From 3965d808c086af9a4e4740ab2c7efe1a7ef6cb01 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Morten=20S=C3=B8rvig?= Date: Fri, 3 Mar 2023 16:00:47 +0100 Subject: [PATCH] QWindow: Cache the devicePixelRatio value MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Make each QWindow instance cache the current DPR value. This will make calling QWindow::devicePixelRatio() less costly, since it now does not have to compute the DPR value on each call. The cache is invalidated when the DevicePixelRatioChange event is sent. The common logic for handling this is implemented in QWindowPrivate::updateDevicePixelRatio(). Change-Id: I97231a230347358d8e565d2fd62e8a398adaedfc Reviewed-by: Tor Arne Vestbø --- src/gui/kernel/qguiapplication.cpp | 13 ++---------- src/gui/kernel/qwindow.cpp | 33 +++++++++++++++++++++--------- src/gui/kernel/qwindow_p.h | 3 +++ 3 files changed, 28 insertions(+), 21 deletions(-) diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp index d26de0b07cb..422c6ee8f69 100644 --- a/src/gui/kernel/qguiapplication.cpp +++ b/src/gui/kernel/qguiapplication.cpp @@ -2565,8 +2565,6 @@ void QGuiApplicationPrivate::processWindowScreenChangedEvent(QWindowSystemInterf if (window->screen() == wse->screen.data()) return; - const qreal oldDevicePixelRatio = window->screen() ? window->screen()->devicePixelRatio() : 1.0; - if (QWindow *topLevelWindow = window->d_func()->topLevelWindow(QWindow::ExcludeTransients)) { if (QScreen *screen = wse->screen.data()) topLevelWindow->d_func()->setTopLevelScreen(screen, false /* recreate */); @@ -2583,12 +2581,7 @@ void QGuiApplicationPrivate::processWindowScreenChangedEvent(QWindowSystemInterf processGeometryChangeEvent(&gce); } #endif - - const qreal newDevicePixelRatio = window->screen() ? window->screen()->devicePixelRatio() : 1.0; - if (!qFuzzyCompare(oldDevicePixelRatio, newDevicePixelRatio)) { - QEvent dprChangeEvent(QEvent::DevicePixelRatioChange); - QGuiApplication::sendSpontaneousEvent(window, &dprChangeEvent); - } + QWindowPrivate::get(window)->updateDevicePixelRatio(); } } @@ -2596,9 +2589,7 @@ void QGuiApplicationPrivate::processWindowDevicePixelRatioChangedEvent(QWindowSy { if (wde->window.isNull()) return; - - QEvent dprChangeEvent(QEvent::DevicePixelRatioChange); - QGuiApplication::sendSpontaneousEvent(wde->window, &dprChangeEvent); + QWindowPrivate::get(wde->window)->updateDevicePixelRatio(); } void QGuiApplicationPrivate::processSafeAreaMarginsChangedEvent(QWindowSystemInterfacePrivate::SafeAreaMarginsChangedEvent *wse) diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp index 2f775ec6648..81a4469a9ef 100644 --- a/src/gui/kernel/qwindow.cpp +++ b/src/gui/kernel/qwindow.cpp @@ -213,8 +213,10 @@ void QWindowPrivate::init(QScreen *targetScreen) isWindow = true; parentWindow = static_cast(q->QObject::parent()); + QScreen *connectScreen = targetScreen ? targetScreen : QGuiApplication::primaryScreen(); + if (!parentWindow) - connectToScreen(targetScreen ? targetScreen : QGuiApplication::primaryScreen()); + connectToScreen(connectScreen); // If your application aborts here, you are probably creating a QWindow // before the screen list is populated. @@ -224,6 +226,7 @@ void QWindowPrivate::init(QScreen *targetScreen) QGuiApplicationPrivate::window_list.prepend(q); requestedFormat = QSurfaceFormat::defaultFormat(); + devicePixelRatio = connectScreen->devicePixelRatio(); } /*! @@ -505,8 +508,6 @@ void QWindowPrivate::create(bool recursive, WId nativeHandle) // the platformWindow, if there was one, is now gone, so make this flag reflect reality now updateRequestPending = false; - const qreal currentDevicePixelRatio = q->devicePixelRatio(); - if (q->parent()) q->parent()->create(); @@ -552,10 +553,7 @@ void QWindowPrivate::create(bool recursive, WId nativeHandle) QPlatformSurfaceEvent e(QPlatformSurfaceEvent::SurfaceCreated); QGuiApplication::sendEvent(q, &e); - if (!qFuzzyCompare(currentDevicePixelRatio, q->devicePixelRatio())) { - QEvent dprChangeEvent(QEvent::DevicePixelRatioChange); - QGuiApplication::sendEvent(q, &dprChangeEvent); - } + updateDevicePixelRatio(); if (needsUpdate) q->requestUpdate(); @@ -1333,14 +1331,29 @@ Qt::ScreenOrientation QWindow::contentOrientation() const qreal QWindow::devicePixelRatio() const { Q_D(const QWindow); + return d->devicePixelRatio; +} + +/* + Updates the cached devicePixelRatio value by polling for a new value. + Sends QEvent::DevicePixelRatioChange to the window if the DPR has changed. +*/ +void QWindowPrivate::updateDevicePixelRatio() +{ + Q_Q(QWindow); // If there is no platform window use the associated screen's devicePixelRatio, // which typically is the primary screen and will be correct for single-display // systems (a very common case). - if (!d->platformWindow) - return screen()->devicePixelRatio(); + const qreal newDevicePixelRatio = platformWindow ? + platformWindow->devicePixelRatio() * QHighDpiScaling::factor(q) : q->screen()->devicePixelRatio(); - return d->platformWindow->devicePixelRatio() * QHighDpiScaling::factor(this); + if (newDevicePixelRatio == devicePixelRatio) + return; + + devicePixelRatio = newDevicePixelRatio; + QEvent dprChangeEvent(QEvent::DevicePixelRatioChange); + QGuiApplication::sendEvent(q, &dprChangeEvent); } Qt::WindowState QWindowPrivate::effectiveState(Qt::WindowStates state) diff --git a/src/gui/kernel/qwindow_p.h b/src/gui/kernel/qwindow_p.h index ef633d093a1..96beb17becf 100644 --- a/src/gui/kernel/qwindow_p.h +++ b/src/gui/kernel/qwindow_p.h @@ -89,6 +89,8 @@ public: void setAutomaticPositionAndResizeEnabled(bool a) { positionAutomatic = resizeAutomatic = a; } + void updateDevicePixelRatio(); + static QWindowPrivate *get(QWindow *window) { return window->d_func(); } static Qt::WindowState effectiveState(Qt::WindowStates); @@ -106,6 +108,7 @@ public: QString windowFilePath; QIcon windowIcon; QRect geometry; + qreal devicePixelRatio = 1.0; Qt::WindowStates windowState = Qt::WindowNoState; QWindow::Visibility visibility = QWindow::Hidden; bool resizeEventPending = true;