QDockWidget: Remove "group" bool trap

The unplug() and startDrag() functions of QMainWindowLayout and
QDockWidget used a boolean argument specifying whether a single dock
widget or a group of dock widgets should be unplugged. The argument
defaulted to true.

That has lead to inconsistent unplug operations, broken item_lists and
crashes, especially when the methods were called without an argument.

To improve code readability, replace bool trap with a meaningful
enum. Remove default arguments, in order to force explicit calls.

This patch does not change behavior, it is just carved out to
facilitate reviews.

Task-number: QTBUG-118578
Task-number: QTBUG-118579
Pick-to: 6.6 6.5
Change-Id: I50341b055f0bb76c2797b2fb1126a10de1fee7dd
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/widgets/widgets/qdockwidget_p.h b/src/widgets/widgets/qdockwidget_p.h
index 2adf62d03e..72cf08177f 100644
--- a/src/widgets/widgets/qdockwidget_p.h
+++ b/src/widgets/widgets/qdockwidget_p.h
@@ -51,6 +51,11 @@ class QDockWidgetPrivate : public QWidgetPrivate
     };
 
 public:
+    enum class DragScope {
+        Group,
+        Widget
+    };
+
     void init();
     void toggleView(bool);
     void toggleTopLevel();
@@ -86,7 +91,7 @@ public:
     void setWindowState(bool floating, bool unplug = false, const QRect &rect = QRect());
     void nonClientAreaMouseEvent(QMouseEvent *event);
     void initDrag(const QPoint &pos, bool nca);
-    void startDrag(bool group = true);
+    void startDrag(DragScope scope);
     void endDrag(bool abort = false);
     void moveEvent(QMoveEvent *event);
     void recalculatePressPos(QResizeEvent *event);