dockwidgets: Resize the rubber-band when our drop target is resized

Bug can be seen on the .gif attached to QTBUG-67611, the floating group
window resizes, but the rubber band still has the old size.

Change-Id: I7232a39574ea06fe036c75c21e7496c0f32f4632
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

2 files changed, 18 insertions, 1 deletions

diff --git a/src/widgets/widgets/qmainwindowlayout.cpp b/src/widgets/widgets/qmainwindowlayout.cpp
index 34ad88913d..d4ce0ffa4c 100644
--- a/src/widgets/widgets/qmainwindowlayout.cpp
+++ b/src/widgets/widgets/qmainwindowlayout.cpp
@@ -317,6 +317,9 @@ bool QDockWidgetGroupWindow::event(QEvent *e)
         // We might need to show the widget again
         destroyOrHideIfEmpty();
         break;
+    case QEvent::Resize:
+        updateCurrentGapRect();
+        emit resized();
     default:
         break;
     }
@@ -548,12 +551,18 @@ bool QDockWidgetGroupWindow::hover(QLayoutItem *widgetItem, const QPoint &mouseP
     currentGapPos = newGapPos;
     newState.insertGap(currentGapPos, widgetItem);
     newState.fitItems();
-    currentGapRect = newState.info(currentGapPos)->itemRect(currentGapPos.last(), true);
     *layoutInfo() = std::move(newState);
+    updateCurrentGapRect();
     layoutInfo()->apply(opts & QMainWindow::AnimatedDocks);
     return true;
 }
 
+void QDockWidgetGroupWindow::updateCurrentGapRect()
+{
+    if (!currentGapPos.isEmpty())
+        currentGapRect = layoutInfo()->info(currentGapPos)->itemRect(currentGapPos.last(), true);
+}
+
 /*
     Remove the gap that was created by hover()
  */
@@ -1979,6 +1988,8 @@ void QMainWindowLayout::setCurrentHoveredFloat(QDockWidgetGroupWindow *w)
         if (currentHoveredFloat) {
             disconnect(currentHoveredFloat.data(), &QObject::destroyed,
                        this, &QMainWindowLayout::updateGapIndicator);
+            disconnect(currentHoveredFloat.data(), &QDockWidgetGroupWindow::resized,
+                       this, &QMainWindowLayout::updateGapIndicator);
             if (currentHoveredFloat)
                 currentHoveredFloat->restore();
         } else if (w) {
@@ -1990,6 +2001,8 @@ void QMainWindowLayout::setCurrentHoveredFloat(QDockWidgetGroupWindow *w)
         if (w) {
             connect(w, &QObject::destroyed,
                     this, &QMainWindowLayout::updateGapIndicator, Qt::UniqueConnection);
+            connect(w, &QDockWidgetGroupWindow::resized,
+                    this, &QMainWindowLayout::updateGapIndicator, Qt::UniqueConnection);
         }
 
         updateGapIndicator();
diff --git a/src/widgets/widgets/qmainwindowlayout_p.h b/src/widgets/widgets/qmainwindowlayout_p.h
index 168d4444b9..53e045aaae 100644
--- a/src/widgets/widgets/qmainwindowlayout_p.h
+++ b/src/widgets/widgets/qmainwindowlayout_p.h
@@ -338,12 +338,16 @@ public:
     bool hasNativeDecos() const;
 
     bool hover(QLayoutItem *widgetItem, const QPoint &mousePos);
+    void updateCurrentGapRect();
     void restore();
     void apply();
 
     QRect currentGapRect;
     QList<int> currentGapPos;
 
+signals:
+    void resized();
+
 protected:
     bool event(QEvent *) override;
     void paintEvent(QPaintEvent*) override;