Bring back workaround for the unwanted scroll-on-bufferswitch

[quassel.git] / src / qtui / chatview.cpp

diff --git a/src/qtui/chatview.cpp b/src/qtui/chatview.cpp
index 1eee224..4a5e286 100644 (file)
--- a/src/qtui/chatview.cpp
+++ b/src/qtui/chatview.cpp
@@ -50,36 +50,44 @@ void ChatView::init(MessageFilter *filter) {
   setAlignment(Qt::AlignBottom);
   setInteractive(true);
 
-  _scene = new ChatScene(filter, filter->idString(), this);
-  connect(_scene, SIGNAL(heightChanged(qreal)), this, SLOT(sceneHeightChanged(qreal)));
+  _scene = new ChatScene(filter, filter->idString(), viewport()->width() - 2, this); // see below: resizeEvent()
+  connect(_scene, SIGNAL(sceneHeightChanged(qreal)), this, SLOT(sceneHeightChanged(qreal)));
   setScene(_scene);
 
+  _lastScrollbarPos = verticalScrollBar()->maximum();
   connect(verticalScrollBar(), SIGNAL(valueChanged(int)), this, SLOT(verticalScrollbarChanged(int)));
 }
 
 void ChatView::resizeEvent(QResizeEvent *event) {
-  scene()->setWidth(event->size().width() - 2);  // FIXME figure out why we have to hardcode the -2 here
+  QGraphicsView::resizeEvent(event);
+  scene()->setWidth(viewport()->width() - 2);  // FIXME figure out why we have to hardcode the -2 here -> Qt-Bug most probably
   verticalScrollBar()->setValue(verticalScrollBar()->maximum());
 }
 
-void ChatView::sceneHeightChanged(qreal h) {
-  Q_UNUSED(h)
-  bool scrollable = qAbs(verticalScrollBar()->value() - verticalScrollBar()->maximum()) <= 2; // be a bit tolerant here, also FIXME (why we need this?)
-  setSceneRect(scene()->sceneRect());
-  if(scrollable) verticalScrollBar()->setValue(verticalScrollBar()->maximum());
+void ChatView::sceneHeightChanged(qreal dh) {
+  QAbstractSlider *vbar = verticalScrollBar();
+  Q_ASSERT(vbar);
+  if(vbar->maximum() - vbar->value() <= dh + 5) // in case we had scrolled only about half a line to the bottom we allow a grace of 5
+    vbar->setValue(vbar->maximum());
 }
 
 void ChatView::verticalScrollbarChanged(int newPos) {
   QAbstractSlider *vbar = verticalScrollBar();
   Q_ASSERT(vbar);
 
-  int relativePos = 100;
-  if(vbar->maximum() - vbar->minimum() != 0)
-    relativePos = (newPos - vbar->minimum()) * 100 / (vbar->maximum() - vbar->minimum());
+  if(vbar->maximum() - vbar->value() <= 5) // FIXME workaround the fact that the view gets scrolled up a few px on buffer change
+    vbar->setValue(vbar->maximum());
+
+  if(newPos < _lastScrollbarPos) {
+    int relativePos = 100;
+    if(vbar->maximum() - vbar->minimum() != 0)
+      relativePos = (newPos - vbar->minimum()) * 100 / (vbar->maximum() - vbar->minimum());
 
-  if(relativePos < 20) {
-    scene()->requestBacklog();
+    if(relativePos < 20) {
+      scene()->requestBacklog();
+    }
   }
+  _lastScrollbarPos = newPos;
 }
 
 MsgId ChatView::lastMsgId() const {