Migrate InputMethodService to WindowProviderService

Also introduce IWindowManager#getDisplayIdToLaunchIme to make IMS
be aware of the launched display to prevent extra onConfigurationChanged
callback

Bug: 149463653
Test: atest MultiDisplaySystemDecorationTests CtsInputMethodTestCases
Test: atest ContextTest ContextIsUiContextTest
Test: manual - moving IME between 2 displays and displayArea within
      display - config change received
Test: manual - the app to show IME crashed and focus is set to the
      next task - no config change

Change-Id: Ie565e30ed5dd3f2cfe27355a6dded76dc3adc14b

core/api/test-current.txt

@@ -1270,6 +1270,12 @@ package android.hardware.soundtrigger {
 
 package android.inputmethodservice {
 
+  public abstract class AbstractInputMethodService extends android.window.WindowProviderService implements android.view.KeyEvent.Callback {
+    method public final int getInitialDisplayId();
+    method @Nullable public final android.os.Bundle getWindowContextOptions();
+    method public final int getWindowType();
+  }
+
   @UiContext public class InputMethodService extends android.inputmethodservice.AbstractInputMethodService {
     field public static final long FINISH_INPUT_NO_FALLBACK_CONNECTION = 156215187L; // 0x94fa793L
   }
@@ -3242,6 +3248,7 @@ package android.window {
   @UiContext public abstract class WindowProviderService extends android.app.Service {
     ctor public WindowProviderService();
     method public final void attachToWindowToken(@NonNull android.os.IBinder);
+    method @NonNull public int getInitialDisplayId();
     method @Nullable public android.os.Bundle getWindowContextOptions();
     method public abstract int getWindowType();
   }

core/java/android/app/ContextImpl.java

@@ -3194,12 +3194,6 @@ class ContextImpl extends Context {
     @UnsupportedAppUsage
     final void setOuterContext(@NonNull Context context) {
         mOuterContext = context;
-        // TODO(b/149463653): check if we still need this method after migrating IMS to
-        //  WindowContext.
-        if (mOuterContext.isUiContext() && mContextType <= CONTEXT_TYPE_DISPLAY_CONTEXT) {
-            mContextType = CONTEXT_TYPE_WINDOW_CONTEXT;
-            mIsConfigurationBasedContext = true;
-        }
     }
 
     @UnsupportedAppUsage

core/java/android/inputmethodservice/AbstractInputMethodService.java

@@ -18,16 +18,23 @@ package android.inputmethodservice;
 
 import android.annotation.MainThread;
 import android.annotation.NonNull;
-import android.app.Service;
+import android.annotation.Nullable;
+import android.content.Context;
 import android.content.Intent;
+import android.content.res.Configuration;
+import android.os.Bundle;
 import android.os.IBinder;
+import android.os.RemoteException;
 import android.util.proto.ProtoOutputStream;
 import android.view.KeyEvent;
 import android.view.MotionEvent;
+import android.view.WindowManager;
+import android.view.WindowManagerGlobal;
 import android.view.inputmethod.InputConnection;
 import android.view.inputmethod.InputContentInfo;
 import android.view.inputmethod.InputMethod;
 import android.view.inputmethod.InputMethodSession;
+import android.window.WindowProviderService;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
@@ -44,9 +51,22 @@ import java.io.PrintWriter;
  * implement.  This base class takes care of reporting your InputMethod from
  * the service when clients bind to it, but provides no standard implementation
  * of the InputMethod interface itself.  Derived classes must implement that
- * interface.
+ * interface.</p>
+ *
+ * <p>After {@link android.os.Build.VERSION_CODES#S}, the maximum possible area to show the soft
+ * input may not be the entire screen. For example, some devices may support to show the soft input
+ * on only half of screen.</p>
+ *
+ * <p>In that case, moving the soft input from one half screen to another will trigger a
+ * {@link android.content.res.Resources} update to match the new {@link Configuration} and
+ * this {@link AbstractInputMethodService} may also receive a
+ * {@link #onConfigurationChanged(Configuration)} callback if there's notable configuration changes
+ * </p>
+ *
+ * @see android.content.ComponentCallbacks#onConfigurationChanged(Configuration)
+ * @see Context#isUiContext Context#isUiContext to see the concept of UI Context.
  */
-public abstract class AbstractInputMethodService extends Service
+public abstract class AbstractInputMethodService extends WindowProviderService
         implements KeyEvent.Callback {
     private InputMethod mInputMethod;
     
@@ -272,9 +292,33 @@ public abstract class AbstractInputMethodService extends Service
     public void notifyUserActionIfNecessary() {
     }
 
+    // TODO(b/149463653): remove it in T. We missed the API deadline in S.
     /** @hide */
     @Override
     public final boolean isUiContext() {
         return true;
     }
+
+    /** @hide */
+    @Override
+    public final int getWindowType() {
+        return WindowManager.LayoutParams.TYPE_INPUT_METHOD;
+    }
+
+    /** @hide */
+    @Override
+    @Nullable
+    public final Bundle getWindowContextOptions() {
+        return null;
+    }
+
+    /** @hide */
+    @Override
+    public final int getInitialDisplayId() {
+        try {
+            return WindowManagerGlobal.getWindowManagerService().getImeDisplayId();
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
 }

core/java/android/inputmethodservice/InputMethodService.java

@@ -629,10 +629,13 @@ public class InputMethodService extends AbstractInputMethodService {
                 throw new IllegalStateException(
                         "attachToken() must be called at most once. token=" + token);
             }
+            attachToWindowToken(token);
             mToken = token;
             mWindow.setToken(token);
         }
 
