum height to maxh.
void QWidget::setMaximumWidth ( int maxw )
Sets the widget's maximum width to maxw. See the "maximumWidth"
property for details.
void QWidget::setMicroFocusHint ( int x, int y, int width, int height, bool
text = TRUE, QFont * f = 0 ) [virtual protected]
When a widget gets focus, it should call setMicroFocusHint() with some
appropriate position and size, x, y, width and height. This has no
visual effect, it just provides hints to any system-specific input
handling tools.
The text argument should be TRUE if this is a position for text input.
In the Windows version of Qt, this method sets the system caret, which
is used for user Accessibility focus handling. If text is TRUE, it also
sets the IME composition window in Far East Asian language input
systems.
In the X11 version of Qt, if text is TRUE, this method sets the XIM
"spot" point for complex language input handling.
The font f is a rendering hint to the currently active input method. If
f is 0 the widget's font is used.
See also microFocusHint.
void QWidget::setMinimumHeight ( int minh )
Sets the widget's minimum height to minh. See the "minimumHeight"
property for details.
void QWidget::setMinimumSize ( const QSize & )
Sets the widget's minimum size. See the "minimumSize" property for
details.
void QWidget::setMinimumSize ( int minw, int minh ) [virtual]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
This function corresponds to setMinimumSize( QSize(minw, minh) ). Sets
the minimum width to minw and the minimum height to minh.
void QWidget::setMinimumWidth ( int minw )
Sets the widget's minimum width to minw. See the "minimumWidth"
property for details.
void QWidget::setMouseTracking ( bool enable ) [virtual slot]
Sets whether mouse tracking is enabled for the widget to enable. See
the "mouseTracking" property for details.
void QWidget::setPalette ( const QPalette & ) [virtual]
Sets the widget's palette. See the "palette" property for details.
Reimplemented in QComboBox, QScrollBar, and QSlider.
void QWidget::setPalette ( const QPalette & p, bool )
This function is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
Use setPalette( const QPalette& p ) instead.
void QWidget::setPaletteBackgroundColor ( const QColor & ) [virtual]
Sets the background color of the widget. See the
"paletteBackgroundColor" property for details.
void QWidget::setPaletteBackgroundPixmap ( const QPixmap & ) [virtual]
Sets the background pixmap of the widget. See the
"paletteBackgroundPixmap" property for details.
void QWidget::setPaletteForegroundColor ( const QColor & )
Sets the foreground color of the widget. See the
"paletteForegroundColor" property for details.
void QWidget::setShown ( bool show ) [slot]
Sets whether the widget is shown to show. See the "shown" property for
details.
void QWidget::setSizeIncrement ( const QSize & )
Sets the size increment of the widget. See the "sizeIncrement" property
for details.
void QWidget::setSizeIncrement ( int w, int h ) [virtual]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Sets the x (width) size increment to w and the y (height) size
increment to h.
void QWidget::setSizePolicy ( QSizePolicy ) [virtual]
Sets the default layout behavior of the widget. See the "sizePolicy"
property for details.
void QWidget::setSizePolicy ( QSizePolicy::SizeType hor, QSizePolicy::SizeType
ver, bool hfw = FALSE )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Sets the size policy of the widget to hor, ver and hfw (height for
width).
See also QSizePolicy::QSizePolicy().
void QWidget::setStyle ( QStyle * style )
Sets the widget's GUI style to style. Ownership of the style object is
not transferred.
If no style is set, the widget uses the application's style,
QApplication::style() instead.
Setting a widget's style has no effect on existing or future child
widgets.
Warning: This function is particularly useful for demonstration
purposes, where you want to show Qt's styling capabilities. Real
applications should avoid it and use one consistent GUI style instead.
See also style(), QStyle, QApplication::style(), and
QApplication::setStyle().
Examples:
QStyle * QWidget::setStyle ( const QString & style )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Sets the widget's GUI style to style using the QStyleFactory.
void QWidget::setTabOrder ( QWidget * first, QWidget * second ) [static]
Moves the second widget around the ring of focus widgets so that
keyboard focus moves from the first widget to the second widget when
the Tab key is pressed.
Note that since the tab order of the second widget is changed, you
should order a chain like this:
setTabOrder( a, b ); // a to b
setTabOrder( b, c ); // a to b to c
setTabOrder( c, d ); // a to b to c to d
not like this:
setTabOrder( c, d ); // c to d WRONG
setTabOrder( a, b ); // a to b AND c to d
setTabOrder( b, c ); // a to b to c, but not c to d
If first or second has a focus proxy, setTabOrder() correctly
substitutes the proxy.
See also focusPolicy and setFocusProxy().
Example: customlayout/main.cpp.
void QWidget::setUpdatesEnabled ( bool enable ) [virtual slot]
Sets whether updates are enabled to enable. See the "updatesEnabled"
property for details.
void QWidget::setWFlags ( WFlags f ) [virtual protected]
Sets the widget flags f.
Widget flags are a combination of Qt::WidgetFlags.
See also testWFlags(), getWFlags(), and clearWFlags().
void QWidget::setWindowOpacity ( double level )
Sets the level of opacity for the window to level. See the
"windowOpacity" property for details.
void QWidget::setWindowState ( uint windowState )
Sets the window state to windowState. The window state is a OR'ed
combination of Qt::WindowState: WindowMinimized, WindowMaximized,
WindowFullScreen and WindowActive.
