+bool ChatView::eventFilter(QObject* watched, QEvent* event)
+{
+ QAbstractSlider* vbar = verticalScrollBar();
+ Q_ASSERT(vbar);
+
+ if (watched != vbar) {
+ // Ignore and pass through all events not featuring the scrollbar
+ return false;
+ }
+ if (event->type() == QEvent::Show) {
+ // FIXME: Workaround for the ChatView scrolling up a fair bit when transitioning from the
+ // vertical scrollbar not being visible, to becoming visible. This happens especially
+ // often when no initial backlog is loaded.
+ if (_backlogRequestedBeforeScrollable) {
+ _backlogRequestedBeforeScrollable = false;
+ vbar->setValue(vbar->maximum());
+ }
+ }
+ // Pass through all events
+ return false;
+}
+
+void ChatView::resizeEvent(QResizeEvent* event)
+{
+ // if view is currently scrolled to bottom, we want it that way after resizing
+ bool atBottom = (_lastScrollbarPos == verticalScrollBar()->maximum());
+
+ QGraphicsView::resizeEvent(event);
+
+ // if scrolling to bottom, do it immediately.
+ if (atBottom) {
+ // we can reduce viewport updates if we scroll to the bottom allready at the beginning
+ verticalScrollBar()->setValue(verticalScrollBar()->maximum());
+ }
+
+ scene()->updateForViewport(viewport()->width(), viewport()->height());
+ adjustSceneRect();
+
+ if (atBottom) {
+ _lastScrollbarPos = verticalScrollBar()->maximum();
+ verticalScrollBar()->setValue(verticalScrollBar()->maximum());
+ }
+ checkChatLineCaches();
+}
+
+void ChatView::adjustSceneRect()
+{
+ // Workaround for QTBUG-6322
+ // If the viewport's sceneRect() is (almost) as wide as as the viewport itself,
+ // Qt wants to reserve space for scrollbars even if they're turned off, resulting in
+ // an ugly white space at the bottom of the ChatView.
+ // Since the view's scene's width actually doesn't matter at all, we just adjust it
+ // by some hopefully large enough value to avoid this problem.
+
+ setSceneRect(scene()->sceneRect().adjusted(0, 0, -25, 0));
+}
+
+void ChatView::mouseMoveWhileSelecting(const QPointF& scenePos)
+{
+ int y = (int)mapFromScene(scenePos).y();
+ _scrollOffset = 0;
+ if (y < 0)
+ _scrollOffset = y;
+ else if (y > height())
+ _scrollOffset = y - height();
+
+ if (_scrollOffset && !_scrollTimer.isActive())
+ _scrollTimer.start();
+}
+
+void ChatView::scrollTimerTimeout()
+{
+ // scroll view
+ QAbstractSlider* vbar = verticalScrollBar();
+ if (_scrollOffset < 0 && vbar->value() > 0)
+ vbar->setValue(qMax(vbar->value() + _scrollOffset, 0));
+ else if (_scrollOffset > 0 && vbar->value() < vbar->maximum())
+ vbar->setValue(qMin(vbar->value() + _scrollOffset, vbar->maximum()));
+}
+
+void ChatView::lastLineChanged(QGraphicsItem* chatLine, qreal offset)
+{
+ Q_UNUSED(chatLine)
+ // disabled until further testing/discussion
+ // if(!scene()->isScrollingAllowed())
+ // return;
+
+ QAbstractSlider* vbar = verticalScrollBar();
+ Q_ASSERT(vbar);
+ if (vbar->maximum() - vbar->value() <= (offset + 5) * _currentScaleFactor) { // 5px grace area
+ vbar->setValue(vbar->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());