Class

GtkCellArea

Description [src] 

abstract class Gtk.CellArea : GObject.InitiallyUnowned
  implements Gtk.Buildable, Gtk.CellLayout {
  /* No available fields */
}

The GtkCellArea is an abstract class for GtkCellLayout widgets (also referred to as “layouting widgets”) to interface with an arbitrary number of GtkCellRenderers and interact with the user for a given GtkTreeModel row.

The cell area handles events, focus navigation, drawing and size requests and allocations for a given row of data.

Usually users dont have to interact with the GtkCellArea directly unless they are implementing a cell-layouting widget themselves.

Requesting area sizes

As outlined in [GtkWidget’s geometry management section][geometry-management], GTK+ uses a height-for-width geometry management system to compute the sizes of widgets and user interfaces. GtkCellArea uses the same semantics to calculate the size of an area for an arbitrary number of GtkTreeModel rows.

When requesting the size of a cell area one needs to calculate the size for a handful of rows, and this will be done differently by different layouting widgets. For instance a GtkTreeViewColumn always lines up the areas from top to bottom while a GtkIconView on the other hand might enforce that all areas received the same width and wrap the areas around, requesting height for more cell areas when allocated less width.

It’s also important for areas to maintain some cell alignments with areas rendered for adjacent rows (cells can appear “columnized” inside an area even when the size of cells are different in each row). For this reason the GtkCellArea uses a GtkCellAreaContext object to store the alignments and sizes along the way (as well as the overall largest minimum and natural size for all the rows which have been calculated with the said context).

The GtkCellAreaContext is an opaque object specific to the GtkCellArea which created it (see gtk_cell_area_create_context()). The owning cell-layouting widget can create as many contexts as it wishes to calculate sizes of rows which should receive the same size in at least one orientation (horizontally or vertically), However, it’s important that the same GtkCellAreaContext which was used to request the sizes for a given GtkTreeModel row be used when rendering or processing events for that row.

In order to request the width of all the rows at the root level of a GtkTreeModel one would do the following:

GtkTreeIter iter;
gint        minimum_width;
gint        natural_width;

valid = gtk_tree_model_get_iter_first (model, &iter);
while (valid)
  {
    gtk_cell_area_apply_attributes (area, model, &iter, FALSE, FALSE);
    gtk_cell_area_get_preferred_width (area, context, widget, NULL, NULL);

    valid = gtk_tree_model_iter_next (model, &iter);
  }
gtk_cell_area_context_get_preferred_width (context, &minimum_width, &natural_width);

Note that in this example it’s not important to observe the returned minimum and natural width of the area for each row unless the cell-layouting object is actually interested in the widths of individual rows. The overall width is however stored in the accompanying GtkCellAreaContext object and can be consulted at any time.

This can be useful since GtkCellLayout widgets usually have to support requesting and rendering rows in treemodels with an exceedingly large amount of rows. The GtkCellLayout widget in that case would calculate the required width of the rows in an idle or timeout source (see g_timeout_add()) and when the widget is requested its actual width in GtkWidgetClass.get_preferred_width() it can simply consult the width accumulated so far in the GtkCellAreaContext object.

A simple example where rows are rendered from top to bottom and take up the full width of the layouting widget would look like:

static void
foo_get_preferred_width (GtkWidget       *widget,
                         gint            *minimum_size,
                         gint            *natural_size)
{
  Foo        *foo  = FOO (widget);
  FooPrivate *priv = foo->priv;

  foo_ensure_at_least_one_handfull_of_rows_have_been_requested (foo);

  gtk_cell_area_context_get_preferred_width (priv->context, minimum_size, natural_size);
}

In the above example the Foo widget has to make sure that some row sizes have been calculated (the amount of rows that Foo judged was appropriate to request space for in a single timeout iteration) before simply returning the amount of space required by the area via the GtkCellAreaContext.

Requesting the height for width (or width for height) of an area is a similar task except in this case the GtkCellAreaContext does not store the data (actually, it does not know how much space the layouting widget plans to allocate it for every row. It’s up to the layouting widget to render each row of data with the appropriate height and width which was requested by the GtkCellArea).