If the window is not visible (i.e. isVisible() returns FALSE), the
window state will take effect when show() is called. For visible
windows, the change is immediate. For example, to toggle between full-
screen and mormal mode, use the following code:
w->setWindowState(w->windowState() ^ WindowFullScreen);
In order to restore and activate a minimized window (while preserving
its maximized and/or full-screen state), use the following:
w->setWindowState(w->windowState() & ~WindowMinimized | WindowActive);
Note: On some window systems WindowActive is not immediate, and may be
ignored in certain cases.
See also Qt::WindowState and windowState().
void QWidget::show () [virtual slot]
Shows the widget and its child widgets.
If its size or position has changed, Qt guarantees that a widget gets
move and resize events just before it is shown.
You almost never have to reimplement this function. If you need to
change some settings before a widget is shown, use showEvent() instead.
If you need to do some delayed initialization use polish().
See also showEvent(), hide(), showMinimized(), showMaximized(),
showNormal(), visible, and polish().
Examples:
Reimplemented in QDialog and QMenuBar.
void QWidget::showEvent ( QShowEvent * ) [virtual protected]
This event handler can be reimplemented in a subclass to receive widget
show events.
Non-spontaneous show events are sent to widgets immediately before they
are shown. The spontaneous show events of top-level widgets are
delivered afterwards.
See also event() and QShowEvent.
Example: qdir/qdir.cpp.
void QWidget::showFullScreen () [slot]
Shows the widget in full-screen mode.
Calling this function only affects top-level widgets.
To return from full-screen mode, call showNormal().
Full-screen mode works fine under Windows, but has certain problems
under X. These problems are due to limitations of the ICCCM protocol
that specifies the communication between X11 clients and the window
manager. ICCCM simply does not understand the concept of non-decorated
full-screen windows. Therefore, the best we can do is to request a
borderless window and place and resize it to fill the entire screen.
Depending on the window manager, this may or may not work. The
borderless window is requested using MOTIF hints, which are at least
partially supported by virtually all modern window managers.
An alternative would be to bypass the window manager entirely and
create a window with the WX11BypassWM flag. This has other severe
problems though, like totally broken keyboard focus and very strange
effects on desktop changes or when the user raises other windows.
X11 window managers that follow modern post-ICCCM specifications
support full-screen mode properly.
See also showNormal(), showMaximized(), show(), hide(), and visible.
void QWidget::showMaximized () [virtual slot]
Shows the widget maximized.
Calling this function only affects top-level widgets.
On X11, this function may not work properly with certain window
managers. See the Window Geometry documentation for an explanation.
See also setWindowState(), showNormal(), showMinimized(), show(),
hide(), and visible.
Examples:
void QWidget::showMinimized () [virtual slot]
Shows the widget minimized, as an icon.
Calling this function only affects top-level widgets.
See also showNormal(), showMaximized(), show(), hide(), visible, and
minimized.
void QWidget::showNormal () [virtual slot]
Restores the widget after it has been maximized or minimized.
Calling this function only affects top-level widgets.
See also setWindowState(), showMinimized(), showMaximized(), show(),
hide(), and visible.
Example: mdi/application.cpp.
QSize QWidget::size () const
Returns the size of the widget excluding any window frame. See the
"size" property for details.
QSize QWidget::sizeHint () const [virtual]
Returns the recommended size for the widget. See the "sizeHint"
property for details.
Reimplemented in QSizeGrip.
QSize QWidget::sizeIncrement () const
Returns the size increment of the widget. See the "sizeIncrement"
property for details.
QSizePolicy QWidget::sizePolicy () const [virtual]
Returns the default layout behavior of the widget. See the "sizePolicy"
property for details.
void QWidget::stackUnder ( QWidget * w ) [slot]
Places the widget under w in the parent widget's stack.
To make this work, the widget itself and w must be siblings.
See also raise() and lower().
QStyle & QWidget::style () const
Returns the GUI style for this widget
See also QWidget::setStyle(), QApplication::setStyle(), and
QApplication::style().
void QWidget::styleChange ( QStyle & oldStyle ) [virtual protected]
This virtual function is called when the style of the widgets changes.
oldStyle is the previous GUI style; you can get the new style from
style().
Reimplement this function if your widget needs to know when its GUI
style changes. You will almost certainly need to update the widget
using update().
The default implementation updates the widget including its geometry.
See also QApplication::setStyle(), style(), update(), and
updateGeometry().
void QWidget::tabletEvent ( QTabletEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive tablet events for the widget.
If you reimplement this handler, it is very important that you ignore()
the event if you do not handle it, so that the widget's parent can
interpret it.
The default implementation ignores the event.
See also QTabletEvent::ignore(), QTabletEvent::accept(), event(), and
QTabletEvent.
WFlags QWidget::testWFlags ( WFlags f ) const
Returns the bitwise AND of the widget flags and f.
Widget flags are a combination of Qt::WidgetFlags.
If you want to test for the presence of multiple flags (or composite
flags such as WStyle_Splash), test the return value for equality
against the argument. For example:
int flags = WStyle_Tool | WStyle_NoBorder;
if ( testWFlags(flags) )
... // WStyle_Tool or WStyle_NoBorder or both are set
if ( testWFlags(flags) == flags )
... // both WStyle_Tool and WStyle_NoBorder are set
See also getWFlags(), setWFlags(), and clearWFlags().
QWidget * QWidget::topLevelWidget () const
Returns the top-level widget for this widget, i.e. the next ancestor
widget that has (or could have) a window-system frame.
If the widget is a top-level, the widget itself is returned.
