An object for rendering a single cell on a
The <gtk-cell-renderer>
is a base class of a set of objects used for
rendering a cell to a <gdk-drawable>
. These objects are used primarily by
the <gtk-tree-view>
widget, though they aren't tied to them in any
specific way. It is worth noting that <gtk-cell-renderer>
is not a
<gtk-widget>
and cannot be treated as such.
The primary use of a <gtk-cell-renderer>
is for drawing a certain
graphical elements on a <gdk-drawable>
. Typically, one cell renderer is
used to draw many cells on the screen. To this extent, it isn't expected that a
CellRenderer keep any permanent state around. Instead, any state is set just
prior to use using <gobject>
s property system. Then, the cell is measured
using gtk-cell-renderer-get-size
. Finally, the cell is rendered in the
correct location using gtk-cell-renderer-render
.
There are a number of rules that must be followed when writing a new
<gtk-cell-renderer>
. First and formost, it's important that a certain set
of properties will always yield a cell renderer of the same size, barring a
<gtk-style>
change. The <gtk-cell-renderer>
also has a number of
generic properties that are expected to be honored by all children.
Beyond merely rendering a cell, cell renderers can optionally provide active
user interface elements. A cell renderer can be activatable like
<gtk-cell-renderer-toggle>
, which toggles when it gets activated by a
mouse click, or it can be editable like <gtk-cell-renderer-text>
,
which allows the user to edit the text using a <gtk-entry>
. To make a
cell renderer activatable or editable, you have to implement the activate
or start-editing virtual functions, respectively.
Derives from
<gtk-object>
.This class defines the following slots:
mode
- Editable mode of the CellRenderer
visible
- Display the cell
sensitive
- Display the cell sensitive
xalign
- The x-align
yalign
- The y-align
xpad
- The xpad
ypad
- The ypad
width
- The fixed width
height
- The fixed height
is-expander
- Row has children
is-expanded
- Row is an expander row, and is expanded
cell-background
- Cell background color as a string
cell-background-gdk
- Cell background color as a GdkColor
cell-background-set
- Whether this tag affects the cell background color
This signal gets emitted when the user cancels the process of editing a cell. For example, an editable cell renderer could be written to cancel editing when the user presses Escape.
See also:
gtk-cell-renderer-editing-canceled
Since 2.4
<gtk-cell-editable>
) (arg1 <gchararray>
)This signal gets emitted when a cell starts to be edited. The indended use of this signal is to do special setup on editable, e.g. adding a
<gtk-entry-completion>
or setting up additional columns in a<gtk-combo-box>
.Note that GTK+ doesn't guarantee that cell renderers will continue to use the same kind of widget for editing in future releases, therefore you should check the type of editable before doing any specific setup, as in the following example:
static void text_editing_started (GtkCellRenderer *cell, GtkCellEditable *editable, const gchar *path, gpointer data) { if (GTK_IS_ENTRY (editable)) { GtkEntry *entry = GTK_ENTRY (editable); /* ... create a GtkEntryCompletion */ gtk_entry_set_completion (entry, completion); } }Since 2.6
<gtk-cell-renderer>
) (window <gdk-window>
) (widget <gtk-widget>
) (background_area <gdk-rectangle>
) (cell_area <gdk-rectangle>
) (expose_area <gdk-rectangle>
) (flags <gtk-cell-renderer-state>
)Invokes the virtual render function of the
<gtk-cell-renderer>
. The three passed-in rectangles are areas of window. Most renderers will draw within cell-area; the xalign, yalign, xpad, and ypad fields of the<gtk-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 tile to cover the entire window. expose-area is a clip rectangle.
- cell
- a
<gtk-cell-renderer>
- window
- a
<gdk-drawable>
to draw to- widget
- the widget owning window
- background-area
- entire cell area (including tree expanders and maybe padding on the sides)
- cell-area
- area normally rendered by a cell renderer
- expose-area
- area that actually needs updating
- flags
- flags that affect rendering
<gtk-cell-renderer>
) (event <gdk-event>
) (widget <gtk-widget>
) (path mchars
) (background_area <gdk-rectangle>
) (cell_area <gdk-rectangle>
) (flags <gtk-cell-renderer-state>
) ⇒ (ret bool
)Passes an activate event to the cell renderer for possible processing. Some cell renderers may use events; for example,
<gtk-cell-renderer-toggle>
toggles when it gets a mouse click.
- cell
- a
<gtk-cell-renderer>
- event
- a
<gdk-event>
- widget
- widget that received the event
- path
- widget-dependent string representation of the event location; e.g. for
<gtk-tree-view>
, a string representation of<gtk-tree-path>
- background-area
- background area as passed to gtk-cell-renderer-render
- cell-area
- cell area as passed to gtk-cell-renderer-render
- flags
- render flags
- ret
- ‘
#t
’ if the event was consumed/handled
<gtk-cell-renderer>
) (event <gdk-event>
) (widget <gtk-widget>
) (path mchars
) (background_area <gdk-rectangle>
) (cell_area <gdk-rectangle>
) (flags <gtk-cell-renderer-state>
) ⇒ (ret <gtk-cell-editable>
)Passes an activate event to the cell renderer for possible processing.
- cell
- a
<gtk-cell-renderer>
- event
- a
<gdk-event>
- widget
- widget that received the event
- path
- widget-dependent string representation of the event location; e.g. for
<gtk-tree-view>
, a string representation of<gtk-tree-path>
- background-area
- background area as passed to gtk-cell-renderer-render
- cell-area
- cell area as passed to gtk-cell-renderer-render
- flags
- render flags
- ret
- A new
<gtk-cell-editable>
, or ‘#f
’
<gtk-cell-renderer>
)‘gtk_cell_renderer_editing_canceled’ has been deprecated since version 2.6 and should not be used in newly-written code. Use
gtk-cell-renderer-stop-editing
insteadCauses the cell renderer to emit the "editing-canceled" signal. This function is for use only by implementations of cell renderers that need to notify the client program that an editing process was canceled and the changes were not committed.
- cell
- A
<gtk-cell-renderer>
Since 2.4
<gtk-cell-renderer>
) (canceled bool
)Informs the cell renderer that the editing is stopped. If canceled is ‘
#t
’, the cell renderer will emit the "editing-canceled" signal. This function should be called by cell renderer implementations in response to the "editing-done" signal of<gtk-cell-editable>
.
- cell
- A
<gtk-cell-renderer>
- canceled
- ‘
#t
’ if the editing has been canceledSince 2.6
<gtk-cell-renderer>
) ⇒ (width int
) (height int
)Fills in width and height with the appropriate size of cell.
- cell
- A
<gtk-cell-renderer>
- width
- location to fill in with the fixed width of the widget, or ‘
#f
’- height
- location to fill in with the fixed height of the widget, or ‘
#f
’
<gtk-cell-renderer>
) (width int
) (height int
)Sets the renderer size to be explicit, independent of the properties set.
- cell
- A
<gtk-cell-renderer>
- width
- the width of the cell renderer, or -1
- height
- the height of the cell renderer, or -1