Bug 1532850 - Implement the backend for prefers-color-scheme on Android. r=geckoview-reviewers,snorp

Differential Revision: https://phabricator.services.mozilla.com/D22272

--HG--
extra : moz-landing-system : lando

mobile/android/base/AndroidManifest.xml.in

@@ -58,7 +58,7 @@
                   android:label="@string/moz_app_displayname"
                   android:taskAffinity="@ANDROID_PACKAGE_NAME@.BROWSER"
                   android:alwaysRetainTaskState="true"
-                  android:configChanges="keyboard|keyboardHidden|mcc|mnc|orientation|screenSize|locale|layoutDirection|smallestScreenSize|screenLayout"
+                  android:configChanges="keyboard|keyboardHidden|mcc|mnc|orientation|screenSize|locale|layoutDirection|smallestScreenSize|screenLayout|uiMode"
                   android:resizeableActivity="true"
                   android:supportsPictureInPicture="true"
                   android:windowSoftInputMode="stateUnspecified|adjustResize"
@@ -352,7 +352,7 @@
         </activity>
 
         <activity android:name="org.mozilla.gecko.customtabs.CustomTabsActivity"
-                  android:configChanges="keyboard|keyboardHidden|mcc|mnc|orientation|screenSize|locale|layoutDirection|smallestScreenSize|screenLayout"
+                  android:configChanges="keyboard|keyboardHidden|mcc|mnc|orientation|screenSize|locale|layoutDirection|smallestScreenSize|screenLayout|uiMode"
                   android:windowSoftInputMode="stateUnspecified|adjustResize"
                   android:theme="@style/GeckoCustomTabs" />
 

mobile/android/geckoview/api.txt

@@ -177,6 +177,7 @@ package org.mozilla.geckoview {
   public final class GeckoRuntime implements android.os.Parcelable {
     ctor public GeckoRuntime();
     method @android.support.annotation.UiThread public void attachTo(@android.support.annotation.NonNull android.content.Context);
+    method @android.support.annotation.UiThread public void configurationChanged(@android.support.annotation.NonNull android.content.res.Configuration);
     method @android.support.annotation.UiThread @android.support.annotation.NonNull public static org.mozilla.geckoview.GeckoRuntime create(@android.support.annotation.NonNull android.content.Context);
     method @android.support.annotation.UiThread @android.support.annotation.NonNull public static org.mozilla.geckoview.GeckoRuntime create(@android.support.annotation.NonNull android.content.Context, @android.support.annotation.NonNull org.mozilla.geckoview.GeckoRuntimeSettings);
     method @android.support.annotation.UiThread @android.support.annotation.NonNull public static synchronized org.mozilla.geckoview.GeckoRuntime getDefault(@android.support.annotation.NonNull android.content.Context);

mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoSystemStateListener.java

@@ -7,6 +7,7 @@ package org.mozilla.gecko;
 
 import android.content.ContentResolver;
 import android.content.Context;
+import android.content.res.Configuration;
 import android.database.ContentObserver;
 import android.hardware.input.InputManager;
 import android.net.Uri;
@@ -31,6 +32,7 @@ public class GeckoSystemStateListener
     private ContentObserver mContentObserver;
     private static Context sApplicationContext;
     private InputManager mInputManager;
+    private static boolean sIsNightMode;
 
     public static GeckoSystemStateListener getInstance() {
         return listenerInstance;
@@ -59,6 +61,9 @@ public class GeckoSystemStateListener
         };
         contentResolver.registerContentObserver(animationSetting, false, mContentObserver);
 
+        sIsNightMode = (sApplicationContext.getResources().getConfiguration().uiMode &
+            Configuration.UI_MODE_NIGHT_MASK) == Configuration.UI_MODE_NIGHT_YES;
+
         mInitialized = true;
     }
 
@@ -109,6 +114,24 @@ public class GeckoSystemStateListener
         contentResolver.notifyChange(animationSetting, null);
     }
 
