From f628977bd38954739187f504990e8e9d8f81e9fe Mon Sep 17 00:00:00 2001
From: Fushan Wen <qydwhotmail@gmail.com>
Date: Sun, 29 May 2022 19:08:17 +0800
Subject: [PATCH] Drop call to setPlatformScreen in
 QHighDpiScaling::setScreenFactor
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Drop call to setPlatformScreen since the only affected variables are
logicalDpi and geometry. Replace setPlatformScreen with updateLogicalDpi
which handles global scale factor changes in QScreen.

Call updateGeometriesWithSignals() to check if there are any changes
in geometry or availableGeometry, since the geometry or availableGeometry
can also change when setting a scale factor.

Move setPlatformScreen to QScreen ctor as the function is not used
elsewhere.

Change-Id: I7acf40bf0643e89a1d9177674d66dc503829f98f
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit 7b2ae3faab15913e006ece25d785e6a8453dd27a)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/gui/kernel/qhighdpiscaling.cpp |  3 +--
 src/gui/kernel/qplatformscreen.h   |  2 +-
 src/gui/kernel/qscreen.cpp         | 40 +++++++++++++++---------------
 src/gui/kernel/qscreen_p.h         |  2 +-
 4 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/src/gui/kernel/qhighdpiscaling.cpp b/src/gui/kernel/qhighdpiscaling.cpp
index 8d6bb625944..2f759158ee6 100644
--- a/src/gui/kernel/qhighdpiscaling.cpp
+++ b/src/gui/kernel/qhighdpiscaling.cpp
@@ -555,9 +555,8 @@ void QHighDpiScaling::setScreenFactor(QScreen *screen, qreal factor)
     else
         QHighDpiScaling::m_namedScreenScaleFactors.insert(name, factor);
 
-    // hack to force re-evaluation of screen geometry
     if (screen->handle())
-        screen->d_func()->setPlatformScreen(screen->handle()); // updates geometries based on scale factor
+        screen->d_func()->updateLogicalDpi();
 }
 
 QPoint QHighDpiScaling::mapPositionToNative(const QPoint &pos, const QPlatformScreen *platformScreen)
diff --git a/src/gui/kernel/qplatformscreen.h b/src/gui/kernel/qplatformscreen.h
index ca828171ff7..1d8e1036066 100644
--- a/src/gui/kernel/qplatformscreen.h
+++ b/src/gui/kernel/qplatformscreen.h
@@ -135,7 +135,7 @@ protected:
     QScopedPointer<QPlatformScreenPrivate> d_ptr;
 
 private:
-    friend class QScreenPrivate;
+    friend QScreen;
 };
 
 // Qt doesn't currently support running with no platform screen
diff --git a/src/gui/kernel/qscreen.cpp b/src/gui/kernel/qscreen.cpp
index 2b22816e3e6..cb4615e0ed1 100644
--- a/src/gui/kernel/qscreen.cpp
+++ b/src/gui/kernel/qscreen.cpp
@@ -41,7 +41,26 @@ QScreen::QScreen(QPlatformScreen *screen)
     : QObject(*new QScreenPrivate(), nullptr)
 {
     Q_D(QScreen);
-    d->setPlatformScreen(screen);
+    d->platformScreen = screen;
+    d->platformScreen->d_func()->screen = this;
+    d->orientation = d->platformScreen->orientation();
+
+    d->logicalDpi = QPlatformScreen::overrideDpi(d->platformScreen->logicalDpi());
+
+    d->refreshRate = d->platformScreen->refreshRate();
+    // safeguard ourselves against buggy platform behavior...
+    if (d->refreshRate < 1.0)
+        d->refreshRate = 60.0;
+
+    d->updateHighDpi();
+    d->updatePrimaryOrientation(); // derived from the geometry
+}
+
+void QScreenPrivate::updateLogicalDpi()
+{
+    Q_Q(QScreen);
+    logicalDpi = QPlatformScreen::overrideDpi(q->handle()->logicalDpi());
+    updateGeometriesWithSignals(); // updates geometries based on scale factor
 }
 
 void QScreenPrivate::updateGeometriesWithSignals()
@@ -71,25 +90,6 @@ void QScreenPrivate::emitGeometryChangeSignals(bool geometryChanged, bool availa
         emit q->physicalDotsPerInchChanged(q->physicalDotsPerInch());
 }
 
-void QScreenPrivate::setPlatformScreen(QPlatformScreen *screen)
-{
-    Q_Q(QScreen);
-    platformScreen = screen;
-    platformScreen->d_func()->screen = q;
-    orientation = platformScreen->orientation();
-
-    logicalDpi = QPlatformScreen::overrideDpi(platformScreen->logicalDpi());
-
-    refreshRate = platformScreen->refreshRate();
-    // safeguard ourselves against buggy platform behavior...
-    if (refreshRate < 1.0)
-        refreshRate = 60.0;
-
-    updateHighDpi();
-    updatePrimaryOrientation(); // derived from the geometry
-}
-
-
 /*!
     Destroys the screen.
  */
diff --git a/src/gui/kernel/qscreen_p.h b/src/gui/kernel/qscreen_p.h
index 1ba0c7c4421..9d7ab504b27 100644
--- a/src/gui/kernel/qscreen_p.h
+++ b/src/gui/kernel/qscreen_p.h
@@ -28,12 +28,12 @@ class QScreenPrivate : public QObjectPrivate
 {
     Q_DECLARE_PUBLIC(QScreen)
 public:
-    void setPlatformScreen(QPlatformScreen *screen);
     void updateHighDpi()
     {
         geometry = platformScreen->deviceIndependentGeometry();
         availableGeometry = QHighDpi::fromNative(platformScreen->availableGeometry(), QHighDpiScaling::factor(platformScreen), geometry.topLeft());
     }
+    void updateLogicalDpi();
 
     void updatePrimaryOrientation();
     void updateGeometriesWithSignals();