qml: Wire up some events for DockWidget

Some events like QEvent::Show, Hide and Close are for QWidget only,
so we have to synthetize them, as KDDW expects them

src/private/quick/DockWidgetQuick.cpp

@@ -13,6 +13,8 @@
 
 #include <Config.h>
 #include <QQuickItem>
+#include <QCloseEvent>
+
 /**
  * @file
  * @brief Represents a dock widget.
@@ -62,8 +64,7 @@ void DockWidgetQuick::setWidget(const QString &qmlFilename)
     DockWidgetBase::setWidget(adapter);
 }
 
-/* TODO_QUICK
-bool DockWidget::event(QEvent *e)
+bool DockWidgetQuick::event(QEvent *e)
 {
     if (e->type() == QEvent::ParentChange) {
         onParentChanged();
@@ -71,13 +72,9 @@ bool DockWidget::event(QEvent *e)
         onShown(e->spontaneous());
     } else if (e->type() == QEvent::Hide) {
         onHidden(e->spontaneous());
+    } else if (e->type() == QEvent::Close) {
+        onClosed(static_cast<QCloseEvent*>(e));
     }
 
-    return QWidget::event(e);
+    return DockWidgetBase::event(e);
 }
-
-void DockWidget::closeEvent(QCloseEvent *e)
-{
-    onClosed(e);
-}
-*/

src/private/quick/DockWidgetQuick.h

@@ -54,6 +54,9 @@ public:
     /// Similar to DockWidgetBase::setWidget(QQuickItem*)
     void setWidget(const QString &qmlFilename);
 
+protected:
+    bool event(QEvent *e) override;
+
 private:
     class Private;
     Private *const d;

src/private/quick/QWidgetAdapter_quick.cpp

@@ -66,10 +66,20 @@ void QWidgetAdapter::itemChange(QQuickItem::ItemChange change, const QQuickItem:
 {
     QQuickItem::itemChange(change, data);
 
-    if (change == QQuickItem::ItemParentHasChanged) {
-        // Emulate the QWidget behaviour as QQuickItem doesn't emit parentChange event.
+    // Emulate the QWidget behaviour as QQuickItem doesn't receive some QEvents.
+    switch (change) {
+    case QQuickItem::ItemVisibleHasChanged: {
         QEvent ev(QEvent::ParentChange);
         event(&ev);
+        break;
+    }
+    case QQuickItem::ItemParentHasChanged: {
+        QEvent ev(isVisible() ? QEvent::Show : QEvent::Hide);
+        event(&ev);
+        break;
+    }
+    default:
+        break;
     }
 }