-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::verticalScrollbarChanged(int newPos) {
+ QAbstractSlider *vbar = verticalScrollBar();
+ Q_ASSERT(vbar);
+
+ // check for backlog request
+ 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();
+ }
+ }
+ _lastScrollbarPos = newPos;