Certain window styles supported by VAqua optionally allow a top and/or bottom window margin to be specified. Window margins are areas at the top or bottom of the window that have a border and whose appearance changes when the window becomes active or inactive. Window margins also allow the window to be moved by dragging.
The intended use of a window margin is to define an area for controls, such as buttons. Controls placed in a window margin should use a textured style.
Window margins are not components; they do not affect the size or border of the content pane. Controls must be arranged to fit in or between the margins.
In a window with a unified tool bar style, the top window margin is automatically
provided and sized to fit the
window tool bar. In other windows, the height of the top margin must be specified,
client property on the root pane;
a plain background is painted, and no tool bar is required.
The specified top margin height includes the border.
A bottom window margin in a window with a unified tool bar style
is painted in a style similar to the button area in an open file dialog.
In other windows, a plain background is painted.
A bottom window margin is specified by setting the
client property on the root pane to the desired height of the margin area, including
Any window with a supported top or bottom window margin will have its content pane set to not opaque so that the window margin background will be visible.