Frame now takes care of its own resize handler

No need to set it from outside

src/MainWindowBase.cpp

@@ -493,9 +493,7 @@ void MainWindowBase::overlayOnSideBar(DockWidgetBase *dw)
     frame->addWidget(dw);
     d->updateOverlayGeometry(dw->d->lastPositions().lastOverlayedGeometry(sb->location()).size());
 
-    auto resizeHandler = new WidgetResizeHandler(true, frame);
-    resizeHandler->setAllowedResizeSides(d->allowedResizeSides(sb->location()));
-
+    frame->setAllowedResizeSides(d->allowedResizeSides(sb->location()));
     frame->QWidgetAdapter::show();
 
     Q_EMIT dw->isOverlayedChanged(true);

src/private/Frame.cpp

@@ -29,6 +29,7 @@
 #include "TabWidget_p.h"
 #include "TitleBar_p.h"
 #include "Utils_p.h"
+#include "WidgetResizeHandler_p.h"
 
 #include <QCloseEvent>
 #include <QTimer>
@@ -75,6 +76,9 @@ Frame::~Frame()
     if (m_layoutItem)
         m_layoutItem->unref();
 
+    delete m_resizeHandler;
+    m_resizeHandler = nullptr;
+
     DockRegistry::self()->unregisterFrame(this);
 
     // Run some disconnects() too, so we don't receive signals during destruction:
@@ -747,3 +751,15 @@ bool Frame::anyDockWidgetsHas(DockWidgetBase::LayoutSaverOption option) const
         return dw->layoutSaverOptions() & option;
     });
 }
+
+void Frame::setAllowedResizeSides(CursorPositions sides)
+{
+    if (sides) {
+        delete m_resizeHandler;
+        m_resizeHandler = new WidgetResizeHandler(true, this);
+        m_resizeHandler->setAllowedResizeSides(sides);
+    } else {
+        delete m_resizeHandler;
+        m_resizeHandler = nullptr;
+    }
+}

src/private/Frame_p.h

@@ -39,6 +39,7 @@ class TabWidget;
 class DockWidgetBase;
 class FloatingWindow;
 class MainWindowBase;
+class WidgetResizeHandler;
 
 /**
  * @brief A DockWidget wrapper that adds a QTabWidget and a TitleBar
@@ -250,6 +251,10 @@ public:
     ///@brief Returns whether at least one dock widget has the specified layout saver option set
     bool anyDockWidgetsHas(DockWidgetBase::LayoutSaverOption) const;
 
+    /// @brief Usually we do resize via the native window manager, but if a widget is docked like
+    /// in MDI mode, or in overlayed mode then we allow the user to resize with mouse
+    void setAllowedResizeSides(CursorPositions sides);
+
 Q_SIGNALS:
     void currentDockWidgetChanged(KDDockWidgets::DockWidgetBase *);
     void numDockWidgetsChanged();
@@ -319,6 +324,7 @@ private:
     void setLayoutWidget(LayoutWidget *);
 
     LayoutWidget *m_layoutWidget = nullptr;
+    WidgetResizeHandler *m_resizeHandler = nullptr;
     FrameOptions m_options = FrameOption_None;
     QPointer<Layouting::Item> m_layoutItem;
     bool m_updatingTitleBar = false;