In order to request the height for width of all the rows at the root level of a GtkTreeModel one would do the following:

GtkTreeIter iter;
gint        minimum_height;
gint        natural_height;
gint        full_minimum_height = 0;
gint        full_natural_height = 0;

valid = gtk_tree_model_get_iter_first (model, &iter);
while (valid)
  {
    gtk_cell_area_apply_attributes (area, model, &iter, FALSE, FALSE);
    gtk_cell_area_get_preferred_height_for_width (area, context, widget,
                                                  width, &minimum_height, &natural_height);

    if (width_is_for_allocation)
       cache_row_height (&iter, minimum_height, natural_height);

    full_minimum_height += minimum_height;
    full_natural_height += natural_height;

    valid = gtk_tree_model_iter_next (model, &iter);
  }

Note that in the above example we would need to cache the heights returned for each row so that we would know what sizes to render the areas for each row. However we would only want to really cache the heights if the request is intended for the layouting widgets real allocation.

In some cases the layouting widget is requested the height for an arbitrary for_width, this is a special case for layouting widgets who need to request size for tens of thousands of rows. For this case it’s only important that the layouting widget calculate one reasonably sized chunk of rows and return that height synchronously. The reasoning here is that any layouting widget is at least capable of synchronously calculating enough height to fill the screen height (or scrolled window height) in response to a single call to GtkWidgetClass.get_preferred_height_for_width(). Returning a perfect height for width that is larger than the screen area is inconsequential since after the layouting receives an allocation from a scrolled window it simply continues to drive the scrollbar values while more and more height is required for the row heights that are calculated in the background.

Rendering Areas

Once area sizes have been aquired at least for the rows in the visible area of the layouting widget they can be rendered at GtkWidgetClass.draw() time.

A crude example of how to render all the rows at the root level runs as follows:

GtkAllocation allocation;
GdkRectangle  cell_area = { 0, };
GtkTreeIter   iter;
gint          minimum_width;
gint          natural_width;

gtk_widget_get_allocation (widget, &allocation);
cell_area.width = allocation.width;

valid = gtk_tree_model_get_iter_first (model, &iter);
while (valid)
  {
    cell_area.height = get_cached_height_for_row (&iter);

    gtk_cell_area_apply_attributes (area, model, &iter, FALSE, FALSE);
    gtk_cell_area_render (area, context, widget, cr,
                          &cell_area, &cell_area, state_flags, FALSE);

    cell_area.y += cell_area.height;

    valid = gtk_tree_model_iter_next (model, &iter);
  }

Note that the cached height in this example really depends on how the layouting widget works. The layouting widget might decide to give every row its minimum or natural height or, if the model content is expected to fit inside the layouting widget without scrolling, it would make sense to calculate the allocation for each row at GtkWidget::size-allocate time using gtk_distribute_natural_allocation().

Handling Events and Driving Keyboard Focus

Passing events to the area is as simple as handling events on any normal widget and then passing them to the gtk_cell_area_event() API as they come in. Usually GtkCellArea is only interested in button events, however some customized derived areas can be implemented who are interested in handling other events. Handling an event can trigger the GtkCellArea::focus-changed signal to fire; as well as GtkCellArea::add-editable in the case that an editable cell was clicked and needs to start editing. You can call gtk_cell_area_stop_editing() at any time to cancel any cell editing that is currently in progress.

The GtkCellArea drives keyboard focus from cell to cell in a way similar to GtkWidget. For layouting widgets that support giving focus to cells it’s important to remember to pass GTK_CELL_RENDERER_FOCUSED to the area functions for the row that has focus and to tell the area to paint the focus at render time.

Layouting widgets that accept focus on cells should implement the GtkWidgetClass.focus() virtual method. The layouting widget is always responsible for knowing where GtkTreeModel rows are rendered inside the widget, so at GtkWidgetClass.focus() time the layouting widget should use the GtkCellArea methods to navigate focus inside the area and then observe the GtkDirectionType to pass the focus to adjacent rows and areas.