Typical usage is changing the window caption:
aWidget->topLevelWidget()->setCaption( "New Caption" );
See also isTopLevel.
void QWidget::unsetCursor () [virtual]
Resets the cursor shape for this widget. See the "cursor" property for
details.
void QWidget::unsetFont ()
Resets the font currently set for the widget. See the "font" property
for details.
void QWidget::unsetPalette ()
Resets the widget's palette. See the "palette" property for details.
void QWidget::update () [slot]
Updates the widget unless updates are disabled or the widget is hidden.
This function does not cause an immediate repaint; instead it schedules
a paint event for processing when Qt returns to the main event loop.
This permits Qt to optimize for more speed and less flicker than a call
to repaint() does.
Calling update() several times normally results in just one
paintEvent() call.
Qt normally erases the widget's area before the paintEvent() call. If
the WRepaintNoErase widget flag is set, the widget is responsible for
painting all its pixels itself.
See also repaint(), paintEvent(), updatesEnabled, erase(), and
setWFlags().
Examples:
void QWidget::update ( int x, int y, int w, int h ) [slot]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Updates a rectangle (x, y, w, h) inside the widget unless updates are
disabled or the widget is hidden.
This function does not cause an immediate repaint; instead it schedules
a paint event for processing when Qt returns to the main event loop.
This permits Qt to optimize for more speed and less flicker and a call
to repaint() does.
Calling update() several times normally results in just one
paintEvent() call.
If w is negative, it is replaced with width() - x. If h is negative, it
is replaced width height() - y.
Qt normally erases the specified area before the paintEvent() call. If
the WRepaintNoErase widget flag is set, the widget is responsible for
painting all its pixels itself.
See also repaint(), paintEvent(), updatesEnabled, and erase().
void QWidget::update ( const QRect & r ) [slot]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Updates a rectangle r inside the widget unless updates are disabled or
the widget is hidden.
This function does not cause an immediate repaint; instead it schedules
a paint event for processing when Qt returns to the main event loop.
This permits Qt to optimize for more speed and less flicker and a call
to repaint() does.
Calling update() several times normally results in just one
paintEvent() call.
void QWidget::updateGeometry ()
Notifies the layout system that this widget has changed and may need to
change geometry.
Call this function if the sizeHint() or sizePolicy() have changed.
For explicitly hidden widgets, updateGeometry() is a no-op. The layout
system will be notified as soon as the widget is shown.
void QWidget::updateMask () [virtual protected]
This function can be reimplemented in a subclass to support transparent
widgets. It should be called whenever a widget changes state in a way
that means that the shape mask must be recalculated.
See also autoMask, setMask(), and clearMask().
QRect QWidget::visibleRect () const
Returns the visible rectangle. See the "visibleRect" property for
details.
void QWidget::wheelEvent ( QWheelEvent * e ) [virtual protected]
This event handler, for event e, can be reimplemented in a subclass to
receive wheel events for the widget.
If you reimplement this handler, it is very important that you ignore()
the event if you do not handle it, so that the widget's parent can
interpret it.
The default implementation ignores the event.
See also QWheelEvent::ignore(), QWheelEvent::accept(), event(), and
QWheelEvent.
int QWidget::width () const
Returns the width of the widget excluding any window frame. See the
"width" property for details.
bool QWidget::winEvent ( MSG * ) [virtual protected]
This special event handler can be reimplemented in a subclass to
receive native Windows events.
In your reimplementation of this function, if you want to stop the
event being handled by Qt, return TRUE. If you return FALSE, this
native event is passed back to Qt, which translates the event into a Qt
event and sends it to the widget.
Warning: This function is not portable.
See also QApplication::winEventFilter().
WId QWidget::winId () const
Returns the window system identifier of the widget.
Portable in principle, but if you use it you are probably about to do
something non-portable. Be careful.
See also find().
void QWidget::windowActivationChange ( bool oldActive ) [virtual protected]
This virtual function is called for a widget when its window is
activated or deactivated by the window system. oldActive is the
previous state; you can get the new setting from isActiveWindow().
Reimplement this function if your widget needs to know when its window
becomes activated or deactivated.
The default implementation updates the visible part of the widget if
the inactive and the active colorgroup are different for colors other
than the highlight and link colors.
See also setActiveWindow(), isActiveWindow, update(), and palette.
double QWidget::windowOpacity () const
Returns the level of opacity for the window. See the "windowOpacity"
property for details.
uint QWidget::windowState () const
Returns the current window state. The window state is a OR'ed
combination of Qt::WindowState: WindowMinimized, WindowMaximized,
WindowFullScreen and WindowActive.
See also Qt::WindowState and setWindowState().
int QWidget::x () const
Returns the x coordinate of the widget relative to its parent including
any window frame. See the "x" property for details.
bool QWidget::x11Event ( XEvent * ) [virtual protected]
This special event handler can be reimplemented in a subclass to
receive native X11 events.
In your reimplementation of this function, if you want to stop the
event being handled by Qt, return TRUE. If you return FALSE, this
native event is passed back to Qt, which translates the event into a Qt
event and sends it to the widget.
Warning: This function is not portable.
See also QApplication::x11EventFilter().
Reimplemented in QXtWidget.
int QWidget::y () const
Returns the y coordinate of the widget relative to its parent and
including any window frame. See the "y" property for details.
Property Documentation
bool acceptDrops
This property holds whether drop events are enabled for this widget.
Setting this property to TRUE announces to the system that this widget
may be able to accept drop events.
