Gtk2::CellRenderer(3) User Contributed Perl DocumentationGtk2::CellRenderer(3)NAMEGtk2::CellRenderer - An object that renders a single cell onto a
Gtk2::Gdk::Drawable
DESCRIPTION
The Gtk2::CellRenderer is the base class for objects which render cells
onto drawables. These objects are used primarily by the
Gtk2::TreeView, though they aren't tied to them in any specific way.
Typically, one cell renderer is used to draw many cells onto the
screen. Thus, the cell renderer doesn't keep state; instead, any state
is set immediately prior to use through the object property system.
The cell is measured with "get_size", and then renderered with
"render".
HIERARCHY
Glib::Object
+----Glib::InitiallyUnowned
+----Gtk2::Object
+----Gtk2::CellRenderer
METHODS
boolean = $cell->activate ($event, $widget, $path, $background_area,
$cell_area, $flags)
· $event (Gtk2::Gdk::Event)
· $widget (Gtk2::Widget)
· $path (string)
· $background_area (Gtk2::Gdk::Rectangle)
· $cell_area (Gtk2::Gdk::Rectangle)
· $flags (Gtk2::CellRendererState)
$cell->editing_canceled
(width, height) = $cell->get_fixed_size
Fetch the fixed size if $cell. Values of -1 mean "this dimension
is not fixed."
$cell->set_fixed_size ($width, $height)
· $width (integer)
· $height (integer)
Set the renderer's size explicitly, independent of object
properties. A value of -1 means "don't use a fixed size for this
dimension."
$cell->render ($drawable, $widget, $background_area, $cell_area,
$expose_area, $flags)
· $drawable (Gtk2::Gdk::Drawable)
· $widget (Gtk2::Widget)
· $background_area (Gtk2::Gdk::Rectangle)
· $cell_area (Gtk2::Gdk::Rectangle)
· $expose_area (Gtk2::Gdk::Rectangle)
· $flags (Gtk2::CellRendererState)
(x_offset, y_offset, width, height) = $cell->get_size ($widget,
$cell_area)
· $widget (Gtk2::Widget)
· $cell_area (Gtk2::Gdk::Rectangle or undef)
celleditable or undef = $cell->start_editing ($event, $widget, $path,
$background_area, $cell_area, $flags)
· $event (Gtk2::Gdk::Event)
· $widget (Gtk2::Widget)
· $path (string)
· $background_area (Gtk2::Gdk::Rectangle)
· $cell_area (Gtk2::Gdk::Rectangle)
· $flags (Gtk2::CellRendererState)
$cell->stop_editing ($canceled)
· $canceled (boolean)
PROPERTIES
'cell-background' (string : writable / private)
Cell background colour as a string
'cell-background-gdk' (Gtk2::Gdk::Color : readable / writable /
private)
Cell background colour as a GdkColor
'cell-background-set' (boolean : readable / writable / private)
Whether this tag affects the cell background colour
'height' (integer : readable / writable / private)
The fixed height
'is-expanded' (boolean : readable / writable / private)
Row is an expander row, and is expanded
'is-expander' (boolean : readable / writable / private)
Row has children
'mode' (Gtk2::CellRendererMode : readable / writable / private)
Editable mode of the CellRenderer
'sensitive' (boolean : readable / writable / private)
Display the cell sensitive
'visible' (boolean : readable / writable / private)
Display the cell
'width' (integer : readable / writable / private)
The fixed width
'xalign' (Glib::Float : readable / writable / private)
The x-align
'xpad' (Glib::UInt : readable / writable / private)
The xpad
'yalign' (Glib::Float : readable / writable / private)
The y-align
'ypad' (Glib::UInt : readable / writable / private)
The ypad
SIGNALS
editing-canceled (Gtk2::CellRenderer)
editing-started (Gtk2::CellRenderer, Gtk2::CellEditable, string)
ENUMS AND FLAGS
enum Gtk2::CellRendererMode
· 'inert' / 'GTK_CELL_RENDERER_MODE_INERT'
· 'activatable' / 'GTK_CELL_RENDERER_MODE_ACTIVATABLE'
· 'editable' / 'GTK_CELL_RENDERER_MODE_EDITABLE'
flags Gtk2::CellRendererState
· 'selected' / 'GTK_CELL_RENDERER_SELECTED'
· 'prelit' / 'GTK_CELL_RENDERER_PRELIT'
· 'insensitive' / 'GTK_CELL_RENDERER_INSENSITIVE'
· 'sorted' / 'GTK_CELL_RENDERER_SORTED'
· 'focused' / 'GTK_CELL_RENDERER_FOCUSED'
DERIVING NEW CELL RENDERERS
Gtk+ provides three cell renderers: Gtk2::CellRendererText,
Gtk2::CellRendererToggle, and Gtk2::CellRendererPixbuf. You may derive
a new renderer from any of these, or directly from Gtk2::CellRenderer
itself.
