Scrollbars
Often an object (such as a document or a list) will not be fit within the confines of its viewer control. In these cases a scrollbar can be affixed to the viewer control. The scrollbar alters which part of the object is currently visible inside the viewer control: it slides the view across the object in one axis (horizontal or vertical).
Guidelines
- Only display scrollbars when they are required for sliding the view. If an object fits inside the viewer control, don't draw scrollbars. If you are using a GtkScrolledWindow, call gtk_scrolled_window_set_policy setting the appropriate axis (or axes) to GTK_POLICY_AUTOMATIC.
- Do not use scrollbars as a replacement for a slider. Scrollbars should only be used affixed to a view that they actively alter, not used as a generic continuous input control.
- Affix scrollbars to the right side of a viewer control (to slide the view vertically), or to the bottom side (to slide the view horizontally). Do not affix scrollbars on the top or left sides of a viewer control.
- Scrollbars should be aligned in both directions with the view they are affixed to on the axis they control. In other words, horizontal scrollbars should span the full length of the viewer control, and vertical scrollbars should span the full height of the viewer control.
- If both horizontal and vertical scrollbars are acting upon a view, alignment will require that small rectangle in the lower right corner where the horizontal and vertical scrollbars meet will be blank. This is OK.
- Scrollbars should affect the view to which they are affixed in realtime: as the user drags or clicks the view should change. Time lag will be disconcerting and negatively impact a users ability to navigate content inside the view.