Lighthouse xcb and xlib: Add support for transparency of GLX windows.

Merge-request: 1231
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>
(cherry picked from commit a3b627e1c5ce03a2500ab35c64729b1995639dcc)

4 files changed, 26 insertions, 10 deletions

diff --git a/src/plugins/platforms/xlib/qxlibintegration.cpp b/src/plugins/platforms/xlib/qxlibintegration.cpp
index 78f907abd2..b0c8bc9560 100644
--- a/src/plugins/platforms/xlib/qxlibintegration.cpp
+++ b/src/plugins/platforms/xlib/qxlibintegration.cpp
@@ -150,7 +150,7 @@ bool QXlibIntegration::hasOpenGL() const
 {
 #if !defined(QT_NO_OPENGL)
 #if !defined(QT_OPENGL_ES_2)
-    QXlibScreen *screen = static_cast<const QXlibScreen *>(mScreens.at(0));
+    QXlibScreen *screen = static_cast<QXlibScreen *>(mScreens.at(0));
     return glXQueryExtension(screen->display()->nativeDisplay(), 0, 0) != 0;
 #else
     static bool eglHasbeenInitialized = false;
diff --git a/src/plugins/platforms/xlib/qxlibwindow.cpp b/src/plugins/platforms/xlib/qxlibwindow.cpp
index 90bcc0d9d5..4efcb1101c 100644
--- a/src/plugins/platforms/xlib/qxlibwindow.cpp
+++ b/src/plugins/platforms/xlib/qxlibwindow.cpp
@@ -102,18 +102,27 @@ QXlibWindow::QXlibWindow(QWidget *window)
         visualInfo = XGetVisualInfo(mScreen->display()->nativeDisplay(), VisualIDMask, &visualInfoTemplate, &matchingCount);
 #endif //!defined(QT_OPENGL_ES_2)
         if (visualInfo) {
-            Colormap cmap = XCreateColormap(mScreen->display()->nativeDisplay(),mScreen->rootWindow(),visualInfo->visual,AllocNone);
+            mDepth = visualInfo->depth;
+            mFormat = (mDepth == 32) ? QImage::Format_ARGB32_Premultiplied : QImage::Format_RGB32;
+            mVisual = visualInfo->visual;
+            Colormap cmap = XCreateColormap(mScreen->display()->nativeDisplay(), mScreen->rootWindow(), visualInfo->visual, AllocNone);
 
             XSetWindowAttributes a;
+            a.background_pixel = WhitePixel(mScreen->display()->nativeDisplay(), mScreen->xScreenNumber());
+            a.border_pixel = BlackPixel(mScreen->display()->nativeDisplay(), mScreen->xScreenNumber());
             a.colormap = cmap;
             x_window = XCreateWindow(mScreen->display()->nativeDisplay(), mScreen->rootWindow(),x, y, w, h,
                                      0, visualInfo->depth, InputOutput, visualInfo->visual,
-                                     CWColormap, &a);
+                                     CWBackPixel|CWBorderPixel|CWColormap, &a);
         } else {
             qFatal("no window!");
         }
 #endif //!defined(QT_NO_OPENGL)
     } else {
+        mDepth = mScreen->depth();
+        mFormat = (mDepth == 32) ? QImage::Format_ARGB32_Premultiplied : QImage::Format_RGB32;
+        mVisual = mScreen->defaultVisual();
+
         x_window = XCreateSimpleWindow(mScreen->display()->nativeDisplay(), mScreen->rootWindow(),
                                        x, y, w, h, 0 /*border_width*/,
                                        mScreen->blackPixel(), mScreen->whitePixel());
diff --git a/src/plugins/platforms/xlib/qxlibwindow.h b/src/plugins/platforms/xlib/qxlibwindow.h
index 08694a5026..2d11224c23 100644
--- a/src/plugins/platforms/xlib/qxlibwindow.h
+++ b/src/plugins/platforms/xlib/qxlibwindow.h
@@ -122,6 +122,10 @@ public:
     Window xWindow() const;
     GC graphicsContext() const;
 
+    inline uint depth() const { return mDepth; }
+    QImage::Format format() const { return mFormat; }
+    Visual* visual() const { return mVisual; }
+
 protected:
     QVector<Atom> getNetWmState() const;
     void setMWMHints(const QXlibMWMHints &mwmhints);
@@ -135,6 +139,10 @@ private:
     Window x_window;
     GC gc;
 
+    uint mDepth;
+    QImage::Format mFormat;
+    Visual* mVisual;
+
     GC createGC();
 
     QPlatformGLContext *mGLContext;
diff --git a/src/plugins/platforms/xlib/qxlibwindowsurface.cpp b/src/plugins/platforms/xlib/qxlibwindowsurface.cpp
index 513f10dc6a..78fe387bb8 100644
--- a/src/plugins/platforms/xlib/qxlibwindowsurface.cpp
+++ b/src/plugins/platforms/xlib/qxlibwindowsurface.cpp
@@ -80,20 +80,19 @@ void QXlibShmImageInfo::destroy()
 
 void QXlibWindowSurface::resizeShmImage(int width, int height)
 {
+    QXlibScreen *screen = QXlibScreen::testLiteScreenForWidget(window());
+    QXlibWindow *win = static_cast<QXlibWindow*>(window()->platformWindow());
 
 #ifdef DONT_USE_MIT_SHM
-    shm_img = QImage(width, height, QImage::Format_RGB32);
+    shm_img = QImage(width, height, win->format());
 #else
 
-    QXlibScreen *screen = QXlibScreen::testLiteScreenForWidget(window());
     if (image_info)
         image_info->destroy();
     else
         image_info = new QXlibShmImageInfo(screen->display()->nativeDisplay());
 
-    Visual *visual = screen->defaultVisual();
-
-    XImage *image = XShmCreateImage (screen->display()->nativeDisplay(), visual, 24, ZPixmap, 0,
+    XImage *image = XShmCreateImage (screen->display()->nativeDisplay(), win->visual(), win->depth(), ZPixmap, 0,
                                      &image_info->shminfo, width, height);
 
 
@@ -160,11 +159,11 @@ void QXlibWindowSurface::flush(QWidget *widget, const QRegion &region, const QPo
 #ifdef DONT_USE_MIT_SHM
     // just convert the image every time...
     if (!shm_img.isNull()) {
-        Visual *visual = DefaultVisual(screen->display(), screen->xScreenNumber());
+        QXlibWindow *win = static_cast<QXlibWindow*>(window()->platformWindow());
 
         QImage image = shm_img;
         //img.convertToFormat(
-        XImage *xi = XCreateImage(screen->display(), visual, 24, ZPixmap,
+        XImage *xi = XCreateImage(screen->display(), win->visual(), win->depth(), ZPixmap,
                                   0, (char *) image.scanLine(0), image.width(), image.height(),
                                   32, image.bytesPerLine());