qquicktableview: upon forceLayout(), check for visible rows/columns at the origin

There is a bug in TableView which will stop the user from
scrolling/flicking back to the first column if it has become
visible after first being hidden.

The reason is that this is somewhat of a special case that
happens only if the current left column is already at the
origin of the viewport, since that will fool tableview into
thinking that there can be no more columns in front of it.

This patch add an extra section to the function that checks
for visibility changes, to detect this special case.

Fixes: QTBUG-93264
Change-Id: Ieaad507b45ea11dc231519e9f49cbf182d6443ba
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>
(cherry picked from commit 546df684e272bbbc5e8b871ae9b224fdb34a4cfa)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 78 insertions, 0 deletions

diff --git a/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp b/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp
index 005aae0639..60ba28ec08 100644
--- a/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp
+++ b/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp
@@ -169,6 +169,8 @@ private slots:
     void checkTableviewInsideAsyncLoader();
     void hideRowsAndColumns_data();
     void hideRowsAndColumns();
+    void hideAndShowFirstColumn();
+    void hideAndShowFirstRow();
     void checkThatRevisionedPropertiesCannotBeUsedInOldImports();
     void checkSyncView_rootView_data();
     void checkSyncView_rootView();
@@ -2423,6 +2425,82 @@ void tst_QQuickTableView::hideRowsAndColumns()
         QVERIFY(!columnsToHideList.contains(column));
 }
 
+void tst_QQuickTableView::hideAndShowFirstColumn()
+{
+    // Check that if we hide the first column, it will move
+    // the second column to the origin of the viewport. Then check
+    // that if we show the first column again, it will reappear at
+    // the origin of the viewport, and as such, pushing the second
+    // column to the right of it.
+    LOAD_TABLEVIEW("hiderowsandcolumns.qml");
+
+    const int modelSize = 5;
+    auto model = TestModelAsVariant(modelSize, modelSize);
+    tableView->setModel(model);
+
+    // Start by making the first column hidden
+    const auto columnsToHideList = QList<int>() << 0;
+    view->rootObject()->setProperty("columnsToHide", QVariant::fromValue(columnsToHideList));
+
+    WAIT_UNTIL_POLISHED;
+
+    const int expectedColumnCount = modelSize - columnsToHideList.count();
+    QCOMPARE(tableViewPrivate->loadedColumns.count(), expectedColumnCount);
+    QCOMPARE(tableViewPrivate->leftColumn(), 1);
+    QCOMPARE(tableView->contentX(), 0);
+    QCOMPARE(tableViewPrivate->loadedTableOuterRect.x(), 0);
+
+    // Make the first column in the model visible again
+    const auto emptyList = QList<int>();
+    view->rootObject()->setProperty("columnsToHide", QVariant::fromValue(emptyList));
+    tableView->forceLayout();
+
+    WAIT_UNTIL_POLISHED;
+
+    QCOMPARE(tableViewPrivate->loadedColumns.count(), modelSize);
+    QCOMPARE(tableViewPrivate->leftColumn(), 0);
+    QCOMPARE(tableView->contentX(), 0);
+    QCOMPARE(tableViewPrivate->loadedTableOuterRect.x(), 0);
+}
+
+void tst_QQuickTableView::hideAndShowFirstRow()
+{
+    // Check that if we hide the first row, it will move
+    // the second row to the origin of the viewport. Then check
+    // that if we show the first row again, it will reappear at
+    // the origin of the viewport, and as such, pushing the second
+    // row below it.
+    LOAD_TABLEVIEW("hiderowsandcolumns.qml");
+
+    const int modelSize = 5;
+    auto model = TestModelAsVariant(modelSize, modelSize);
+    tableView->setModel(model);
+
+    // Start by making the first row hidden
+    const auto rowsToHideList = QList<int>() << 0;
+    view->rootObject()->setProperty("rowsToHide", QVariant::fromValue(rowsToHideList));
+
+    WAIT_UNTIL_POLISHED;
+
+    const int expectedRowsCount = modelSize - rowsToHideList.count();
+    QCOMPARE(tableViewPrivate->loadedRows.count(), expectedRowsCount);
+    QCOMPARE(tableViewPrivate->topRow(), 1);
+    QCOMPARE(tableView->contentY(), 0);
+    QCOMPARE(tableViewPrivate->loadedTableOuterRect.y(), 0);
+
+    // Make the first row in the model visible again
+    const auto emptyList = QList<int>();
+    view->rootObject()->setProperty("rowsToHide", QVariant::fromValue(emptyList));
+    tableView->forceLayout();
+
+    WAIT_UNTIL_POLISHED;
+
+    QCOMPARE(tableViewPrivate->loadedRows.count(), modelSize);
+    QCOMPARE(tableViewPrivate->topRow(), 0);
+    QCOMPARE(tableView->contentY(), 0);
+    QCOMPARE(tableViewPrivate->loadedTableOuterRect.y(), 0);
+}
+
 void tst_QQuickTableView::checkThatRevisionedPropertiesCannotBeUsedInOldImports()
 {
     // Check that if you use a QQmlAdaptorModel together with a Repeater, the