If the widget is the desktop (QWidget::isDesktop()), this may fail if
another application is using the desktop; you can call acceptDrops() to
test if this occurs.
Warning: Do not modify this property in a Drag&Drop event handler.
Set this property's value with setAcceptDrops() and get this property's
value with acceptDrops().
bool autoMask
This property holds whether the auto mask feature is enabled for the
widget.
Transparent widgets use a mask to define their visible region. QWidget
has some built-in support to make the task of recalculating the mask
easier. When setting auto mask to TRUE, updateMask() will be called
whenever the widget is resized or changes its focus state. Note that
you must reimplement updateMask() (which should include a call to
setMask()) or nothing will happen.
Note: when you re-implement resizeEvent(), focusInEvent() or
focusOutEvent() in your custom widgets and still want to ensure that
the auto mask calculation works, you should add:
if ( autoMask() )
updateMask();
at the end of your event handlers. This is true for all member
functions that change the appearance of the widget in a way that
requires a recalculation of the mask.
While being a technically appealing concept, masks have a big drawback:
when using complex masks that cannot be expressed easily with
relatively simple regions, they can be very slow on some window
systems. The classic example is a transparent label. The complex shape
of its contents makes it necessary to represent its mask by a bitmap,
which consumes both memory and time. If all you want is to blend the
background of several neighboring widgets together seamlessly, you will
probably want to use setBackgroundOrigin() rather than a mask.
See also updateMask(), setMask(), clearMask(), and backgroundOrigin.
Set this property's value with setAutoMask() and get this property's
value with autoMask().
QBrush backgroundBrush
This property holds the widget's background brush.
The background brush depends on a widget's palette and its background
mode.
See also backgroundColor(), backgroundPixmap(), eraseColor(), palette,
and QApplication::setPalette().
Get this property's value with backgroundBrush().
BackgroundMode backgroundMode
This property holds the color role used for painting the background of
the widget.
setPaletteBackgroundColor() reads this property to determine which
entry of the palette to set.
For most widgets the default suffices (PaletteBackground, typically
gray), but some need to use PaletteBase (the background color for text
output, typically white) or another role.
QListBox, which is "sunken" and uses the base color to contrast with
its environment, does this in its constructor:
setBackgroundMode( PaletteBase );
You will never need to set the background mode of a built-in widget in
Qt, but you might consider setting it in your custom widgets, so that
setPaletteBackgroundColor() works as expected.
Note that two of the BackgroundMode values make no sense for
setBackgroundMode(), namely FixedPixmap and FixedColor. You must call
setBackgroundPixmap() and setPaletteBackgroundColor() instead.
Set this property's value with setBackgroundMode() and get this
property's value with backgroundMode().
BackgroundOrigin backgroundOrigin
This property holds the origin of the widget's background.
The origin is either WidgetOrigin (the default), ParentOrigin,
WindowOrigin or AncestorOrigin.
This only makes a difference if the widget has a background pixmap, in
which case positioning matters. Using WindowOrigin for several
neighboring widgets makes the background blend together seamlessly.
AncestorOrigin allows blending backgrounds seamlessly when an ancestor
of the widget has an origin other than WindowOrigin.
See also backgroundPixmap() and backgroundMode.
Set this property's value with setBackgroundOrigin() and get this
property's value with backgroundOrigin().
QSize baseSize
This property holds the base size of the widget.
The base size is used to calculate a proper widget size if the widget
defines sizeIncrement().
See also sizeIncrement.
Set this property's value with setBaseSize() and get this property's
value with baseSize().
QString caption
This property holds the window caption (title).
This property only makes sense for top-level widgets. If no caption has
been set, the caption is QString::null.
See also icon and iconText.
Set this property's value with setCaption() and get this property's
value with caption().
QRect childrenRect
This property holds the bounding rectangle of the widget's children.
Hidden children are excluded.
See also childrenRegion and geometry.
Get this property's value with childrenRect().
QRegion childrenRegion
This property holds the combined region occupied by the widget's
children.
Hidden children are excluded.
See also childrenRect and geometry.
Get this property's value with childrenRegion().
QColorGroup colorGroup
This property holds the current color group of the widget palette.
The color group is determined by the state of the widget. A disabled
widget has the QPalette::disabled() color group, a widget with keyboard
focus has the QPalette::active() color group, and an inactive widget
has the QPalette::inactive() color group.
See also palette.
Get this property's value with colorGroup().
QCursor cursor
This property holds the cursor shape for this widget.
The mouse cursor will assume this shape when it's over this widget. See
the list of predefined cursor objects for a range of useful shapes.
An editor widget might use an I-beam cursor:
setCursor( IbeamCursor );
If no cursor has been set, or after a call to unsetCursor(), the
parent's cursor is used. The function unsetCursor() has no effect on
top-level widgets.
See also QApplication::setOverrideCursor().
Set this property's value with setCursor(), get this property's value
with cursor(), and reset this property's value with unsetCursor().
bool customWhatsThis
This property holds whether the widget wants to handle What's This help
manually.
The default implementation of customWhatsThis() returns FALSE, which
means the widget will not receive any events in Whats This mode.
The widget may leave What's This mode by calling
QWhatsThis::leaveWhatsThisMode(), with or without actually displaying
any help text.
You can also reimplement customWhatsThis() if your widget is a" passive
interactor" supposed to work under all circumstances. Simply don't call
QWhatsThis::leaveWhatsThisMode() in that case.
See also QWhatsThis::inWhatsThisMode() and
QWhatsThis::leaveWhatsThisMode().