A basic example of how the GtkWidgetClass.focus() virtual method should be implemented:

static gboolean
foo_focus (GtkWidget       *widget,
           GtkDirectionType direction)
{
  Foo        *foo  = FOO (widget);
  FooPrivate *priv = foo->priv;
  gint        focus_row;
  gboolean    have_focus = FALSE;

  focus_row = priv->focus_row;

  if (!gtk_widget_has_focus (widget))
    gtk_widget_grab_focus (widget);

  valid = gtk_tree_model_iter_nth_child (priv->model, &iter, NULL, priv->focus_row);
  while (valid)
    {
      gtk_cell_area_apply_attributes (priv->area, priv->model, &iter, FALSE, FALSE);

      if (gtk_cell_area_focus (priv->area, direction))
        {
           priv->focus_row = focus_row;
           have_focus = TRUE;
           break;
        }
      else
        {
          if (direction == GTK_DIR_RIGHT ||
              direction == GTK_DIR_LEFT)
            break;
          else if (direction == GTK_DIR_UP ||
                   direction == GTK_DIR_TAB_BACKWARD)
           {
              if (focus_row == 0)
                break;
              else
               {
                  focus_row--;
                  valid = gtk_tree_model_iter_nth_child (priv->model, &iter, NULL, focus_row);
               }
            }
          else
            {
              if (focus_row == last_row)
                break;
              else
                {
                  focus_row++;
                  valid = gtk_tree_model_iter_next (priv->model, &iter);
                }
            }
        }
    }
    return have_focus;
}

Note that the layouting widget is responsible for matching the GtkDirectionType values to the way it lays out its cells.

Cell Properties

The GtkCellArea introduces cell properties for GtkCellRenderers in very much the same way that GtkContainer introduces [child properties][child-properties] for GtkWidgets. This provides some general interfaces for defining the relationship cell areas have with their cells. For instance in a GtkCellAreaBox a cell might “expand” and receive extra space when the area is allocated more than its full natural request, or a cell might be configured to “align” with adjacent rows which were requested and rendered with the same GtkCellAreaContext.

Use gtk_cell_area_class_install_cell_property() to install cell properties for a cell area class and gtk_cell_area_class_find_cell_property() or gtk_cell_area_class_list_cell_properties() to get information about existing cell properties.

To set the value of a cell property, use gtk_cell_area_cell_set_property(), gtk_cell_area_cell_set() or gtk_cell_area_cell_set_valist(). To obtain the value of a cell property, use gtk_cell_area_cell_get_property(), gtk_cell_area_cell_get() or gtk_cell_area_cell_get_valist().

Hierarchy

hierarchy this GtkCellArea implements_0 GtkBuildable this--implements_0 implements_1 GtkCellLayout this--implements_1 ancestor_0 GInitiallyUnowned ancestor_0--this ancestor_1 GObject ancestor_1--ancestor_0

Ancestors

Descendants

Implements

Instance methods

gtk_cell_area_activate

Activates area, usually by activating the currently focused cell, however some subclasses which embed widgets in the area can also activate a widget if it currently has the focus.

since: 3.0

gtk_cell_area_activate_cell

This is used by GtkCellArea subclasses when handling events to activate cells, the base GtkCellArea class activates cells for keyboard events for free in its own GtkCellArea->activate() implementation.

since: 3.0

gtk_cell_area_add

Adds renderer to area with the default child cell properties.

since: 3.0

gtk_cell_area_add_focus_sibling

Adds sibling to renderer’s focusable area, focus will be drawn around renderer and all of its siblings if renderer can focus for a given row.

since: 3.0

gtk_cell_area_add_with_properties

Adds renderer to area, setting cell properties at the same time. See gtk_cell_area_add() and gtk_cell_area_cell_set() for more details.

since: 3.0

gtk_cell_area_apply_attributes

Applies any connected attributes to the renderers in area by pulling the values from tree_model.

since: 3.0

gtk_cell_area_attribute_connect

Connects an attribute to apply values from column for the GtkTreeModel in use.

since: 3.0

gtk_cell_area_attribute_disconnect

Disconnects attribute for the renderer in area so that attribute will no longer be updated with values from the model.

since: 3.0

gtk_cell_area_attribute_get_column

Returns the model column that an attribute has been mapped to, or -1 if the attribute is not mapped.

since: 3.14

gtk_cell_area_cell_get

Gets the values of one or more cell properties for renderer in area.

since: 3.0

gtk_cell_area_cell_get_property

Gets the value of a cell property for renderer in area.

since: 3.0

gtk_cell_area_cell_get_valist

Gets the values of one or more cell properties for renderer in area.

since: 3.0

gtk_cell_area_cell_set

Sets one or more cell properties for cell in area.

since: 3.0

gtk_cell_area_cell_set_property

Sets a cell property for renderer in area.

since: 3.0

gtk_cell_area_cell_set_valist

Sets one or more cell properties for renderer in area.

