Differential D20607 Diff 56529 3rdparty/ext_qt/0034-Update-QT_SCREEN_SCALE_FACTORS.patch

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3rdparty/ext_qt/0034-Update-QT_SCREEN_SCALE_FACTORS.patch

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1​From f58ea52d89d9230ab9d441d96f6884044c4c686d Mon Sep 17 00:00:00 2001
2​From: Friedemann Kleint <Friedemann.Kleint@qt.io>
3​Date: Wed, 27 Feb 2019 08:46:47 +0100
4​Subject: [PATCH 34/36] Update QT_SCREEN_SCALE_FACTORS
5​MIME-Version: 1.0
6​Content-Type: text/plain; charset=UTF-8
7​Content-Transfer-Encoding: 8bit
8​
9​Store name->factor associations in a global QHash instead of on the
10​QScreen object, making them survive QScreen object deletion, for
11​example on disconnect/ connect cycles.
12​
13​Make factors set with QT_SCREEN_SCALE_FACTORS override the screen
14​factors computed from platform plugin DPI values. This matches the use
15​case for QT_SCREEN_SCALE_FACTORS (but not the general scale factors
16​combine by multiplication?rinciple)
17​
18​Done-with: Friedemann Kleint <Friedemann.Kleint@qt.io>
19​Task-number: QTBUG-53022
20​Change-Id: I12771249314ab0c073e609d62f57ac0d18d3b6ce
21​---
22​ src/gui/kernel/qhighdpiscaling.cpp | 62 ++++++++++++++++++++++--------
23​ src/gui/kernel/qhighdpiscaling_p.h | 2 +-
24​ 2 files changed, 47 insertions(+), 17 deletions(-)
25​
26​diff --git a/src/gui/kernel/qhighdpiscaling.cpp b/src/gui/kernel/qhighdpiscaling.cpp
27​index fc8084c45a..b1350599b7 100644
28​--- a/src/gui/kernel/qhighdpiscaling.cpp
29​+++ b/src/gui/kernel/qhighdpiscaling.cpp
30​@@ -61,6 +61,12 @@ static const char scaleFactorRoundingPolicyEnvVar[] = "QT_SCALE_FACTOR_ROUNDING_
31​ static const char dpiAdjustmentPolicyEnvVar[] = "QT_DPI_ADJUSTMENT_POLICY";
32​ static const char usePhysicalDpiEnvVar[] = "QT_USE_PHYSICAL_DPI";
33​
34​+// Per-screen scale factors for named screens set with QT_SCREEN_SCALE_FACTORS
35​+// are stored here. Use a global hash to keep the factor across screen
36​+// disconnect/connect cycles where the screen object may be deleted.
37​+typedef QHash<QString, qreal> QScreenScaleFactorHash;
38​+Q_GLOBAL_STATIC(QScreenScaleFactorHash, qNamedScreenScaleFactors);
39​+
40​ // Reads and interprets the given environment variable as a bool,
41​ // returns the default value if not set.
42​ static bool qEnvironmentVariableAsBool(const char *name, bool defaultValue)
43​@@ -478,20 +484,19 @@ void QHighDpiScaling::updateHighDpiScaling()
44​ int i = 0;
45​ const auto specs = qgetenv(screenFactorsEnvVar).split(';');
46​ for (const QByteArray &spec : specs) {
47​- QScreen *screen = 0;
48​ int equalsPos = spec.lastIndexOf('=');
49​- double factor = 0;
50​+ qreal factor = 0;
51​ if (equalsPos > 0) {
52​ // support "name=factor"
53​ QByteArray name = spec.mid(0, equalsPos);
54​ QByteArray f = spec.mid(equalsPos + 1);
55​ bool ok;
56​ factor = f.toDouble(&ok);
57​- if (ok) {
58​+ if (ok && factor > 0 ) {
59​ const auto screens = QGuiApplication::screens();
60​ for (QScreen *s : screens) {
61​ if (s->name() == QString::fromLocal8Bit(name)) {
62​- screen = s;
63​+ setScreenFactor(s, factor);
64​ break;
65​ }
66​ }
67​@@ -500,11 +505,11 @@ void QHighDpiScaling::updateHighDpiScaling()
68​ // listing screens in order
69​ bool ok;
70​ factor = spec.toDouble(&ok);
71​- if (ok && i < QGuiApplication::screens().count())
72​- screen = QGuiApplication::screens().at(i);
73​+ if (ok && factor > 0 && i < QGuiApplication::screens().count()) {
74​+ QScreen *screen = QGuiApplication::screens().at(i);
75​+ setScreenFactor(screen, factor);
76​+ }
77​ }
78​- if (screen)
79​- setScreenFactor(screen, factor);
80​ ++i;
81​ }
82​ }
83​@@ -540,7 +545,14 @@ void QHighDpiScaling::setScreenFactor(QScreen *screen, qreal factor)
84​ m_screenFactorSet = true;
85​ m_active = true;
86​ }
87​- screen->setProperty(scaleFactorProperty, QVariant(factor));
88​+
89​+ // Prefer associating the factor with screen name over the object
90​+ // since the screen object may be deleted on screen disconnects.