Get this property's value with customWhatsThis().
bool enabled
This property holds whether the widget is enabled.
An enabled widget receives keyboard and mouse events; a disabled widget
does not. In fact, an enabled widget only receives keyboard events when
it is in focus.
Some widgets display themselves differently when they are disabled. For
example a button might draw its label grayed out. If your widget needs
to know when it becomes enabled or disabled, you can reimplement the
enabledChange() function.
Disabling a widget implicitly disables all its children. Enabling
respectively enables all child widgets unless they have been explicitly
disabled.
See also enabled, isEnabledTo(), QKeyEvent, QMouseEvent, and
enabledChange().
Set this property's value with setEnabled() and get this property's
value with isEnabled().
bool focus
This property holds whether this widget (or its focus proxy) has the
keyboard input focus.
Effectively equivalent to qApp->focusWidget() == this.
See also setFocus(), clearFocus(), focusPolicy, and
QApplication::focusWidget().
Get this property's value with hasFocus().
bool focusEnabled
This property holds whether the widget accepts keyboard focus.
Keyboard focus is initially disabled (i.e. focusPolicy() ==
QWidget::NoFocus).
You must enable keyboard focus for a widget if it processes keyboard
events. This is normally done from the widget's constructor. For
instance, the QLineEdit constructor calls
setFocusPolicy(QWidget::StrongFocus).
See also focusPolicy, focusInEvent(), focusOutEvent(), keyPressEvent(),
keyReleaseEvent(), and enabled.
Get this property's value with isFocusEnabled().
FocusPolicy focusPolicy
This property holds the way the widget accepts keyboard focus.
The policy is QWidget::TabFocus if the widget accepts keyboard focus by
tabbing, QWidget::ClickFocus if the widget accepts focus by clicking,
QWidget::StrongFocus if it accepts both, and QWidget::NoFocus (the
default) if it does not accept focus at all.
You must enable keyboard focus for a widget if it processes keyboard
events. This is normally done from the widget's constructor. For
instance, the QLineEdit constructor calls
setFocusPolicy(QWidget::StrongFocus).
See also focusEnabled, focusInEvent(), focusOutEvent(),
keyPressEvent(), keyReleaseEvent(), and enabled.
Set this property's value with setFocusPolicy() and get this property's
value with focusPolicy().
QFont font
This property holds the font currently set for the widget.
The fontInfo() function reports the actual font that is being used by
the widget.
As long as no special font has been set, or after unsetFont() is
called, this is either a special font for the widget class, the
parent's font or (if this widget is a top level widget), the default
application font.
This code fragment sets a 12 point helvetica bold font:
QFont f( "Helvetica", 12, QFont::Bold );
setFont( f );
In addition to setting the font, setFont() informs all children about
the change.
See also fontChange(), fontInfo(), fontMetrics(), and ownFont.
Set this property's value with setFont(), get this property's value
with font(), and reset this property's value with unsetFont().
QRect frameGeometry
This property holds geometry of the widget relative to its parent
including any window frame.
See the Window Geometry documentation for an overview of geometry
issues with top-level widgets.
See also geometry, x, y, and pos.
Get this property's value with frameGeometry().
QSize frameSize
This property holds the size of the widget including any window frame.
Get this property's value with frameSize().
bool fullScreen
This property holds whether the widget is full screen.
Get this property's value with isFullScreen().
See also windowState(), minimized, and maximized.
QRect geometry
This property holds the geometry of the widget relative to its parent
and excluding the window frame.
When changing the geometry, the widget, if visible, receives a move
event (moveEvent()) and/or a resize event (resizeEvent()) immediately.
If the widget is not currently visible, it is guaranteed to receive
appropriate events before it is shown.
The size component is adjusted if it lies outside the range defined by
minimumSize() and maximumSize().
setGeometry() is virtual, and all other overloaded setGeometry()
implementations in Qt call it.
Warning: Calling setGeometry() inside resizeEvent() or moveEvent() can
lead to infinite recursion.
See the Window Geometry documentation for an overview of top-level
widget geometry.
See also frameGeometry, rect, pos, size, moveEvent(), resizeEvent(),
minimumSize, and maximumSize.
Set this property's value with setGeometry() and get this property's
value with geometry().
int height
This property holds the height of the widget excluding any window
frame.
See the Window Geometry documentation for an overview of top-level
widget geometry.
See also geometry, width, and size.
Get this property's value with height().
bool hidden
This property holds whether the widget is explicitly hidden.
If FALSE, the widget is visible or would become visible if all its
ancestors became visible.
See also hide(), show(), visible, isVisibleTo(), and shown.
Set this property's value with setHidden() and get this property's
value with isHidden().
QPixmap icon
This property holds the widget's icon.
This property only makes sense for top-level widgets. If no icon has
been set, icon() returns 0.
See also iconText, caption, and Setting the Application Icon.
Set this property's value with setIcon() and get this property's value
with icon().
QString iconText
This property holds the widget's icon text.
This property only makes sense for top-level widgets. If no icon text
has been set, this functions returns QString::null.
See also icon and caption.
Set this property's value with setIconText() and get this property's
value with iconText().
bool inputMethodEnabled
This property holds enables or disables the use of input methods for
this widget.
Most Widgets (as eg. buttons) that do not handle text input should have
the input method disabled if they have focus. This is the default.
If a widget handles text input it should set this property to TRUE.
Set this property's value with setInputMethodEnabled() and get this
property's value with isInputMethodEnabled().
bool isActiveWindow
This property holds whether this widget is the active window.
