castor@media-lab.MEDIA.MIT.EDU (Carlos Rabell) (03/12/91)
I want to get the Graphics Context of an existing window so I can change its colors at will. Right now it works fine but since I'm using a GC that I created, when I try to use the window again the original colors come out again. Carlos Rabell -MIT Media-Lab-
ekberg@asl.dl.nec.COM (Tom Ekberg) (03/12/91)
The purpose of a GC is to store parameters used to change pixels in a drawable during a drawing operation. Changing GCs will not affect pixels that are not in the `scope' of a drawing operation. If you want to change colors in a window, you need to change the colormap in some way. For example, if a window allocates a color cell in the colormap using XAllocColorCells (assuming pseudo color) and places a color there, you can change the color to something else by using XStoreColor. Another way to change colors is to use two colormaps, placing different colors in each one. By changing the colormap for a window you will also change the colors. -- tom, ekberg@asl.dl.nec.com (x3503)