+    @WrapForJNI(calledFrom = "gecko")
+    /**
+     * For prefers-color-scheme media queries feature.
+     */
+    private static boolean isNightMode() {
+        return sIsNightMode;
+    }
+
+    public void updateNightMode(final int newUIMode) {
+        boolean isNightMode = (newUIMode & Configuration.UI_MODE_NIGHT_MASK)
+            == Configuration.UI_MODE_NIGHT_YES;
+        if (isNightMode == sIsNightMode) {
+            return;
+        }
+        sIsNightMode = isNightMode;
+        onDeviceChanged();
+    }
+
     @WrapForJNI(stubName = "OnDeviceChanged", calledFrom = "ui", dispatchTo = "gecko")
     private static native void nativeOnDeviceChanged();
 

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoRuntime.java

@@ -11,6 +11,7 @@ import android.content.ComponentName;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.content.pm.ServiceInfo;
+import android.content.res.Configuration;
 import android.os.Build;
 import android.os.Parcel;
 import android.os.Parcelable;
@@ -433,6 +434,17 @@ public final class GeckoRuntime implements Parcelable {
         GeckoScreenOrientation.getInstance().update();
     }
 
+    /**
+     * Notify Gecko that the device configuration has changed.
+     * @param newConfig The new Configuration object,
+     *                  {@link android.content.res.Configuration}.
+     */
+    @UiThread
+    public void configurationChanged(final @NonNull Configuration newConfig) {
+        ThreadUtils.assertOnUiThread();
+        GeckoSystemStateListener.getInstance().updateNightMode(newConfig.uiMode);
+    }
+
     /**
      * Notify Gecko that the screen orientation has changed.
      * @param newOrientation The new screen orientation, as retrieved e.g. from the current

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/GeckoView.java

@@ -465,6 +465,7 @@ public class GeckoView extends FrameLayout {
             // we will miss such rotations and the screen orientation will not be
             // updated.
             mRuntime.orientationChanged(newConfig.orientation);
+            mRuntime.configurationChanged(newConfig);
         }
     }
 

mobile/android/geckoview/src/main/java/org/mozilla/geckoview/doc-files/CHANGELOG.md

@@ -8,6 +8,12 @@ exclude: true
 
 <h1> GeckoView API Changelog. </h1>
 
+## v68
+- Added [`GeckoRuntime#configurationChanged`][68.1] to notify the device
+  configuration has changed.
+
+[68.1]: ../GeckoRuntime.html#configurationChanged
+
 ## v67
 - Added [`setAutomaticFontSizeAdjustment`][67.2] to
   [`GeckoRuntimeSettings`][67.3] for automatically adjusting font size settings
@@ -209,4 +215,4 @@ exclude: true
 [65.24]: ../CrashReporter.html#sendCrashReport-android.content.Context-android.os.Bundle-java.lang.String-
 [65.25]: ../GeckoResult.html
 
-[api-version]: 09c473360eb5e17aa801fa0f966cd8671cf2f3d2
+[api-version]: e1330c0e7cfa08420041813f07f24a9389020564

widget/android/nsLookAndFeel.cpp

@@ -400,6 +400,16 @@ nsresult nsLookAndFeel::GetIntImpl(IntID aID, int32_t& aResult) {
       aResult = java::GeckoAppShell::GetAllPointerCapabilities();
       break;
 
+    case eIntID_SystemUsesDarkTheme:
+      // Bail out if AndroidBridge hasn't initialized since we try to query
+      // this vailue via nsMediaFeatures::InitSystemMetrics without initializing
+      // AndroidBridge on xpcshell tests.
+      if (!jni::IsAvailable()) {
+        return NS_ERROR_FAILURE;
+      }
+      aResult = java::GeckoSystemStateListener::IsNightMode() ? 1 : 0;
+      break;
+
     default:
       aResult = 0;
       rv = NS_ERROR_FAILURE;