Android: Handle light/dark mode changes

Update Theme's style according to current UiMode.

New style.json file for dark mode was added (stored in separate
subdirectory 'darkUiMode/'). Theme_DeviceDefault_DayNight[0] is used for
extraction for API 29 or higher. Style is updated each time when UiMode
is changed.

[0]https://developer.android.com/reference/android/R.style#Theme_DeviceDefault_DayNight

Task-number: QTBUG-83185
Pick-to: 6.4 6.2
Change-Id: Id26059231f41761d822d494ac6c641bf3cba3322
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>

7 files changed, 137 insertions, 22 deletions

diff --git a/src/android/jar/src/org/qtproject/qt/android/ExtractStyle.java b/src/android/jar/src/org/qtproject/qt/android/ExtractStyle.java
index 6792247eeb..672a2e28d3 100644
--- a/src/android/jar/src/org/qtproject/qt/android/ExtractStyle.java
+++ b/src/android/jar/src/org/qtproject/qt/android/ExtractStyle.java
@@ -34,6 +34,7 @@ import android.graphics.drawable.ScaleDrawable;
 import android.graphics.drawable.StateListDrawable;
 import android.graphics.drawable.VectorDrawable;
 import android.os.Build;
+import android.os.Bundle;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.util.TypedValue;
@@ -135,6 +136,42 @@ public class ExtractStyle {
     Context m_context;
     private final HashMap<String, DrawableCache> m_drawableCache = new HashMap<>();
 
+    private static final String EXTRACT_STYLE_KEY = "extract.android.style";
+    private static final String EXTRACT_STYLE_MINIMAL_KEY = "extract.android.style.option";
+
+    private static boolean m_missingNormalStyle = false;
+    private static boolean m_missingDarkStyle = false;
+    private static String  m_stylePath = null;
+    private static boolean m_extractMinimal = false;
+
+    public static void setup(Bundle loaderParams) {
+        if (loaderParams.containsKey(EXTRACT_STYLE_KEY)) {
+            m_stylePath = loaderParams.getString(EXTRACT_STYLE_KEY);
+
+            boolean darkModeFileMissing = !(new File(m_stylePath + "darkUiMode/style.json").exists());
+            m_missingDarkStyle = Build.VERSION.SDK_INT > 28 && darkModeFileMissing;
+
+            m_missingNormalStyle = !(new File(m_stylePath + "style.json").exists());
+
+            m_extractMinimal = loaderParams.containsKey(EXTRACT_STYLE_MINIMAL_KEY) &&
+                               loaderParams.getBoolean(EXTRACT_STYLE_MINIMAL_KEY);
+        }
+    }
+
+    public static void runIfNeeded(Context context, boolean extractDarkMode) {
+        if (m_stylePath == null)
+            return;
+        if (extractDarkMode) {
+            if (m_missingDarkStyle) {
+                new ExtractStyle(context, m_stylePath + "darkUiMode/", m_extractMinimal);
+                m_missingDarkStyle = false;
+            }
+        } else if (m_missingNormalStyle) {
+            new ExtractStyle(context, m_stylePath, m_extractMinimal);
+            m_missingNormalStyle = false;
+        }
+    }
+
     public ExtractStyle(Context context, String extractPath, boolean minimal) {
         m_minimal = minimal;
         m_extractPath = extractPath + "/";
diff --git a/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java b/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java
index 63298c0730..ec890d1d61 100644
--- a/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java
+++ b/src/android/jar/src/org/qtproject/qt/android/QtActivityDelegate.java
@@ -84,8 +84,6 @@ public class QtActivityDelegate
     private static final String ENVIRONMENT_VARIABLES_KEY = "environment.variables";
     private static final String APPLICATION_PARAMETERS_KEY = "application.parameters";
     private static final String STATIC_INIT_CLASSES_KEY = "static.init.classes";
-    private static final String EXTRACT_STYLE_KEY = "extract.android.style";
-    private static final String EXTRACT_STYLE_MINIMAL_KEY = "extract.android.style.option";
 
     public static final int SYSTEM_UI_VISIBILITY_NORMAL = 0;
     public static final int SYSTEM_UI_VISIBILITY_FULLSCREEN = 1;
@@ -707,11 +705,8 @@ public class QtActivityDelegate
             libraries.remove(libraries.size() - 1);
         }
 