The active window is the window that contains the widget that has
keyboard focus.
When popup windows are visible, this property is TRUE for both the
active window and for the popup.
See also setActiveWindow() and QApplication::activeWindow().
Get this property's value with isActiveWindow().
bool isDesktop
This property holds whether the widget is a desktop widget, i.e.
represents the desktop.
A desktop widget is also a top-level widget.
See also isTopLevel and QApplication::desktop().
Get this property's value with isDesktop().
bool isDialog
This property holds whether the widget is a dialog widget.
A dialog widget is a secondary top-level widget, i.e. a top-level
widget with a parent.
See also isTopLevel and QDialog.
Get this property's value with isDialog().
bool isModal
This property holds whether the widget is a modal widget.
This property only makes sense for top-level widgets. A modal widget
prevents widgets in all other top-level widgets from getting any input.
See also isTopLevel, isDialog, and QDialog.
Get this property's value with isModal().
bool isPopup
This property holds whether the widget is a popup widget.
A popup widget is created by specifying the widget flag WType_Popup to
the widget constructor. A popup widget is also a top-level widget.
See also isTopLevel.
Get this property's value with isPopup().
bool isTopLevel
This property holds whether the widget is a top-level widget.
A top-level widget is a widget which usually has a frame and a caption
(title). Popup and desktop widgets are also top-level widgets.
A top-level widget can have a parent widget. It will then be grouped
with its parent and deleted when the parent is deleted, minimized when
the parent is minimized etc. If supported by the window manager, it
will also have a common taskbar entry with its parent.
QDialog and QMainWindow widgets are by default top-level, even if a
parent widget is specified in the constructor. This behavior is
specified by the WType_TopLevel widget flag.
See also topLevelWidget(), isDialog, isModal, isPopup, isDesktop, and
parentWidget().
Get this property's value with isTopLevel().
bool maximized
This property holds whether this widget is maximized.
This property is only relevant for top-level widgets.
Note that due to limitations in some window-systems, this does not
always report the expected results (e.g. if the user on X11 maximizes
the window via the window manager, Qt has no way of distinguishing this
from any other resize). This is expected to improve as window manager
protocols evolve.
See also windowState(), showMaximized(), visible, show(), hide(),
showNormal(), and minimized.
Get this property's value with isMaximized().
int maximumHeight
This property holds the widget's maximum height.
This property corresponds to maximumSize().height().
See also maximumSize and maximumWidth.
Set this property's value with setMaximumHeight() and get this
property's value with maximumHeight().
QSize maximumSize
This property holds the widget's maximum size.
The widget cannot be resized to a larger size than the maximum widget
size.
See also maximumWidth, maximumHeight, maximumSize, minimumSize, and
sizeIncrement.
Set this property's value with setMaximumSize() and get this property's
value with maximumSize().
int maximumWidth
This property holds the widget's maximum width.
This property corresponds to maximumSize().width().
See also maximumSize and maximumHeight.
Set this property's value with setMaximumWidth() and get this
property's value with maximumWidth().
QRect microFocusHint
This property holds the currently set micro focus hint for this widget.
See the documentation of setMicroFocusHint() for more information.
Get this property's value with microFocusHint().
bool minimized
This property holds whether this widget is minimized (iconified).
This property is only relevant for top-level widgets.
See also showMinimized(), visible, show(), hide(), showNormal(), and
maximized.
Get this property's value with isMinimized().
int minimumHeight
This property holds the widget's minimum height.
This property corresponds to minimumSize().height().
See also minimumSize and minimumWidth.
Set this property's value with setMinimumHeight() and get this
property's value with minimumHeight().
QSize minimumSize
This property holds the widget's minimum size.
The widget cannot be resized to a smaller size than the minimum widget
size. The widget's size is forced to the minimum size if the current
size is smaller.
If you use a layout inside the widget, the minimum size will be set by
the layout and not by setMinimumSize(), unless you set the layout's
resize mode to QLayout::FreeResize.
See also minimumWidth, minimumHeight, maximumSize, sizeIncrement, and
QLayout::resizeMode.
Set this property's value with setMinimumSize() and get this property's
value with minimumSize().
QSize minimumSizeHint
This property holds the recommended minimum size for the widget.
If the value of this property is an invalid size, no minimum size is
recommended.
The default implementation of minimumSizeHint() returns an invalid size
if there is no layout for this widget, and returns the layout's minimum
size otherwise. Most built-in widgets reimplement minimumSizeHint().
QLayout will never resize a widget to a size smaller than
minimumSizeHint.
See also QSize::isValid(), size, minimumSize, and sizePolicy.
Get this property's value with minimumSizeHint().
int minimumWidth
This property holds the widget's minimum width.
This property corresponds to minimumSize().width().
See also minimumSize and minimumHeight.
Set this property's value with setMinimumWidth() and get this
property's value with minimumWidth().
bool mouseTracking
This property holds whether mouse tracking is enabled for the widget.
If mouse tracking is disabled (the default), the widget only receives
mouse move events when at least one mouse button is pressed while the
mouse is being moved.
If mouse tracking is enabled, the widget receives mouse move events
even if no buttons are pressed.
See also mouseMoveEvent() and QApplication::setGlobalMouseTracking().
Set this property's value with setMouseTracking() and get this
property's value with hasMouseTracking().
bool ownCursor
This property holds whether the widget uses its own cursor.
If FALSE, the widget uses its parent widget's cursor.
See also cursor.
