Support RasterGLSurface windows

In an attempt to make QOpenGLWidget and QQuickWidget working on Wayland.

Since Qt 5.3 all widget windows are of type RasterGLSurface (given that
the plugin reports this capability which wayland will, with this patch).
Such a window can behave either like a raster or an OpenGL window.

This concept maps badly to platform plugins that have a rigid separation
between raster and OpenGL platform window implementations. From now on,
the OpenGL window implementation, that is used pretty much always,
except for raw RasterSurface windows, must be prepared to behave like
a raster window too, which involves having a backingstore.

Change-Id: I0226704b8d5893843fcae68059c5fe9ad2f5e761
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>

1 files changed, 30 insertions, 17 deletions

diff --git a/src/client/qwaylandshmbackingstore.cpp b/src/client/qwaylandshmbackingstore.cpp
index 0677ed0d3..14e1285d3 100644
--- a/src/client/qwaylandshmbackingstore.cpp
+++ b/src/client/qwaylandshmbackingstore.cpp
@@ -39,14 +39,12 @@
 **
 ****************************************************************************/
 #include "qwaylandshmbackingstore_p.h"
-
-#include <QtCore/qdebug.h>
-
+#include "qwaylandwindow_p.h"
 #include "qwaylanddisplay_p.h"
-#include "qwaylandshmwindow_p.h"
 #include "qwaylandscreen_p.h"
 #include "qwaylanddecoration_p.h"
 
+#include <QtCore/qdebug.h>
 #include <QtGui/QPainter>
 
 #include <wayland-client.h>
@@ -156,9 +154,7 @@ QWaylandShmBackingStore::~QWaylandShmBackingStore()
 
 QPaintDevice *QWaylandShmBackingStore::paintDevice()
 {
-    if (!windowDecoration())
-        return mBackBuffer->image();
-    return mBackBuffer->imageInsideMargins(windowDecorationMargins());
+    return contentSurface();
 }
 
 void QWaylandShmBackingStore::beginPaint(const QRegion &)
@@ -166,13 +162,11 @@ void QWaylandShmBackingStore::beginPaint(const QRegion &)
     mPainting = true;
     ensureSize();
 
-    if (waylandWindow()->attached() && mBackBuffer == waylandWindow()->attached() && mFrameCallback) {
-        QWaylandShmWindow *waylandWindow = static_cast<QWaylandShmWindow *>(window()->handle());
-        Q_ASSERT(waylandWindow->windowType() == QWaylandWindow::Shm);
-        waylandWindow->waitForFrameSync();
-    }
+    QWaylandWindow *window = waylandWindow();
+    if (window->attached() && mBackBuffer == window->attached() && mFrameCallback)
+        window->waitForFrameSync();
 
-    waylandWindow()->setCanResize(false);
+    window->setCanResize(false);
 }
 
 void QWaylandShmBackingStore::endPaint()
@@ -190,9 +184,15 @@ void QWaylandShmBackingStore::ensureSize()
 
 void QWaylandShmBackingStore::flush(QWindow *window, const QRegion &region, const QPoint &offset)
 {
+    // Invoked when the window is of type RasterSurface or when the window is
+    // RasterGLSurface and there are no child widgets requiring OpenGL composition.
+
+    // For the case of RasterGLSurface + having to compose, the composeAndFlush() is
+    // called instead. The default implementation from QPlatformBackingStore is sufficient
+    // however so no need to reimplement that.
+
     Q_UNUSED(window);
     Q_UNUSED(offset);
-    Q_ASSERT(waylandWindow()->windowType() == QWaylandWindow::Shm);
 
     if (windowDecoration() && windowDecoration()->isDirty())
         updateDecorations();
@@ -260,6 +260,11 @@ QImage *QWaylandShmBackingStore::entireSurface() const
     return mBackBuffer->image();
 }
 
+QImage *QWaylandShmBackingStore::contentSurface() const
+{
+    return windowDecoration() ? mBackBuffer->imageInsideMargins(windowDecorationMargins()) : mBackBuffer->image();
+}
+
 void QWaylandShmBackingStore::updateDecorations()
 {
     QPainter decorationPainter(entireSurface());
@@ -302,11 +307,19 @@ QMargins QWaylandShmBackingStore::windowDecorationMargins() const
     return QMargins();
 }
 
-QWaylandShmWindow *QWaylandShmBackingStore::waylandWindow() const
+QWaylandWindow *QWaylandShmBackingStore::waylandWindow() const
 {
-    return static_cast<QWaylandShmWindow *>(window()->handle());
+    return static_cast<QWaylandWindow *>(window()->handle());
 }
 
+QImage QWaylandShmBackingStore::toImage() const
+{
+    // Invoked from QPlatformBackingStore::composeAndFlush() that is called
+    // instead of flush() for widgets that have renderToTexture children
+    // (QOpenGLWidget, QQuickWidget).
+
+    return *contentSurface();
+}
 
 void QWaylandShmBackingStore::done(void *data, wl_callback *callback, uint32_t time)
 {
@@ -315,7 +328,7 @@ void QWaylandShmBackingStore::done(void *data, wl_callback *callback, uint32_t t
             static_cast<QWaylandShmBackingStore *>(data);
     if (callback != self->mFrameCallback) // others, like QWaylandWindow, may trigger callbacks too
         return;
-    QWaylandShmWindow *window = self->waylandWindow();
+    QWaylandWindow *window = self->waylandWindow();
     wl_callback_destroy(self->mFrameCallback);
     self->mFrameCallback = 0;