+
+ Q_ASSERT(start == 0 || start >= _lines.count() || _lines.at(start - 1)->pos().y() + _lines.at(start - 1)->height() == _lines.at(start)->pos().y());
+
+ // update sceneRect
+ // when searching for the first non-date-line we have to take into account that our
+ // model still contains the just removed lines so we cannot simply call updateSceneRect()
+ int numRows = model()->rowCount();
+ QModelIndex firstLineIdx;
+ _firstLineRow = -1;
+ bool needOffset = false;
+ do {
+ _firstLineRow++;
+ if(_firstLineRow >= start && _firstLineRow <= end) {
+ _firstLineRow = end + 1;
+ needOffset = true;
+ }
+ firstLineIdx = model()->index(_firstLineRow, 0);
+ } while((Message::Type)(model()->data(firstLineIdx, MessageModel::TypeRole).toInt()) == Message::DayChange && _firstLineRow < numRows);
+
+ if(needOffset)
+ _firstLineRow -= end - start + 1;
+ updateSceneRect();
+}
+
+void ChatScene::updateForViewport(qreal width, qreal height) {
+ _viewportHeight = height;
+ setWidth(width);
+}
+
+void ChatScene::setWidth(qreal width) {
+ if(width == _sceneRect.width())
+ return;
+
+ // clock_t startT = clock();
+
+ // disabling the index while doing this complex updates is about
+ // 2 to 10 times faster!
+ //setItemIndexMethod(QGraphicsScene::NoIndex);
+
+ QList<ChatLine *>::iterator lineIter = _lines.end();
+ QList<ChatLine *>::iterator lineIterBegin = _lines.begin();
+ qreal linePos = _sceneRect.y() + _sceneRect.height();
+ qreal contentsWidth = width - secondColumnHandle()->sceneRight();
+ while(lineIter != lineIterBegin) {
+ lineIter--;
+ (*lineIter)->setGeometryByWidth(width, contentsWidth, linePos);
+ }
+ //setItemIndexMethod(QGraphicsScene::BspTreeIndex);
+
+ updateSceneRect(width);
+ setHandleXLimits();
+
+// clock_t endT = clock();
+// qDebug() << "resized" << _lines.count() << "in" << (float)(endT - startT) / CLOCKS_PER_SEC << "sec";