Get this property's value with ownCursor().
bool ownFont
This property holds whether the widget uses its own font.
If FALSE, the widget uses its parent widget's font.
See also font.
Get this property's value with ownFont().
bool ownPalette
This property holds whether the widget uses its own palette.
If FALSE, the widget uses its parent widget's palette.
See also palette.
Get this property's value with ownPalette().
QPalette palette
This property holds the widget's palette.
As long as no special palette has been set, or after unsetPalette() has
been called, this is either a special palette for the widget class, the
parent's palette or (if this widget is a top level widget), the default
application palette.
Instead of defining an entirely new palette, you can also use the
paletteBackgroundColor, paletteBackgroundPixmap and
paletteForegroundColor convenience properties to change a widget's
background and foreground appearance only.
See also ownPalette, colorGroup, and QApplication::palette().
Set this property's value with setPalette(), get this property's value
with palette(), and reset this property's value with unsetPalette().
QColor paletteBackgroundColor
This property holds the background color of the widget.
The palette background color is usually set implicitly by
setBackgroundMode(), although it can also be set explicitly by
setPaletteBackgroundColor(). setPaletteBackgroundColor() is a
convenience function that creates and sets a modified QPalette with
setPalette(). The palette is modified according to the widget's
background mode. For example, if the background mode is PaletteButton
the color used for the palette's QColorGroup::Button color entry is
set.
If there is a background pixmap (set using
setPaletteBackgroundPixmap()), then the return value of this function
is indeterminate.
See also paletteBackgroundPixmap, paletteForegroundColor, palette, and
colorGroup.
Set this property's value with setPaletteBackgroundColor(), get this
property's value with paletteBackgroundColor(), and reset this
property's value with unsetPalette().
QPixmap paletteBackgroundPixmap
This property holds the background pixmap of the widget.
The palette background pixmap is usually set implicitly by
setBackgroundMode(), although it can also be set explicitly by
setPaletteBackgroundPixmap(). setPaletteBackgroundPixmap() is a
convenience function that creates and sets a modified QPalette with
setPalette(). The palette is modified according to the widget's
background mode. For example, if the background mode is PaletteButton
the pixmap used for the palette's QColorGroup::Button color entry is
set.
If there is a plain background color (set using
setPaletteBackgroundColor()), then this function returns 0.
See also paletteBackgroundColor, paletteForegroundColor, palette, and
colorGroup.
Set this property's value with setPaletteBackgroundPixmap(), get this
property's value with paletteBackgroundPixmap(), and reset this
property's value with unsetPalette().
QColor paletteForegroundColor
This property holds the foreground color of the widget.
setPaletteForegroundColor() is a convenience function that creates and
sets a modified QPalette with setPalette(). The palette is modified
according to the widget's background mode. For example, if the
background mode is PaletteButton the palette entry
QColorGroup::ButtonText is set to color.
See also palette, QApplication::setPalette(), backgroundMode,
foregroundColor(), backgroundMode, and setEraseColor().
Set this property's value with setPaletteForegroundColor(), get this
property's value with paletteForegroundColor(), and reset this
property's value with unsetPalette().
QPoint pos
This property holds the position of the widget within its parent
widget.
If the widget is a top-level widget, the position is that of the widget
on the desktop, including its frame.
When changing the position, the widget, if visible, receives a move
event (moveEvent()) immediately. If the widget is not currently
visible, it is guaranteed to receive an event before it is shown.
move() is virtual, and all other overloaded move() implementations in
Qt call it.
Warning: Calling move() or setGeometry() inside moveEvent() can lead to
infinite recursion.
See the Window Geometry documentation for an overview of top-level
widget geometry.
See also frameGeometry, size, x, and y.
Set this property's value with move() and get this property's value
with pos().
QRect rect
This property holds the internal geometry of the widget excluding any
window frame.
The rect property equals QRect(0, 0, width(), height()).
See the Window Geometry documentation for an overview of top-level
widget geometry.
See also size.
Get this property's value with rect().
bool shown
This property holds whether the widget is shown.
If TRUE, the widget is visible or would become visible if all its
ancestors became visible.
See also hide(), show(), visible, isVisibleTo(), and hidden.
Set this property's value with setShown() and get this property's value
with isShown().
QSize size
This property holds the size of the widget excluding any window frame.
When resizing, the widget, if visible, receives a resize event
(resizeEvent()) immediately. If the widget is not currently visible, it
is guaranteed to receive an event before it is shown.
The size is adjusted if it lies outside the range defined by
minimumSize() and maximumSize(). Furthermore, the size is always at
least QSize(1, 1). For toplevel widgets, the minimum size might be
larger, depending on the window manager.
If you want a top-level window to have a fixed size, call
setResizeMode( QLayout::FreeResize ) on its layout.
resize() is virtual, and all other overloaded resize() implementations
in Qt call it.
Warning: Calling resize() or setGeometry() inside resizeEvent() can
lead to infinite recursion.
See also pos, geometry, minimumSize, maximumSize, and resizeEvent().
Set this property's value with resize() and get this property's value
with size().
QSize sizeHint
This property holds the recommended size for the widget.
If the value of this property is an invalid size, no size is
recommended.
The default implementation of sizeHint() returns an invalid size if
there is no layout for this widget, and returns the layout's preferred
size otherwise.
See also QSize::isValid(), minimumSizeHint, sizePolicy, minimumSize,
and updateGeometry().
Get this property's value with sizeHint().
QSize sizeIncrement
This property holds the size increment of the widget.