since: 3.0

gtk_cell_area_copy_context

This is sometimes needed for cases where rows need to share alignments in one orientation but may be separately grouped in the opposing orientation.

since: 3.0

gtk_cell_area_create_context

Creates a GtkCellAreaContext to be used with area for all purposes. GtkCellAreaContext stores geometry information for rows for which it was operated on, it is important to use the same context for the same row of data at all times (i.e. one should render and handle events with the same GtkCellAreaContext which was used to request the size of those rows of data).

since: 3.0

gtk_cell_area_event

Delegates event handling to a GtkCellArea.

since: 3.0

gtk_cell_area_focus

This should be called by the area’s owning layout widget when focus is to be passed to area, or moved within area for a given direction and row data.

since: 3.0

gtk_cell_area_foreach

Calls callback for every GtkCellRenderer in area.

since: 3.0

gtk_cell_area_foreach_alloc

Calls callback for every GtkCellRenderer in area with the allocated rectangle inside cell_area.

since: 3.0

gtk_cell_area_get_cell_allocation

Derives the allocation of renderer inside area if area were to be renderered in cell_area.

since: 3.0

gtk_cell_area_get_cell_at_position

Gets the GtkCellRenderer at x and y coordinates inside area and optionally returns the full cell allocation for it inside cell_area.

since: 3.0

gtk_cell_area_get_current_path_string

Gets the current GtkTreePath string for the currently applied GtkTreeIter, this is implicitly updated when gtk_cell_area_apply_attributes() is called and can be used to interact with renderers from GtkCellArea subclasses.

since: 3.0

gtk_cell_area_get_edit_widget

Gets the GtkCellEditable widget currently used to edit the currently edited cell.

since: 3.0

gtk_cell_area_get_edited_cell

Gets the GtkCellRenderer in area that is currently being edited.

since: 3.0

gtk_cell_area_get_focus_cell

Retrieves the currently focused cell for area.

since: 3.0

gtk_cell_area_get_focus_from_sibling

Gets the GtkCellRenderer which is expected to be focusable for which renderer is, or may be a sibling.

since: 3.0

gtk_cell_area_get_focus_siblings

Gets the focus sibling cell renderers for renderer.

since: 3.0

gtk_cell_area_get_preferred_height

Retrieves a cell area’s initial minimum and natural height.

since: 3.0

gtk_cell_area_get_preferred_height_for_width

Retrieves a cell area’s minimum and natural height if it would be given the specified width.

since: 3.0

gtk_cell_area_get_preferred_width

Retrieves a cell area’s initial minimum and natural width.

since: 3.0

gtk_cell_area_get_preferred_width_for_height

Retrieves a cell area’s minimum and natural width if it would be given the specified height.

since: 3.0

gtk_cell_area_get_request_mode

Gets whether the area prefers a height-for-width layout or a width-for-height layout.

since: 3.0

gtk_cell_area_has_renderer

Checks if area contains renderer.

since: 3.0

gtk_cell_area_inner_cell_area

This is a convenience function for GtkCellArea implementations to get the inner area where a given GtkCellRenderer will be rendered. It removes any padding previously added by gtk_cell_area_request_renderer().

since: 3.0

gtk_cell_area_is_activatable

Returns whether the area can do anything when activated, after applying new attributes to area.

since: 3.0

gtk_cell_area_is_focus_sibling

Returns whether sibling is one of renderer’s focus siblings (see gtk_cell_area_add_focus_sibling()).

since: 3.0

gtk_cell_area_remove

Removes renderer from area.

since: 3.0

gtk_cell_area_remove_focus_sibling

Removes sibling from renderer’s focus sibling list (see gtk_cell_area_add_focus_sibling()).

since: 3.0

gtk_cell_area_render

Renders area’s cells according to area’s layout onto widget at the given coordinates.

since: 3.0

gtk_cell_area_request_renderer

This is a convenience function for GtkCellArea implementations to request size for cell renderers. It’s important to use this function to request size and then use gtk_cell_area_inner_cell_area() at render and event time since this function will add padding around the cell for focus painting.

since: 3.0

gtk_cell_area_set_focus_cell

Explicitly sets the currently focused cell to renderer.

since: 3.0

gtk_cell_area_stop_editing

Explicitly stops the editing of the currently edited cell.

since: 3.0

Methods inherited from GObject (43)

Please see GObject for a full list of methods.

