Merge pull request #553 from abarth/immersive

Add support for immersive mode on Android

sky/packages/sky/lib/mojo/activity.dart

@@ -8,7 +8,7 @@ import 'dart:async';
 import 'package:sky/mojo/shell.dart' as shell;
 import 'package:sky_services/activity/activity.mojom.dart';
 
-export 'package:sky_services/activity/activity.mojom.dart' show Intent, ComponentName, StringExtra;
+export 'package:sky_services/activity/activity.mojom.dart' show Intent, ComponentName, StringExtra, SystemUIVisibility_STANDARD, SystemUIVisibility_FULLSCREEN, SystemUIVisibility_IMMERSIVE;
 
 /// Dart wrapper around Activity mojo service available in Sky on Android.
 ///
@@ -55,6 +55,15 @@ void updateTaskDescription(String label, Color color) {
   _activity.ptr.setTaskDescription(description);
 }
 
+int _cachedSystemUiVisibility = SystemUIVisibility_STANDARD;
+
+void setSystemUiVisibility(int visibility) {
+  if (_cachedSystemUiVisibility == visibility)
+    return;
+  _cachedSystemUiVisibility = visibility;
+  _activity.ptr.setSystemUiVisibility(visibility);
+}
+
 Future<String> getFilesDir() async => (await _activity.ptr.getFilesDir()).path;
 
 Future<String> getCacheDir() async => (await _activity.ptr.getCacheDir()).path;

sky/services/activity/activity.mojom

@@ -28,6 +28,12 @@ struct TaskDescription {
   uint32 primaryColor;
 };
 
+enum SystemUIVisibility {
+  STANDARD,
+  FULLSCREEN,
+  IMMERSIVE,
+};
+
 // TODO(abarth): This interface seems very specific to Android. Do we want to
 //               have a higher-level abstraction here? Do we want a collection
 //               of services that only work on specific platforms? We need to
@@ -36,6 +42,7 @@ interface Activity {
   StartActivity(Intent intent);
   FinishCurrentActivity();
   SetTaskDescription(TaskDescription description);
+  SetSystemUIVisibility(SystemUIVisibility visibility);
 
   // These are stored off the Activity on Android, but probably belong in a
   // separate FileSystem service.

sky/services/activity/src/org/domokit/activity/ActivityImpl.java

@@ -6,14 +6,16 @@ package org.domokit.activity;
 
 import android.content.ActivityNotFoundException;
 import android.net.Uri;
-import android.util.Log;
 import android.os.Build;
+import android.util.Log;
+import android.view.View;
 
 import org.chromium.mojo.system.MojoException;
 import org.chromium.mojom.activity.Activity;
 import org.chromium.mojom.activity.ComponentName;
 import org.chromium.mojom.activity.Intent;
 import org.chromium.mojom.activity.StringExtra;
+import org.chromium.mojom.activity.SystemUiVisibility;
 import org.chromium.mojom.activity.TaskDescription;
 
 /**
@@ -96,6 +98,28 @@ public class ActivityImpl implements Activity {
         );
     }
 
+    @Override
+    public void setSystemUiVisibility(int visibility) {
+      if (sCurrentActivity == null) {
+          return;
+      }
+      int flags = View.SYSTEM_UI_FLAG_LAYOUT_STABLE |
+                  View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
+
+      if (visibility >= SystemUiVisibility.FULLSCREEN) {
+          flags |= View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION |
+                   View.SYSTEM_UI_FLAG_HIDE_NAVIGATION |
+                   View.SYSTEM_UI_FLAG_FULLSCREEN;
+      }
+
+      if (visibility >= SystemUiVisibility.IMMERSIVE) {
+          flags |= View.SYSTEM_UI_FLAG_IMMERSIVE |
+                   View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY;
+      }
+
+      sCurrentActivity.getWindow().getDecorView().setSystemUiVisibility(flags);
+    }
+
     @Override
     public void getFilesDir(GetFilesDirResponse callback) {
         String path = null;