diff --git a/src/widgets/graphicsview/qgraphicsview.cpp b/src/widgets/graphicsview/qgraphicsview.cpp index f7dab4724b..8e362ce1e0 100644 --- a/src/widgets/graphicsview/qgraphicsview.cpp +++ b/src/widgets/graphicsview/qgraphicsview.cpp @@ -335,10 +335,10 @@ void QGraphicsViewPrivate::recalculateContentSize() { Q_Q(QGraphicsView); - QSize maxSize = q->maximumViewportSize(); + const QSize maxSize = q->maximumViewportSize(); int width = maxSize.width(); int height = maxSize.height(); - QRectF viewRect = matrix.mapRect(q->sceneRect()); + const QRectF viewRect = matrix.mapRect(q->sceneRect()); bool frameOnlyAround = (q->style()->styleHint(QStyle::SH_ScrollView_FrameOnlyAroundContents, nullptr, q)); if (frameOnlyAround) { @@ -350,9 +350,8 @@ void QGraphicsViewPrivate::recalculateContentSize() // Adjust the maximum width and height of the viewport based on the width // of visible scroll bars. - int scrollBarExtent = q->style()->pixelMetric(QStyle::PM_ScrollBarExtent, nullptr, q); - if (frameOnlyAround) - scrollBarExtent += frameWidth * 2; + const int scrollBarExtent = q->style()->pixelMetric(QStyle::PM_ScrollBarExtent, nullptr, q) + + (frameOnlyAround ? frameWidth * 2 : 0); // We do not need to subtract the width scrollbars whose policy is // Qt::ScrollBarAlwaysOn, this was already done by maximumViewportSize(). @@ -374,62 +373,70 @@ void QGraphicsViewPrivate::recalculateContentSize() // Setting the ranges of these scroll bars can/will cause the values to // change, and scrollContentsBy() will be called correspondingly. This // will reset the last center point. - QPointF savedLastCenterPoint = lastCenterPoint; + const QPointF savedLastCenterPoint = lastCenterPoint; // Remember the former indent settings - qreal oldLeftIndent = leftIndent; - qreal oldTopIndent = topIndent; + const qreal oldLeftIndent = leftIndent; + const qreal oldTopIndent = topIndent; // If the whole scene fits horizontally, we center the scene horizontally, // and ignore the horizontal scroll bars. - int left = q_round_bound(viewRect.left()); - int right = q_round_bound(viewRect.right() - width); + const int left = q_round_bound(viewRect.left()); + const int right = q_round_bound(viewRect.right() - width); if (left >= right) { - hbar->setRange(0, 0); - switch (alignment & Qt::AlignHorizontal_Mask) { case Qt::AlignLeft: leftIndent = -viewRect.left(); break; case Qt::AlignRight: - leftIndent = width - viewRect.width() - viewRect.left() - 1; + leftIndent = maxSize.width() - viewRect.width() - viewRect.left() - 1; break; case Qt::AlignHCenter: default: - leftIndent = width / 2 - (viewRect.left() + viewRect.right()) / 2; + leftIndent = maxSize.width() / 2 - (viewRect.left() + viewRect.right()) / 2; break; } + + hbar->setRange(0, 0); } else { + leftIndent = 0; + hbar->setRange(left, right); hbar->setPageStep(width); hbar->setSingleStep(width / 20); - leftIndent = 0; + + if (oldLeftIndent != 0) + hbar->setValue(-oldLeftIndent); } // If the whole scene fits vertically, we center the scene vertically, and // ignore the vertical scroll bars. - int top = q_round_bound(viewRect.top()); - int bottom = q_round_bound(viewRect.bottom() - height); + const int top = q_round_bound(viewRect.top()); + const int bottom = q_round_bound(viewRect.bottom() - height); if (top >= bottom) { - vbar->setRange(0, 0); - switch (alignment & Qt::AlignVertical_Mask) { case Qt::AlignTop: topIndent = -viewRect.top(); break; case Qt::AlignBottom: - topIndent = height - viewRect.height() - viewRect.top() - 1; + topIndent = maxSize.height() - viewRect.height() - viewRect.top() - 1; break; case Qt::AlignVCenter: default: - topIndent = height / 2 - (viewRect.top() + viewRect.bottom()) / 2; + topIndent = maxSize.height() / 2 - (viewRect.top() + viewRect.bottom()) / 2; break; } + + vbar->setRange(0, 0); } else { + topIndent = 0; + vbar->setRange(top, bottom); vbar->setPageStep(height); vbar->setSingleStep(height / 20); - topIndent = 0; + + if (oldTopIndent != 0) + vbar->setValue(-oldTopIndent); } // Restorethe center point from before the ranges changed. diff --git a/tests/auto/widgets/graphicsview/qgraphicsview/tst_qgraphicsview.cpp b/tests/auto/widgets/graphicsview/qgraphicsview/tst_qgraphicsview.cpp index d5807c1958..27fbcc2b3b 100644 --- a/tests/auto/widgets/graphicsview/qgraphicsview/tst_qgraphicsview.cpp +++ b/tests/auto/widgets/graphicsview/qgraphicsview/tst_qgraphicsview.cpp @@ -248,6 +248,8 @@ private slots: #ifndef QT_NO_CURSOR void QTBUG_7438_cursor(); #endif + void resizeContentsOnItemDrag_data(); + void resizeContentsOnItemDrag(); public slots: void dummySlot() {} @@ -4960,5 +4962,111 @@ void tst_QGraphicsView::QTBUG_70255_scrollTo() QCOMPARE(point, QPoint(0, -500)); } +void tst_QGraphicsView::resizeContentsOnItemDrag_data() +{ + QTest::addColumn("alignment"); + QTest::addColumn("orientation"); + QTest::addRow("Center right") << Qt::Alignment(Qt::AlignCenter) << Qt::Horizontal; + QTest::addRow("Center down") << Qt::Alignment(Qt::AlignCenter) << Qt::Vertical; + QTest::addRow("BottomLeft right") << (Qt::AlignBottom | Qt::AlignLeft) << Qt::Horizontal; + QTest::addRow("TopRight down") << (Qt::AlignTop | Qt::AlignRight) << Qt::Vertical; +} + +void tst_QGraphicsView::resizeContentsOnItemDrag() +{ + QFETCH(Qt::Alignment, alignment); + QFETCH(Qt::Orientation, orientation); + + QGraphicsView view; + QGraphicsScene scene; + view.setFixedSize(200, 200); + view.setScene(&scene); + + view.setAlignment(alignment); + + class MovableItem : public QGraphicsEllipseItem + { + public: + using QGraphicsEllipseItem::QGraphicsEllipseItem; + + QList scenePositions; + + protected: + void mousePressEvent(QGraphicsSceneMouseEvent *event) override + { + scenePositions << event->scenePos(); + } + void mouseMoveEvent(QGraphicsSceneMouseEvent *event) override + { + scenePositions << event->scenePos(); + QGraphicsEllipseItem::mouseMoveEvent(event); + } + }; + + MovableItem item(-10, -10, 20, 20); + item.setFlags(QGraphicsItem::ItemIsMovable); + scene.addItem(&item); + view.show(); + QVERIFY(QTest::qWaitForWindowExposed(&view)); + + // Position the item near the relevant edge of the view, with a few pixels + // to go until the scrollbars should be showing. + if (orientation == Qt::Horizontal) + item.setPos(view.width() - item.rect().width() - 5, 0); + else + item.setPos(0, view.height() - item.rect().height() - 5); + QApplication::processEvents(); // queued connection used to trigger recalculateContentSize + QPoint mousePos = view.mapFromScene(item.pos()); + + QTest::mousePress(view.viewport(), Qt::LeftButton, {}, mousePos); + QCOMPARE(item.scenePositions.count(), 1); + QCOMPARE(item.scenePositions.takeLast(), view.mapToScene(mousePos)); + + auto lastItemPos = item.pos(); + auto lastScenePos = view.mapToScene(mousePos); + int overshoot = 0; + const QScrollBar *scrollBar = orientation == Qt::Horizontal + ? view.horizontalScrollBar() + : view.verticalScrollBar(); + // Drag the item until the scroll bars become visible, and then for a few more pixels. + // Verify that the item doesn't jump when the scrollbar shows. + while (overshoot < 10) { + if (orientation == Qt::Horizontal) + mousePos.rx() += 1; + else + mousePos.ry() += 1; + QTest::mouseMove(view.viewport(), mousePos); + QApplication::processEvents(); // queued connection used to trigger recalculateContentSize + const bool scrollbarAvailable = scrollBar->maximum() > scrollBar->minimum(); + bool allowMoreEvents = false; + if (scrollbarAvailable) { + if (!overshoot) { + QTRY_VERIFY(scrollBar->isVisible()); + // scrollbar becoming visible triggers event replay, so we get more than one + allowMoreEvents = true; + } + ++overshoot; + } + if (allowMoreEvents) + QCOMPARE_GE(item.scenePositions.count(), 1); + else + QCOMPARE(item.scenePositions.count(), 1); + const auto scenePos = item.scenePositions.takeLast(); + item.scenePositions.clear(); + + const auto same = orientation == Qt::Horizontal ? &QPointF::y : &QPointF::x; + const auto moved = orientation == Qt::Horizontal ? &QPointF::x : &QPointF::y; + QCOMPARE((item.pos().*same)(), (lastItemPos.*same)()); + QCOMPARE_GE((item.pos().*moved)() - (lastItemPos.*moved)(), 1); + QCOMPARE_LE((item.pos().*moved)() - (lastItemPos.*moved)(), 2); + lastItemPos = item.pos(); + + QCOMPARE((scenePos.*same)(), (lastScenePos.*same)()); + QCOMPARE_GE((scenePos.*moved)() - (lastScenePos.*moved)(), 1); + QCOMPARE_LE((scenePos.*moved)() - (lastScenePos.*moved)(), 2); + lastScenePos = scenePos; + } +} + QTEST_MAIN(tst_QGraphicsView) #include "tst_qgraphicsview.moc"