Methods inherited from GtkBuildable (10)
gtk_buildable_add_child

Adds a child to buildable. type is an optional string describing how the child should be added.

since: 2.12

gtk_buildable_construct_child

Constructs a child of buildable with the name name.

since: 2.12

gtk_buildable_custom_finished

This is similar to gtk_buildable_parser_finished() but is called once for each custom tag handled by the buildable.

since: 2.12

gtk_buildable_custom_tag_end

This is called at the end of each custom element handled by the buildable.

since: 2.12

gtk_buildable_custom_tag_start

This is called for each unknown element under <child>.

since: 2.12

gtk_buildable_get_internal_child

Get the internal child called childname of the buildable object.

since: 2.12

gtk_buildable_get_name

Gets the name of the buildable object.

since: 2.12

gtk_buildable_parser_finished

Called when the builder finishes the parsing of a [GtkBuilder UI definition][BUILDER-UI]. Note that this will be called once for each time gtk_builder_add_from_file() or gtk_builder_add_from_string() is called on a builder.

since: 2.12

gtk_buildable_set_buildable_property

Sets the property name name to value on the buildable object.

since: 2.12

gtk_buildable_set_name

Sets the name of the buildable object.

since: 2.12

Methods inherited from GtkCellLayout (10)
gtk_cell_layout_add_attribute

Adds an attribute mapping to the list in cell_layout.

since: 2.4

gtk_cell_layout_clear

Unsets all the mappings on all renderers on cell_layout and removes all renderers from cell_layout.

since: 2.4

gtk_cell_layout_clear_attributes

Clears all existing attributes previously set with gtk_cell_layout_set_attributes().

since: 2.4

gtk_cell_layout_get_area

Returns the underlying GtkCellArea which might be cell_layout if called on a GtkCellArea or might be NULL if no GtkCellArea is used by cell_layout.

since: 3.0

gtk_cell_layout_get_cells

Returns the cell renderers which have been added to cell_layout.

since: 2.12

gtk_cell_layout_pack_end

Adds the cell to the end of cell_layout. If expand is FALSE, then the cell is allocated no more space than it needs. Any unused space is divided evenly between cells for which expand is TRUE.

since: 2.4

gtk_cell_layout_pack_start

Packs the cell into the beginning of cell_layout. If expand is FALSE, then the cell is allocated no more space than it needs. Any unused space is divided evenly between cells for which expand is TRUE.

since: 2.4

gtk_cell_layout_reorder

Re-inserts cell at position.

since: 2.4

gtk_cell_layout_set_attributes

Sets the attributes in list as the attributes of cell_layout.

since: 2.4

gtk_cell_layout_set_cell_data_func

Sets the GtkCellLayoutDataFunc to use for cell_layout.

since: 2.4

Properties

Gtk.CellArea:edit-widget

The widget currently editing the edited cell.

since: 3.0

Gtk.CellArea:edited-cell

The cell in the area that is currently edited.

since: 3.0

Gtk.CellArea:focus-cell

The cell in the area that currently has focus.

since: 3.0

Signals

Gtk.CellArea::add-editable

Indicates that editing has started on renderer and that editable should be added to the owning cell-layouting widget at cell_area.

since: 3.0

Gtk.CellArea::apply-attributes

This signal is emitted whenever applying attributes to area from model.

since: 3.0

Gtk.CellArea::focus-changed

Indicates that focus changed on this area. This signal is emitted either as a result of focus handling or event handling.

since: 3.0

Gtk.CellArea::remove-editable

Indicates that editing finished on renderer and that editable should be removed from the owning cell-layouting widget.

since: 3.0

Signals inherited from GObject (1)
GObject::notify

The notify signal is emitted on an object when one of its properties has its value set through g_object_set_property(), g_object_set(), et al.

