Update overlay geometries when central widget changes size

We were only updating the overlays when the main window changed
size, but it can happen that only the central widget changes size,
for example when you remove or add a toolbar

Fixes #227

Changelog

@@ -1,5 +1,5 @@
 * v1.4.1 (unreleased)
- - 
+ - Fixed overlayed dock widgets being misplaced when removing a toolbar (#227)
 
 * v1.4.0 (16 July 2021)
   - No longer supports Qt versions less than 5.12

src/MainWindow.cpp

@@ -39,6 +39,7 @@ using namespace KDDockWidgets;
 namespace KDDockWidgets {
 class MyCentralWidget : public QWidget
 {
+    Q_OBJECT
 public:
     explicit MyCentralWidget(QWidget *parent = nullptr)
         : QWidget(parent)
@@ -47,6 +48,14 @@ public:
     }
 
     ~MyCentralWidget() override;
+
+    void resizeEvent(QResizeEvent *ev) override
+    {
+        QWidget::resizeEvent(ev);
+        Q_EMIT resized(ev->oldSize(), ev->size());
+    }
+Q_SIGNALS:
+    void resized(QSize oldSize, QSize newSize);
 };
 }
 
@@ -114,6 +123,8 @@ MainWindow::MainWindow(const QString &name, MainWindowOptions options,
                 d->updateMargins(); // logical dpi might have changed
                 Q_EMIT DockRegistry::self()->windowChangedScreen(windowHandle());
             });
+
+    connect(d->m_centralWidget, &MyCentralWidget::resized, this, &MainWindowBase::centralWidgetResized);
 }
 
 MainWindow::~MainWindow()
@@ -147,3 +158,5 @@ QRect MainWindow::centralAreaGeometry() const
 {
     return centralWidget()->geometry();
 }
+
+#include "MainWindow.moc"

src/MainWindowBase.cpp

@@ -56,6 +56,13 @@ public:
         return m_options & MainWindowOption_HasCentralFrame;
     }
 
+
+    void updateOverlayedDockWidgetGeometries()
+    {
+        if (m_overlayedDockWidget)
+            updateOverlayGeometry(m_overlayedDockWidget->d->frame()->QWidgetAdapter::size());
+    }
+
     CursorPositions allowedResizeSides(SideBarLocation loc) const;
 
     QRect rectForOverlay(Frame *, SideBarLocation) const;
@@ -80,6 +87,10 @@ MainWindowBase::MainWindowBase(const QString &uniqueName, KDDockWidgets::MainWin
 
     connect(d->m_layoutWidget, &LayoutWidget::visibleWidgetCountChanged, this,
             &MainWindowBase::frameCountChanged);
+
+    connect(this, &MainWindowBase::centralWidgetResized, this, [this] {
+        d->updateOverlayedDockWidgetGeometries();
+    });
 }
 
 MainWindowBase::~MainWindowBase()
@@ -636,8 +647,7 @@ void MainWindowBase::setUniqueName(const QString &uniqueName)
 
 void MainWindowBase::onResized(QResizeEvent *)
 {
-    if (d->m_overlayedDockWidget)
-        d->updateOverlayGeometry(d->m_overlayedDockWidget->d->frame()->QWidgetAdapter::size());
+    d->updateOverlayedDockWidgetGeometries();
 }
 
 bool MainWindowBase::deserialize(const LayoutSaver::MainWindow &mw)

src/MainWindowBase.h

@@ -225,6 +225,9 @@ Q_SIGNALS:
     /// can be tabbed together, in which case this signal isn't emitted.
     void frameCountChanged(int);
 
+    /// @brief emitted when the MainWindow::centralWidget() changes size
+    void centralWidgetResized(QSize oldSize, QSize newSize);
+
 private:
     class Private;
     Private *const d;