rem: WMSetWindowUPosition(panel->win,
add: WMSetWindowInitialPosition(panel->win,
context: ShowTexturePanel(TexturePanel *panel){    Display *dpy = WMScreenDisplay(WMWidgetScreen(panel->win));    Screen *scr = DefaultScreenOfDisplay(dpy);    WMSetWindowUPosition(panel->win, 			 (WidthOfScreen(scr)-WMWidgetWidth(panel->win))/2,			 (HeightOfScreen(scr)-WMWidgetHeight(panel->win))/2);    WMMapWidget(panel->win);}