Add "Preffer color scheme" option

BUG: 439891
CCBUG: 497331

Signed-off-by: Juraj Oravec <jurajoravec@mailo.com>

src/lib/app/mainapplication.cpp

@@ -67,6 +67,8 @@
 #include <QRegularExpression>
 #include <QtWebEngineWidgetsVersion>
 #include <QtWebEngineCoreVersion>
+#include <QtGuiVersion>
+#include <QStyleHints>
 
 #include <QWebEngineNotification>
 #include <QWebEngineUrlScheme>
@@ -149,10 +151,6 @@ MainApplication::MainApplication(int &argc, char** argv)
     }
 #endif
 
-    QByteArray chromium_flags = qgetenv("QTWEBENGINE_CHROMIUM_FLAGS");
-    chromium_flags.append(" --enable-features=WebRTCPipeWireCapturer");
-    qputenv("QTWEBENGINE_CHROMIUM_FLAGS", chromium_flags);
-
     QUrl startUrl;
     QString startProfile;
     QStringList messages;
@@ -287,11 +285,8 @@ MainApplication::MainApplication(int &argc, char** argv)
     profileManager.initCurrentProfile(startProfile);
 
     Settings::createSettings(DataPaths::currentProfilePath() + QLatin1String("/settings.ini"));
-    if (Settings::globalSettings()->value("Web-Browser-Settings/hardwareAccel", false).toBool()) {
-	    chromium_flags.append(" --enable-oop-rasterization --enable-gpu-rasterization --enable-native-gpu-memory-buffers --use-gl=desktop");
-	    qputenv("QTWEBENGINE_CHROMIUM_FLAGS", chromium_flags);
-    }
 
+    setChromiumFlags();
     NetworkManager::registerSchemes();
     registerAllowedSchemes();
 
@@ -412,6 +407,33 @@ MainApplication::~MainApplication()
     Settings::syncSettings();
 }
 
+void MainApplication::setChromiumFlags()
+{
+    QByteArray chromium_flags = qgetenv("QTWEBENGINE_CHROMIUM_FLAGS");
+    chromium_flags.append(" --enable-features=WebRTCPipeWireCapturer");
+
+    if (Settings::globalSettings()->value("Web-Browser-Settings/hardwareAccel", false).toBool()) {
+        chromium_flags.append(" --enable-oop-rasterization --enable-gpu-rasterization --enable-native-gpu-memory-buffers --use-gl=desktop");
+    }
+
+    int prefferColorScheme = Settings::globalSettings()->value("Web-Browser-Settings/prefferColorScheme", Qz::ColorScheme_Auto).toInt();
+    if (   (prefferColorScheme == Qz::ColorScheme_Dark)
+#if QTGUI_VERSION >= QT_VERSION_CHECK(6, 5, 0)
+        || ((prefferColorScheme == Qz::ColorScheme_Auto) && (styleHints()->colorScheme() == Qt::ColorScheme::Dark))
+#endif
+    ) {
+        chromium_flags.append(" --blink-settings=preferredColorScheme=0");
+    }
+    else if ((prefferColorScheme == Qz::ColorScheme_Light)
+#if QTGUI_VERSION >= QT_VERSION_CHECK(6, 5, 0)
+        || ((prefferColorScheme == Qz::ColorScheme_Auto) && (styleHints()->colorScheme() == Qt::ColorScheme::Light))
+#endif
+    ) {
+        chromium_flags.append(" --blink-settings=preferredColorScheme=1");
+    }
+    qputenv("QTWEBENGINE_CHROMIUM_FLAGS", chromium_flags);
+}
+
 bool MainApplication::isClosing() const
 {
     return m_isClosing;

src/lib/app/mainapplication.h

@@ -71,6 +71,8 @@ public:
     explicit MainApplication(int &argc, char** argv);
     ~MainApplication();
 
