basic support for multiple top level windows in the VNC backend

This supports a simple stack of windows, with the most recently created
sitting on top.

4 files changed, 59 insertions, 11 deletions

diff --git a/src/plugins/graphicssystems/vnc/qgraphicssystem_vnc.cpp b/src/plugins/graphicssystems/vnc/qgraphicssystem_vnc.cpp
index 9a7c198..b50e5b5 100644
--- a/src/plugins/graphicssystems/vnc/qgraphicssystem_vnc.cpp
+++ b/src/plugins/graphicssystems/vnc/qgraphicssystem_vnc.cpp
@@ -45,6 +45,7 @@
 #include <QtCore/qdebug.h>
 
 #include <qvncserver.h>
+#include <QtGui/QPainter>
 
 
 
@@ -77,6 +78,23 @@ QVNCDirtyMap *QVNCGraphicsSystemScreen::dirtyMap()
 
 void QVNCGraphicsSystemScreen::setDirty(const QRect &rect)
 {
+    QPainter compositePainter(mScreenImage);
+
+    // Blank the affected area, just in case there's nothing to display here
+    // Question - What's the background color?
+    // Another option would be to push a base level window that is the size of the display
+
+    compositePainter.fillRect(rect, Qt::black);
+
+    for (int i = 0; i < windowStack.length(); i++) {
+        QRect windowRect = windowStack[i]->geometry();
+        QRect intersect = windowRect.intersected(rect);
+        QRect windowIntersect = intersect.translated(-windowRect.left(),
+                                                     -windowRect.top());
+        compositePainter.drawImage(intersect, windowStack[i]->image(),
+                                   windowIntersect);
+    }
+
     d_ptr->setDirty(rect);
 }
 
@@ -104,6 +122,14 @@ QWindowSurface *QVNCGraphicsSystem::createWindowSurface(QWidget *widget) const
 {
     if (widget->windowType() == Qt::Desktop)
         return 0;   // Don't create an explicit window surface for the destkop.
-    return new QVNCWindowSurface
+    QVNCWindowSurface * newSurface = new QVNCWindowSurface
         (const_cast<QVNCGraphicsSystem *>(this), mPrimaryScreen, widget);
+    mPrimaryScreen->addWindowSurface(newSurface);
+    return newSurface;
+}
+
+void QVNCGraphicsSystemScreen::removeWindowSurface(QVNCWindowSurface * surface)
+{
+    windowStack.removeOne(surface);
+    setDirty(surface->geometry());
 }
diff --git a/src/plugins/graphicssystems/vnc/qgraphicssystem_vnc.h b/src/plugins/graphicssystems/vnc/qgraphicssystem_vnc.h
index 375b467..d593096 100644
--- a/src/plugins/graphicssystems/vnc/qgraphicssystem_vnc.h
+++ b/src/plugins/graphicssystems/vnc/qgraphicssystem_vnc.h
@@ -43,6 +43,7 @@
 #define QGRAPHICSSYSTEM_VNC_H
 
 #include <QtGui/private/qgraphicssystem_p.h>
+#include "qwindowsurface_vnc.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -68,6 +69,9 @@ public:
 
     void setDirty(const QRect &rect);
 
+    void removeWindowSurface(QVNCWindowSurface * surface);
+    void addWindowSurface(QVNCWindowSurface * surface) { windowStack.append(surface); }
+
 public:
     QRect mGeometry;
     int mDepth;
@@ -77,6 +81,8 @@ public:
     QVNCServer *server;
 
     QVNCGraphicsSystemScreenPrivate *d_ptr;
+private:
+    QList<QVNCWindowSurface *> windowStack;
 };
 
 class QVNCGraphicsSystemPrivate;
@@ -92,6 +98,7 @@ public:
 
     QList<QGraphicsSystemScreen *> screens() const { return mScreens; }
 
+
 private:
     QVNCGraphicsSystemScreen *mPrimaryScreen;
     QList<QGraphicsSystemScreen *> mScreens;
diff --git a/src/plugins/graphicssystems/vnc/qwindowsurface_vnc.cpp b/src/plugins/graphicssystems/vnc/qwindowsurface_vnc.cpp
index 07668fb..af171f5 100644
--- a/src/plugins/graphicssystems/vnc/qwindowsurface_vnc.cpp
+++ b/src/plugins/graphicssystems/vnc/qwindowsurface_vnc.cpp
@@ -53,15 +53,17 @@ QVNCWindowSurface::QVNCWindowSurface(QVNCGraphicsSystem *graphicsSystem,
     : QWindowSurface(window),
       mScreen(screen)
 {
+    mImage = QImage(window->size(), mScreen->format());
 }
 
 QVNCWindowSurface::~QVNCWindowSurface()
 {
+    mScreen->removeWindowSurface(this);
 }
 
 QPaintDevice *QVNCWindowSurface::paintDevice()
 {
-    return mScreen->mScreenImage;
+    return &mImage;
 }
 
 void QVNCWindowSurface::flush(QWidget *widget, const QRegion &region, const QPoint &offset)
@@ -69,20 +71,30 @@ void QVNCWindowSurface::flush(QWidget *widget, const QRegion &region, const QPoi
     Q_UNUSED(widget);
     Q_UNUSED(offset);
 
-    QRect rect = geometry();
-    QPoint topLeft = rect.topLeft();
-
-    mScreen->setDirty(region.boundingRect());
-    // server->flush(region);
-
+    QRect currentGeometry = geometry();
+    // If this is a move, redraw the previous location
+    if (oldGeometry != currentGeometry) {
+        mScreen->setDirty(oldGeometry);
+        oldGeometry = currentGeometry;
+    }
+
+    QRect dirtyClient = region.boundingRect();
+    QRect dirtyRegion(currentGeometry.left() + dirtyClient.left(),
+                      currentGeometry.top() + dirtyClient.top(),
+                      dirtyClient.width(),
+                      dirtyClient.height());
+    mScreen->setDirty(dirtyRegion);
 }
 
-void QVNCWindowSurface::setGeometry(const QRect &)
+void QVNCWindowSurface::setGeometry(const QRect &rect)
 {
+    // store previous geometry for screen update
+    oldGeometry = geometry();
 
-// any size you like as long as it's full-screen...
+    // change the widget's QImage if this is a resize
+    if (mImage.size() != rect.size())
+        mImage = QImage(rect.size(), mScreen->format());
 
-    QRect rect(mScreen->availableGeometry());
     QApplicationPrivate::handleGeometryChange(this->window(), rect);
 
     QWindowSurface::setGeometry(rect);
diff --git a/src/plugins/graphicssystems/vnc/qwindowsurface_vnc.h b/src/plugins/graphicssystems/vnc/qwindowsurface_vnc.h
index 3fd1f12..b9af493 100644
--- a/src/plugins/graphicssystems/vnc/qwindowsurface_vnc.h
+++ b/src/plugins/graphicssystems/vnc/qwindowsurface_vnc.h
@@ -64,10 +64,13 @@ public:
 
     void beginPaint(const QRegion &region);
     void endPaint(const QRegion &region);
+    inline const QImage image() { return mImage; }
 
 private:
     QVNCGraphicsSystem *mGraphicsSystem;
     QVNCGraphicsSystemScreen *mScreen;
+    QRect oldGeometry;
+    QImage mImage;
 };
 
 QT_END_NAMESPACE