Who owns the root-window? The AES or the application?The desktop.
All AES applications can install a desktop, not just the shell. So in this case there must be multiple root windows.
The standard way to set a new desktop in AES is to use wind_set(WF_NEWDESK, object...). The AES draws this object-tree whenever (parts of) the desktop needs to be redrawn. Unless userdefs are involved the application that owns the desktop doesn't know when or where thedesktop is redrawn. I don't see how any application can consider the rootwindow as any other window.The AES sends a redraw-message to the root-window-owner for the root-window. That's all.
From tos.hyp:"Normally the working area of the desktop appears as a solid green area (in colour resolutions) or as a grey raster pattern (in monochrome operation). The screen-manager attends to the screen redraws all on its own; with a call of wind_set, other application programs can anchor any other object tree as a background. In that case too the screen-manager looks after any required redraws of sections of the image."
The desktop resource tree is installed using wind_set(). The application that owns the resource tree is not responsible to redraw the contents of the desktop - this is done by the AES itself. What you describe sounds like some internal mechanism in XaAES (yes, I'm aware that XaAES treats the root window as a normal window).
Jo Even