queued dispatch of keyboard and mouse events

Mouse and Key events can't be handed off directly to QApplicationPrivate::
andleMouseEvent() and QApplicationPrivate::handleKeyEvent() from methods that
are called as the slot for a QAbstractSocket::readyRead() signal. Doing so can
result in event starvation in the case of things like QMenu::exec() that have
their own event loop.

2 files changed, 48 insertions, 4 deletions

diff --git a/src/plugins/graphicssystems/vnc/qvncserver.cpp b/src/plugins/graphicssystems/vnc/qvncserver.cpp
index fcff255..c2fb676 100644
--- a/src/plugins/graphicssystems/vnc/qvncserver.cpp
+++ b/src/plugins/graphicssystems/vnc/qvncserver.cpp
@@ -389,6 +389,10 @@ void QVNCServer::init(uint port)
     qvnc_cursor = 0;
 #endif
     encoder = 0;
+
+    eventTimer.setInterval(0);
+    eventTimer.setSingleShot(true);
+    connect(&eventTimer, SIGNAL(timeout()), this, SLOT(sendInputEvents()));
 }
 
 QVNCServer::~QVNCServer()
@@ -819,6 +823,30 @@ static bool buttonChange(Qt::MouseButtons before, Qt::MouseButtons after, Qt::Mo
     return false;
 }
 
+void QVNCServer::sendInputEvents()
+{
+    EventPair pair;
+    for (int i = 0 ; i < eventList.count(); i++) {
+        pair = eventList[i];
+        switch(pair.first) {
+        case MouseEvent: {
+            QMouseEvent *me = static_cast<QMouseEvent *>(pair.second);
+            QApplicationPrivate::handleMouseEvent(0, *me);
+            delete me;
+            break;
+        }
+        case KeyboardEvent: {
+            QKeyEvent *ke = static_cast<QKeyEvent *>(pair.second);
+            QApplicationPrivate::handleKeyEvent(0, ke);
+            delete ke;
+            break;
+        }
+        }
+    }
+    eventList.clear();
+    Q_ASSERT(eventList.count() == 0);
+}
+
 void QVNCServer::pointerEvent()
 {
     QRfbPointerEvent ev;
@@ -834,8 +862,13 @@ void QVNCServer::pointerEvent()
         bool isPress;
         if (buttonChange(buttons, ev.buttons, &button, &isPress))
             type = isPress ? QEvent::MouseButtonPress : QEvent::MouseButtonRelease;
-        QMouseEvent me(type, QPoint(ev.x, ev.y), QPoint(ev.x, ev.y), button, ev.buttons, keymod);
-        QApplicationPrivate::handleMouseEvent(0, me);
+        QMouseEvent * me = new QMouseEvent(type, QPoint(ev.x, ev.y), QPoint(ev.x, ev.y), button, ev.buttons, keymod);
+        EventPair pair;
+        pair.first = MouseEvent;
+        pair.second = me;
+        eventList.append(pair);
+        if (!eventTimer.isActive())
+            eventTimer.start();
         buttons = ev.buttons;
         handleMsg = false;
     }
@@ -861,8 +894,13 @@ void QVNCServer::keyEvent()
             QString str;
             if (ev.unicode && ev.unicode != 0xffff)
                 str = QString(ev.unicode);
-            QKeyEvent keyEvent(type, ev.keycode, keymod, str);
-            QApplicationPrivate::handleKeyEvent(0, &keyEvent);
+            QKeyEvent *keyEvent = new QKeyEvent(type, ev.keycode, keymod, str);
+            EventPair pair;
+            pair.first = KeyboardEvent;
+            pair.second = keyEvent;
+            eventList.append(pair);
+            if (!eventTimer.isActive())
+                eventTimer.start();
         }
         handleMsg = false;
     }
diff --git a/src/plugins/graphicssystems/vnc/qvncserver.h b/src/plugins/graphicssystems/vnc/qvncserver.h
index 79b2098..be84c3c 100644
--- a/src/plugins/graphicssystems/vnc/qvncserver.h
+++ b/src/plugins/graphicssystems/vnc/qvncserver.h
@@ -482,6 +482,7 @@ private slots:
     void readClient();
     void checkUpdate();
     void discardClient();
+    void sendInputEvents();
 
 private:
     void init(uint port);
@@ -519,6 +520,11 @@ private:
 
     QRfbEncoder *encoder;
     QVNCCursor *cursor;
+
+    enum EventType { MouseEvent, KeyboardEvent };
+    QTimer eventTimer;
+    typedef QPair<EventType, QInputEvent *> EventPair;
+    QList<EventPair> eventList;
 };