QHeaderView: respect min/maximumSectionSize property

QHeaderView::resizeSection() did not check if the given section size is
inside the min/max property bounds.
Also on calling setMin/MaximumSectionSize() the current section sizes
were not checked if they are inside the new given bounds.
This is a small behavior change when a user is setting the section size
via resizeSection() without respecting the min/maxSectionSizes.

Task-number: QTBUG-64173
Change-Id: Ia9c9eebf058d60c776ab5f8f8336642013ec553f
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>

3 files changed, 136 insertions, 9 deletions

diff --git a/src/widgets/itemviews/qheaderview.cpp b/src/widgets/itemviews/qheaderview.cpp
index 6ee3f0cfca..a21b8feeb1 100644
--- a/src/widgets/itemviews/qheaderview.cpp
+++ b/src/widgets/itemviews/qheaderview.cpp
@@ -886,6 +886,10 @@ void QHeaderView::resizeSection(int logical, int size)
     if (logical < 0 || logical >= count() || size < 0 || size > maxSizeSection)
         return;
 
+    // make sure to not exceed bounds when setting size programmatically
+    if (size > 0)
+        size = qBound(minimumSectionSize(), size, maximumSectionSize());
+
     if (isSectionHidden(logical)) {
         d->hiddenSectionSize.insert(logical, size);
         return;
@@ -1661,9 +1665,25 @@ void QHeaderView::setMinimumSectionSize(int size)
     Q_D(QHeaderView);
     if (size < -1 || size > maxSizeSection)
         return;
+    // larger new min size - check current section sizes
+    const bool needSizeCheck = size > d->minimumSectionSize;
     d->minimumSectionSize = size;
     if (d->minimumSectionSize > maximumSectionSize())
-        d->maximumSectionSize = size;
+        setMaximumSectionSize(size);
+
+    if (needSizeCheck) {
+        if (d->hasAutoResizeSections()) {
+            d->doDelayedResizeSections();
+        } else {
+            for (int visual = 0; visual < d->sectionCount(); ++visual) {
+                if (d->isVisualIndexHidden(visual))
+                    continue;
+                if (d->headerSectionSize(visual) < d->minimumSectionSize)
+                    resizeSection(logicalIndex(visual), size);
+            }
+        }
+    }
+
 }
 
 /*!
@@ -1700,7 +1720,22 @@ void QHeaderView::setMaximumSectionSize(int size)
     if (minimumSectionSize() > size)
         d->minimumSectionSize = size;
 
+    // smaller new max size - check current section sizes
+    const bool needSizeCheck = size < d->maximumSectionSize;
     d->maximumSectionSize = size;
+
+    if (needSizeCheck) {
+        if (d->hasAutoResizeSections()) {
+            d->doDelayedResizeSections();
+        } else {
+            for (int visual = 0; visual < d->sectionCount(); ++visual) {
+                if (d->isVisualIndexHidden(visual))
+                    continue;
+                if (d->headerSectionSize(visual) > d->maximumSectionSize)
+                    resizeSection(logicalIndex(visual), size);
+            }
+        }
+    }
 }
 
 
@@ -3431,9 +3466,11 @@ void QHeaderViewPrivate::resizeSections(QHeaderView::ResizeMode globalMode, bool
             int logicalIndex = q->logicalIndex(i);
             sectionSize = qMax(viewSectionSizeHint(logicalIndex),
                                q->sectionSizeHint(logicalIndex));
-            if (sectionSize > q->maximumSectionSize())
-                sectionSize = q->maximumSectionSize();
         }
+        sectionSize = qBound(q->minimumSectionSize(),
+                             sectionSize,
+                             q->maximumSectionSize());
+
         section_sizes.append(sectionSize);
         lengthToStretch -= sectionSize;
     }
diff --git a/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp b/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp
index 8d90f9e59f..a5d131a436 100644
--- a/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp
+++ b/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp
@@ -239,13 +239,15 @@ private slots:
     void testStreamWithHide();
     void testStylePosition();
     void stretchAndRestoreLastSection();
-
+    void testMinMaxSectionSizeStretched();
+    void testMinMaxSectionSizeNotStretched();
     void sizeHintCrash();
 
 protected:
     void setupTestData(bool use_reset_model = false);
     void additionalInit();
     void calculateAndCheck(int cppline, const int precalced_comparedata[]);
+    void testMinMaxSectionSize(bool stretchLastSection);
 