When the user resizes the window, the size will move in steps of
sizeIncrement().width() pixels horizontally and sizeIncrement.height()
pixels vertically, with baseSize() as the basis. Preferred widget sizes
are for non-negative integers i and j:
width = baseSize().width() + i * sizeIncrement().width();
height = baseSize().height() + j * sizeIncrement().height();
Note that while you can set the size increment for all widgets, it only
affects top-level widgets.
Warning: The size increment has no effect under Windows, and may be
disregarded by the window manager on X.
See also size, minimumSize, and maximumSize.
Set this property's value with setSizeIncrement() and get this
property's value with sizeIncrement().
QSizePolicy sizePolicy
This property holds the default layout behavior of the widget.
If there is a QLayout that manages this widget's children, the size
policy specified by that layout is used. If there is no such QLayout,
the result of this function is used.
The default policy is Preferred/Preferred, which means that the widget
can be freely resized, but prefers to be the size sizeHint() returns.
Button-like widgets set the size policy to specify that they may
stretch horizontally, but are fixed vertically. The same applies to
lineedit controls (such as QLineEdit, QSpinBox or an editable
QComboBox) and other horizontally orientated widgets (such as
QProgressBar). QToolButton's are normally square, so they allow growth
in both directions. Widgets that support different directions (such as
QSlider, QScrollBar or QHeader) specify stretching in the respective
direction only. Widgets that can provide scrollbars (usually subclasses
of QScrollView) tend to specify that they can use additional space, and
that they can make do with less than sizeHint().
See also sizeHint, QLayout, QSizePolicy, and updateGeometry().
Set this property's value with setSizePolicy() and get this property's
value with sizePolicy().
bool underMouse
This property holds whether the widget is under the mouse cursor.
This value is not updated properly during drag and drop operations.
See also QEvent::Enter and QEvent::Leave.
Get this property's value with hasMouse().
bool updatesEnabled
This property holds whether updates are enabled.
Calling update() and repaint() has no effect if updates are disabled.
Paint events from the window system are processed normally even if
updates are disabled.
setUpdatesEnabled() is normally used to disable updates for a short
period of time, for instance to avoid screen flicker during large
changes.
Example:
setUpdatesEnabled( FALSE );
bigVisualChanges();
setUpdatesEnabled( TRUE );
repaint();
See also update(), repaint(), and paintEvent().
Set this property's value with setUpdatesEnabled() and get this
property's value with isUpdatesEnabled().
bool visible
This property holds whether the widget is visible.
Calling show() sets the widget to visible status if all its parent
widgets up to the top-level widget are visible. If an ancestor is not
visible, the widget won't become visible until all its ancestors are
shown.
Calling hide() hides a widget explicitly. An explicitly hidden widget
will never become visible, even if all its ancestors become visible,
unless you show it.
A widget receives show and hide events when its visibility status
changes. Between a hide and a show event, there is no need to waste CPU
cycles preparing or displaying information to the user. A video
application, for example, might simply stop generating new frames.
A widget that happens to be obscured by other windows on the screen is
considered to be visible. The same applies to iconified top-level
widgets and windows that exist on another virtual desktop (on platforms
that support this concept). A widget receives spontaneous show and hide
events when its mapping status is changed by the window system, e.g. a
spontaneous hide event when the user minimizes the window, and a
spontaneous show event when the window is restored again.
See also show(), hide(), hidden, isVisibleTo(), minimized, showEvent(),
and hideEvent().
Get this property's value with isVisible().
QRect visibleRect
This property holds the visible rectangle.
This property is obsolete. It is provided to keep old source working.
We strongly advise against using it in new code.
No longer necessary, you can simply call repaint(). If you do not need
the rectangle for repaint(), use clipRegion() instead.
Get this property's value with visibleRect().
int width
This property holds the width of the widget excluding any window frame.
See the Window Geometry documentation for an overview of top-level
widget geometry.
See also geometry, height, and size.
Get this property's value with width().
double windowOpacity
This property holds the level of opacity for the window.
The valid range of opacity is from 1.0 (completely opaque) to 0.0
(completely transparent).
By default the value of this property is 1.0.
This feature is only present on Mac OS X and Windows 2000 and up.
Warning: Changing this property from opaque to transparent might issue
a paint event that needs to be processed before the window is displayed
correctly. This affects mainly the use of QPixmap::grabWindow(). Also
note that semi-transparent windows update and resize significantely
slower than opaque windows.
Set this property's value with setWindowOpacity() and get this
property's value with windowOpacity().
int x
This property holds the x coordinate of the widget relative to its
parent including any window frame.
See the Window Geometry documentation for an overview of top-level
widget geometry.
See also frameGeometry, y, and pos.
Get this property's value with x().
int y
This property holds the y coordinate of the widget relative to its
parent and including any window frame.
See the Window Geometry documentation for an overview of top-level
widget geometry.
See also frameGeometry, x, and pos.
Get this property's value with y().
SEE ALSO
http://doc.trolltech.com/qwidget.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
license file included in the distribution for a complete license
statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports help us to
help you. Thank you.
The definitive Qt documentation is provided in HTML format; it is
located at $QTDIR/doc/html and can be read using Qt Assistant or with a
web browser. This man page is provided as a convenience for those users
who prefer man pages, although this format is not officially supported
by Trolltech.
If you find errors in this manual page, please report them to qt-
bugs@trolltech.com. Please include the name of the manual page
(qwidget.3qt) and the Qt version (3.3.8).
Trolltech AS 2 February 2007 QWidget(3qt)