There are a number of rules that must be followed when writing a new
cell renderer. First and foremost, it's important that a certain set
of properties always yields a cell of the same size, barring a
Gtk2::Style change. The cell renderer also has a number of generic
properties that are expected to be honored by all children.
The new renderer must be a GObject, so you must follow the normal
procedure for creating a new Glib::Object (i.e., either
Glib::Object::Subclass or Glib::Type::register_object). The new
subclass can customize the object's behavior by providing new
implementations of these four methods:
(x_offset, y_offset, width, height) = GET_SIZE ($cell, $widget,
$cell_area)
o $cell (Gtk2::CellRenderer)
o $widget (Gtk2::Widget) widget to which $cell is rendering
o $cell_area (Gtk2::Gdk::Rectangle or undef) The area a cell will
be allocated, or undef.
Return Values:
- x_offset - x offset of cell relative to $cell_area
- y_offset - y offset of cell relative to $cell_area
- width - width needed to render cell
- height - height needed to render cell
This is called to calculate the size of the cell for display,
taking into account the padding and alignment properties of the
parent. This one will be called very often. If you need to know
your cell's data, then get it from the appropriate object
properties, which will be set accordingly before this method is
called.
RENDER ($cell, $drawable, $widget, $background_area, $cell_area,
$expose_area, $flags)
o $cell (Gtk2::CellRenderer)
o $drawable (Gtk2::Gdk::Drawable) window on which to draw
o $widget (Gtk2::Widget) widget owning $drawable
o $background_area (Gtk2::Gdk::Rectangle) entire cell area
(including tree expanders and maybe padding on the sides)
o $cell_area (Gtk2::Gdk::Rectangle) area normally rendered by a
cell renderer
o $expose_area (Gtk2::Gdk::Rectangle) area that actually needs
updating
o $flags (Gtk2::CellRendererState) flags that affect rendering
This is called to render the cell onto the screen. As with
GET_SIZE, the data for the cell comes from object properties. In
general, you'll want to make use of Gtk2::Style methods for drawing
anything fancy.
The three passed-in rectangles are areas of $drawable. Most
renderers draw within $cell_area; the xalign, yalign, xpad, and
ypad fields of the cell renderer should be honored with respect to
$cell_area. $background_area includes the blank space around the
cell, and also the area containing the tree expander; so the
$background_area rectangles for all cells cover the entire
$drawable. $expose_area is a clip rectangle.
boolean = ACTIVATE ($cell, $event, $widget, $path, $background_area,
$cell_area, $flags)
o $cell (Gtk2::CellRenderer)
o $event (Gtk2::Gdk::Event)
o $widget (Gtk2::Widget) widget that received the event
o $path (string) widget-dependent string representation of the
event location; e.g. for a Gtk2::TreeView, a string representation
of a Gtk2::TreePath.
o $background_area (Gtk2::Gdk::Rectangle) background area as passed
to "RENDER".
o $cell_area (Gtk2::Gdk::Rectangle) cell area as passed to
"RENDER".
o $flags (Gtk2::CellRendererState) render flags
This method is called when an event occurs on a cell. Implementing
it is not mandatory. The return value should be TRUE if the event
was consumed/handled.
celleditable or undef = START_EDITING ($cell, $event, $widget, $path,
$background_area, $cell_area, $flags)
o $cell (Gtk2::CellRenderer)
o $event (Gtk2::Gdk::Event)
o $widget (Gtk2::Widget) widget that received the event
o $path (string) widget-dependent string representation of the
event location; e.g. for a Gtk2::TreeView, a string representation
of a Gtk2::TreePath.
o $background_area (Gtk2::Gdk::Rectangle) background area as passed
to "RENDER".
o $cell_area (Gtk2::Gdk::Rectangle) cell area as passed to
"RENDER".
o $flags (Gtk2::CellRendererState) render flags
For cells that are editable, this is called to put the cell into
editing mode. If the return value is an object is a
Gtk2::CellEditable, that widget will be used to edit the value; the
calling code takes care of sizing, placing, and showing the
editable, you just need to return it. If the return value is
undef, the editing is aborted.
Note: for backward compatibility, the bizarre and non-standard scheme
used for this in 1.02x is still supported, but is deprecated and should
not be used in new code, and since i don't want people to use it any
more i will not document it here.
SEE ALSO
Gtk2, Glib::Object, Glib::InitiallyUnowned, Gtk2::Object
COPYRIGHT
Copyright (C) 2003-2006 by the gtk2-perl team.
This software is licensed under the LGPL. See Gtk2 for a full notice.
perl v5.10.0 2008-08-29 Gtk2::CellRenderer(3)