4 files changed, 154 insertions, 1 deletions
diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index 35890c811428..b0235b031e03 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -4385,11 +4385,12 @@ public final class ActivityThread extends ClientTransactionHandler
         try {
             if (localLOGV) Slog.v(TAG, "Creating service " + data.info.name);
 
-            ContextImpl context = ContextImpl.createAppContext(this, packageInfo);
             Application app = packageInfo.makeApplication(false, mInstrumentation);
             java.lang.ClassLoader cl = packageInfo.getClassLoader();
             service = packageInfo.getAppFactory()
                     .instantiateService(cl, data.info.name, data.intent);
+            final ContextImpl context = ContextImpl.getImpl(service
+                    .createServiceBaseContext(this, packageInfo));
             // Service resources must be initialized with the same loaders as the application
             // context.
             context.getResources().addLoaders(
diff --git a/core/java/android/app/Service.java b/core/java/android/app/Service.java
index 2ceea7f1a6a8..0ab3f2f4be46 100644
--- a/core/java/android/app/Service.java
+++ b/core/java/android/app/Service.java
@@ -861,6 +861,19 @@ public abstract class Service extends ContextWrapper implements ComponentCallbac
     }
 
     /**
+     * Creates the base {@link Context} of this {@link Service}.
+     * Users may override this API to create customized base context.
+     *
+     * @see android.window.WindowProviderService WindowProviderService class for example
+     * @see ContextWrapper#attachBaseContext(Context)
+     *
+     * @hide
+     */
+    public Context createServiceBaseContext(ActivityThread mainThread, LoadedApk packageInfo) {
+        return ContextImpl.createAppContext(mainThread, packageInfo);
+    }
+
+    /**
      * @hide
      * Clean up any references to avoid leaks.
      */
diff --git a/core/java/android/window/WindowContextController.java b/core/java/android/window/WindowContextController.java
index 88584f4b2571..d84f571931fd 100644
--- a/core/java/android/window/WindowContextController.java
+++ b/core/java/android/window/WindowContextController.java
@@ -105,6 +105,7 @@ public class WindowContextController {
      * a {@link com.android.server.wm.DisplayArea} by
      * {@link #attachToDisplayArea(int, int, Bundle)}.
      *
+     * @see WindowProviderService#attachToWindowToken(IBinder))
      * @see IWindowManager#attachWindowContextToWindowToken(IBinder, IBinder)
      */
     public void attachToWindowToken(IBinder windowToken) {
diff --git a/core/java/android/window/WindowProviderService.java b/core/java/android/window/WindowProviderService.java
new file mode 100644
index 000000000000..b8619fbcf334
--- /dev/null
+++ b/core/java/android/window/WindowProviderService.java
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.window;
+
+import static android.view.Display.DEFAULT_DISPLAY;
+
+import android.annotation.CallSuper;
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.SuppressLint;
+import android.annotation.TestApi;
+import android.annotation.UiContext;
+import android.app.ActivityThread;
+import android.app.LoadedApk;
+import android.app.Service;
+import android.content.Context;
+import android.hardware.display.DisplayManager;
+import android.os.Bundle;
+import android.os.IBinder;
+import android.view.Display;
+import android.view.WindowManager;
+import android.view.WindowManager.LayoutParams.WindowType;
+import android.view.WindowManagerImpl;
+
+// TODO(b/159767464): handle #onConfigurationChanged(Configuration)
+/**
+ * A {@link Service} responsible for showing a non-activity window, such as software keyboards or
+ * accessibility overlay windows. This {@link Service} has similar behavior to
+ * {@link WindowContext}, but is represented as {@link Service}.
+ *
+ * @see android.inputmethodservice.InputMethodService
+ * @see android.accessibilityservice.AccessibilityService
+ *
+ * @hide
+ */
+@TestApi
+@UiContext
+public abstract class WindowProviderService extends Service {
+
+    private final WindowTokenClient mWindowToken = new WindowTokenClient();
+    private final WindowContextController mController = new WindowContextController(mWindowToken);
+    private WindowManager mWindowManager;
+
+    /**
+     * Returns the type of this {@link WindowProviderService}.
+     * Each inheriting class must implement this method to provide the type of the window. It is
+     * used similar to {@code type} of {@link Context#createWindowContext(int, Bundle)}
+     *
+     * @see Context#createWindowContext(int, Bundle)
+     *
+     * @hide
+     */
+    @TestApi
+    @SuppressLint("OnNameExpected")
+    // Suppress the lint because it is not a callback and users should provide window type
+    // so we cannot make it final.
+    public abstract @WindowType int getWindowType();
+
+    /**
+     * Returns the option of this {@link WindowProviderService}.
+     * Default is {@code null}. The inheriting class can implement this method to provide the
+     * customization {@code option} of the window. It is used similar to {@code options} of
+     * {@link Context#createWindowContext(int, Bundle)}
+     *
+     * @see Context#createWindowContext(int, Bundle)
+     *
+     * @hide
+     */
+    @TestApi
+    @SuppressLint({"OnNameExpected", "NullableCollection"})
+    // Suppress the lint because it is not a callback and users may override this API to provide
+    // launch option. Also, the return value of this API is null by default.
+    @Nullable
+    public Bundle getWindowContextOptions() {
+        return null;
+    }
+
+    /**
+     * Attaches this WindowProviderService to the {@code windowToken}.
+     *
+     * @hide
+     */
+    @TestApi
+    public final void attachToWindowToken(@NonNull IBinder windowToken) {
+        mController.attachToWindowToken(windowToken);
+    }
+
+    /** @hide */
+    @Override
+    public final Context createServiceBaseContext(ActivityThread mainThread,
+            LoadedApk packageInfo) {
+        final Context context = super.createServiceBaseContext(mainThread, packageInfo);
+        // Always associate with the default display at initialization.
+        final Display defaultDisplay = context.getSystemService(DisplayManager.class)
+                .getDisplay(DEFAULT_DISPLAY);
+        return context.createTokenContext(mWindowToken, defaultDisplay);
+    }
+
+    @CallSuper
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        mWindowToken.attachContext(this);
+        mController.attachToDisplayArea(getWindowType(), getDisplayId(), getWindowContextOptions());
+        mWindowManager = WindowManagerImpl.createWindowContextWindowManager(this);
+    }
+
+    @SuppressLint("OnNameExpected")
+    @Override
+    // Suppress the lint because ths is overridden from Context.
+    public @Nullable Object getSystemService(@NonNull String name) {
+        if (WINDOW_SERVICE.equals(name)) {
+            return mWindowManager;
+        }
+        return super.getSystemService(name);
+    }
+
+    @CallSuper
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        mController.detachIfNeeded();
+    }
+}