qtquick: Implement the rubber band

When hovering a drop indicator we now see the blue rubberband

src/CMakeLists.txt

@@ -92,6 +92,7 @@ if(${PROJECT_NAME}_QTQUICK)
       private/quick/TitleBarQuick.cpp
       private/quick/QmlTypes.cpp
       private/quick/FrameQuick.cpp
+      private/quick/RubberBandQuick.cpp
       private/quick/MainWindowQuick.cpp
       private/quick/MainWindowWrapper.cpp
       )

src/FrameworkWidgetFactory.cpp

@@ -37,6 +37,7 @@
 # include "quick/FrameQuick_p.h"
 # include "quick/TitleBarQuick_p.h"
 # include "quick/FloatingWindowQuick_p.h"
+# include "quick/RubberBandQuick.h"
 # include "multisplitter/Separator_quick.h"
 #endif
 
@@ -199,7 +200,7 @@ Layouting::Separator *DefaultWidgetFactory::createSeparator(Layouting::Widget *p
 
 QWidgetOrQuick *DefaultWidgetFactory::createRubberBand(QWidgetOrQuick *parent) const
 {
-    return new QWidgetOrQuick(parent);
+    return new RubberBandQuick(parent);
 }
 
 SideBar *DefaultWidgetFactory::createSideBar(SideBarLocation loc, MainWindowBase *parent) const

src/kddockwidgets_qtquick.qrc

@@ -4,6 +4,7 @@
         <file>private/quick/qml/DropArea.qml</file>
         <file>private/quick/qml/FloatingWindow.qml</file>
         <file>private/quick/qml/Frame.qml</file>
+        <file>private/quick/qml/RubberBand.qml</file>
         <file>private/quick/qml/TitleBarBase.qml</file>
         <file>private/quick/qml/TitleBar.qml</file>
         <file>private/quick/qml/TitleBarButton.qml</file>

src/private/quick/RubberBandQuick.cpp

@@ -0,0 +1,25 @@
+/*
+  This file is part of KDDockWidgets.
+
+  SPDX-FileCopyrightText: 2019-2020 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.com>
+  Author: Sérgio Martins <sergio.martins@kdab.com>
+
+  SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only
+
+  Contact KDAB at <info@kdab.com> for commercial licensing options.
+*/
+
+#include "RubberBandQuick.h"
+#include "Config.h"
+
+using namespace KDDockWidgets;
+
+RubberBandQuick::RubberBandQuick(QQuickItem *parent)
+    : QWidgetAdapter(parent)
+{
+    setVisible(false);
+    setZ(1000);
+    QQuickItem *visualItem = createItem(Config::self().qmlEngine(), QStringLiteral("qrc:/kddockwidgets/private/quick/qml/RubberBand.qml"));
+    visualItem->setParent(this);
+    visualItem->setParentItem(this);
+}

src/private/quick/RubberBandQuick.h

@@ -0,0 +1,29 @@
+/*
+  This file is part of KDDockWidgets.
+
+  SPDX-FileCopyrightText: 2019-2020 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.com>
+  Author: Sérgio Martins <sergio.martins@kdab.com>
+
+  SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only
+
+  Contact KDAB at <info@kdab.com> for commercial licensing options.
+*/
+
+#ifndef KDDOCKWIDGETS_RUBBERBAND_H
+#define KDDOCKWIDGETS_RUBBERBAND_H
+
+#include "QWidgetAdapter.h"
+
+namespace KDDockWidgets
+{
+
+class RubberBandQuick : public QWidgetAdapter
+{
+    Q_OBJECT
+public:
+    explicit RubberBandQuick(QQuickItem *parent = nullptr);
+};
+
+}
+
+#endif

src/private/quick/qml/RubberBand.qml

@@ -0,0 +1,25 @@
+/*
+  This file is part of KDDockWidgets.
+
+  SPDX-FileCopyrightText: 2019-2020 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.com>
+  Author: Sérgio Martins <sergio.martins@kdab.com>
+
+  SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only
+
+  Contact KDAB at <info@kdab.com> for commercial licensing options.
+*/
+
+import QtQuick 2.9
+
+Rectangle {
+    id: root
+    color: "#555ca1c5"
+
+    radius: 1
+    border {
+        color: "#5ca1c5"
+        width: 1
+    }
+
+    anchors.fill: parent
+}