From a705b4ec1f6f7133390054f8b6b8077ef0550311 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Morten=20Johan=20S=C3=B8rvig?= Date: Mon, 22 Jun 2015 12:32:11 +0200 Subject: Introduce cross platform high-dpi scaling Add a coordinate scaling layer to QtGui, which supports 'devicePixelRatio' type high-dpi on all platforms, in production and also for development and testing purposes. High-DPI scaling is opt-in, by setting environment variables: QT_SCALE_FACTOR - sets a global scale factor QT_AUTO_SCREEN_SCALE_FACTOR - sets per-screen scale factors, where the scale factors are provided by the platform plugin. This QtGui scaling can be used instead of or in addition to scaling done by the window system. This distinction is not visible to applications [when they use Qt API], which will see a change in the value returned by the devicePixelRatio() accessors as usual. Introduce a new (private to Qt) coordinate system: native pixels. The coordinate system stack now looks like: device-independent pixels (app, upper parts of Qt) native pixels (lower parts of Qt Gui, platform plugins) device pixels (backing stores and OpenGL) Add private QHighDpi namespace with scaling functions that convert between device-independent pixels and native pixels: T toNativePixels(T, QWindow *); T fromNativePixels(T, QWindow *); Add scaling calls the QWindow (and friends) cross-platform implementation, around the calls to QPlatformWindow functions. QPlatformWindow now uses native coordinates - platform code remains largely unchanged since native coordinates are window system coordinates. QWindow now uses (possibly) scaled coordinates. This means that platform plugins no longer can rely on QWindow::geometry() and related functions. QPlatformWindow::windowGeometry() and other convenience functions have been added for use when the platform plugin needs to convert scaled geometry to native geometry. Add Qt::AA_NoHighDpiScaling, which can be use to disable any scaling in QtGui, effectively ignoring the environment variables. (Note that this does not disable any scaling done by the window system.) Contributions from Friedemann and Paul. Task-number: QTBUG-46615 Change-Id: I673bbd69c130e73b13cce83be11bfb28f580bf60 Reviewed-by: Lars Knoll --- src/gui/kernel/qplatformscreen.cpp | 57 ++++++++++++++++++++++++++++++++++---- 1 file changed, 51 insertions(+), 6 deletions(-) (limited to 'src/gui/kernel/qplatformscreen.cpp') diff --git a/src/gui/kernel/qplatformscreen.cpp b/src/gui/kernel/qplatformscreen.cpp index 9aab102de3..2fb53fe16b 100644 --- a/src/gui/kernel/qplatformscreen.cpp +++ b/src/gui/kernel/qplatformscreen.cpp @@ -40,6 +40,7 @@ #include #include #include +#include QT_BEGIN_NAMESPACE @@ -96,6 +97,23 @@ QWindow *QPlatformScreen::topLevelAt(const QPoint & pos) const return 0; } +/*! + Find the sibling screen corresponding to \a globalPos. + + Returns this screen if no suitable screen is found at the position. + */ +const QPlatformScreen *QPlatformScreen::screenForPosition(const QPoint &point) const +{ + if (!geometry().contains(point)) { + Q_FOREACH (const QPlatformScreen* screen, virtualSiblings()) { + if (screen->geometry().contains(point)) + return screen; + } + } + return this; +} + + /*! Returns a list of all the platform screens that are part of the same virtual desktop. @@ -156,17 +174,37 @@ QDpi QPlatformScreen::logicalDpi() const } /*! - Reimplement this function in subclass to return the device pixel - ratio for the screen. This is the ratio between physical pixels - and device-independent pixels. + Reimplement this function in subclass to return the device pixel ratio + for the screen. This is the ratio between physical pixels and the + device-independent pixels of the windowing system. The default + implementation returns 1.0. - \sa QPlatformWindow::devicePixelRatio(); + \sa QPlatformWindow::devicePixelRatio() + \sa QPlatformScreen::pixelDensity() */ qreal QPlatformScreen::devicePixelRatio() const { return 1.0; } +/*! + Reimplement this function in subclass to return the pixel density of the + screen. This is the scale factor needed to make a low-dpi application + usable on this screen. The default implementation returns 1.0. + + Returning something else than 1.0 from this function causes Qt to + apply the scale factor to the application's coordinate system. + This is different from devicePixelRatio, which reports a scale + factor already applied by the windowing system. A platform plugin + typically implements one (or none) of these two functions. + + \sa QPlatformWindow::devicePixelRatio() +*/ +qreal QPlatformScreen::pixelDensity() const +{ + return 1.0; +} + /*! Reimplement this function in subclass to return the vertical refresh rate of the screen, in Hz. @@ -290,8 +328,8 @@ void QPlatformScreen::resizeMaximizedWindows() // 'screen()' still has the old geometry info while 'this' has the new geometry info const QRect oldGeometry = screen()->geometry(); const QRect oldAvailableGeometry = screen()->availableGeometry(); - const QRect newGeometry = geometry(); - const QRect newAvailableGeometry = availableGeometry(); + const QRect newGeometry = deviceIndependentGeometry(); + const QRect newAvailableGeometry = QHighDpi::fromNative(availableGeometry(), QHighDpiScaling::factor(this), newGeometry.topLeft()); // make sure maximized and fullscreen windows are updated for (int i = 0; i < windows.size(); ++i) { @@ -393,6 +431,13 @@ QRect QPlatformScreen::mapBetween(Qt::ScreenOrientation a, Qt::ScreenOrientation return rect; } +QRect QPlatformScreen::deviceIndependentGeometry() const +{ + qreal scaleFactor = QHighDpiScaling::factor(this); + QRect nativeGeometry = geometry(); + return QRect(nativeGeometry.topLeft(), QHighDpi::fromNative(nativeGeometry.size(), scaleFactor)); +} + /*! Returns a hint about this screen's subpixel layout structure. -- cgit v1.2.3