From 1241e4f3c3ec010ae121f5d56c3e9405ec43231f Mon Sep 17 00:00:00 2001
From: Andy Shaw <andy.shaw@qt.io>
Date: Fri, 6 Nov 2020 13:30:12 +0100
Subject: [PATCH 19/28] Show a tableview even if the syncView has an empty
 model

By showing the tableview, we can be sure that headerviews will be
visible even in the syncView has an empty model.

Fixes: QTBUG-87526
Change-Id: I68c8b119122a2d2f88c2afbeb2d6c71a83a3ce33
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
(cherry picked from commit 27c254203b3e7dd6d3a4445feb205fbe98c32d30)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/quick/items/qquicktableview.cpp           |  7 +--
 .../qquicktableview/tst_qquicktableview.cpp   | 43 +++++++++++++++++++
 2 files changed, 45 insertions(+), 5 deletions(-)

diff --git a/src/quick/items/qquicktableview.cpp b/src/quick/items/qquicktableview.cpp
index 7b73fcb393..1349d308d7 100644
--- a/src/quick/items/qquicktableview.cpp
+++ b/src/quick/items/qquicktableview.cpp
@@ -1760,11 +1760,8 @@ void QQuickTableViewPrivate::calculateTopLeft(QPoint &topLeftCell, QPointF &topL
         const auto syncView_d = syncView->d_func();
 
         if (syncView_d->loadedItems.isEmpty()) {
-            // The sync view contains no loaded items. This probably means
-            // that it has not been rebuilt yet. Which also means that
-            // we cannot rebuild anything before this happens.
-            topLeftCell.rx() = kEdgeIndexNotSet;
-            topLeftCell.ry() = kEdgeIndexNotSet;
+            topLeftCell.rx() = 0;
+            topLeftCell.ry() = 0;
             return;
         }
 
diff --git a/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp b/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp
index 54f73c6e0c..d489a873e4 100644
--- a/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp
+++ b/tests/auto/quick/qquicktableview/tst_qquicktableview.cpp
@@ -176,6 +176,7 @@ private slots:
     void checkSyncView_connect_late_data();
     void checkSyncView_connect_late();
     void checkSyncView_pageFlicking();
+    void checkSyncView_emptyModel();
     void delegateWithRequiredProperties();
     void checkThatFetchMoreIsCalledWhenScrolledToTheEndOfTable();
     void replaceModel();
@@ -2731,6 +2732,48 @@ void tst_QQuickTableView::checkSyncView_pageFlicking()
     QVERIFY(tableViewPrivate->scheduledRebuildOptions & QQuickTableViewPrivate::RebuildOption::CalculateNewTopLeftRow);
 }
 
+void tst_QQuickTableView::checkSyncView_emptyModel()
+{
+    // When a tableview has a syncview with an empty model then it should still be
+    // showing the tableview without depending on the syncview. This is particularly
+    // important for headerviews for example
+    LOAD_TABLEVIEW("syncviewsimple.qml");
+    GET_QML_TABLEVIEW(tableViewH);
+    GET_QML_TABLEVIEW(tableViewV);
+    GET_QML_TABLEVIEW(tableViewHV);
+    QQuickTableView *views[] = {tableViewH, tableViewV, tableViewHV};
+
+    auto model = TestModelAsVariant(100, 100);
+
+    for (auto view : views)
+        view->setModel(model);
+
+    WAIT_UNTIL_POLISHED_ARG(tableViewHV);
+
+    // Check that geometry properties are mirrored
+    QCOMPARE(tableViewH->columnSpacing(), tableView->columnSpacing());
+    QCOMPARE(tableViewH->rowSpacing(), 0);
+    QCOMPARE(tableViewH->contentWidth(), tableView->contentWidth());
+    QVERIFY(tableViewH->contentHeight() > 0);
+    QCOMPARE(tableViewV->columnSpacing(), 0);
+    QCOMPARE(tableViewV->rowSpacing(), tableView->rowSpacing());
+    QCOMPARE(tableViewV->contentHeight(), tableView->contentHeight());
+    QVERIFY(tableViewV->contentWidth() > 0);
+
+    QCOMPARE(tableViewH->contentX(), tableView->contentX());
+    QCOMPARE(tableViewH->contentY(), 0);
+    QCOMPARE(tableViewV->contentX(), 0);
+    QCOMPARE(tableViewV->contentY(), tableView->contentY());
+    QCOMPARE(tableViewHV->contentX(), tableView->contentX());
+    QCOMPARE(tableViewHV->contentY(), tableView->contentY());
+
+    QCOMPARE(tableViewHPrivate->loadedTableOuterRect.left(), tableViewPrivate->loadedTableOuterRect.left());
+    QCOMPARE(tableViewHPrivate->loadedTableOuterRect.top(), 0);
+
+    QCOMPARE(tableViewVPrivate->loadedTableOuterRect.top(), tableViewPrivate->loadedTableOuterRect.top());
+    QCOMPARE(tableViewVPrivate->loadedTableOuterRect.left(), 0);
+}
+
 void tst_QQuickTableView::checkThatFetchMoreIsCalledWhenScrolledToTheEndOfTable()
 {
     LOAD_TABLEVIEW("plaintableview.qml");
-- 
2.31.1