isCOBOL Evolve : User Interface : Working With UI and Controls : Creating a control : Controls background
Controls background
Most of the graphical controls can only have a Background-Color.
FRAME, LIST-BOX, RIBBON, SCROLL-PANE, TAB-CONTROL, TOOL-BAR, TREE-VIEW and WINDOW, instead, provide different background possibilities.
They can have three types of background:
• a single opaque background color, specified by Background-Color,
• a gradient effect specified by the Gradient-Color-1, Gradient-Color-1 and Gradient-Orientation,
• a background image specified by Background-Bitmap-Handle and Background-Bitmap-Scale.
These backgrounds can’t be combined on the same control, only one of them can be used. If more than one background is specified, they are applied according to the following list of priorities. Items are listed from the most important to the least important:
1. the background image
2. the gradient effect
3. the background color
When scroll-bars are displayed on the control, allowing the user to change the visible content, the background doesn’t change along with the content of the control, but it remain fixed on the visible area of the control.