     QWidget *topLevel;
     QHeaderView *view;
@@ -402,6 +404,7 @@ void tst_QHeaderView::init()
     QCOMPARE(view->length(), 0);
     QCOMPARE(view->sizeHint(), QSize(0,0));
     QCOMPARE(view->sectionSizeHint(0), -1);
+    view->setMinimumSectionSize(0);    // system default min size can be to large
 
     /*
     model = new QStandardItemModel(1, 1);
@@ -1604,6 +1607,7 @@ static QByteArray savedState()
     QStandardItemModel m(4, 4);
     QHeaderView h1(Qt::Horizontal);
     h1.setModel(&m);
+    h1.setMinimumSectionSize(0);    // system default min size can be to large
     h1.swapSections(0, 2);
     h1.resizeSection(1, 10);
     h1.setSortIndicatorShown(true);
@@ -2194,6 +2198,7 @@ void tst_QHeaderView::task248050_hideRow()
     //this is the sequence of events that make the task fail
     protected_QHeaderView header(Qt::Vertical);
     QStandardItemModel model(0, 1);
+    header.setMinimumSectionSize(0);    // system default min size can be to large
     header.setStretchLastSection(false);
     header.setDefaultSectionSize(17);
     header.setModel(&model);
@@ -3182,5 +3187,76 @@ void tst_QHeaderView::stretchAndRestoreLastSection()
     QCOMPARE(header.sectionSize(9), someOtherSectionSize);
 }
 
+void tst_QHeaderView::testMinMaxSectionSizeStretched()
+{
+    testMinMaxSectionSize(true);
+}
+
+void tst_QHeaderView::testMinMaxSectionSizeNotStretched()
+{
+    testMinMaxSectionSize(false);
+}
+
+static void waitFor(const std::function<bool()> &func)
+{
+    for (int i = 0; i < 100; i++)
+    {
+        if (func())
+          return;
+        QTest::qWait(10);
+    }
+}
+
+void tst_QHeaderView::testMinMaxSectionSize(bool stretchLastSection)
+{
+    QStandardItemModel m(5, 5);
+    QTableView tv;
+    tv.setModel(&m);
+    tv.show();
+
+    const int sectionSizeMin = 20;
+    const int sectionSizeMax = 40;
+    const int defaultSectionSize = 30;
+
+    QVERIFY(QTest::qWaitForWindowExposed(&tv));
+
+    QHeaderView &header = *tv.horizontalHeader();
+    header.setMinimumSectionSize(sectionSizeMin);
+    header.setMaximumSectionSize(sectionSizeMax);
+    header.setDefaultSectionSize(defaultSectionSize);
+    header.setStretchLastSection(stretchLastSection);
+
+    // check defaults
+    QCOMPARE(header.sectionSize(0), defaultSectionSize);
+    QCOMPARE(header.sectionSize(3), defaultSectionSize);
+
+    // do not go above maxSectionSize
+    header.resizeSection(0, sectionSizeMax + 1);
+    QCOMPARE(header.sectionSize(0), sectionSizeMax);
+
+    // do not go below minSectionSize
+    header.resizeSection(0, sectionSizeMin - 1);
+    QCOMPARE(header.sectionSize(0), sectionSizeMin);
+
+    // change section size on max change
+    header.setMinimumSectionSize(sectionSizeMin);
+    header.setMaximumSectionSize(sectionSizeMax);
+    header.resizeSection(0, sectionSizeMax);
+    QCOMPARE(header.sectionSize(0), sectionSizeMax);
+    header.setMaximumSectionSize(defaultSectionSize);
+    waitFor([this, &header, defaultSectionSize]() { return header.sectionSize(0) == defaultSectionSize; });
+    QCOMPARE(header.sectionSize(0), defaultSectionSize);
+
+    // change section size on min change
+    header.setMinimumSectionSize(sectionSizeMin);
+    header.setMaximumSectionSize(sectionSizeMax);
+    header.resizeSection(0, sectionSizeMin);
+    QCOMPARE(header.sectionSize(0), sectionSizeMin);
+    header.setMinimumSectionSize(defaultSectionSize);
+    waitFor([this, &header, defaultSectionSize]() { return header.sectionSize(0) == defaultSectionSize; });
+    QCOMPARE(header.sectionSize(0), defaultSectionSize);
+}
+
+
 QTEST_MAIN(tst_QHeaderView)
 #include "tst_qheaderview.moc"
diff --git a/tests/auto/widgets/itemviews/qtableview/tst_qtableview.cpp b/tests/auto/widgets/itemviews/qtableview/tst_qtableview.cpp
index b558bd9b4e..06c80bf8d2 100644
--- a/tests/auto/widgets/itemviews/qtableview/tst_qtableview.cpp
+++ b/tests/auto/widgets/itemviews/qtableview/tst_qtableview.cpp
@@ -426,6 +426,9 @@ public:
                      this, SLOT(slotCurrentChanged(QModelIndex,QModelIndex)));
         connect(selectionModel(), SIGNAL(selectionChanged(QItemSelection,QItemSelection)),
                      this, SLOT(itemSelectionChanged(QItemSelection,QItemSelection)));
+        // Allow small sections in this test, since this test was made before we correctly enforced minimum sizes.
+        horizontalHeader()->setMinimumSectionSize(0);
+        verticalHeader()->setMinimumSectionSize(0);
     }
 
