Enable making window-screen associations from QML

Qt Quick provides a Screen attached property to query information
about the screen an item's window belongs to. This is a good start,
but has two problems: it lacks some virtual desktop related info
(e.g. the position in the virtual desktop) and it cannot be used in
combination with the Window element in order to achieve a QML
equivalent of QWindow::setScreen().

Therefore add the missing virtualX and virtualY properties and
introduce Qt.application.screens. The latter is an equivalent to
QGuiApplication::screens() and is a JS array the elements of which
can be set as the value of the new Window.targetScreen property.

This means that a call like
window->setScreen(QGuiApplication::screens()[0]) translates to
Window { targetScreen: Qt.application.screens[0]; ... } when using the
Window type from QML. Screen addition or removal can be acted upon via
onScreensChanged.

QQuickScreenAttached has been split into two in order to allow reusing the
QScreen wrapping queries for other purposes as well.

Task-number: QTBUG-56115
Change-Id: I4b2fbd873315b40d0afe878da2fc50966c00e2e0
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

1 files changed, 36 insertions, 12 deletions

diff --git a/src/quick/items/qquickscreen_p.h b/src/quick/items/qquickscreen_p.h
index 06d9a06070..06efb3ab45 100644
--- a/src/quick/items/qquickscreen_p.h
+++ b/src/quick/items/qquickscreen_p.h
@@ -63,10 +63,10 @@ class QQuickItem;
 class QQuickWindow;
 class QScreen;
 
-class Q_AUTOTEST_EXPORT QQuickScreenAttached : public QObject
+
+class Q_AUTOTEST_EXPORT QQuickScreenInfo : public QObject
 {
     Q_OBJECT
-
     Q_PROPERTY(QString name READ name NOTIFY nameChanged)
     Q_PROPERTY(int width READ width NOTIFY widthChanged)
     Q_PROPERTY(int height READ height NOTIFY heightChanged)
@@ -79,11 +79,12 @@ class Q_AUTOTEST_EXPORT QQuickScreenAttached : public QObject
     Q_PROPERTY(Qt::ScreenOrientation primaryOrientation READ primaryOrientation NOTIFY primaryOrientationChanged)
     // TODO Qt 6 Remove this orientation -> incomplete device orientation -> better use OrientationSensor
     Q_PROPERTY(Qt::ScreenOrientation orientation READ orientation NOTIFY orientationChanged)
-    Q_PROPERTY(Qt::ScreenOrientations orientationUpdateMask READ orientationUpdateMask
-               WRITE setOrientationUpdateMask NOTIFY orientationUpdateMaskChanged)
+
+    Q_PROPERTY(int virtualX READ virtualX NOTIFY virtualXChanged REVISION 1)
+    Q_PROPERTY(int virtualY READ virtualY NOTIFY virtualYChanged REVISION 1)
 
 public:
-    QQuickScreenAttached(QObject* attachee);
+    QQuickScreenInfo(QObject *parent = nullptr);
 
     QString name() const;
     int width() const;
@@ -95,13 +96,11 @@ public:
     qreal devicePixelRatio() const;
     Qt::ScreenOrientation primaryOrientation() const;
     Qt::ScreenOrientation orientation() const;
-    Qt::ScreenOrientations orientationUpdateMask() const;
-    void setOrientationUpdateMask(Qt::ScreenOrientations mask);
+    int virtualX() const;
+    int virtualY() const;
 
-    //Treats int as Qt::ScreenOrientation, due to QTBUG-20639
-    Q_INVOKABLE int angleBetween(int a, int b);
-
-    void windowChanged(QQuickWindow*);
+    void setWrappedScreen(QScreen *screen);
+    QScreen *wrappedScreen() const;
 
 Q_SIGNALS:
     void nameChanged();
@@ -113,13 +112,37 @@ Q_SIGNALS:
     void devicePixelRatioChanged();
     void primaryOrientationChanged();
     void orientationChanged();
+    Q_REVISION(1) void virtualXChanged();
+    Q_REVISION(1) void virtualYChanged();
+
+protected:
+    QPointer<QScreen> m_screen;
+};
+
+class Q_AUTOTEST_EXPORT QQuickScreenAttached : public QQuickScreenInfo
+{
+    Q_OBJECT
+    Q_PROPERTY(Qt::ScreenOrientations orientationUpdateMask READ orientationUpdateMask
+               WRITE setOrientationUpdateMask NOTIFY orientationUpdateMaskChanged)
+
+public:
+    QQuickScreenAttached(QObject* attachee);
+
+    Qt::ScreenOrientations orientationUpdateMask() const;
+    void setOrientationUpdateMask(Qt::ScreenOrientations mask);
+
+    //Treats int as Qt::ScreenOrientation, due to QTBUG-20639
+    Q_INVOKABLE int angleBetween(int a, int b);
+
+    void windowChanged(QQuickWindow*);
+
+Q_SIGNALS:
     void orientationUpdateMaskChanged();
 
 protected Q_SLOTS:
     void screenChanged(QScreen*);
 
 private:
-    QPointer<QScreen> m_screen;
     QQuickWindow* m_window;
     QQuickItem* m_attachee;
     Qt::ScreenOrientations m_updateMask;
@@ -136,5 +159,6 @@ public:
 QT_END_NAMESPACE
 
 QML_DECLARE_TYPEINFO(QQuickScreen, QML_HAS_ATTACHED_PROPERTIES)
+QML_DECLARE_TYPE(QQuickScreenInfo)
 
 #endif