Gtk.CellLayout¶

Implementations:: Gtk.CellArea, Gtk.CellView, Gtk.ComboBox, Gtk.EntryCompletion, Gtk.IconView, Gtk.TreeViewColumn

Methods¶

	`add_attribute` (cell, attribute, column)
	`clear` ()
	`clear_attributes` (cell)
	`get_area` ()
	`get_cells` ()
	`pack_end` (cell, expand)
	`pack_start` (cell, expand)
	`reorder` (cell, position)
	`set_cell_data_func` (cell, func, *func_data)

Virtual Methods¶

	`do_add_attribute` (cell, attribute, column)
	`do_clear` ()
	`do_clear_attributes` (cell)
	`do_get_area` ()
	`do_get_cells` ()
	`do_pack_end` (cell, expand)
	`do_pack_start` (cell, expand)
	`do_reorder` (cell, position)
	`do_set_cell_data_func` (cell, func, func_data)

Properties¶

None

Signals¶

None

Fields¶

None

Class Details¶

class Gtk.CellLayout¶

Bases:: GObject.GInterface
Structure:: Gtk.CellLayoutIface

Gtk.CellLayout is an interface to be implemented by all objects which want to provide a Gtk.TreeViewColumn like API for packing cells, setting attributes and data funcs.

One of the notable features provided by implementations of Gtk.CellLayout are attributes. Attributes let you set the properties in flexible ways. They can just be set to constant values like regular properties. But they can also be mapped to a column of the underlying tree model with gtk_cell_layout_set_attributes(), which means that the value of the attribute can change from cell to cell as they are rendered by the cell renderer. Finally, it is possible to specify a function with Gtk.CellLayout.set_cell_data_func() that is called to determine the value of the attribute for each cell that is rendered.

GtkCellLayouts as Gtk.Buildable

Implementations of Gtk.CellLayout which also implement the Gtk.Buildable interface (Gtk.CellView, Gtk.IconView, Gtk.ComboBox, Gtk.EntryCompletion, Gtk.TreeViewColumn) accept Gtk.CellRenderer objects as <child> elements in UI definitions. They support a custom <attributes> element for their children, which can contain multiple <attribute> elements. Each <attribute> element has a name attribute which specifies a property of the cell renderer; the content of the element is the attribute value.

This is an example of a UI definition fragment specifying attributes:

<object class="GtkCellView">
  <child>
    <object class="GtkCellRendererText"/>
    <attributes>
      <attribute name="text">0</attribute>
    </attributes>
  </child>
</object>

Furthermore for implementations of Gtk.CellLayout that use a Gtk.CellArea to lay out cells (all GtkCellLayouts in GTK+ use a Gtk.CellArea) ‘cell properties [cell-properties]’ can also be defined in the format by specifying the custom <cell-packing> attribute which can contain multiple <property> elements defined in the normal way.

Here is a UI definition fragment specifying cell properties:

<object class="GtkTreeViewColumn">
  <child>
    <object class="GtkCellRendererText"/>
    <cell-packing>
      <property name="align">True</property>
      <property name="expand">False</property>
    </cell-packing>
  </child>
</object>

Subclassing Gtk.CellLayout implementations

When subclassing a widget that implements Gtk.CellLayout like Gtk.IconView or Gtk.ComboBox, there are some considerations related to the fact that these widgets internally use a Gtk.CellArea. The cell area is exposed as a construct-only property by these widgets. This means that it is possible to e.g. do

combo = g_object_new (GTK_TYPE_COMBO_BOX, "cell-area", my_cell_area, NULL);

to use a custom cell area with a combo box. But construct properties are only initialized after instance init() functions have run, which means that using functions which rely on the existence of the cell area in your subclass’ init() function will cause the default cell area to be instantiated. In this case, a provided construct property value will be ignored (with a warning, to alert you to the problem).

static void
my_combo_box_init (MyComboBox *b)
{
  GtkCellRenderer *cell;

  cell = gtk_cell_renderer_pixbuf_new ();
  // The following call causes the default cell area for combo boxes,
  // a GtkCellAreaBox, to be instantiated
  gtk_cell_layout_pack_start (GTK_CELL_LAYOUT (b), cell, FALSE);
  ...
}

GtkWidget *
my_combo_box_new (GtkCellArea *area)
{
  // This call is going to cause a warning about area being ignored
  return g_object_new (MY_TYPE_COMBO_BOX, "cell-area", area, NULL);
}

If supporting alternative cell areas with your derived widget is not important, then this does not have to concern you. If you want to support alternative cell areas, you can do so by moving the problematic calls out of init() and into a constructor() for your class.

add_attribute(cell, attribute, column)[source]¶

Parameters:

cell (Gtk.CellRenderer) – a Gtk.CellRenderer
attribute (str) – an attribute on the renderer
column (int) – the column position on the model to get the attribute from

Adds an attribute mapping to the list in self.

The column is the column of the model to get a value from, and the attribute is the parameter on cell to be set from the value. So for example if column 2 of the model contains strings, you could have the “text” attribute of a Gtk.CellRendererText get its values from column 2.

New in version 2.4.

clear()[source]¶: Unsets all the mappings on all renderers on self and removes all renderers from self.

