type Gtk_Cell_Layout is new Glib.Types.GType_Interface;
type Gtk_Cell_Layout_Data_Func is access procedure (Cell_Layout : Gtk_Cell_Layout; Cell : not null access Gtk.Cell_Renderer.Gtk_Cell_Renderer_Record'Class; Tree_Model : Gtk.Tree_Model.Gtk_Tree_Model; Iter : Gtk.Tree_Model.Gtk_Tree_Iter);
Null_Gtk_Cell_Layout : constant Gtk_Cell_Layout;
function Get_Type return Glib.GType;
procedure Add_Attribute
( | Cell_Layout | : Gtk_Cell_Layout; |
Cell | : not null access Gtk.Cell_Renderer.Gtk_Cell_Renderer_Record'Class; | |
Attribute | : UTF8_String; | |
Column | : Gint); |
procedure Clear
( | Cell_Layout | : Gtk_Cell_Layout); |
procedure Clear_Attributes
( | Cell_Layout | : Gtk_Cell_Layout; |
Cell | : not null access Gtk.Cell_Renderer.Gtk_Cell_Renderer_Record'Class); |
function Get_Cells
( | Cell_Layout | : Gtk_Cell_Layout) return Glib.Object.Object_Simple_List.Glist; |
procedure Pack_End
( | Cell_Layout | : Gtk_Cell_Layout; |
Cell | : not null access Gtk.Cell_Renderer.Gtk_Cell_Renderer_Record'Class; | |
Expand | : Boolean); |
procedure Pack_Start
( | Cell_Layout | : Gtk_Cell_Layout; |
Cell | : not null access Gtk.Cell_Renderer.Gtk_Cell_Renderer_Record'Class; | |
Expand | : Boolean); |
procedure Reorder
( | Cell_Layout | : Gtk_Cell_Layout; |
Cell | : not null access Gtk.Cell_Renderer.Gtk_Cell_Renderer_Record'Class; | |
Position | : Gint); |
procedure Set_Cell_Data_Func
( | Cell_Layout | : Gtk_Cell_Layout; |
Cell | : not null access Gtk.Cell_Renderer.Gtk_Cell_Renderer_Record'Class; | |
Func | : Gtk_Cell_Layout_Data_Func); |
function "+"
( | W | : Gtk_Cell_Layout) return Gtk_Cell_Layout; |
Gtk.Cell_Layout.Gtk_Cell_Layout is an interface to be implemented by all objects which want to provide a Gtk.Tree_View_Column.Gtk_Tree_View_Column<!-- -->-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 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.Cell_Layout.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 (Gtk.Cell_View.Gtk_Cell_View, Gtk.Icon_View.Gtk_Icon_View, Gtk.Combo_Box.Gtk_Combo_Box, Gtk.Entry_Completion.Gtk_Entry_Completion, Gtk.Tree_View_Column.Gtk_Tree_View_Column) 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. == 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 Gtk.Cell_Area.Gtk_Cell_Area to lay out cells (all GtkCellLayouts in GTK+ use a GtkCellArea) <link linkend="cell-properties">cell properties</link> 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. == 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 Gtk.Cell_Layout.Gtk_Cell_Layout like Gtk.Icon_View.Gtk_Icon_View or Gtk.Combo_Box.Gtk_Combo_Box, there are some considerations related to the fact that these widgets internally use a Gtk.Cell_Area.Gtk_Cell_Area. 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.