ScrolledWindowRef

public struct ScrolledWindowRef : ScrolledWindowProtocol, GWeakCapturing

GtkScrolledWindow is a container that accepts a single child widget, makes that child scrollable using either internally added scrollbars or externally associated adjustments, and optionally draws a frame around the child.

Widgets with native scrolling support, i.e. those whose classes implement the GtkScrollable interface, are added directly. For other types of widget, the class GtkViewport acts as an adaptor, giving scrollability to other widgets. GtkScrolledWindow’s implementation of gtk_container_add() intelligently accounts for whether or not the added child is a GtkScrollable. If it isn’t, GtkScrolledWindow wraps the child in a GtkViewport and adds that for you. Therefore, you can just add any child widget and not worry about the details.

If gtk_container_add() has added a GtkViewport for you, you can remove both your added child widget from the GtkViewport, and the GtkViewport from the GtkScrolledWindow, like this:

(C Language Example):

GtkWidget *scrolled_window = gtk_scrolled_window_new (NULL, NULL);
GtkWidget *child_widget = gtk_button_new ();

// GtkButton is not a GtkScrollable, so GtkScrolledWindow will automatically
// add a GtkViewport.
gtk_container_add (GTK_CONTAINER (scrolled_window),
                   child_widget);

// Either of these will result in child_widget being unparented:
gtk_container_remove (GTK_CONTAINER (scrolled_window),
                      child_widget);
// or
gtk_container_remove (GTK_CONTAINER (scrolled_window),
                      gtk_bin_get_child (GTK_BIN (scrolled_window)));

Unless GtkScrolledWindow:policy is GTK_POLICY_NEVER or GTK_POLICY_EXTERNAL, GtkScrolledWindow adds internal GtkScrollbar widgets around its child. The scroll position of the child, and if applicable the scrollbars, is controlled by the GtkScrolledWindow:hadjustment and GtkScrolledWindow:vadjustment that are associated with the GtkScrolledWindow. See the docs on GtkScrollbar for the details, but note that the “step_increment” and “page_increment” fields are only effective if the policy causes scrollbars to be present.

If a GtkScrolledWindow doesn’t behave quite as you would like, or doesn’t have exactly the right layout, it’s very possible to set up your own scrolling with GtkScrollbar and for example a GtkGrid.

Touch support

GtkScrolledWindow has built-in support for touch devices. When a touchscreen is used, swiping will move the scrolled window, and will expose ‘kinetic’ behavior. This can be turned off with the GtkScrolledWindow:kinetic-scrolling property if it is undesired.

GtkScrolledWindow also displays visual ‘overshoot’ indication when the content is pulled beyond the end, and this situation can be captured with the GtkScrolledWindow::edge-overshot signal.

If no mouse device is present, the scrollbars will overlayed as narrow, auto-hiding indicators over the content. If traditional scrollbars are desired although no mouse is present, this behaviour can be turned off with the GtkScrolledWindow:overlay-scrolling property.

CSS nodes

GtkScrolledWindow has a main CSS node with name scrolledwindow.

It uses subnodes with names overshoot and undershoot to draw the overflow and underflow indications. These nodes get the .left, .right, .top or .bottom style class added depending on where the indication is drawn.

GtkScrolledWindow also sets the positional style classes (.left, .right, .top, .bottom) and style classes related to overlay scrolling (.overlay-indicator, .dragging, .hovering) on its scrollbars.

If both scrollbars are visible, the area where they meet is drawn with a subnode named junction.

The ScrolledWindowRef type acts as a lightweight Swift reference to an underlying GtkScrolledWindow instance. It exposes methods that can operate on this data type through ScrolledWindowProtocol conformance. Use ScrolledWindowRef only as an unowned reference to an existing GtkScrolledWindow instance.