New in version 2.4.

clear_attributes(cell)[source]¶

Parameters:: cell (Gtk.CellRenderer) – a Gtk.CellRenderer to clear the attribute mapping on

Clears all existing attributes previously set with gtk_cell_layout_set_attributes().

New in version 2.4.

get_area()[source]¶

Returns:: the cell area used by self, or None in case no cell area is used.
Return type:: Gtk.CellArea or None

Returns the underlying Gtk.CellArea which might be self if called on a Gtk.CellArea or might be None if no Gtk.CellArea is used by self.

New in version 3.0.

get_cells()[source]¶

Returns:: a list of cell renderers. The list, but not the renderers has been newly allocated and should be freed with g_list_free() when no longer needed.
Return type:: [Gtk.CellRenderer]

Returns the cell renderers which have been added to self.

New in version 2.12.

pack_end(cell, expand)[source]¶

Parameters:

cell (Gtk.CellRenderer) – a Gtk.CellRenderer
expand (bool) – True if cell is to be given extra space allocated to self

Adds the cell to the end of self. 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.

Note that reusing the same cell renderer is not supported.

New in version 2.4.

pack_start(cell, expand)[source]¶

Parameters:

cell (Gtk.CellRenderer) – a Gtk.CellRenderer
expand (bool) – True if cell is to be given extra space allocated to self

Packs the cell into the beginning of self. 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.

Note that reusing the same cell renderer is not supported.

New in version 2.4.

reorder(cell, position)[source]¶

Parameters:

cell (Gtk.CellRenderer) – a Gtk.CellRenderer to reorder
position (int) – new position to insert cell at

Re-inserts cell at position.

Note that cell has already to be packed into self for this to function properly.

New in version 2.4.

set_cell_data_func(cell, func, *func_data)[source]¶

Parameters:

cell (Gtk.CellRenderer) – a Gtk.CellRenderer
func (Gtk.CellLayoutDataFunc or None) – the Gtk.CellLayoutDataFunc to use, or None
func_data (object or None) – user data for func

Sets the Gtk.CellLayoutDataFunc to use for self.

This function is used instead of the standard attributes mapping for setting the column value, and should set the value of self’s cell renderer(s) as appropriate.

func may be None to remove a previously set function.

New in version 2.4.

do_add_attribute(cell, attribute, column) virtual¶

Parameters:

cell (Gtk.CellRenderer) – a Gtk.CellRenderer
attribute (str) – an attribute on the renderer
column (int) – the column position on the model to get the attribute from

Adds an attribute mapping to the list in cell_layout.

The column is the column of the model to get a value from, and the attribute is the parameter on cell to be set from the value. So for example if column 2 of the model contains strings, you could have the “text” attribute of a Gtk.CellRendererText get its values from column 2.

New in version 2.4.

do_clear() virtual¶: Unsets all the mappings on all renderers on cell_layout and removes all renderers from cell_layout.

New in version 2.4.

do_clear_attributes(cell) virtual¶

Parameters:: cell (Gtk.CellRenderer) – a Gtk.CellRenderer to clear the attribute mapping on

Clears all existing attributes previously set with gtk_cell_layout_set_attributes().

New in version 2.4.

do_get_area() virtual¶

Returns:: the cell area used by cell_layout, or None in case no cell area is used.
Return type:: Gtk.CellArea or None

Returns the underlying Gtk.CellArea which might be cell_layout if called on a Gtk.CellArea or might be None if no Gtk.CellArea is used by cell_layout.

New in version 3.0.

do_get_cells() virtual¶

Returns:: a list of cell renderers. The list, but not the renderers has been newly allocated and should be freed with g_list_free() when no longer needed.
Return type:: [Gtk.CellRenderer]

Returns the cell renderers which have been added to cell_layout.

New in version 2.12.

do_pack_end(cell, expand) virtual¶

Parameters:

cell (Gtk.CellRenderer) – a Gtk.CellRenderer
expand (bool) – True if cell is to be given extra space allocated to cell_layout

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.

Note that reusing the same cell renderer is not supported.

New in version 2.4.

do_pack_start(cell, expand) virtual¶

Parameters:

cell (Gtk.CellRenderer) – a Gtk.CellRenderer
expand (bool) – True if cell is to be given extra space allocated to cell_layout

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.

Note that reusing the same cell renderer is not supported.

New in version 2.4.

do_reorder(cell, position) virtual¶

Parameters:

cell (Gtk.CellRenderer) – a Gtk.CellRenderer to reorder
position (int) – new position to insert cell at

Re-inserts cell at position.

Note that cell has already to be packed into cell_layout for this to function properly.

New in version 2.4.

do_set_cell_data_func(cell, func, func_data) virtual¶

Parameters:

cell (Gtk.CellRenderer) – a Gtk.CellRenderer
func (Gtk.CellLayoutDataFunc or None) – the Gtk.CellLayoutDataFunc to use, or None
func_data (object or None) – user data for func

Sets the Gtk.CellLayoutDataFunc to use for cell_layout.

This function is used instead of the standard attributes mapping for setting the column value, and should set the value of cell_layout’s cell renderer(s) as appropriate.

func may be None to remove a previously set function.

New in version 2.4.