pie(n) tkpiechart pie class pie(n)______________________________________________________________________________NAMEpie - 2D or 3D pie chart object in a canvas
SYNOPSIS
package require stooop 4.1
package require switched 2.2
package require tkpiechart 6.6
stooop::new pie canvas x y ?options?
switched::configure pieObject ?options?
switched::cget pieObject option
stooop::delete pieObject
pie::newSlice pieObject ?labelText?
pie::deleteSlice pieObject sliceObject
pie::sizeSlice pieObject sliceObject unitShare ?displayedValue?
pie::labelSlice pieObject sliceObject string
pie::selectedSlices pieObject
_________________________________________________________________DESCRIPTION
A pie object is used to visualize a set of values, usually as shares of
a total. Each value is represented by a colored slice, which may have a
2 dimensional or 3 dimensional look. Each slice is associated with a
label displaying the data name, and a numerical field showing the per‐
centage taken by the slice. The labels are placed by the chosen labeler
object (-labeler option). Each label color matches its related slice.
A pie chart is made of Tk canvas items, found in pieBoxLabeler, piePe‐
ripheralLabeler and canvasLabel objects, that compose the pie object.
The pie constructor creates the pie itself and its background slice
within the parent canvas. Once the pie object exists, slices can be
created and resized. At the time the pie is created, the parent Tk can‐
vas widget must exist.
Slice colors are automatically generated, using a default color list
for all pies, unless another list is used (using the -colors option).
When a 3D look is used, the slice edge is darker than its top while
using the same color tone.
stooop::new pie canvas x y ?options?
Creates a pie object in the specified Tk canvas. The upper left
corner of the pie is placed at the specified coordinates in the
canvas. The pie object identifier is returned (referred to as
pieObject in this document).
switched::configure pieObject ?options?
Configures a pie object or returns all the options with their
current values if no options are passed as parameters.
switched::cget pieObject option
Returns an option value for the specified pie object.
stooop::delete pieObject
Deletes the specified pie object.
OVERVIEW
The pie class is part of the tkpiechart extension that allows the pro‐
grammer to create and dynamically update 2D or 3D pie charts in a
Tcl/Tk application. The tkpiechart package is written in Tcl only,
using object oriented techniques thanks to the stooop package, included
in tcllib.
OPTIONS-autoupdate boolean
Boolean value specifying whether all the slices and their labels
are redrawn when a slice size is changed. On by default. Turn it
off and invoke pie::update if you change many slices at once and
want to improve performance.
-background color
Slices may or may not fill up the 100% of the pie. The unoccu‐
pied part of the pie is a slice that takes 100% of the pie. It
is by default transparent with a black border. The color of this
background slice may be set by the user using color names as in
the -background standard option (see the Tk options manual page
for more details). When the pie has a 3D look, the background of
a slice edge is darker than the top and uses the same color
tone.
-colors list
Specifies a list of colors for slices. In this case, the slice
colors will successively be drawn from the list in the list
order, cycling through if there are more slices than colors in
the list. Colors are specified in the same format as the -back‐
ground option.
-height value
Specifies the total height for the pie, including the room taken
by the labeler labels. The pie slices are resized when labels
are added or deleted (when adding or deleting slices) so that
the total height remains constant. This value may be specified
in any of the forms described in the canvas COORDINATES manual
section.
-labeler object
Specifies a placer object for the slice labels, so that, for
example, slice values may be placed next to them. If not speci‐
fied, the pieBoxLabeler (see corresponding manual) is used, the
other option being the piePeripheralLabeler class. Each labeler
has a specific behavior which may be set via its options. The
labeler object is automatically deleted when the pie object is
itself deleted. The labeler cannot be changed once the pie is
created.
-selectable boolean
Boolean value specifying whether slices are selectable or not.
Acceptable values are those defined by the Tcl language itself
for boolean values. If selectable, slices can be selected with
the first mouse button, by clicking on either the slice or its
label. Selection can be extended by using the classical control
or shift clicks. The list of currently selected slices can be
retrieved at any time using the selectedSlices pie class member
procedure.
-title text
Title text to be placed above the pie.
-titlefont value
Font for the title text.
-titleoffset value
Distance between the bottom of the title text and the top of the
pie slices. This value may be specified in any of the forms
described in the sizes section below.
-thickness value
The thickness is set to 0 by default, giving the pie a simple 2D
shape, much faster to display. A positive thickness value will
give the pie a 3D look with matched darker colors for the slices
edges. These values may be specified in any of the forms
described in the SIZES section below.
-width value
Specifies the total width for the pie, including the room taken
by the labeler labels. The pie slices are resized when labels
are added or deleted (when adding or deleting slices) so that
the total width remains constant. This value may be specified in
any of the forms described in the canvas COORDINATES manual sec‐
tion.
MEMBER PROCEDURES
pie::newSlice pieObject ?labelText?
Creates a slice. A unique object identifier is returned
(referred to as sliceObject in this document). The slice color
is automatically allocated and the slice label placed using the
specified labeler (using the -labeler option). The slice itself
is placed after (clockwise) the existing slices. The slice
object identifier will be used for sizing and resizing the
slice.
If the label text is not specified, it will be set to "slice n",
n being the number of the slice in the order of creation (first
slice is number 1).
pie::deleteSlice pieObject sliceObject
Deletes a slice. The following slices (clockwise) if any are
then moved to compensate for the empty space left by the deleted
slice.
pie::sizeSlice pieObject sliceObject unitShare ?displayedValue?
Sizes or resizes a slice. The slice is then automatically recal‐
culated so it occupies the proper share of the whole pie. The
unitShare parameter is a floating point number expressed in
share (between 0 and 1) of the whole pie. The following slices
(clockwise) are moved to accommodate the new slice size. The
slice size value next to the slice label is also updated with
the new share value or displayedValue if specified.
pie::labelSlice pieObject sliceObject string
Updates a slice label. Can be invoked at any time.
pie::selectedSlices pieObject
Returns a list of currently selected slice objects.
TAGS
The whole pie, the pie graphics (all slices), and each slice have the
following specific tags:
· pie(pieObject)
· pieSlices(pieObject)
· slice(sliceObject)
For example, the whole pie can be moved using the canvas move command
on the pie tag, or bindings on slices can be set using the slice tags
(see the canvas manual page ITEM IDS AND TAGS section for more informa‐
tion).
SIZES
All sizes related to pies are stored as floating point numbers. The
coordinates and sizes are specified in screen units, which are floating
point numbers optionally followed by one of several letters as speci‐
fied in the canvas COORDINATES manual section.
LIMITATIONS
If the number of slices is too big, identical colors will be used for
some of the slices. You may set your own colors in this case.
SEE ALSO
canvasLabel, pieBoxLabeler, piePeripheralLabeler
KEYWORDS
canvas, labeler, pie, slice
COPYRIGHT
Copyright (c) 1995-2004 Jean-Luc Fontaine <jfontain@free.fr>
tkpiechart 6.6 pie(n)
