Add the possibility of setting the margin used for overlay docks

(cherry-picked from commit 9b8759c472)

src/controllers/MainWindow.cpp

@@ -128,6 +128,7 @@ public:
     Controllers::DockWidget *m_persistentCentralDockWidget = nullptr;
     KDBindings::ScopedConnection m_visibleWidgetCountConnection;
     const bool m_supportsAutoHide;
+    int m_overlayMargin = 1;
 };
 
 MainWindow::MainWindow(View *view, const QString &uniqueName, MainWindowOptions options)
@@ -299,7 +300,7 @@ QRect MainWindow::Private::rectForOverlay(Controllers::Frame *frame, SideBarLoca
     const QMargins centerWidgetMargins = q->centerWidgetMargins();
 
     QRect rect;
-    const int margin = 1;
+    const int margin = m_overlayMargin;
     switch (location) {
     case SideBarLocation::North:
     case SideBarLocation::South: {
@@ -842,3 +843,18 @@ QRect MainWindow::centralAreaGeometry() const
     auto v = dynamic_cast<Views::MainWindowViewInterface *>(view());
     return v->centralAreaGeometry();
 }
+
+int MainWindow::overlayMargin() const
+{
+    return d->m_overlayMargin;
+}
+
+void MainWindow::setOverlayMargin(int margin)
+{
+    if (margin == d->m_overlayMargin)
+        return;
+
+
+    d->m_overlayMargin = margin;
+    Q_EMIT overlayMarginChanged(margin);
+}

src/controllers/MainWindow.h

@@ -187,6 +187,13 @@ public:
     /// if all dock widgets were closed (0 or more)
     bool closeDockWidgets(bool force = false);
 
+    /// @brief Returns the margin used by overlay docks. Default: 1
+    int overlayMargin() const;
+
+    /// @brief Sets the margin used by overlay docks.
+    /// Does not modify currently overlayed docks
+    void setOverlayMargin(int margin);
+
     /// @brief Sets the content's margins
     void setContentsMargins(int, int, int, int);
 
@@ -229,6 +236,8 @@ Q_SIGNALS:
     /// can be tabbed together, in which case this signal isn't emitted.
     void frameCountChanged(int);
 
+    void overlayMarginChanged(int margin);
+
 private:
     void init(const QString &name);