Add QHeaderView::setFirstSectionMovable(), useful for flat treeviews

QTreeView makes columns movable except for the first one
(since Qt 5.0, see commit e0fc088c0c). This is indeed best
for actual trees, but not when using QTreeView as a flat
multi-column list (with no "root decoration"). Then it should
be possible to move the first column.

[ChangeLog][QtWidgets][QHeaderView] Flat treeviews can now allow
the user to move the first column (like in Qt 4.x) using the new
method QHeaderView::setFirstSectionMovable().

Change-Id: I6b5025e40850bf5c4c373124ee81f657f3f09d29
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp b/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp
index 273e90e110..8d90f9e59f 100644
--- a/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp
+++ b/tests/auto/widgets/itemviews/qheaderview/tst_qheaderview.cpp
@@ -514,6 +514,12 @@ void tst_QHeaderView::movable()
     QCOMPARE(view->sectionsMovable(), false);
     view->setSectionsMovable(true);
     QCOMPARE(view->sectionsMovable(), true);
+
+    QCOMPARE(view->firstSectionMovable(), true);
+    view->setFirstSectionMovable(false);
+    QCOMPARE(view->firstSectionMovable(), false);
+    view->setFirstSectionMovable(true);
+    QCOMPARE(view->firstSectionMovable(), true);
 }
 
 void tst_QHeaderView::clickable()