Add (1,1)-sized root widget so Qt doesnt create a large backing store buffer

3 files changed, 21 insertions, 3 deletions

diff --git a/src/sessionserver.cpp b/src/sessionserver.cpp
index 6550501..922638b 100644
--- a/src/sessionserver.cpp
+++ b/src/sessionserver.cpp
@@ -6,7 +6,17 @@
 
 SessionServer::SessionServer(QWidget *widget, Session *session, Server *server)
 {
-    rootWidget = widget;
+    // Crate a "fake" root widget sized (1,1)
+    // This will prevent Qt from creating a large
+    // backing store.
+    fakeRoot = new QWidget();
+    fakeRoot->resize(1, 1);
+    fakeRoot->move(0, 0);
+
+    rootWidget = fakeRoot;
+    widget->setParent(fakeRoot);
+    widget->move(0, 0);
+
     widgetEventHandler = new WidgetEventHandler(rootWidget, server);
         
     rootWidget->setAttribute(Qt::WA_DontShowOnScreen);
@@ -35,6 +45,8 @@ SessionServer::SessionServer(QWidget *widget, Session *session, Server *server)
 SessionServer::~SessionServer()
 {
     delete widgetEventHandler;
+    rootWidget->setParent(0);
+    delete fakeRoot;
 }
 
 void SessionServer::handleRequest(HttpRequest *request, HttpResponse *response)
diff --git a/src/sessionserver.h b/src/sessionserver.h
index d312453..7a8a635 100644
--- a/src/sessionserver.h
+++ b/src/sessionserver.h
@@ -16,6 +16,7 @@ private slots:
 
 public:
     QWidget *rootWidget;
+    QWidget *fakeRoot;
     WidgetEventHandler *widgetEventHandler;
 };
 
diff --git a/src/widgeteventhandler.cpp b/src/widgeteventhandler.cpp
index a45ec84..45b6b94 100644
--- a/src/widgeteventhandler.cpp
+++ b/src/widgeteventhandler.cpp
@@ -64,7 +64,7 @@ void WidgetEventHandler::recursivelyInstallEventHandler(QWidget *widget)
 {
     if (server->sendUpdatesForPlainQWidgets == false &&
         qstrcmp(widget->metaObject()->className(), "QWidget") == 0) {
-        qDebug() << "skip plain widget" << widget;
+        //qDebug() << "skip plain widget" << widget;
     } else {
         widget->installEventFilter(this);
     }
@@ -113,7 +113,7 @@ bool WidgetEventHandler::eventFilter(QObject *object, QEvent *event)
     if (event->type() == QEvent::Paint) {
         if (server->sendUpdatesForPlainQWidgets == false &&
             qstrcmp(widget->metaObject()->className(), "QWidget") == 0) {
-            qDebug() << "skip plain widget" << widget;
+           // qDebug() << "skip plain widget" << widget;
             return false;
         }
 
@@ -314,6 +314,11 @@ void WidgetEventHandler::handlePositionUpdate(json_object *request)
 
 void WidgetEventHandler::widgetPaint(QWidget *widget, const QRect &updateRect)
 {
+    if (server->sendUpdatesForPlainQWidgets == false &&
+        qstrcmp(widget->metaObject()->className(), "QWidget") == 0) {
+            return ;
+    }
+
     QImage image(widget->size(), QImage::Format_ARGB32_Premultiplied);
     DEBUG << "widget->size" << widget->size();
     image.fill(QColor(0,0,0,0).rgba()); // fill with transparent pixels