Class structure 

struct GtkCellAreaClass {
  void (* add) (
    GtkCellArea* area,
    GtkCellRenderer* renderer
  );
  void (* remove) (
    GtkCellArea* area,
    GtkCellRenderer* renderer
  );
  void (* foreach) (
    GtkCellArea* area,
    GtkCellCallback callback,
    gpointer callback_data
  );
  void (* foreach_alloc) (
    GtkCellArea* area,
    GtkCellAreaContext* context,
    GtkWidget* widget,
    const GdkRectangle* cell_area,
    const GdkRectangle* background_area,
    GtkCellAllocCallback callback,
    gpointer callback_data
  );
  gint (* event) (
    GtkCellArea* area,
    GtkCellAreaContext* context,
    GtkWidget* widget,
    GdkEvent* event,
    const GdkRectangle* cell_area,
    GtkCellRendererState flags
  );
  void (* render) (
    GtkCellArea* area,
    GtkCellAreaContext* context,
    GtkWidget* widget,
    cairo_t* cr,
    const GdkRectangle* background_area,
    const GdkRectangle* cell_area,
    GtkCellRendererState flags,
    gboolean paint_focus
  );
  void (* apply_attributes) (
    GtkCellArea* area,
    GtkTreeModel* tree_model,
    GtkTreeIter* iter,
    gboolean is_expander,
    gboolean is_expanded
  );
  GtkCellAreaContext* (* create_context) (
    GtkCellArea* area
  );
  GtkCellAreaContext* (* copy_context) (
    GtkCellArea* area,
    GtkCellAreaContext* context
  );
  GtkSizeRequestMode (* get_request_mode) (
    GtkCellArea* area
  );
  void (* get_preferred_width) (
    GtkCellArea* area,
    GtkCellAreaContext* context,
    GtkWidget* widget,
    gint* minimum_width,
    gint* natural_width
  );
  void (* get_preferred_height_for_width) (
    GtkCellArea* area,
    GtkCellAreaContext* context,
    GtkWidget* widget,
    gint width,
    gint* minimum_height,
    gint* natural_height
  );
  void (* get_preferred_height) (
    GtkCellArea* area,
    GtkCellAreaContext* context,
    GtkWidget* widget,
    gint* minimum_height,
    gint* natural_height
  );
  void (* get_preferred_width_for_height) (
    GtkCellArea* area,
    GtkCellAreaContext* context,
    GtkWidget* widget,
    gint height,
    gint* minimum_width,
    gint* natural_width
  );
  void (* set_cell_property) (
    GtkCellArea* area,
    GtkCellRenderer* renderer,
    guint property_id,
    const GValue* value,
    GParamSpec* pspec
  );
  void (* get_cell_property) (
    GtkCellArea* area,
    GtkCellRenderer* renderer,
    guint property_id,
    GValue* value,
    GParamSpec* pspec
  );
  gboolean (* focus) (
    GtkCellArea* area,
    GtkDirectionType direction
  );
  gboolean (* is_activatable) (
    GtkCellArea* area
  );
  gboolean (* activate) (
    GtkCellArea* area,
    GtkCellAreaContext* context,
    GtkWidget* widget,
    const GdkRectangle* cell_area,
    GtkCellRendererState flags,
    gboolean edit_only
  );
  void (* _gtk_reserved1) (
void
  );
  void (* _gtk_reserved2) (
void
  );
  void (* _gtk_reserved3) (
void
  );
  void (* _gtk_reserved4) (
void
  );
  void (* _gtk_reserved5) (
void
  );
  void (* _gtk_reserved6) (
void
  );
  void (* _gtk_reserved7) (
void
  );
  void (* _gtk_reserved8) (
void
  );
  
}

No description available.

Class members
add: void (* add) ( GtkCellArea* area, GtkCellRenderer* renderer )

Adds a GtkCellRenderer to the area.

remove: void (* remove) ( GtkCellArea* area, GtkCellRenderer* renderer )

Removes a GtkCellRenderer from the area.

foreach: void (* foreach) ( GtkCellArea* area, GtkCellCallback callback, gpointer callback_data )

Calls the GtkCellCallback function on every GtkCellRenderer in the area with the provided user data until the callback returns TRUE.

foreach_alloc: void (* foreach_alloc) ( GtkCellArea* area, GtkCellAreaContext* context, GtkWidget* widget, const GdkRectangle* cell_area, const GdkRectangle* background_area, GtkCellAllocCallback callback, gpointer callback_data )

Calls the GtkCellAllocCallback function on every GtkCellRenderer in the area with the allocated area for the cell and the provided user data until the callback returns TRUE.

event: gint (* event) ( GtkCellArea* area, GtkCellAreaContext* context, GtkWidget* widget, GdkEvent* event, const GdkRectangle* cell_area, GtkCellRendererState flags )

Handle an event in the area, this is generally used to activate a cell at the event location for button events but can also be used to generically pass events to GtkWidgets drawn onto the area.