+    void setChromiumFlags();
+
     bool isClosing() const;
     bool isPrivate() const;
     bool isPortable() const;

src/lib/app/qzcommon.h

@@ -111,6 +111,12 @@ enum NewTabPositionFlag {
 Q_DECLARE_FLAGS(NewTabPositionFlags, NewTabPositionFlag)
 Q_DECLARE_OPERATORS_FOR_FLAGS(Qz::NewTabPositionFlags)
 
+enum ColorScheme {
+    ColorScheme_Auto = 0,
+    ColorScheme_Light,
+    ColorScheme_Dark
+};
+
 }
 
 #if defined(Q_OS_WIN) || defined(Q_OS_OS2)

src/lib/preferences/preferences.cpp

@@ -63,6 +63,7 @@
 #include <QWebEngineSettings>
 #include <QLibraryInfo>
 #include <QtWebEngineWidgetsVersion>
+#include <QtGuiVersion>
 
 static QString createLanguageItem(const QString &lang)
 {
@@ -308,6 +309,19 @@ Preferences::Preferences(BrowserWindow* window)
     ui->forceDarkMode->hide();
 #endif
 
+    int prefferColorSchemeSetting = settings.value(QSL("prefferColorScheme"), Qz::ColorScheme_Auto).toInt();
+#if QTGUI_VERSION >= QT_VERSION_CHECK(6, 5, 0)
+    ui->prefferColorScheme->addItem(tr("Auto"), Qz::ColorScheme_Auto);
+#endif
+    ui->prefferColorScheme->addItem(tr("Light"), Qz::ColorScheme_Light);
+    ui->prefferColorScheme->addItem(tr("Dark"), Qz::ColorScheme_Dark);
+#if QTGUI_VERSION < QT_VERSION_CHECK(6, 5, 0)
+    if (prefferColorSchemeSetting > 0) {
+        prefferColorSchemeSetting--;
+    }
+#endif
+    ui->prefferColorScheme->setCurrentIndex(prefferColorSchemeSetting);
+
     const auto levels = WebView::zoomLevels();
     for (int level : levels) {
         ui->defaultZoomLevel->addItem(tr("%1%").arg(QString::number(level)));
@@ -1016,6 +1030,7 @@ void Preferences::saveSettings()
 #if QTWEBENGINECORE_VERSION >= QT_VERSION_CHECK(6, 7, 0)
     settings.setValue(QSL("forceDarkMode"), ui->forceDarkMode->isChecked());
 #endif
+    settings.setValue(QSL("prefferColorScheme"), ui->prefferColorScheme->currentData().toInt());
 #ifdef Q_OS_WIN
     settings.setValue(QSL("CheckDefaultBrowser"), ui->checkDefaultBrowser->isChecked());
 #endif

src/lib/preferences/preferences.ui

@@ -160,7 +160,7 @@
         <x>0</x>
         <y>0</y>
         <width>783</width>
-        <height>651</height>
+        <height>723</height>
        </rect>
       </property>
       <layout class="QVBoxLayout" name="verticalLayout_4">
@@ -1145,6 +1145,33 @@
                    </property>
                   </widget>
                  </item>
+                 <item>
+                  <layout class="QHBoxLayout" name="horizontalLayout_22">
+                   <item>
+                    <widget class="QLabel" name="label_16">
+                     <property name="text">
+                      <string>Preffer color scheme:</string>
+                     </property>
+                    </widget>
+                   </item>
+                   <item>
+                    <widget class="QComboBox" name="prefferColorScheme"/>
+                   </item>
+                   <item>
+                    <spacer name="horizontalSpacer_40">
+                     <property name="orientation">
+                      <enum>Qt::Horizontal</enum>
+                     </property>
+                     <property name="sizeHint" stdset="0">
+                      <size>
+                       <width>40</width>
+                       <height>20</height>
+                      </size>
+                     </property>
+                    </spacer>
+                   </item>
+                  </layout>
+                 </item>
                 </layout>
                </item>
                <item row="2" column="0">