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GtkCellRenderer

GtkCellRenderer — An object for rendering a single cell on a GdkDrawable

Synopsis


#include <gtk/gtk.h>

enum                GtkCellRendererState;
enum                GtkCellRendererMode;
                    GtkCellRenderer;
                    GtkCellRendererClass;
void                gtk_cell_renderer_get_size          (GtkCellRenderer *cell,
                                                         GtkWidget *widget,
                                                         const GdkRectangle *cell_area,
                                                         gint *x_offset,
                                                         gint *y_offset,
                                                         gint *width,
                                                         gint *height);
void                gtk_cell_renderer_render            (GtkCellRenderer *cell,
                                                         GdkWindow *window,
                                                         GtkWidget *widget,
                                                         const GdkRectangle *background_area,
                                                         const GdkRectangle *cell_area,
                                                         const GdkRectangle *expose_area,
                                                         GtkCellRendererState flags);
gboolean            gtk_cell_renderer_activate          (GtkCellRenderer *cell,
                                                         GdkEvent *event,
                                                         GtkWidget *widget,
                                                         const gchar *path,
                                                         const GdkRectangle *background_area,
                                                         const GdkRectangle *cell_area,
                                                         GtkCellRendererState flags);
GtkCellEditable *   gtk_cell_renderer_start_editing     (GtkCellRenderer *cell,
                                                         GdkEvent *event,
                                                         GtkWidget *widget,
                                                         const gchar *path,
                                                         const GdkRectangle *background_area,
                                                         const GdkRectangle *cell_area,
                                                         GtkCellRendererState flags);
void                gtk_cell_renderer_editing_canceled  (GtkCellRenderer *cell);
void                gtk_cell_renderer_stop_editing      (GtkCellRenderer *cell,
                                                         gboolean canceled);
void                gtk_cell_renderer_get_fixed_size    (GtkCellRenderer *cell,
                                                         gint *width,
                                                         gint *height);
void                gtk_cell_renderer_set_fixed_size    (GtkCellRenderer *cell,
                                                         gint width,
                                                         gint height);

Properties

  "cell-background"          gchar*                : Write
  "cell-background-gdk"      GdkColor*             : Read / Write
  "cell-background-set"      gboolean              : Read / Write
  "editing"                  gboolean              : Read
  "height"                   gint                  : Read / Write
  "is-expanded"              gboolean              : Read / Write
  "is-expander"              gboolean              : Read / Write
  "mode"                     GtkCellRendererMode   : Read / Write
  "sensitive"                gboolean              : Read / Write
  "visible"                  gboolean              : Read / Write
  "width"                    gint                  : Read / Write
  "xalign"                   gfloat                : Read / Write
  "xpad"                     guint                 : Read / Write
  "yalign"                   gfloat                : Read / Write
  "ypad"                     guint                 : Read / Write

Signals

  "editing-canceled"                               : Run First
  "editing-started"                                : Run First

Description

The GtkCellRenderer is a base class of a set of objects used for rendering a cell to a GdkDrawable. These objects are used primarily by the GtkTreeView widget, though they aren't tied to them in any specific way. It is worth noting that GtkCellRenderer is not a GtkWidget and cannot be treated as such.

The primary use of a GtkCellRenderer is for drawing a certain graphical elements on a GdkDrawable. 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 GObjects 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 GtkCellRenderer. First and formost, it's important that a certain set of properties will always yield a cell renderer of the same size, barring a GtkStyle change. The GtkCellRenderer 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 GtkCellRendererToggle, which toggles when it gets activated by a mouse click, or it can be editable like GtkCellRendererText, which allows the user to edit the text using a GtkEntry. To make a cell renderer activatable or editable, you have to implement the activate or start_editing virtual functions, respectively.

Details

enum GtkCellRendererState

typedef enum
{
  GTK_CELL_RENDERER_SELECTED    = 1 << 0,
  GTK_CELL_RENDERER_PRELIT      = 1 << 1,
  GTK_CELL_RENDERER_INSENSITIVE = 1 << 2,
  /* this flag means the cell is in the sort column/row */
  GTK_CELL_RENDERER_SORTED      = 1 << 3,
  GTK_CELL_RENDERER_FOCUSED     = 1 << 4
} GtkCellRendererState;

Tells how a cell is to be rendererd.

GTK_CELL_RENDERER_SELECTED

The cell is currently selected, and probably has a selection colored background to render to.

GTK_CELL_RENDERER_PRELIT

The mouse is hovering over the cell.

