Pad++ Programmer's Guide
raise and lower commands. Pad++ also supports a notion of layers which can be used to force certain items to be drawn above or below other items. Every item sits on a layer, and every item on a layer is drawn sequentially before items on any other layers are drawn. In addition, the visibility of layers can be turned on and off so layers can be used to quickly control visibility. See the layer command to define new layers and the -visiblelayers itemconfigure option to control visibility of layers.Pad++ also supports sticky items. These are items that do not move as the view changes, but instead always appear at a fixed position relative to the screen. Sticky items can be used to implement things like status lines and windows. Sticky items are put on the regular display list and can appear above or below any other item. If you want sticky items to appear above other items, then you should put them on a special layer which is raised above the main layer.
Copyright Computer Science Department, The University of New Mexico