-        if (loaderParams.containsKey(EXTRACT_STYLE_KEY)) {
-            String path = loaderParams.getString(EXTRACT_STYLE_KEY);
-            new ExtractStyle(m_activity, path, loaderParams.containsKey(EXTRACT_STYLE_MINIMAL_KEY) &&
-                                               loaderParams.getBoolean(EXTRACT_STYLE_MINIMAL_KEY));
-        }
+        ExtractStyle.setup(loaderParams);
+        ExtractStyle.runIfNeeded(m_activity, isUiModeDark(m_activity.getResources().getConfiguration()));
 
         QtNative.setEnvironmentVariables(loaderParams.getString(ENVIRONMENT_VARIABLES_KEY));
         QtNative.setEnvironmentVariable("QT_ANDROID_FONTS_MONOSPACE",
@@ -971,13 +966,20 @@ public class QtActivityDelegate
             updateFullScreen();
     }
 
+    boolean isUiModeDark(Configuration config)
+    {
+        return (config.uiMode & Configuration.UI_MODE_NIGHT_MASK) == Configuration.UI_MODE_NIGHT_YES;
+    }
+
     private void handleUiModeChange(int uiMode)
     {
         switch (uiMode) {
             case Configuration.UI_MODE_NIGHT_NO:
+                ExtractStyle.runIfNeeded(m_activity, false);
                 QtNative.handleUiDarkModeChanged(0);
                 break;
             case Configuration.UI_MODE_NIGHT_YES:
+                ExtractStyle.runIfNeeded(m_activity, true);
                 QtNative.handleUiDarkModeChanged(1);
                 break;
         }
diff --git a/src/android/java/src/org/qtproject/qt/android/bindings/QtActivity.java b/src/android/java/src/org/qtproject/qt/android/bindings/QtActivity.java
index 9cef8146fd..94d3c2dee1 100644
--- a/src/android/java/src/org/qtproject/qt/android/bindings/QtActivity.java
+++ b/src/android/java/src/org/qtproject/qt/android/bindings/QtActivity.java
@@ -65,8 +65,14 @@ public class QtActivity extends Activity
     public QtActivity()
     {
         m_loader = new QtActivityLoader(this);
-        QT_ANDROID_THEMES = new String[] {"Theme_Holo_Light"};
-        QT_ANDROID_DEFAULT_THEME = "Theme_Holo_Light";
+
+        if (Build.VERSION.SDK_INT < 29) {
+            QT_ANDROID_THEMES = new String[] {"Theme_Holo_Light"};
+            QT_ANDROID_DEFAULT_THEME = "Theme_Holo_Light";
+        } else {
+            QT_ANDROID_THEMES = new String[] {"Theme_DeviceDefault_DayNight"};
+            QT_ANDROID_DEFAULT_THEME = "Theme_DeviceDefault_DayNight";
+        }
     }
 
 
diff --git a/src/android/java/src/org/qtproject/qt/android/bindings/QtLoader.java b/src/android/java/src/org/qtproject/qt/android/bindings/QtLoader.java
index 883c0d6478..fea193a4db 100644
--- a/src/android/java/src/org/qtproject/qt/android/bindings/QtLoader.java
+++ b/src/android/java/src/org/qtproject/qt/android/bindings/QtLoader.java
@@ -331,7 +331,7 @@ public abstract class QtLoader {
                     }
                 }
 
-                if (!(new File(stylePath)).exists() && !extractOption.equals("none")) {
+                if (!extractOption.equals("none")) {
                     loaderParams.putString(EXTRACT_STYLE_KEY, stylePath);
                     loaderParams.putBoolean(EXTRACT_STYLE_MINIMAL_KEY, extractOption.equals("minimal"));
                 }
diff --git a/src/plugins/platforms/android/qandroidplatformintegration.cpp b/src/plugins/platforms/android/qandroidplatformintegration.cpp
index 57546bdbca..0d5b473477 100644
--- a/src/plugins/platforms/android/qandroidplatformintegration.cpp
+++ b/src/plugins/platforms/android/qandroidplatformintegration.cpp
@@ -460,7 +460,7 @@ QStringList QAndroidPlatformIntegration::themeNames() const
 QPlatformTheme *QAndroidPlatformIntegration::createPlatformTheme(const QString &name) const
 {
     if (androidThemeName == name)
-        return new QAndroidPlatformTheme(m_androidPlatformNativeInterface);
+        return QAndroidPlatformTheme::instance(m_androidPlatformNativeInterface);
 