GTK_CELL_RENDERER_INSENSITIVE

The cell is drawn in an insensitive manner

GTK_CELL_RENDERER_SORTED

The cell is in a sorted row

GTK_CELL_RENDERER_FOCUSED

The cell is in the focus row.

enum GtkCellRendererMode

typedef enum
{
  GTK_CELL_RENDERER_MODE_INERT,
  GTK_CELL_RENDERER_MODE_ACTIVATABLE,
  GTK_CELL_RENDERER_MODE_EDITABLE
} GtkCellRendererMode;

Identifies how the user can interact with a particular cell.

GTK_CELL_RENDERER_MODE_INERT

The cell is just for display and cannot be interacted with. Note that this doesn't mean that eg. the row being drawn can't be selected -- just that a particular element of it cannot be individually modified.

GTK_CELL_RENDERER_MODE_ACTIVATABLE

The cell can be clicked.

GTK_CELL_RENDERER_MODE_EDITABLE

The cell can be edited or otherwise modified.

GtkCellRenderer

typedef struct _GtkCellRenderer GtkCellRenderer;


GtkCellRendererClass

typedef struct {
  GtkObjectClass parent_class;

  /* vtable - not signals */
  void             (* get_size)      (GtkCellRenderer      *cell,
				      GtkWidget            *widget,
				      GdkRectangle         *cell_area,
				      gint                 *x_offset,
				      gint                 *y_offset,
				      gint                 *width,
				      gint                 *height);
  void             (* render)        (GtkCellRenderer      *cell,
				      GdkDrawable          *window,
				      GtkWidget            *widget,
				      GdkRectangle         *background_area,
				      GdkRectangle         *cell_area,
				      GdkRectangle         *expose_area,
				      GtkCellRendererState  flags);
  gboolean         (* activate)      (GtkCellRenderer      *cell,
				      GdkEvent             *event,
				      GtkWidget            *widget,
				      const gchar          *path,
				      GdkRectangle         *background_area,
				      GdkRectangle         *cell_area,
				      GtkCellRendererState  flags);
  GtkCellEditable *(* start_editing) (GtkCellRenderer      *cell,
				      GdkEvent             *event,
				      GtkWidget            *widget,
				      const gchar          *path,
				      GdkRectangle         *background_area,
				      GdkRectangle         *cell_area,
				      GtkCellRendererState  flags);

  /* Signals */
  void (* editing_canceled) (GtkCellRenderer *cell);
  void (* editing_started)  (GtkCellRenderer *cell,
			     GtkCellEditable *editable,
			     const gchar     *path);

  /* Padding for future expansion */
  void (*_gtk_reserved1) (void);
  void (*_gtk_reserved2) (void);
} GtkCellRendererClass;


gtk_cell_renderer_get_size ()

void                gtk_cell_renderer_get_size          (GtkCellRenderer *cell,
                                                         GtkWidget *widget,
                                                         const GdkRectangle *cell_area,
                                                         gint *x_offset,
                                                         gint *y_offset,
                                                         gint *width,
                                                         gint *height);

Obtains the width and height needed to render the cell. Used by view widgets to determine the appropriate size for the cell_area passed to gtk_cell_renderer_render(). If cell_area is not NULL, fills in the x and y offsets (if set) of the cell relative to this location.

Please note that the values set in width and height, as well as those in x_offset and y_offset are inclusive of the xpad and ypad properties.

cell :

a GtkCellRenderer

widget :

the widget the renderer is rendering to

cell_area :

The area a cell will be allocated, or NULL

x_offset :

location to return x offset of cell relative to cell_area, or NULL

y_offset :

location to return y offset of cell relative to cell_area, or NULL

width :

location to return width needed to render a cell, or NULL

height :

location to return height needed to render a cell, or NULL

gtk_cell_renderer_render ()

void                gtk_cell_renderer_render            (GtkCellRenderer *cell,
                                                         GdkWindow *window,
                                                         GtkWidget *widget,
                                                         const GdkRectangle *background_area,
                                                         const GdkRectangle *cell_area,
                                                         const GdkRectangle *expose_area,
                                                         GtkCellRendererState flags);

Invokes the virtual render function of the GtkCellRenderer. 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 GtkCellRenderer 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 GtkCellRenderer

window :

a GdkDrawable 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_activate ()

gboolean            gtk_cell_renderer_activate          (GtkCellRenderer *cell,
                                                         GdkEvent *event,
                                                         GtkWidget *widget,
                                                         const gchar *path,
                                                         const GdkRectangle *background_area,
                                                         const GdkRectangle *cell_area,
                                                         GtkCellRendererState flags);

Passes an activate event to the cell renderer for possible processing. Some cell renderers may use events; for example, GtkCellRendererToggle toggles when it gets a mouse click.

cell :

a GtkCellRenderer

event :

a GdkEvent

widget :

widget that received the event

path :

widget-dependent string representation of the event location; e.g. for GtkTreeView, a string representation of GtkTreePath

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

Returns :

