qt-bugs@ issue : N34454
bugs.kde.org number : 67101
applied: no
author: Hamish Rodda <rodda@kde.org>

Qt doesn't take screen rotation into account when determining desktop width
and height

Qt doesn't detect a change in desktop size when the rotation of the screen
changes to be at right angles (90 and 270 degrees) to the normal rotation (0
degrees). The xlib functions DisplayWidth / DisplayHeight and WidthOfScreen /
HeightOfScreen do not take into account the rotation of the screen.

This causes KDE not to reconfigure itself when the rotation of the screen is
changed.

This patch switches width and height of the desktop when the screen is rotated
to 90 or 270 degrees.  I've only done this for the non-xinerama case, and only
for QDesktopWidget.  I imagine that xinerama needs to have this change made
too.

Index: src/kernel/qapplication_x11.cpp
===================================================================
RCS file: /home/kde/qt-copy/src/kernel/qapplication_x11.cpp,v
retrieving revision 1.95
diff -u -p -r1.95 qapplication_x11.cpp
--- src/kernel/qapplication_x11.cpp	20 Oct 2003 13:53:50 -0000	1.95
+++ src/kernel/qapplication_x11.cpp	8 Nov 2003 03:05:57 -0000
@@ -3493,10 +3493,23 @@ int QApplication::x11ProcessEvent( XEven
 
 	// update the size for desktop widget
 	int scr = XRRRootToScreen( appDpy, event->xany.window );
+
+	// Determine if we're at right-angles & thus DisplayWidth/DisplayHeight should be switched
+	XRRScreenConfiguration* xrrconfig;
+	xrrconfig = XRRGetScreenInfo( appDpy, event->xany.window );
+	Rotation rotation;
+	XRRConfigCurrentConfiguration( xrrconfig, &rotation );
+	XRRFreeScreenConfigInfo( xrrconfig );
+
 	QWidget *w = desktop()->screen( scr );
 	QSize oldSize( w->size() );
-	w->crect.setWidth( DisplayWidth( appDpy, scr ) );
-        w->crect.setHeight( DisplayHeight( appDpy, scr ) );
+	if (rotation & (RR_Rotate_90 | RR_Rotate_270)) {
+	    w->crect.setWidth( DisplayHeight( appDpy, scr ) );
+	    w->crect.setHeight( DisplayWidth( appDpy, scr ) );
+	} else {
+	    w->crect.setWidth( DisplayWidth( appDpy, scr ) );
+	    w->crect.setHeight( DisplayHeight( appDpy, scr ) );
+	}
 	if ( w->size() != oldSize ) {
 	    QResizeEvent e( w->size(), oldSize );
 	    QApplication::sendEvent( w, &e );
Index: src/kernel/qdesktopwidget_x11.cpp
===================================================================
RCS file: /home/kde/qt-copy/src/kernel/qdesktopwidget_x11.cpp,v
retrieving revision 1.19
diff -u -p -r1.19 qdesktopwidget_x11.cpp
--- src/kernel/qdesktopwidget_x11.cpp	16 May 2003 13:02:39 -0000	1.19
+++ src/kernel/qdesktopwidget_x11.cpp	8 Nov 2003 03:05:58 -0000
@@ -44,6 +44,9 @@ extern int qt_x11_create_desktop_on_scre
 // defined in qapplication_x11.cpp
 extern Atom qt_net_workarea;
 extern bool qt_net_supports(Atom atom);
+#ifndef QT_NO_XRANDR
+extern bool qt_use_xrandr;
+#endif
 
 // function to update the workarea of the screen
 static bool qt_desktopwidget_workarea_dirty = TRUE;
@@ -154,6 +157,22 @@ void QDesktopWidgetPrivate::init()
 		y = 0;
 		w = WidthOfScreen(ScreenOfDisplay(QPaintDevice::x11AppDisplay(), i));
 		h = HeightOfScreen(ScreenOfDisplay(QPaintDevice::x11AppDisplay(), i));
+
+#ifndef QT_NO_XRANDR
+		if (qt_use_xrandr) {
+		    XRRScreenConfiguration* xrrconfig;
+		    xrrconfig = XRRGetScreenInfo(QPaintDevice::x11AppDisplay(), QPaintDevice::x11AppRootWindow( i ));
+		    Rotation rotation;
+		    XRRConfigCurrentConfiguration(xrrconfig, &rotation);
+		    XRRFreeScreenConfigInfo(xrrconfig);
+
+		    if (rotation & (RR_Rotate_90 | RR_Rotate_270)) {
+			int tmp = h;
+			h = w;
+			w = tmp;
+		    }
+		}
+#endif
 	    }
 
 	rects[i].setRect(x, y, w, h);