     return 0;
 }
@@ -523,6 +523,9 @@ void QAndroidPlatformIntegration::setAppearance(Qt::Appearance newAppearance)
     if (m_appearance == newAppearance)
         return;
     m_appearance = newAppearance;
+
+    QMetaObject::invokeMethod(qGuiApp,
+                    [] () { QAndroidPlatformTheme::instance()->updateAppearance();});
 }
 
 void QAndroidPlatformIntegration::setScreenSizeParameters(const QSize &physicalSize,
diff --git a/src/plugins/platforms/android/qandroidplatformtheme.cpp b/src/plugins/platforms/android/qandroidplatformtheme.cpp
index 6f950dc4fb..f11de02d44 100644
--- a/src/plugins/platforms/android/qandroidplatformtheme.cpp
+++ b/src/plugins/platforms/android/qandroidplatformtheme.cpp
@@ -158,6 +158,9 @@ QJsonObject AndroidStyle::loadStyleData()
     if (!stylePath.isEmpty() && !stylePath.endsWith(slashChar))
         stylePath += slashChar;
 
+    if (QAndroidPlatformIntegration::appearance() == Qt::Appearance::Dark)
+        stylePath += "darkUiMode/"_L1;
+
     Q_ASSERT(!stylePath.isEmpty());
 
     QString androidTheme = QLatin1StringView(qgetenv("QT_ANDROID_THEME"));
@@ -185,13 +188,22 @@ QJsonObject AndroidStyle::loadStyleData()
     return document.object();
 }
 
-static std::shared_ptr<AndroidStyle> loadAndroidStyle(QPalette *defaultPalette)
+static void loadAndroidStyle(QPalette *defaultPalette, std::shared_ptr<AndroidStyle> &style)
 {
     double pixelDensity = QHighDpiScaling::isActive() ? QtAndroid::pixelDensity() : 1.0;
-    std::shared_ptr<AndroidStyle> style = std::make_shared<AndroidStyle>();
+    if (style) {
+        style->m_standardPalette = QPalette();
+        style->m_palettes.clear();
+        style->m_fonts.clear();
+        style->m_QWidgetsFonts.clear();
+    } else {
+        style = std::make_shared<AndroidStyle>();
+    }
+
     style->m_styleData = AndroidStyle::loadStyleData();
+
     if (style->m_styleData.isEmpty())
-        return std::shared_ptr<AndroidStyle>();
+        return;
 
     {
         QFont font("Droid Sans Mono"_L1, 14.0 * 100 / 72);
@@ -293,11 +305,43 @@ static std::shared_ptr<AndroidStyle> loadAndroidStyle(QPalette *defaultPalette)
             // Extract palette information
         }
     }
-    return style;
+}
+
+QAndroidPlatformTheme *QAndroidPlatformTheme::m_instance = nullptr;
+
+QAndroidPlatformTheme *QAndroidPlatformTheme::instance(
+    QAndroidPlatformNativeInterface *androidPlatformNativeInterface)
+{
+    if (androidPlatformNativeInterface && !m_instance) {
+        m_instance = new QAndroidPlatformTheme(androidPlatformNativeInterface);
+    }
+    return m_instance;
 }
 
 QAndroidPlatformTheme::QAndroidPlatformTheme(QAndroidPlatformNativeInterface *androidPlatformNativeInterface)
 {
+    updateStyle();
+
+    androidPlatformNativeInterface->m_androidStyle = m_androidStyleData;
+
+    // default in case the style has not set a font
+    m_systemFont = QFont("Roboto"_L1, 14.0 * 100 / 72); // keep default size the same after changing from 100 dpi to 72 dpi
+}
+
+QAndroidPlatformTheme::~QAndroidPlatformTheme()
+{
+    m_instance = nullptr;
+}
+
+void QAndroidPlatformTheme::updateAppearance()
+{
+    updateStyle();
+    QWindowSystemInterface::handleThemeChange();
+}
+
+void QAndroidPlatformTheme::updateStyle()
+{
+    QColor windowText = Qt::black;
     QColor background(229, 229, 229);
     QColor light = background.lighter(150);
     QColor mid(background.darker(130));
@@ -314,7 +358,27 @@ QAndroidPlatformTheme::QAndroidPlatformTheme(QAndroidPlatformNativeInterface *an
     QColor highlight(148, 210, 231);
     QColor disabledShadow = shadow.lighter(150);
 