TRUE if the event was consumed/handled

gtk_cell_renderer_start_editing ()

GtkCellEditable *   gtk_cell_renderer_start_editing     (GtkCellRenderer *cell,
                                                         GdkEvent *event,
                                                         GtkWidget *widget,
                                                         const gchar *path,
                                                         const GdkRectangle *background_area,
                                                         const GdkRectangle *cell_area,
                                                         GtkCellRendererState flags);

Passes an activate event to the cell renderer for possible processing.

cell :

a GtkCellRenderer

event :

a GdkEvent

widget :

widget that received the event

path :

widget-dependent string representation of the event location; e.g. for GtkTreeView, a string representation of GtkTreePath

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

Returns :

A new GtkCellEditable, or NULL

gtk_cell_renderer_editing_canceled ()

void                gtk_cell_renderer_editing_canceled  (GtkCellRenderer *cell);

Warning

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() instead

Causes 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 GtkCellRenderer

Since 2.4


gtk_cell_renderer_stop_editing ()

void                gtk_cell_renderer_stop_editing      (GtkCellRenderer *cell,
                                                         gboolean canceled);

Informs the cell renderer that the editing is stopped. If canceled is TRUE, 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 GtkCellEditable.

cell :

A GtkCellRenderer

canceled :

TRUE if the editing has been canceled

Since 2.6


gtk_cell_renderer_get_fixed_size ()

void                gtk_cell_renderer_get_fixed_size    (GtkCellRenderer *cell,
                                                         gint *width,
                                                         gint *height);

Fills in width and height with the appropriate size of cell.

cell :

A GtkCellRenderer

width :

location to fill in with the fixed width of the widget, or NULL

height :

location to fill in with the fixed height of the widget, or NULL

gtk_cell_renderer_set_fixed_size ()

void                gtk_cell_renderer_set_fixed_size    (GtkCellRenderer *cell,
                                                         gint width,
                                                         gint height);

Sets the renderer size to be explicit, independent of the properties set.

cell :

A GtkCellRenderer

width :

the width of the cell renderer, or -1

height :

the height of the cell renderer, or -1

Property Details

The "cell-background" property

  "cell-background"          gchar*                : Write

Cell background color as a string.

Default value: NULL


The "cell-background-gdk" property

  "cell-background-gdk"      GdkColor*             : Read / Write

Cell background color as a GdkColor.


The "cell-background-set" property

  "cell-background-set"      gboolean              : Read / Write

Whether this tag affects the cell background color.

Default value: FALSE


The "editing" property

  "editing"                  gboolean              : Read

Whether the cell renderer is currently in editing mode.

Default value: FALSE


The "height" property

  "height"                   gint                  : Read / Write

The fixed height.

Allowed values: >= G_MAXULONG

Default value: -1


The "is-expanded" property

  "is-expanded"              gboolean              : Read / Write

Row is an expander row, and is expanded.

Default value: FALSE


The "is-expander" property

  "is-expander"              gboolean              : Read / Write

Row has children.

Default value: FALSE


The "mode" property

  "mode"                     GtkCellRendererMode   : Read / Write

Editable mode of the CellRenderer.

Default value: GTK_CELL_RENDERER_MODE_INERT


The "sensitive" property

  "sensitive"                gboolean              : Read / Write

Display the cell sensitive.

Default value: TRUE


The "visible" property

  "visible"                  gboolean              : Read / Write

Display the cell.

Default value: TRUE


The "width" property

  "width"                    gint                  : Read / Write

The fixed width.

Allowed values: >= G_MAXULONG

Default value: -1


The "xalign" property

  "xalign"                   gfloat                : Read / Write

The x-align.

Allowed values: [0,1]

Default value: 0.5


The "xpad" property

  "xpad"                     guint                 : Read / Write

The xpad.

Default value: 0


The "yalign" property

  "yalign"                   gfloat                : Read / Write

The y-align.

Allowed values: [0,1]

Default value: 0.5


The "ypad" property

  "ypad"                     guint                 : Read / Write

The ypad.

Default value: 0

Signal Details

The "editing-canceled" signal

void                user_function                      (GtkCellRenderer *renderer,
                                                        gpointer         user_data)      : Run First

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_stop_editing().

renderer :

the object which received the signal

user_data :

user data set when the signal handler was connected.

Since 2.4


The "editing-started" signal

void                user_function                      (GtkCellRenderer *renderer,
                                                        GtkCellEditable *editable,
                                                        gchar           *path,
                                                        gpointer         user_data)      : Run First

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 GtkEntryCompletion or setting up additional columns in a GtkComboBox.

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);
    }
}

renderer :

the object which received the signal

editable :

the GtkCellEditable

path :

the path identifying the edited cell

user_data :

user data set when the signal handler was connected.

Since 2.6