Try to make the QTBUG-6322 workaround work in more cases

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

diff --git a/src/qtui/chatview.cpp b/src/qtui/chatview.cpp
index e7386ef..695b513 100644 (file)
--- a/src/qtui/chatview.cpp
+++ b/src/qtui/chatview.cpp
@@ -37,7 +37,9 @@ ChatView::ChatView(BufferId bufferId, QWidget *parent)
     AbstractChatView(),
     _bufferContainer(0),
     _currentScaleFactor(1),
-    _invalidateFilter(false)
+    _invalidateFilter(false),
+    _verticalOffset(0),
+    _verticalOffsetStable(false)
 {
   QList<BufferId> filterList;
   filterList.append(bufferId);
@@ -57,7 +59,8 @@ ChatView::ChatView(MessageFilter *filter, QWidget *parent)
 
 void ChatView::init(MessageFilter *filter) {
   setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
-  setAlignment(Qt::AlignBottom);
+  setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
+  setAlignment(Qt::AlignLeft|Qt::AlignBottom);
   setInteractive(true);
   //setOptimizationFlags(QGraphicsView::DontClipPainter | QGraphicsView::DontAdjustForAntialiasing);
   // setOptimizationFlags(QGraphicsView::DontAdjustForAntialiasing);
@@ -69,8 +72,8 @@ void ChatView::init(MessageFilter *filter) {
   _scrollTimer.setSingleShot(true);
   connect(&_scrollTimer, SIGNAL(timeout()), SLOT(scrollTimerTimeout()));
 
-  _scene = new ChatScene(filter, filter->idString(), viewport()->width() - 4, this); // see below: resizeEvent()
-  connect(_scene, SIGNAL(sceneRectChanged(const QRectF &)), this, SLOT(sceneRectChanged(const QRectF &)));
+  _scene = new ChatScene(filter, filter->idString(), viewport()->width(), this);
+  connect(_scene, SIGNAL(sceneRectChanged(const QRectF &)), this, SLOT(adjustSceneRect()));
   connect(_scene, SIGNAL(lastLineChanged(QGraphicsItem *, qreal)), this, SLOT(lastLineChanged(QGraphicsItem *, qreal)));
   connect(_scene, SIGNAL(mouseMoveWhileSelecting(const QPointF &)), this, SLOT(mouseMoveWhileSelecting(const QPointF &)));
   setScene(_scene);
@@ -119,15 +122,58 @@ void ChatView::resizeEvent(QResizeEvent *event) {
 
   // we can reduce viewport updates if we scroll to the bottom allready at the beginning
   verticalScrollBar()->setValue(verticalScrollBar()->maximum());
-
-  // FIXME: without the hardcoded -4 Qt reserves space for a horizontal scrollbar even though it's disabled permanently.
-  // this does only occur on QtX11 (at least not on Qt for Mac OS). Seems like a Qt Bug.
-  scene()->updateForViewport(viewport()->width() - 4, viewport()->height());
+  scene()->updateForViewport(viewport()->width(), viewport()->height());
+  adjustSceneRect();
 
   _lastScrollbarPos = verticalScrollBar()->maximum();
   verticalScrollBar()->setValue(verticalScrollBar()->maximum());
 }
 
+// Workaround for QTBUG-6322
+// The viewport rect gets some margins where it shouldn't, resulting in scrollbars to appear
+void ChatView::adjustSceneRect() {
+  QRectF rect = scene()->sceneRect(); // qDebug() << "sceneRect" << rect;
+  if(rect.height() <= viewport()->height()) {
+    setSceneRect(rect);
+    return;
+  }
+
+  if(_verticalOffsetStable && rect.height() > viewport()->height())
+    setSceneRect(rect.adjusted(0, 0, 0, _verticalOffset));
+  else
+    setSceneRect(rect);
+
+  QScrollBar *vbar = verticalScrollBar();
+  qreal sceneHeight = rect.height();
+  qreal viewHeight = vbar->maximum() + viewport()->height() - vbar->minimum();
+  if(sceneHeight != viewHeight) {
+    qreal voffset = sceneHeight - viewHeight; //voffset *= _currentScaleFactor;
+    // qDebug() << "Adjusting ChatView offset to" << voffset << "(QTBUG-6322)";
+    if(sceneHeight + voffset <= viewport()->height()) {
+      setSceneRect(rect.adjusted(0, -voffset, 0, 0));
+      _verticalOffsetStable = false;
+      return;
+    } else {
+      _verticalOffsetStable = true;
+      _verticalOffset = voffset;
+      setSceneRect(rect.adjusted(0, 0, 0, voffset));
+    }
+    if(vbar->maximum() + viewport()->height() - vbar->minimum() != sceneHeight) {
+      //qWarning() << "Workaround for QTBUG-6322 failed!1!!" << vbar->maximum() + viewport()->height() - vbar->minimum() << sceneHeight;
+      _verticalOffsetStable = false;
+      adjustSceneRect();
+      return;
+    }
+    if(voffset == _verticalOffset)
+      _verticalOffsetStable = true;
+    else {
+      //if(voffset <= 0)
+        _verticalOffset = voffset;
+    }
+  } //else
+    //_verticalOffsetStable = true;
+}
+
 void ChatView::mouseMoveWhileSelecting(const QPointF &scenePos) {
   int y = (int)mapFromScene(scenePos).y();
   _scrollOffset = 0;