-    m_defaultPalette = QPalette(Qt::black,background,light,dark,mid,text,base);
+    if (appearance() == Qt::Appearance::Dark) {
+        // Colors were prepared based on Theme.DeviceDefault.DayNight
+        windowText = QColor(250, 250, 250);
+        background = QColor(48, 48, 48);
+        light = background.darker(150);
+        mid = background.lighter(130);
+        midLight = mid.darker(110);
+        base = background;
+        disabledBase = background;
+        dark = background.darker(150);
+        darkDisabled = dark.darker(110);
+        text = QColor(250, 250, 250);
+        highlightedText = QColor(250, 250, 250);
+        disabledText = QColor(96, 96, 96);
+        button = QColor(48, 48, 48);
+        shadow = QColor(32, 32, 32);
+        highlight = QColor(102, 178, 204);
+        disabledShadow = shadow.darker(150);
+    }
+
+    m_defaultPalette = QPalette(windowText,background,light,dark,mid,text,base);
     m_defaultPalette.setBrush(QPalette::Midlight, midLight);
     m_defaultPalette.setBrush(QPalette::Button, button);
     m_defaultPalette.setBrush(QPalette::Shadow, shadow);
@@ -330,12 +394,9 @@ QAndroidPlatformTheme::QAndroidPlatformTheme(QAndroidPlatformNativeInterface *an
     m_defaultPalette.setBrush(QPalette::Active, QPalette::Highlight, highlight);
     m_defaultPalette.setBrush(QPalette::Inactive, QPalette::Highlight, highlight);
     m_defaultPalette.setBrush(QPalette::Disabled, QPalette::Highlight, highlight.lighter(150));
-    m_androidStyleData = loadAndroidStyle(&m_defaultPalette);
-    QGuiApplication::setPalette(m_defaultPalette);
-    androidPlatformNativeInterface->m_androidStyle = m_androidStyleData;
 
-    // default in case the style has not set a font
-    m_systemFont = QFont("Roboto"_L1, 14.0 * 100 / 72); // keep default size the same after changing from 100 dpi to 72 dpi
+    loadAndroidStyle(&m_defaultPalette, m_androidStyleData);
+    QGuiApplication::setPalette(m_defaultPalette);
 }
 
 QPlatformMenuBar *QAndroidPlatformTheme::createPlatformMenuBar() const
diff --git a/src/plugins/platforms/android/qandroidplatformtheme.h b/src/plugins/platforms/android/qandroidplatformtheme.h
index 0fc3c152c5..38e653ab71 100644
--- a/src/plugins/platforms/android/qandroidplatformtheme.h
+++ b/src/plugins/platforms/android/qandroidplatformtheme.h
@@ -30,7 +30,9 @@ class QAndroidPlatformNativeInterface;
 class QAndroidPlatformTheme: public QPlatformTheme
 {
 public:
-    QAndroidPlatformTheme(QAndroidPlatformNativeInterface * androidPlatformNativeInterface);
+    ~QAndroidPlatformTheme();
+    void updateAppearance();
+    void updateStyle();
     QPlatformMenuBar *createPlatformMenuBar() const override;
     QPlatformMenu *createPlatformMenu() const override;
     QPlatformMenuItem *createPlatformMenuItem() const override;
@@ -43,8 +45,12 @@ public:
     bool usePlatformNativeDialog(DialogType type) const override;
     QPlatformDialogHelper *createPlatformDialogHelper(DialogType type) const override;
 
+    static QAndroidPlatformTheme *instance(
+                    QAndroidPlatformNativeInterface * androidPlatformNativeInterface = nullptr);
 
 private:
+    QAndroidPlatformTheme(QAndroidPlatformNativeInterface * androidPlatformNativeInterface);
+    static QAndroidPlatformTheme * m_instance;
     std::shared_ptr<AndroidStyle> m_androidStyleData;
     QPalette m_defaultPalette;
     QFont m_systemFont;