CellLayout

Deprecated since version 4.10: List views use widgets to display their contents. See LayoutManager for layout manager delegate objects

class CellLayout(*args, **kwargs)

Implementations: CellArea, CellAreaBox, CellView, ComboBox, ComboBoxText, EntryCompletion, IconView, TreeViewColumn

An interface for packing cells

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

One of the notable features provided by implementations of GtkCellLayout 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 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 set_cell_data_func() that is called to determine the value of the attribute for each cell that is rendered.

GtkCellLayouts as GtkBuildable

Implementations of GtkCellLayout which also implement the GtkBuildable interface (GtkCellView, GtkIconView, GtkComboBox, GtkEntryCompletion, GtkTreeViewColumn) accept GtkCellRenderer 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 GtkCellLayout that use a GtkCellArea to lay out cells (all GtkCellLayout’s in GTK use a GtkCellArea) cell properties can also be defined in the format by specifying the custom <cell-packing> attribute which can contain multiple <property> elements.

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 GtkCellLayout implementations

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

GtkWIdget *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.

Methods

class CellLayout
add_attribute(cell: CellRenderer, attribute: str, column: int) → None

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 property on cell to be set from that value. So for example if column 2 of the model contains strings, you could have the “text” attribute of a GtkCellRendererText get its values from column 2. In this context “attribute” and “property” are used interchangeably.

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

  • cell – a GtkCellRenderer

  • attribute – a property on the renderer

  • column – the column position on the model to get the attribute from

clear() → None

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

Deprecated since version 4.10: Please do not use it in newly written code

clear_attributes(cell: CellRenderer) → None

Clears all existing attributes previously set with set_attributes().

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

cell – a GtkCellRenderer to clear the attribute mapping on

get_area() → CellArea | None

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

Deprecated since version 4.10: Please do not use it in newly written code

get_cells() → list[CellRenderer]

Returns the cell renderers which have been added to cell_layout.

Deprecated since version 4.10: Please do not use it in newly written code

pack_end(cell: CellRenderer, expand: bool) → None

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.

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

  • cell – a GtkCellRenderer

  • expand – True if cell is to be given extra space allocated to cell_layout

pack_start(cell: CellRenderer, expand: bool) → None

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.

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

  • cell – a GtkCellRenderer

  • expand – True if cell is to be given extra space allocated to cell_layout

reorder(cell: CellRenderer, position: int) → None

Re-inserts cell at position.

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

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

  • cell – a GtkCellRenderer to reorder

  • position – new position to insert cell at

set_cell_data_func(cell: CellRenderer, func: Callable[[...], None] | None = None, *func_data: Any) → None

Sets the GtkCellLayout``DataFunc 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.

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

  • cell – a GtkCellRenderer

  • func – the ``GtkCellLayout``DataFunc to use

  • func_data – user data for func

Virtual Methods

class CellLayout
do_add_attribute(cell: CellRenderer, attribute: str, column: int) → None

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 property on cell to be set from that value. So for example if column 2 of the model contains strings, you could have the “text” attribute of a GtkCellRendererText get its values from column 2. In this context “attribute” and “property” are used interchangeably.

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

  • cell – a GtkCellRenderer

  • attribute – a property on the renderer

  • column – the column position on the model to get the attribute from

do_clear() → None

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

Deprecated since version 4.10: Please do not use it in newly written code

do_clear_attributes(cell: CellRenderer) → None

Clears all existing attributes previously set with set_attributes().

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

cell – a GtkCellRenderer to clear the attribute mapping on

do_get_area() → CellArea | None

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

Deprecated since version 4.10: Please do not use it in newly written code

do_get_cells() → list[CellRenderer]

Returns the cell renderers which have been added to cell_layout.

Deprecated since version 4.10: Please do not use it in newly written code

do_pack_end(cell: CellRenderer, expand: bool) → None

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.

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

  • cell – a GtkCellRenderer

  • expand – True if cell is to be given extra space allocated to cell_layout

do_pack_start(cell: CellRenderer, expand: bool) → None

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.

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

  • cell – a GtkCellRenderer

  • expand – True if cell is to be given extra space allocated to cell_layout

do_reorder(cell: CellRenderer, position: int) → None

Re-inserts cell at position.

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

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

  • cell – a GtkCellRenderer to reorder

  • position – new position to insert cell at

do_set_cell_data_func(cell: CellRenderer, func: Callable[[...], None] | None = None, *func_data: Any) → None

Sets the GtkCellLayout``DataFunc 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.

Deprecated since version 4.10: Please do not use it in newly written code

Parameters:

  • cell – a GtkCellRenderer

  • func – the ``GtkCellLayout``DataFunc to use

  • func_data – user data for func