gtk:widget, gobject:initially-unowned, gtk:accessible, gtk:buildable, gtk:constraint-target, gobject:object, common-lisp:standard-object, common-lisp:t

None

The gtk:scrolled-window widget 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.

Figure: GtkScrolledWindow

Widgets with native scrolling support, that is, those whose classes implement the gtk:scrollable interface, are added directly. For other types of widgets, the gtk:viewport class acts as an adaptor, giving scrollability to other widgets. The gtk:scrolled-window-child function intelligently accounts for whether or not the added child is a gtk:scrollable widget. If it is not, then it wraps the child in a gtk:viewport widget. Therefore, you can just add any child widget and not worry about the details.

If the gtk:scrolled-window-child function has added a gtk:viewport widget for you, you can remove both your added child widget from the gtk:viewport widget, and the gtk:viewport widget from the gtk:scrolled-window widget, like this:

(let ((window (make-instance 'gtk:scrolled-window))
      (child (make-instance 'gtk:button)))


  ;; GtkButton is not a GtkScrollable, so GtkScrolledWindow will
  ;; automatically add a GtkViewport.
  (setf (gtk:scrolled-window window) child)


  ;; Either of these will result in child being unparented:
  (setf (gtk:scrolled-window-child window) nil)
  ;; or
  (setf (gtk:viewport-child (gtk:scrolled-window-child window)) nil)
  ... )  

Unless the hscrollbar-policy and vscrollbar-policy properties are :never or :external, the gtk:scrolled-window widget adds internal gtk:scrollbar widgets around its child. The scroll position of the child, and if applicable the scrollbars, is controlled by the hadjustment and vadjustment properties that are associated with the gtk:scrolled-window widget. See the docs on the gtk:scrollbar widget for the details, but note that the step-increment and page-increment properties are only effective if the policy causes scrollbars to be present.

If a gtk:scrolled-window widget does not behave quite as you would like, or does not have exactly the right layout, it is very possible to set up your own scrolling with the gtk:scrollbar widget and for example a gtk:grid widget.

Touch support

The gtk:scrolled-window widget 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 kinetic-scrolling property if it is undesired.

The gtk:scrolled-window widget also displays visual 'overshoot' indication when the content is pulled beyond the end, and this situation can be captured with the "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 overlay-scrolling property. The gtk:scrolled-window implementation 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.

The gtk:scrolled-window implementation also sets the .left, .right, .top, .bottom positional style classes and .overlay-indicator, .dragging, .hovering style classes related to overlay scrolling on its scrollbars.

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

The "edge-overshot" signal

lambda (window pos)    :run-last      

window

The gtk:scrolled-window widget which received the signal.

pos

The edge side as a value of the gtk:position-type enumeration that was hit.

The signal is emitted whenever user initiated scrolling makes the scrolled window firmly surpass, for example, with some edge resistance, the lower or upper limits defined by the adjustment in that orientation. A similar behavior without edge resistance is provided by the "edge-reached" signal. Note: The pos argument is LTR/RTL aware, so callers should be aware too if intending to provide behavior on horizontal edges.

The "edge-reached" signal

lambda (window pos)    :run-last      

window

The gtk:scrolled-window widget which received the signal.

pos

The edge side as a value of the gtk:position-type enumeration that was hit.

The signal is emitted whenever user-initiated scrolling makes the scrolled window exactly reach the lower or upper limits defined by the adjustment in that orientation. A similar behavior with edge resistance is provided by the "edge-overshot" signal. Note: The pos argument is LTR/RTL aware, so callers should be aware too if intending to provide behavior on horizontal edges.

The "move-focus-out" signal

lambda (window direction)    :action      

window

The gtk:scrolled-window widget which received the signal.

direction

Either the :tab-forward or :tab-backward value of the gtk:direction-type enumeration.

The signal is a keybinding signal which gets emitted when focus is moved away from the scrolled window by a keybinding. The "move-focus" signal is emitted with the direction value on this scrolled windows toplevel parent in the container hierarchy. The default bindings for this signal are the Tab+Ctrl and Tab+Ctrl+Shift keys.

The "scroll-child" signal

lambda (window scroll horizontal)    :action        

window

The gtk:scrolled-window widget which received the signal.

scroll

The value of the gtk:scroll-type enumeration describing how much to scroll.

horizontal

The boolean whether the keybinding scrolls the child horizontally or not.

Returns

The boolean whether the scroll happened.

The signal is a keybinding signal which gets emitted when a keybinding that scrolls is pressed. The horizontal or vertical adjustment is updated which triggers a signal that the scrolled windows child may listen to and scroll itself.