Expander
GtkExpander allows the user to reveal its child by clicking on an expander triangle.
This is similar to the triangles used in a GtkTreeView.
Normally you use an expander as you would use a frame; you create the child widget and use method@Gtk.Expander.set_child to add it to the expander. When the expander is toggled, it will take care of showing and hiding the child automatically.
Special Usage
There are situations in which you may prefer to show and hide the expanded widget yourself, such as when you want to actually create the widget at expansion time. In this case, create a GtkExpander but do not add a child to it. The expander widget has an property@Gtk.Expander:expanded property which can be used to monitor its expansion state. You should watch this property with a signal connection as follows:
static void
expander_callback (GObject *object,
GParamSpec *param_spec,
gpointer user_data)
{
GtkExpander *expander;
expander = GTK_EXPANDER (object);
if (gtk_expander_get_expanded (expander))
{
// Show or create widgets
}
else
{
// Hide or destroy widgets
}
}
static void
create_expander (void)
{
GtkWidget *expander = gtk_expander_new_with_mnemonic ("_More Options");
g_signal_connect (expander, "notify::expanded",
G_CALLBACK (expander_callback), NULL);
// ...
}GtkExpander as GtkBuildable
The GtkExpander implementation of the GtkBuildable interface supports placing a child in the label position by specifying “label” as the “type” attribute of a <child> element. A normal content child can be specified without specifying a <child> type attribute.
An example of a UI definition fragment with GtkExpander:
<object class="GtkExpander">
<child type="label">
<object class="GtkLabel" id="expander-label"/>
</child>
<child>
<object class="GtkEntry" id="expander-content"/>
</child>
</object>CSS nodes
expander-widget
╰── box
├── title
│ ├── expander
│ ╰── <label widget>
╰── <child>GtkExpander has a main node expander-widget, and subnode box containing the title and child widget. The box subnode title contains node expander, i.e. the expand/collapse arrow; then the label widget if any. The arrow of an expander that is showing its child gets the :checked pseudoclass set on it.
Accessibility
GtkExpander uses the %GTK_ACCESSIBLE_ROLE_BUTTON role.
Constructors
Properties
The accessible role of the given GtkAccessible implementation.
A list of css classes applied to this widget.
Whether the widget should grab focus when it is clicked with the mouse.
Enables or disables the emission of the ::query-tooltip signal on @widget.
Whether to use the hexpand property.
A widget to display instead of the usual expander label.
The GtkLayoutManager instance to use to compute the preferred size of the widget, and allocate its children.
Margin on bottom side of widget.
Margin on start of widget, horizontally.
Whether the widget will receive the default action when it is focused.
When this property is true, the expander will resize the toplevel widget containing the expander upon expanding and collapsing.
The scale factor of the widget.
Sets the text of tooltip to be the given string, which is marked up with Pango markup.
Sets the text of tooltip to be the given string.
Whether an underline in the text indicates a mnemonic.
Whether to use the vexpand property.
Functions
Enable or disable an action installed with gtk_widget_class_install_action().
Looks up the action in the action groups associated with
Activates the default.activate action from @widget.
For widgets that can be “activated” (buttons, menu items, etc.), this function activates them.
Adds @controller to @widget so that it will receive events.
Adds a style class to @widget.
Adds a widget to the list of mnemonic labels for this widget.
Queues an animation frame update and adds a callback to be called before each frame.
This function is only used by GtkWidget subclasses, to assign a size, position and (optionally) baseline to their child widgets.
Requests the user's screen reader to announce the given message.
Called by widgets as the user moves around the window using keyboard shortcuts.
Computes the bounds for @widget in the coordinate space of @target.
Computes whether a container should give this widget extra space when possible.
Translates the given @point in @widget's coordinates to coordinates relative to @target’s coordinate system.
Computes a matrix suitable to describe a transformation from
Activates the GtkExpander.
Signals that all holders of a reference to the widget should release the reference that they hold.
Emitted when the text direction of a widget changes.
Emitted when @widget is hidden.
Emitted if keyboard navigation fails.
Emitted when @widget is going to be mapped.
Emitted when a widget is activated via a mnemonic.
Emitted when the focus is moved.
Emitted when the widget’s tooltip is about to be shown.
