Module: Gtk::Scrollable

Defined in:
(unknown)

Overview

GtkScrollable is an interface for widgets with native scrolling ability.

To implement this interface you should override the [propertyGtk.Scrollable:hadjustment] and [propertyGtk.Scrollable:vadjustment] properties.

Creating a scrollable widget

All scrollable widgets should do the following.

  • When a parent widget sets the scrollable child widget’s adjustments, the widget should connect to the [signalGtk.Adjustment::value-changed] signal. The child widget should then populate the adjustments’ properties as soon as possible, which usually means queueing an allocation right away and populating the properties in the [vfuncGtk.Widget.size_allocate] implementation.

  • Because its preferred size is the size for a fully expanded widget, the scrollable widget must be able to cope with underallocations. This means that it must accept any value passed to its [vfuncGtk.Widget.size_allocate] implementation.

  • When the parent allocates space to the scrollable child widget, the widget must ensure the adjustments’ property values are correct and up to date, for example using [methodGtk.Adjustment.configure].

  • When any of the adjustments emits the [signalGtk.Adjustment::value-changed] signal, the scrollable widget should scroll its contents.

Instance Method Summary collapse

Instance Method Details

#get_border(border) ⇒ Boolean

Returns the size of a non-scrolling border around the outside of the scrollable.

An example for this would be treeview headers. GTK can use this information to display overlaid graphics, like the overshoot indication, at the right position.

Parameters:

  • border (Gtk::Border) —

    return location for the results

Returns:

  • (Boolean) —

    true if border has been set

#hadjustment ⇒ Gtk::Adjustment

Retrieves the GtkAdjustment used for horizontal scrolling.

Returns:

#hadjustment=(hadjustment) ⇒ nil

Sets the horizontal adjustment of the GtkScrollable.

Parameters:

Returns:

  • (nil)

#hscroll_policy ⇒ Gtk::ScrollablePolicy

Gets the horizontal GtkScrollablePolicy.

Returns:

#hscroll_policy=(policy) ⇒ nil

Sets the GtkScrollablePolicy.

The policy determines whether horizontal scrolling should start below the minimum width or below the natural width.

Parameters:

Returns:

  • (nil)

#vadjustment ⇒ Gtk::Adjustment

Retrieves the GtkAdjustment used for vertical scrolling.

Returns:

#vadjustment=(vadjustment) ⇒ nil

Sets the vertical adjustment of the GtkScrollable.

Parameters:

Returns:

  • (nil)

#vscroll_policy ⇒ Gtk::ScrollablePolicy

Gets the vertical GtkScrollablePolicy.

Returns:

#vscroll_policy=(policy) ⇒ nil

Sets the GtkScrollablePolicy.

The policy determines whether vertical scrolling should start below the minimum height or below the natural height.

Parameters:

Returns:

  • (nil)