QHighDpi: window geometry scaling functions

Add functions which scales window geometry:

	framNativeWindowGeometry()
	toNativeWindowGeometry()

These correctly handles top-level and child windows,
where top-level window positions scale around the screen
origin while child window positions scale around (0, 0).

Modify call cites to use the new functions. We no longer
need the isTopLevel checks at the call site.

Change-Id: I0158672d46a3f52dfc7d37d021fc5cebd7859200
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

src/gui/kernel/qhighdpiscaling_p.h

@@ -279,6 +279,22 @@ T toNativeGlobalPosition(const T &value, const C *context)
     return scale(value, so.factor, so.origin);
 }
 
+template <typename T, typename C>
+T fromNativeWindowGeometry(const T &value, const C *context)
+{
+    QHighDpiScaling::ScaleAndOrigin so = QHighDpiScaling::scaleAndOrigin(context);
+    QPoint effectiveOrigin = (context && context->isTopLevel()) ? so.origin : QPoint(0,0);
+    return scale(value, qreal(1) / so.factor, effectiveOrigin);
+}
+
+template <typename T, typename C>
+T toNativeWindowGeometry(const T &value, const C *context)
+{
+    QHighDpiScaling::ScaleAndOrigin so = QHighDpiScaling::scaleAndOrigin(context);
+    QPoint effectiveOrigin = (context && context->isTopLevel()) ? so.origin : QPoint(0,0);
+    return scale(value, so.factor, effectiveOrigin);
+}
+
 template <typename T>
 inline T fromNative(const T &value, qreal scaleFactor, QPoint origin = QPoint(0, 0))
 {

src/gui/kernel/qplatformwindow.cpp

@@ -849,7 +849,7 @@ QSize QPlatformWindow::windowSizeIncrement() const
 */
 QRect QPlatformWindow::windowGeometry() const
 {
-    return QHighDpi::toNativePixels(window()->geometry(), window());
+    return QHighDpi::toNativeWindowGeometry(window()->geometry(), window());
 }
 
 /*!
@@ -857,7 +857,7 @@ QRect QPlatformWindow::windowGeometry() const
 */
 QRect QPlatformWindow::windowFrameGeometry() const
 {
-    return QHighDpi::toNativePixels(window()->frameGeometry(), window());
+    return QHighDpi::toNativeWindowGeometry(window()->frameGeometry(), window());
 }
 
 /*!
@@ -868,10 +868,10 @@ QRect QPlatformWindow::windowFrameGeometry() const
 
 QRectF QPlatformWindow::closestAcceptableGeometry(const QWindow *qWindow, const QRectF &nativeRect)
 {
-    const QRectF rectF = QHighDpi::fromNativePixels(nativeRect, qWindow);
+    const QRectF rectF = QHighDpi::fromNativeWindowGeometry(nativeRect, qWindow);
     const QRectF correctedGeometryF = qt_window_private(const_cast<QWindow *>(qWindow))->closestAcceptableGeometry(rectF);
     return !correctedGeometryF.isEmpty() && rectF != correctedGeometryF
-        ? QHighDpi::toNativePixels(correctedGeometryF, qWindow) : nativeRect;
+        ? QHighDpi::toNativeWindowGeometry(correctedGeometryF, qWindow) : nativeRect;
 }
 
 QRectF QPlatformWindow::windowClosestAcceptableGeometry(const QRectF &nativeRect) const

src/gui/kernel/qwindow.cpp

@@ -1784,9 +1784,7 @@ QRect QWindow::geometry() const
     Q_D(const QWindow);
     if (d->platformWindow) {
         const auto nativeGeometry = d->platformWindow->geometry();
-        return isTopLevel()
-            ? QHighDpi::fromNativePixels(nativeGeometry, this)
-            : QHighDpi::fromNativeLocalPosition(nativeGeometry, this);
+        return QHighDpi::fromNativeWindowGeometry(nativeGeometry, this);
     }
     return d->geometry;
 }
@@ -1816,7 +1814,7 @@ QRect QWindow::frameGeometry() const
     Q_D(const QWindow);
     if (d->platformWindow) {
         QMargins m = frameMargins();
-        return QHighDpi::fromNativePixels(d->platformWindow->geometry(), this).adjusted(-m.left(), -m.top(), m.right(), m.bottom());
+        return QHighDpi::fromNativeWindowGeometry(d->platformWindow->geometry(), this).adjusted(-m.left(), -m.top(), m.right(), m.bottom());
     }
     return d->geometry;
 }
@@ -1833,7 +1831,7 @@ QPoint QWindow::framePosition() const
     Q_D(const QWindow);
     if (d->platformWindow) {
         QMargins margins = frameMargins();
-        return QHighDpi::fromNativePixels(d->platformWindow->geometry().topLeft(), this) - QPoint(margins.left(), margins.top());
+        return QHighDpi::fromNativeWindowGeometry(d->platformWindow->geometry().topLeft(), this) - QPoint(margins.left(), margins.top());
     }
     return d->geometry.topLeft();
 }
@@ -1851,7 +1849,7 @@ void QWindow::setFramePosition(const QPoint &point)
     d->positionPolicy = QWindowPrivate::WindowFrameInclusive;
     d->positionAutomatic = false;
     if (d->platformWindow) {
-        d->platformWindow->setGeometry(QHighDpi::toNativePixels(QRect(point, size()), this));
+        d->platformWindow->setGeometry(QHighDpi::toNativeWindowGeometry(QRect(point, size()), this));
     } else {
         d->geometry.moveTopLeft(point);
     }

src/gui/kernel/qwindowsysteminterface.cpp

@@ -300,18 +300,14 @@ QWindowSystemInterfacePrivate::GeometryChangeEvent::GeometryChangeEvent(QWindow
 {
     if (const QPlatformWindow *pw = window->handle()) {
         const auto nativeGeometry = pw->QPlatformWindow::geometry();
-        requestedGeometry = window->isTopLevel()
-            ? QHighDpi::fromNativePixels(nativeGeometry, window)
-            : QHighDpi::fromNativeLocalPosition(nativeGeometry, window);
+        requestedGeometry = QHighDpi::fromNativeWindowGeometry(nativeGeometry, window);
     }
 }
 
 QT_DEFINE_QPA_EVENT_HANDLER(void, handleGeometryChange, QWindow *window, const QRect &newRect)
 {
     Q_ASSERT(window);
-    const auto newRectDi = window->isTopLevel()
-        ? QHighDpi::fromNativePixels(newRect, window)
-        : QHighDpi::fromNativeLocalPosition(newRect, window);
+    const auto newRectDi = QHighDpi::fromNativeWindowGeometry(newRect, window);
     auto e = new QWindowSystemInterfacePrivate::GeometryChangeEvent(window, newRectDi);
     if (window->handle()) {
         // Persist the new geometry so that QWindow::geometry() can be queried in the resize event

src/platformsupport/input/evdevtouch/qevdevtouchhandler.cpp

@@ -720,7 +720,7 @@ QRect QEvdevTouchScreenData::screenGeometry() const
 {
     if (m_forceToActiveWindow) {
         QWindow *win = QGuiApplication::focusWindow();
-        return win ? QHighDpi::toNativePixels(win->geometry(), win) : QRect();
+        return win ? QHighDpi::toNativeWindowGeometry(win->geometry(), win) : QRect();
     }
 
     // Now it becomes tricky. Traditionally we picked the primaryScreen()