A panel is a both a container and a containee window. It serves mainly as a geometry management device, but the 'border creates a container with a border. Unlike a pane% object, a panel% object can be hidden or disabled.
A panel% object has a degenerate placement strategy for managing its children; it places them all in the upper left corner and does not stretch any of them. The horizontal-panel% and vertical-panel% classes provide useful geometry management.
enabled : any/c = #t
vert-margin : (integer-in 0 1000) = 0
horiz-margin : (integer-in 0 1000) = 0
border : (integer-in 0 1000) = 0
spacing : (integer-in 0 1000) = 0
min-width : (integer-in 0 10000) = graphical-minimum-width
min-height : (integer-in 0 10000) = graphical-minimum-height
stretchable-width : any/c = #t
stretchable-height : any/c = #t
If the 'border style is specified, the window is created with a thin border (only in this case, the client size of the panel may be less than its total size). If style includes 'deleted, then the panel is created as hidden, and it does not affect its parent’s geometry; the panel can be made active later by calling parent’s add-child method.
For information about the enabled argument, see window<%>. For information about the horiz-margin and vert-margin arguments, see subarea<%>. For information about the border, spacing, and alignment arguments, see area-container<%>. For information about the min-width, min-height, stretchable-width, and stretchable-height arguments, see area<%>.