     // enum CursorAction and moveCursor() are protected in QTableView.
@@ -738,6 +741,8 @@ void tst_QTableView::headerSections()
     QHeaderView *vheader = view.verticalHeader();
 
     view.setModel(&model);
+    hheader->setMinimumSectionSize(columnWidth);
+    vheader->setMinimumSectionSize(rowHeight);
     view.show();
 
     hheader->doItemsLayout();
@@ -1147,6 +1152,9 @@ void tst_QTableView::moveCursor()
     QtTestTableView view;
 
     view.setModel(&model);
+    // we have to make sure that PgUp/PgDown can scroll to the bottom/top
+    view.resize(view.horizontalHeader()->length() + 50,
+                view.verticalHeader()->length() + 50);
     view.hideRow(hideRow);
     view.hideColumn(hideColumn);
     if (moveColumn.first != moveColumn.second)
@@ -2085,6 +2093,8 @@ void tst_QTableView::visualRect()
 
     QTableView view;
     view.setModel(&model);
+    view.horizontalHeader()->setMinimumSectionSize(0);
+    view.verticalHeader()->setMinimumSectionSize(0);
     // Make sure that it has 1 pixel between each cell.
     view.setGridStyle(Qt::SolidLine);
     for (int i = 0; i < view.verticalHeader()->count(); ++i)
@@ -3533,6 +3543,9 @@ void tst_QTableView::editSpanFromDirections()
 
     TableViewWithCursorExposed view;
     view.setModel(model.data());
+    // we have to make sure that PgUp/PgDown can scroll to the bottom/top
+    view.resize(view.horizontalHeader()->length() + 50,
+                view.verticalHeader()->length() + 50);
     view.setSpan(row, column, rowSpan, columnSpan);
     view.show();
     QVERIFY(QTest::qWaitForWindowActive(&view));
@@ -3978,7 +3991,7 @@ void tst_QTableView::mouseWheel_data()
             << 10 + qApp->wheelScrollLines() << 10 + qApp->wheelScrollLines();
     QTest::newRow("scroll down per pixel")
             << int(QAbstractItemView::ScrollPerPixel) << -120
-            << 10 + qApp->wheelScrollLines() * 89 << 10 + qApp->wheelScrollLines() * 28;
+            << 10 + qApp->wheelScrollLines() * 91 << 10 + qApp->wheelScrollLines() * 46;
 }
 
 void tst_QTableView::mouseWheel()
@@ -3992,16 +4005,17 @@ void tst_QTableView::mouseWheel()
     QWidget topLevel;
     QtTestTableView view(&topLevel);
     view.resize(500, 500);
-    for (int r = 0; r < 100; ++r)
-        view.setRowHeight(r, 50);
-    for (int c = 0; c < 100; ++c)
-        view.setColumnWidth(c, 100);
     topLevel.show();
 
     QVERIFY(QTest::qWaitForWindowExposed(&topLevel));
 
     view.setModel(&model);
 
+    for (int r = 0; r < 100; ++r)
+        view.setRowHeight(r, 50);
+    for (int c = 0; c < 100; ++c)
+        view.setColumnWidth(c, 100);
+
     view.setHorizontalScrollMode((QAbstractItemView::ScrollMode)scrollMode);
     view.setVerticalScrollMode((QAbstractItemView::ScrollMode)scrollMode);
     view.horizontalScrollBar()->setValue(10);