jwdb@dutnak2.tudelft.nl (Jan Willem de Bruijn) (08/30/90)
Has anyone ever managed to create transparent windows (or widgets) using the Xtoolkit? It says in the Intrinsics Programming Manual that the background attribute of a window can be transparent, but nowhere is it explained how to accomplish that. Say, e.g., that I wanted to have a transparent background for the Command widget in the xgoodbye application from Chapter 2 (as you can tell from this, I am just learning to program using the toolkit), how would I go about it? The obvious way, to put: *goodbye.background: transparent in the application-defaults file (or in ~/.Xdefaults) is not accepted by the toolkit. (It results in the warning "Cannot allocate colormap entry for "transparent"".) Surely, transparent windows could be useful; but, come to think of it, I have never seen one on the X window system, unless the ghost window that appears when you move a window using the window manager is actually a transparent window. -- JanWillem de Bruijn ...!uunet!mcsun!hp4nl!dutrun!dutnak2!jwdb Seismics and Acoustics jwdb@dutnak2.tudelft.nl Faculty of Applied Physics Discipline is never an end in itself, Delft University of Technology only a means to an end.
pothiers%pi3.local%netvax@CCC.NERSC.GOV (Steve Pothier) (08/31/90)
Has anyone ever managed to create transparent windows (or widgets) using the Xtoolkit? It says in the Intrinsics Programming Manual that the background attribute of a window can be transparent, but nowhere is it explained how to accomplish that. Well, sort of. I've set the background to none (NULL?). When the widget came up whatever was behind the widget appeared in place of the background. I said "Oh, great. Its transparent" then moved the window. The background remained the same (i.e. it didn't get update to reflect the new obscured display.). I was using MWM and my own widget. ============================================================================== Steve Pothier pothiers%tuva.sainet@ccc.nersc.arpa Science Applications International Tucson, AZ 602-748-7400 ==============================================================================
adri@dutncp8.tudelft.nl (A.B. van Woerkom) (09/03/90)
jwdb@dutnak2.tudelft.nl (Jan Willem de Bruijn) writes: >Has anyone ever managed to create transparent windows (or widgets) >using the Xtoolkit? It says in the Intrinsics Programming Manual >that the background attribute of a window can be transparent, but >nowhere is it explained how to accomplish that. When you set the background_pixmap field in the window attibutes to None the background of the window will be set equal to whatever it is behind your window when it is mapped, thus creating a transparent effect. However when the things behind your window change your window's background won't change with it. Also when your move your window the initial background will move with it. >Say, e.g., that I wanted to have a transparent background for the >Command widget in the xgoodbye application from Chapter 2 (as you >can tell from this, I am just learning to program using the toolkit), >how would I go about it? The obvious way, to put: > >*goodbye.background: transparent > >in the application-defaults file (or in ~/.Xdefaults) is not accepted >by the toolkit. You have to set *goobye.backgroundPixmap (to None) instead. This only can be done, however, from your program (XtSetArg and all that) because there is no string to pixmap converter (but you can allways write and register one yourself :-)). To get a really tranparent window, but one on which you can't draw, set the window type to InputOnly on creation, but how to archieve this from Xt I don't know. ________________________________________________________________________ Adri van Woerkom, adri@dutncp6.tudelft.nl Delft University of Technology, Faculty of Applied Physics, Department Physics Informatics, section Computational Physics, Lorentzweg 1, 2628 CJ DELFT, The Netherlands ________________________________________________________________________ "Do you want the usual answer or the truth?" (Igor Strawinsky)