diff options
| -rw-r--r-- | src/corelib/global/qnamespace.h | 3 | ||||
| -rw-r--r-- | src/corelib/global/qnamespace.qdoc | 16 | ||||
| -rw-r--r-- | src/gui/kernel/qhighdpiscaling.cpp | 36 |
3 files changed, 40 insertions, 15 deletions
diff --git a/src/corelib/global/qnamespace.h b/src/corelib/global/qnamespace.h index de8a17fa51..c4f5415a01 100644 --- a/src/corelib/global/qnamespace.h +++ b/src/corelib/global/qnamespace.h @@ -496,7 +496,8 @@ public: AA_UseSoftwareOpenGL = 17, AA_ShareOpenGLContexts = 18, AA_SetPalette = 19, - AA_NoHighDpiScaling = 20, + AA_EnableHighDpiScaling = 20, + AA_DisableHighDpiScaling = 21, // Add new attributes before this line AA_AttributeCount diff --git a/src/corelib/global/qnamespace.qdoc b/src/corelib/global/qnamespace.qdoc index 443eae5a11..e789daafbd 100644 --- a/src/corelib/global/qnamespace.qdoc +++ b/src/corelib/global/qnamespace.qdoc @@ -200,10 +200,22 @@ \value AA_SetPalette Indicates whether a palette was explicitly set on the QApplication/QGuiApplication. This value has been added in Qt 5.5. - \value AA_NoHighDpiScaling Disables all high-DPI scaling in Qt, exposing window + \value AA_EnableHighDpiScaling. Enables high-DPI scaling in Qt on supported + platforms (see also \l{High DPI Displays}). Supported platforms are + X11, Windows and Android. Enabling makes Qt scale the main (device + independent) coordinate system according to display scale factors + provided by the operating system. This corresponds to setting the + QT_AUTO_SCREEN_SCALE_FACTOR environment variable to 1. This value + has been added in Qt 5.6. This attribute must be set before + Q(Gui)Application is constructed. + + \value AA_DisableHighDpiScaling Disables high-DPI scaling in Qt, exposing window system coordinates. Note that the window system may do its own scaling, so this does not guarantee that QPaintDevice::devicePixelRatio() will - be equal to 1. This value has been added in Qt 5.6. + be equal to 1. In addition, scale factors set by QT_SCALE_FACTOR will not + be affected. This corresponds to setting the QT_AUTO_SCREEN_SCALE_FACTOR + environment variable to 0. This value has been added in Qt 5.6. This + attribute must be set before Q(Gui)Application is constructed. The following values are obsolete: diff --git a/src/gui/kernel/qhighdpiscaling.cpp b/src/gui/kernel/qhighdpiscaling.cpp index daba9f94a1..a002b8c48d 100644 --- a/src/gui/kernel/qhighdpiscaling.cpp +++ b/src/gui/kernel/qhighdpiscaling.cpp @@ -49,7 +49,7 @@ static const char scaleFactorEnvVar[] = "QT_SCALE_FACTOR"; static const char autoScreenEnvVar[] = "QT_AUTO_SCREEN_SCALE_FACTOR"; static const char screenFactorsEnvVar[] = "QT_SCREEN_SCALE_FACTORS"; -static inline qreal initialScaleFactor() +static inline qreal initialGlobalScaleFactor() { qreal result = 1; @@ -134,19 +134,31 @@ QDpi QHighDpiScaling::m_logicalDpi = QDpi(-1,-1); // The scaled logical DPI of t Initializes the QHighDpiScaling global variables. Called before the platform plugin is created. */ -void QHighDpiScaling::initHighDpiScaling() + +static inline bool usePixelDensity() { - if (QCoreApplication::testAttribute(Qt::AA_NoHighDpiScaling)) { - m_factor = 1; - m_active = false; - return; - } - m_factor = initialScaleFactor(); - bool usePlatformPluginPixelDensity = qEnvironmentVariableIsSet(autoScreenEnvVar) - || qgetenv(legacyDevicePixelEnvVar).toLower() == "auto"; + // Determine if we should set a scale factor based on the pixel density + // reported by the platform plugin. There are several enablers and several + // disablers. A single disable may veto all other enablers. + if (QCoreApplication::testAttribute(Qt::AA_DisableHighDpiScaling)) + return false; + bool screenEnvValueOk; + const int screenEnvValue = qEnvironmentVariableIntValue(autoScreenEnvVar, &screenEnvValueOk); + if (screenEnvValueOk && screenEnvValue < 1) + return false; + return QCoreApplication::testAttribute(Qt::AA_EnableHighDpiScaling) + || (screenEnvValueOk && screenEnvValue > 0) + || (qEnvironmentVariableIsSet(legacyDevicePixelEnvVar) && qgetenv(legacyDevicePixelEnvVar).toLower() == "auto"); +} +void QHighDpiScaling::initHighDpiScaling() +{ + // Determine if there is a global scale factor set. + m_factor = initialGlobalScaleFactor(); m_globalScalingActive = !qFuzzyCompare(m_factor, qreal(1)); - m_usePixelDensity = usePlatformPluginPixelDensity; + + m_usePixelDensity = usePixelDensity(); + m_pixelDensityScalingActive = false; //set in updateHighDpiScaling below // we update m_active in updateHighDpiScaling, but while we create the @@ -156,7 +168,7 @@ void QHighDpiScaling::initHighDpiScaling() void QHighDpiScaling::updateHighDpiScaling() { - if (QCoreApplication::testAttribute(Qt::AA_NoHighDpiScaling)) + if (QCoreApplication::testAttribute(Qt::AA_DisableHighDpiScaling)) return; if (m_usePixelDensity && !m_pixelDensityScalingActive) { |