RE: Window overlay problem -- RPG400-L

Steven,

I know I'm probably late to the game but I thought I'd add my thoughts to this one.

I have always coded my window definitions as follows:

(note this information is pertinent to programs that only display widows - and are overlaying a panel from another program, but will work for any window definition)

Use a dummy "panel" record format with the keywords ASSUME and OVERLAY specified. This will tell the operating system to assume that a panel has already been written to the screen and to NOT clear it when you write the window to the screen. You must then specify the KEEP keyword on the window definition (or the record format you EXFMT, that specifies the window with the WINDOW keyword). This is needed if you are going to ever call further programs that also display windows. The KEEP keyword will ensure that the screen doesn't flicker when any subsequent windows overlay your window - it will ensure that your window is kept on the screen until the next screen is painted. If you specify KEEP on a panel (for example the DUMMY record format) then the background will go black when a window from another program is painted to the screen and you'll be left with your two windows hanging in space. This is because the KEEP will be active for the whole screen (panel) - but you only want to keep the window - and not touch the surrounding panel formats. They were painted by another program so your panel KEEP will blank them, not keep them. Obviously, your new window program will have a dummy panel record format that specifies ASSUME and OVERLAY so the panels are protected and wont be lost.

I also specify the following DSPF additional parameters:

Enhanced display . . . . . . . .   *YES
Restore display  . . . . . . . .   *YES
Defer write  . . . . . . . . . .   *YES

By doing the above I have several panel programs that call window programs, that themselves call further window programs. I never get screen flicker, drop-out or screen loss of any kind. I can overlay any number of windows without problems. The look is akin to the whole application running within a single program.

Now you can prompt to your heart's content and splatter your screen with windows. <grin>

I hope this helps.

Cheers

Larry Ducie