91​+ const QString name = screen->name();
92​+ if (!name.isEmpty())
93​+ qNamedScreenScaleFactors()->insert(name, factor);
94​+ else
95​+ screen->setProperty(scaleFactorProperty, QVariant(factor));
96​
97​ // hack to force re-evaluation of screen geometry
98​ if (screen->handle())
99​@@ -568,15 +580,33 @@ QPoint QHighDpiScaling::mapPositionFromNative(const QPoint &pos, const QPlatform
100​ qreal QHighDpiScaling::screenSubfactor(const QPlatformScreen *screen)
101​ {
102​ qreal factor = qreal(1.0);
103​- if (screen) {
104​- if (m_usePixelDensity)
105​- factor *= roundScaleFactor(rawScaleFactor(screen));
106​- if (m_screenFactorSet) {
107​- QVariant screenFactor = screen->screen()->property(scaleFactorProperty);
108​- if (screenFactor.isValid())
109​- factor *= screenFactor.toReal();
110​+ if (!screen)
111​+ return factor;
112​+
113​+ // Unlike the other code where factors are combined
114​+ // by multiplication, factors from QT_SCREEN_SCALE_FACTORS takes
115​+ // precedence over the factor computed from platform plugin
116​+ // DPI. The rationale is that the user is setting the factor
117​+ // to override erroneous DPI values.
118​+ bool screenPropertyUsed = false;
119​+ if (m_screenFactorSet) {
120​+ // Check if there is a factor set on the screen object or
121​+ // associated with the screen name. These are mutually
122​+ // exclusive, so checking order is not significant.
123​+ QVariant byIndex = screen->screen()->property(scaleFactorProperty);
124​+ auto byName = qNamedScreenScaleFactors()->find(screen->name());
125​+ if (byIndex.isValid()) {
126​+ screenPropertyUsed = true;
127​+ factor = byIndex.toReal();
128​+ } else if (byName != qNamedScreenScaleFactors()->end()) {
129​+ screenPropertyUsed = true;
130​+ factor = *byName;
131​ }
132​ }
133​+
134​+ if (!screenPropertyUsed && m_usePixelDensity)
135​+ factor = roundScaleFactor(rawScaleFactor(screen));
136​+
137​ return factor;
138​ }
139​
140​diff --git a/src/gui/kernel/qhighdpiscaling_p.h b/src/gui/kernel/qhighdpiscaling_p.h
141​index 55bddfeb88..d3f71854a8 100644
142​--- a/src/gui/kernel/qhighdpiscaling_p.h
143​+++ b/src/gui/kernel/qhighdpiscaling_p.h
144​@@ -101,7 +101,7 @@ public:
145​ static void initHighDpiScaling();
146​ static void updateHighDpiScaling();
147​ static void setGlobalFactor(qreal factor);
148​- static void setScreenFactor(QScreen *window, qreal factor);
149​+ static void setScreenFactor(QScreen *screen, qreal factor);
150​
151​ static bool isActive() { return m_active; }
152​ static qreal factor(const QWindow *window);
153​--
154​2.18.0.windows.1
155​