render: void (* render) ( GtkCellArea* area, GtkCellAreaContext* context, GtkWidget* widget, cairo_t* cr, const GdkRectangle* background_area, const GdkRectangle* cell_area, GtkCellRendererState flags, gboolean paint_focus )

Actually render the area’s cells to the specified rectangle, background_area should be correctly distributed to the cells corresponding background areas.

apply_attributes: void (* apply_attributes) ( GtkCellArea* area, GtkTreeModel* tree_model, GtkTreeIter* iter, gboolean is_expander, gboolean is_expanded )

Apply the cell attributes to the cells. This is implemented as a signal and generally GtkCellArea subclasses don’t need to implement it since it is handled by the base class.

create_context: GtkCellAreaContext* (* create_context) ( GtkCellArea* area )

Creates and returns a class specific GtkCellAreaContext to store cell alignment and allocation details for a said GtkCellArea class.

copy_context: GtkCellAreaContext* (* copy_context) ( GtkCellArea* area, GtkCellAreaContext* context )

Creates a new GtkCellAreaContext in the same state as the passed context with any cell alignment data and allocations intact.

get_request_mode: GtkSizeRequestMode (* get_request_mode) ( GtkCellArea* area )

This allows an area to tell its layouting widget whether it prefers to be allocated in GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH or GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT mode.

get_preferred_width: void (* get_preferred_width) ( GtkCellArea* area, GtkCellAreaContext* context, GtkWidget* widget, gint* minimum_width, gint* natural_width )

Calculates the minimum and natural width of the areas cells with the current attributes applied while considering the particular layouting details of the said GtkCellArea. While requests are performed over a series of rows, alignments and overall minimum and natural sizes should be stored in the corresponding GtkCellAreaContext.

get_preferred_height_for_width: void (* get_preferred_height_for_width) ( GtkCellArea* area, GtkCellAreaContext* context, GtkWidget* widget, gint width, gint* minimum_height, gint* natural_height )

Calculates the minimum and natural height for the area if the passed context would be allocated the given width. When implementing this virtual method it is safe to assume that context has already stored the aligned cell widths for every GtkTreeModel row that context will be allocated for since this information was stored at GtkCellAreaClass.get_preferred_width() time. This virtual method should also store any necessary alignments of cell heights for the case that the context is allocated a height.

get_preferred_height: void (* get_preferred_height) ( GtkCellArea* area, GtkCellAreaContext* context, GtkWidget* widget, gint* minimum_height, gint* natural_height )

Calculates the minimum and natural height of the areas cells with the current attributes applied. Essentially this is the same as GtkCellAreaClass.get_preferred_width() only for areas that are being requested as GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT.

get_preferred_width_for_height: void (* get_preferred_width_for_height) ( GtkCellArea* area, GtkCellAreaContext* context, GtkWidget* widget, gint height, gint* minimum_width, gint* natural_width )

Calculates the minimum and natural width for the area if the passed context would be allocated the given height. The same as GtkCellAreaClass.get_preferred_height_for_width() only for handling requests in the GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT mode.

set_cell_property: void (* set_cell_property) ( GtkCellArea* area, GtkCellRenderer* renderer, guint property_id, const GValue* value, GParamSpec* pspec )

This should be implemented to handle changes in child cell properties for a given GtkCellRenderer that were previously installed on the GtkCellAreaClass with gtk_cell_area_class_install_cell_property().

get_cell_property: void (* get_cell_property) ( GtkCellArea* area, GtkCellRenderer* renderer, guint property_id, GValue* value, GParamSpec* pspec )

This should be implemented to report the values of child cell properties for a given child GtkCellRenderer.

focus: gboolean (* focus) ( GtkCellArea* area, GtkDirectionType direction )

This virtual method should be implemented to navigate focus from cell to cell inside the GtkCellArea. The GtkCellArea should move focus from cell to cell inside the area and return FALSE if focus logically leaves the area with the following exceptions: When the area contains no activatable cells, the entire area recieves focus. Focus should not be given to cells that are actually “focus siblings” of other sibling cells (see gtk_cell_area_get_focus_from_sibling()). Focus is set by calling gtk_cell_area_set_focus_cell().

is_activatable: gboolean (* is_activatable) ( GtkCellArea* area )

Returns whether the GtkCellArea can respond to GtkCellAreaClass.activate(), usually this does not need to be implemented since the base class takes care of this however it can be enhanced if the GtkCellArea subclass can handle activation in other ways than activating its GtkCellRenderers.

activate: gboolean (* activate) ( GtkCellArea* area, GtkCellAreaContext* context, GtkWidget* widget, const GdkRectangle* cell_area, GtkCellRendererState flags, gboolean edit_only )

This is called when the layouting widget rendering the GtkCellArea activates the focus cell (see gtk_cell_area_get_focus_cell()).