Emitted when @widget is associated with a GdkSurface.
Emitted when @widget is shown.
Emitted when the widget state changes.
Emitted when @widget is going to be unmapped.
Emitted when the GdkSurface associated with @widget is destroyed.
Creates a new PangoContext with the appropriate font map, font options, font description, and base direction for drawing text for this widget.
Creates a new PangoLayout with the appropriate font map, font description, and base direction for drawing text for this widget.
Clears the template children for the given widget.
Checks to see if a drag movement has passed the GTK drag threshold.
Retrieves the accessible parent for an accessible object.
Retrieves the accessible role of an accessible object.
Returns the baseline that has currently been allocated to @widget.
Returns the height that has currently been allocated to @widget.
Returns the width that has currently been allocated to @widget.
Gets the first ancestor of @widget with type @widget_type.
Retrieves the accessible implementation for the given GtkAccessible.
Returns the baseline that has currently been allocated to @widget.
Gets the ID of the @buildable object.
Gets the value set with gtk_widget_set_child_visible().
Gets the clipboard object for @widget.
Gets the reading direction for a particular widget.
Get the GdkDisplay for the toplevel window associated with this widget.
Retrieves the first accessible child of an accessible object.
Returns the widget’s first child.
Returns the current focus child of @widget.
Gets the font map of @widget.
Obtains the frame clock for a widget.
Returns the widget’s last child.
Retrieves the next accessible sibling of an accessible object
Returns the widget’s next sibling.
Gets a PangoContext with the appropriate font map, font description, and base direction for this widget.
Query a platform state, such as focus.
Retrieves the minimum and natural size of a widget, taking into account the widget’s preference for height-for-width management.
Returns the widget’s previous sibling.
Gets the primary clipboard of @widget.
Determines whether @widget is realized.
Gets whether the widget prefers a height-for-width layout or a width-for-height layout.
Returns the widget’s sensitivity.
Gets the settings object holding the settings used for this widget.
Returns the content width or height of the widget.
Returns the widget state as a flag set.
Returns the style context associated to @widget.
Fetch an object build from the template XML for @widget_type in this @widget instance.
Determines whether the widget is visible.
Returns whether @css_class is currently applied to @widget.
Determines whether @widget is the current default widget within its toplevel.
Determines if the widget should show a visible indication that it has the global input focus.
Returns whether the widget is currently being destroyed.
Creates and initializes child widgets defined in templates.
Inserts @group into @widget.
Inserts @widget into the child widget list of @parent.
Inserts @widget into the child widget list of @parent.
Determines whether @widget is somewhere inside @ancestor, possibly with intermediate containers.
Determines whether @widget can be drawn to.
Returns the widget’s effective sensitivity.
Emits the ::keynav-failed signal on the widget.
Returns the widgets for which this widget is the target of a mnemonic.
Emits the ::mnemonic-activate signal.
Returns a GListModel to track the children of @widget.
Returns a GListModel to track the class@Gtk.EventControllers of @widget.
Flags the widget for a rerun of the vfunc@Gtk.Widget.size_allocate function.
Flags a widget to have its size renegotiated.
Removes @controller from @widget, so that it doesn't process events anymore.
Removes a style from @widget.
Removes a widget from the list of mnemonic labels for this widget.
Removes a tick callback previously registered with gtk_widget_add_tick_callback().
Resets the accessible @property to its default value.
Resets the accessible @relation to its default value.
Resets the accessible @state to its default value.
Sets the parent and sibling of an accessible object.
Sets whether @widget should be mapped along with its parent.
Sets a named cursor to be shown when pointer devices point towards @widget.
Sets the reading direction on a particular widget.
Set @child as the current focus child of @widget.
Sets the font map to use for Pango rendering.
Set all margins to the same value.
Set start and end margin to horizontal and top and bottom margin to vertical
Set margins.
Sets the sensitivity of a widget.
Sets the minimum size of a widget.
Turns on flag values in the current widget state.
Sets the visibility state of @widget.
Returns whether @widget should contribute to the measuring and allocation of its parent.
Triggers a tooltip query on the display where the toplevel of @widget is located.
Turns off flag values for the current widget state.
Updates the next accessible sibling of @self.