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authorTimothy Pearson <[email protected]>2011-07-10 15:24:15 -0500
committerTimothy Pearson <[email protected]>2011-07-10 15:24:15 -0500
commitbd0f3345a938b35ce6a12f6150373b0955b8dd12 (patch)
tree7a520322212d48ebcb9fbe1087e7fca28b76185c /examples/opengl/overlay_x11/main.cpp
downloadqt3-bd0f3345a938b35ce6a12f6150373b0955b8dd12.tar.gz
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Add Qt3 development HEAD version
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+/****************************************************************************
+**
+** Example application showing how to use Qt and Qt OpenGL Extension on an
+** X11 overlay visual
+**
+** Copyright (C) 1999-2008 Trolltech ASA. All rights reserved.
+**
+** This file is part of an example program for Qt. This example
+** program may be used, distributed and modified without limitation.
+**
+*****************************************************************************/
+
+#include <qapplication.h>
+#include "gearwidget.h"
+#include "rubberbandwidget.h"
+
+#if defined(Q_WS_X11)
+#include <X11/Xlib.h>
+#endif
+
+QColor findOverlayTransparentColor()
+{
+ QColor invalidColor;
+
+#if defined(Q_WS_X11)
+
+ Display* appDisplay;
+ Visual* appVisual;
+
+ // The static methods are called 'App' in Qt 2.x
+#if QT_VERSION < 200
+ appDisplay = QPaintDevice::x__Display();
+ appVisual = (Visual*)QPaintDevice::x11Visual();
+#else
+ appDisplay = QPaintDevice::x11AppDisplay();
+ appVisual = (Visual*)QPaintDevice::x11AppVisual();
+#endif
+
+ qDebug( "Default Visual ID: 0x%x", (int)XVisualIDFromVisual(appVisual) );
+
+ typedef struct OverlayProp {
+ long visual;
+ long type;
+ long value;
+ long layer;
+ } OverlayProp;
+
+ QWidget* rootWin = QApplication::desktop();
+ if ( !rootWin )
+ return invalidColor; // Should not happen
+
+ Atom overlayVisualsAtom = XInternAtom( appDisplay,
+ "SERVER_OVERLAY_VISUALS", True );
+ if ( overlayVisualsAtom == None ) {
+ warning( "Server has no overlay visuals" );
+ return invalidColor;
+ }
+
+ Atom actualType;
+ int actualFormat;
+ ulong nItems;
+ ulong bytesAfter;
+ OverlayProp* overlayProp;
+ int res = XGetWindowProperty( appDisplay, QApplication::desktop()->winId(),
+ overlayVisualsAtom, 0, 10000, False,
+ overlayVisualsAtom, &actualType,
+ &actualFormat, &nItems, &bytesAfter,
+ (uchar**)&overlayProp );
+
+ if ( res != Success || actualType != overlayVisualsAtom
+ || actualFormat != 32 || nItems < 4 ) {
+ warning( "Failed to get overlay visual property from server" );
+ return invalidColor;
+ }
+
+
+ for ( uint i = 0; i < nItems/4; i++ ) {
+ if ( (VisualID)overlayProp[i].visual == XVisualIDFromVisual(appVisual)
+ && overlayProp[i].type == 1 )
+ return QColor( qRgb( 1, 2, 3 ), overlayProp[i].value );
+ }
+
+ qWarning( "Default visual is not in overlay plane" );
+ return invalidColor;
+
+#else // defined(Q_WS_X11)
+ qWarning( "Wrong window system - Only X11 has overlay support." );
+ return invalidColor;
+#endif
+}
+
+
+int main( int argc, char **argv )
+{
+ QApplication::setColorSpec( QApplication::CustomColor );
+ QApplication a( argc, argv );
+
+ if ( !QGLFormat::hasOpenGL() ) {
+ qWarning( "This system has no OpenGL support. Exiting." );
+ return -1;
+ }
+
+ QColor transparentColor = findOverlayTransparentColor();
+ if ( !transparentColor.isValid() ) {
+ qWarning( "Failed to get transparent color for overlay. Exiting." );
+ return -1;
+ }
+
+ QWidget top;
+ a.setMainWidget( &top );
+ top.setGeometry( 50, 50, 600, 400 );
+
+ // Make an OpenGL widget. It will use the deepest visual available
+ // (typically a TrueColor visual), which typically is in the normal layer.
+ GearWidget g( &top );
+ g.setGeometry( 20, 20, 560, 360 );
+
+ // Put the rubberband widget (which uses the default, i.e. overlay visual)
+ // on top of the OpenGL widget:
+ RubberbandWidget r( transparentColor, &top );
+ r.setGeometry( 20, 20, 560, 360 );
+
+ top.show();
+ return a.exec();
+}