+        // TODO(b/149463653): remove updateInputMethodDisplay(int displayId) since we'll get the
+        // right display by attachToWindowToken
         /**
          * {@inheritDoc}
          * @hide

core/java/android/view/IWindowManager.aidl

@@ -865,4 +865,11 @@ interface IWindowManager
     void unregisterCrossWindowBlurEnabledListener(ICrossWindowBlurEnabledListener listener);
 
     boolean isTaskSnapshotSupported();
+
+    /**
+     * Returns the preferred display ID to show software keyboard.
+     *
+     * @see android.window.WindowProviderService#getLaunchedDisplayId
+     */
+    int getImeDisplayId();
 }

core/java/android/window/WindowProviderService.java

@@ -36,7 +36,6 @@ 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
@@ -89,6 +88,20 @@ public abstract class WindowProviderService extends Service {
         return null;
     }
 
+    /**
+     * Returns the display ID to launch this {@link WindowProviderService}.
+     *
+     * @hide
+     */
+    @TestApi
+    @SuppressLint({"OnNameExpected"})
+    // Suppress the lint because it is not a callback and users may override this API to provide
+    // display.
+    @NonNull
+    public int getInitialDisplayId() {
+        return DEFAULT_DISPLAY;
+    }
+
     /**
      * Attaches this WindowProviderService to the {@code windowToken}.
      *
@@ -104,10 +117,9 @@ public abstract class WindowProviderService extends Service {
     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 display = context.getSystemService(DisplayManager.class)
-        final Display defaultDisplay = context.getSystemService(DisplayManager.class)
+                .getDisplay(getInitialDisplayId());
-                .getDisplay(DEFAULT_DISPLAY);
+        return context.createTokenContext(mWindowToken, display);
-        return context.createTokenContext(mWindowToken, defaultDisplay);
     }
 
     @CallSuper

core/tests/coretests/src/android/content/ContextTest.java

@@ -32,7 +32,6 @@ import android.content.res.Configuration;
 import android.graphics.PixelFormat;
 import android.hardware.display.DisplayManager;
 import android.hardware.display.VirtualDisplay;
-import android.inputmethodservice.InputMethodService;
 import android.media.ImageReader;
 import android.os.UserHandle;
 import android.view.Display;
@@ -139,13 +138,6 @@ public class ContextTest {
         assertThat(systemUiContext.isUiContext()).isTrue();
     }
 
-    @Test
-    public void testIsUiContext_InputMethodService_returnsTrue() {
-        final InputMethodService ims = new InputMethodService();
-
-        assertTrue(ims.isUiContext());
-    }
-
     @Test
     public void testGetDisplayFromDisplayContextDerivedContextOnPrimaryDisplay() {
         verifyGetDisplayFromDisplayContextDerivedContext(false /* onSecondaryDisplay */);

services/core/java/com/android/server/wm/WindowManagerService.java

@@ -46,6 +46,7 @@ import static android.provider.Settings.Global.DEVELOPMENT_WM_DISPLAY_SETTINGS_P
 import static android.view.Display.DEFAULT_DISPLAY;
 import static android.view.Display.INVALID_DISPLAY;
 import static android.view.WindowManager.DISPLAY_IME_POLICY_FALLBACK_DISPLAY;
+import static android.view.WindowManager.DISPLAY_IME_POLICY_LOCAL;
 import static android.view.WindowManager.LayoutParams.FIRST_APPLICATION_WINDOW;
 import static android.view.WindowManager.LayoutParams.FIRST_SUB_WINDOW;
 import static android.view.WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM;
@@ -8632,4 +8633,23 @@ public class WindowManagerService extends IWindowManager.Stub
             return snapshot != null && snapshot.hasImeSurface();
         }
     }
+
+    @Override
+    public int getImeDisplayId() {
+        // TODO(b/189805422): Add a toast to notify users that IMS may get extra
+        //  onConfigurationChanged callback when perDisplayFocus is enabled.
+        //  Enabling perDisplayFocus means that we track focus on each display, so we don't have
+        //  the "top focus" display and getTopFocusedDisplayContent returns the default display
+        //  as the fallback. It leads to InputMethodService receives an extra onConfiguration
+        //  callback when InputMethodService move from a secondary display to another display
+        //  with the same display metrics because InputMethodService will always associate with
+        //  the ImeContainer on the default display in onCreate and receive a configuration update
+        //  to match default display ImeContainer and then receive another configuration update
+        //  from attachToWindowToken.
+        synchronized (mGlobalLock) {
+            final DisplayContent dc = mRoot.getTopFocusedDisplayContent();
+            return dc.getImePolicy() == DISPLAY_IME_POLICY_LOCAL ? dc.getDisplayId()
+                    : DEFAULT_DISPLAY;
+        }
+    }
 }