diff options
-rw-r--r-- | src/widgets/itemviews/qlistview.cpp | 34 | ||||
-rw-r--r-- | tests/auto/widgets/itemviews/qlistview/tst_qlistview.cpp | 25 |
2 files changed, 57 insertions, 2 deletions
diff --git a/src/widgets/itemviews/qlistview.cpp b/src/widgets/itemviews/qlistview.cpp index 135f89d4ac..5706be4b6d 100644 --- a/src/widgets/itemviews/qlistview.cpp +++ b/src/widgets/itemviews/qlistview.cpp @@ -1846,14 +1846,44 @@ void QCommonListViewBase::updateHorizontalScrollBar(const QSize &step) { horizontalScrollBar()->setSingleStep(step.width() + spacing()); horizontalScrollBar()->setPageStep(viewport()->width()); - horizontalScrollBar()->setRange(0, contentsSize.width() - viewport()->width()); + + // If both scroll bars are set to auto, we might end up in a situation with enough space + // for the actual content. But still one of the scroll bars will become enabled due to + // the other one using the space. The other one will become invisible in the same cycle. + // -> Infinite loop, QTBUG-39902 + const bool bothScrollBarsAuto = qq->verticalScrollBarPolicy() == Qt::ScrollBarAsNeeded && + qq->horizontalScrollBarPolicy() == Qt::ScrollBarAsNeeded; + + if (bothScrollBarsAuto && contentsSize.width() - qq->verticalScrollBar()->width() <= viewport()->width() + && contentsSize.height() - qq->horizontalScrollBar()->height() <= viewport()->height()) { + // break the infinite loop described above by setting the range to 0, 0. + // QAbstractScrollArea will then hide the scroll bar for us + horizontalScrollBar()->setRange(0, 0); + } else { + horizontalScrollBar()->setRange(0, contentsSize.width() - viewport()->width()); + } } void QCommonListViewBase::updateVerticalScrollBar(const QSize &step) { verticalScrollBar()->setSingleStep(step.height() + spacing()); verticalScrollBar()->setPageStep(viewport()->height()); - verticalScrollBar()->setRange(0, contentsSize.height() - viewport()->height()); + + // If both scroll bars are set to auto, we might end up in a situation with enough space + // for the actual content. But still one of the scroll bars will become enabled due to + // the other one using the space. The other one will become invisible in the same cycle. + // -> Infinite loop, QTBUG-39902 + const bool bothScrollBarsAuto = qq->verticalScrollBarPolicy() == Qt::ScrollBarAsNeeded && + qq->horizontalScrollBarPolicy() == Qt::ScrollBarAsNeeded; + + if (bothScrollBarsAuto && contentsSize.width() - qq->verticalScrollBar()->width() <= viewport()->width() + && contentsSize.height() - qq->horizontalScrollBar()->height() <= viewport()->height()) { + // break the infinite loop described above by setting the range to 0, 0. + // QAbstractScrollArea will then hide the scroll bar for us + verticalScrollBar()->setRange(0, 0); + } else { + verticalScrollBar()->setRange(0, contentsSize.height() - viewport()->height()); + } } void QCommonListViewBase::scrollContentsBy(int dx, int dy, bool /*scrollElasticBand*/) diff --git a/tests/auto/widgets/itemviews/qlistview/tst_qlistview.cpp b/tests/auto/widgets/itemviews/qlistview/tst_qlistview.cpp index b36b5aef8a..bb05db0b15 100644 --- a/tests/auto/widgets/itemviews/qlistview/tst_qlistview.cpp +++ b/tests/auto/widgets/itemviews/qlistview/tst_qlistview.cpp @@ -155,6 +155,7 @@ private slots: void spacing(); void testScrollToWithHidden(); void testViewOptions(); + void taskQTBUG_39902_mutualScrollBars(); }; // Testing get/set functions @@ -2355,5 +2356,29 @@ void tst_QListView::testViewOptions() QCOMPARE(options.decorationPosition, QStyleOptionViewItem::Top); } +void tst_QListView::taskQTBUG_39902_mutualScrollBars() +{ + QWidget window; + window.resize(400, 300); + QListView *view = new QListView(&window); + QStandardItemModel model(200, 1); + const QSize itemSize(100, 20); + for (int i = 0; i < model.rowCount(); ++i) + model.setData(model.index(i, 0), itemSize, Qt::SizeHintRole); + view->setModel(&model); + + window.show(); + QVERIFY(QTest::qWaitForWindowExposed(&window)); + // make sure QListView is done with layouting the items (1/10 sec, like QListView) + QTest::qWait(100); + + model.setRowCount(2); + for (int i = 0; i < model.rowCount(); ++i) + model.setData(model.index(i, 0), itemSize, Qt::SizeHintRole); + view->resize(itemSize.width() + view->frameWidth() * 2, model.rowCount() * itemSize.height() + view->frameWidth() * 2); + // this will end up in a stack overflow, if QTBUG-39902 is not fixed + QTest::qWait(100); +} + QTEST_MAIN(tst_QListView) #include "tst_qlistview.moc" |