
4
Frames
A frame is a container for other windows. It manages the geometry and placement of
subwindows that do not overlap and are fixed within the boundary of the frame. The
OPEN LOOK specification refers to subwindows, or panes, as tiled windows because they do
not overlap one another. Subwindow types include canvases, text subwindows, panels, and
scrollbars. These subwindows cannot exist without a parent frame to manage them. Figure
4-1 shows the class hierarchy for the FRAME package.
Generic
Object
(Drawable) Window Frame
Figure 4-1. Frame package class hierarchy
Figure 4-2 shows an example of a screen that displays three frames, each one containing at
least one subwindow. Note that frames do overlap. The File Manager frame has the key-
board focus, as indicated by the title bar having its foreground and background colors
reversed. The setting of the keyboard focus is handled by the window manager, not the
FRAME package. In this case, an OPEN LOOK window manager is using click-to-type to set
the keyboard focus. This is demonstrated by the cursor’s location within an unselected frame
(the Edit: File frame).
The
FRAME
package provides the following capabilities:
• A communication path between the application and the window manager.
• A mechanism to receive input for the application.
• A visual container for user interface objects.
• A method to group windows with related functionality.
• A mechanism ...