_gtk_reserved1: void (* _gtk_reserved1) ( void )

No description available.

_gtk_reserved2: void (* _gtk_reserved2) ( void )

No description available.

_gtk_reserved3: void (* _gtk_reserved3) ( void )

No description available.

_gtk_reserved4: void (* _gtk_reserved4) ( void )

No description available.

_gtk_reserved5: void (* _gtk_reserved5) ( void )

No description available.

_gtk_reserved6: void (* _gtk_reserved6) ( void )

No description available.

_gtk_reserved7: void (* _gtk_reserved7) ( void )

No description available.

_gtk_reserved8: void (* _gtk_reserved8) ( void )

No description available.

Virtual methods

Gtk.CellAreaClass.activate

Activates area, usually by activating the currently focused cell, however some subclasses which embed widgets in the area can also activate a widget if it currently has the focus.

since: 3.0

Gtk.CellAreaClass.add

Adds renderer to area with the default child cell properties.

since: 3.0

Gtk.CellAreaClass.apply_attributes

Applies any connected attributes to the renderers in area by pulling the values from tree_model.

since: 3.0

Gtk.CellAreaClass.copy_context

This is sometimes needed for cases where rows need to share alignments in one orientation but may be separately grouped in the opposing orientation.

since: 3.0

Gtk.CellAreaClass.create_context

Creates a GtkCellAreaContext to be used with area for all purposes. GtkCellAreaContext stores geometry information for rows for which it was operated on, it is important to use the same context for the same row of data at all times (i.e. one should render and handle events with the same GtkCellAreaContext which was used to request the size of those rows of data).

since: 3.0

Gtk.CellAreaClass.event

Delegates event handling to a GtkCellArea.

since: 3.0

Gtk.CellAreaClass.focus

This should be called by the area’s owning layout widget when focus is to be passed to area, or moved within area for a given direction and row data.

since: 3.0

Gtk.CellAreaClass.foreach

Calls callback for every GtkCellRenderer in area.

since: 3.0

Gtk.CellAreaClass.foreach_alloc

Calls callback for every GtkCellRenderer in area with the allocated rectangle inside cell_area.

since: 3.0

Gtk.CellAreaClass.get_cell_property

This should be implemented to report the values of child cell properties for a given child GtkCellRenderer.

Gtk.CellAreaClass.get_preferred_height

Retrieves a cell area’s initial minimum and natural height.

since: 3.0

Gtk.CellAreaClass.get_preferred_height_for_width

Retrieves a cell area’s minimum and natural height if it would be given the specified width.

since: 3.0

Gtk.CellAreaClass.get_preferred_width

Retrieves a cell area’s initial minimum and natural width.

since: 3.0

Gtk.CellAreaClass.get_preferred_width_for_height

Retrieves a cell area’s minimum and natural width if it would be given the specified height.

since: 3.0

Gtk.CellAreaClass.get_request_mode

Gets whether the area prefers a height-for-width layout or a width-for-height layout.

since: 3.0

Gtk.CellAreaClass.is_activatable

Returns whether the area can do anything when activated, after applying new attributes to area.

since: 3.0

Gtk.CellAreaClass.remove

Removes renderer from area.

since: 3.0

Gtk.CellAreaClass.render

Renders area’s cells according to area’s layout onto widget at the given coordinates.

since: 3.0

Gtk.CellAreaClass.set_cell_property

This should be implemented to handle changes in child cell properties for a given GtkCellRenderer that were previously installed on the GtkCellAreaClass with gtk_cell_area_class_install_cell_property().

Class methods

gtk_cell_area_class_find_cell_property

Finds a cell property of a cell area class by name.

since: 3.0

gtk_cell_area_class_install_cell_property

Installs a cell property on a cell area class.

since: 3.0

gtk_cell_area_class_list_cell_properties

Returns all cell properties of a cell area class.

since: 3.0