Update View translation APIs.

This change doesn't contain the virtual view part and the API
dispatchTranslationRequests, it will be done in another change.

Bug: 178046780
Test: manual
Test: atest CtsTranslationTestCases
CTS-Coverage-Bug: 177960696

Change-Id: I65fe1db19c9dff21c0caca425fbb7d08559e730b

core/api/current.txt

@@ -48273,6 +48273,7 @@ package android.view {
     method protected int computeVerticalScrollRange();
     method public android.view.accessibility.AccessibilityNodeInfo createAccessibilityNodeInfo();
     method public void createContextMenu(android.view.ContextMenu);
+    method @Nullable public android.view.translation.ViewTranslationRequest createTranslationRequest(@NonNull int[]);
     method @Deprecated public void destroyDrawingCache();
     method public android.view.WindowInsets dispatchApplyWindowInsets(android.view.WindowInsets);
     method public boolean dispatchCapturedPointerEvent(android.view.MotionEvent);
@@ -48493,6 +48494,7 @@ package android.view {
     method @Nullable public android.graphics.drawable.Drawable getVerticalScrollbarThumbDrawable();
     method @Nullable public android.graphics.drawable.Drawable getVerticalScrollbarTrackDrawable();
     method public int getVerticalScrollbarWidth();
+    method @Nullable public android.view.translation.ViewTranslationCallback getViewTranslationCallback();
     method public android.view.ViewTreeObserver getViewTreeObserver();
     method public int getVisibility();
     method public final int getWidth();
@@ -48636,6 +48638,7 @@ package android.view {
     method public void onStartTemporaryDetach();
     method public boolean onTouchEvent(android.view.MotionEvent);
     method public boolean onTrackballEvent(android.view.MotionEvent);
+    method public void onTranslationResponse(@NonNull android.view.translation.ViewTranslationResponse);
     method @CallSuper public void onVisibilityAggregated(boolean);
     method protected void onVisibilityChanged(@NonNull android.view.View, int);
     method public void onWindowFocusChanged(boolean);
@@ -48844,6 +48847,7 @@ package android.view {
     method public void setVerticalScrollbarPosition(int);
     method public void setVerticalScrollbarThumbDrawable(@Nullable android.graphics.drawable.Drawable);
     method public void setVerticalScrollbarTrackDrawable(@Nullable android.graphics.drawable.Drawable);
+    method public void setViewTranslationCallback(@NonNull android.view.translation.ViewTranslationCallback);
     method public void setVisibility(int);
     method @Deprecated public void setWillNotCacheDrawing(boolean);
     method public void setWillNotDraw(boolean);
@@ -52665,6 +52669,12 @@ package android.view.translation {
     method public void onStarted(@NonNull String, @NonNull String);
   }
 
+  @UiThread public interface ViewTranslationCallback {
+    method public boolean onClearTranslation(@NonNull android.view.View);
+    method public boolean onHideTranslation(@NonNull android.view.View);
+    method public boolean onShowTranslation(@NonNull android.view.View);
+  }
+
   public final class ViewTranslationRequest implements android.os.Parcelable {
     method public int describeContents();
     method @NonNull public android.view.autofill.AutofillId getAutofillId();

core/java/android/view/View.java

@@ -151,6 +151,8 @@ import android.view.inputmethod.InputConnection;
 import android.view.inspector.InspectableProperty;
 import android.view.inspector.InspectableProperty.EnumEntry;
 import android.view.inspector.InspectableProperty.FlagEntry;
+import android.view.translation.TranslationSpec.DataFormat;
+import android.view.translation.ViewTranslationCallback;
 import android.view.translation.ViewTranslationRequest;
 import android.view.translation.ViewTranslationResponse;
 import android.widget.Checkable;
@@ -5253,6 +5255,9 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
     @Nullable
     private String[] mOnReceiveContentMimeTypes;
 
+    @Nullable
+    private ViewTranslationCallback mViewTranslationCallback;
+
     /**
      * Simple constructor to use when creating a view from code.
      *
@@ -30717,71 +30722,62 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
         }
     }
 
+    //TODO(b/1960696): update javadoc when dispatchRequestTranslation is ready.
     /**
-     * Returns a {@link ViewTranslationRequest} to the {@link onStartUiTranslation} which represents
-     * the content to be translated.
+     * Returns a {@link ViewTranslationRequest} which represents the content to be translated.
      *
-     * <p>The default implementation does nothing and return null.</p>
+     * <p>The default implementation does nothing and returns null.</p>
      *
-     * @hide
-     *
-     * @return the {@link ViewTranslationRequest} which contains the information to be translated.
+     * @param supportedFormats the supported translation formats. For now, the only possible value
+     * is the {@link android.view.translation.TranslationSpec#DATA_FORMAT_TEXT}.
+     * @return the {@link ViewTranslationRequest} which contains the information to be translated or
+     * {@code null} if this View doesn't support translation.
+     * The {@link AutofillId} must be set on the returned value.
      */
     @Nullable
-    //TODO(b/178046780): initial version for demo. Will mark public when the design is reviewed.
-    public ViewTranslationRequest onCreateTranslationRequest() {
+    public ViewTranslationRequest createTranslationRequest(
+            @NonNull @DataFormat int[] supportedFormats) {
         return null;
     }
 
     /**
-     * Called when the user wants to show the original text instead of the translated text.
+     * Returns a {@link ViewTranslationCallback} that is used to display/hide the translated
+     * information. If the View supports displaying translated content, it should implement
+     * {@link ViewTranslationCallback}.
      *
-     * @hide
+     * <p>The default implementation returns null if developers don't set the customized
+     * {@link ViewTranslationCallback} by {@link #setViewTranslationCallback} </p>
      *
-     * <p> The default implementation does nothing.
+     * @return a {@link ViewTranslationCallback} that is used to control how to display the
+     * translated information or {@code null} if this View doesn't support translation.
      */
-    //TODO(b/178046780): initial version for demo. Will mark public when the design is reviewed.
-    public void onPauseUiTranslation() {
-        // no-op
+    @Nullable
+    public ViewTranslationCallback getViewTranslationCallback() {
+        return mViewTranslationCallback;
     }
 
     /**
-     * User can switch back to show the original text, this method called when the user wants to
-     * re-show the translated text again.
+     * Sets a {@link ViewTranslationCallback} that is used to display/hide the translated
+     * information. Developers can provide the customized implementation for show/hide translated
+     * information.
      *
-     * @hide
-     *
-     * <p> The default implementation does nothing.</p>
+     * @param callback a {@link ViewTranslationCallback} that is used to control how to display the
+     * translated information
      */
-    //TODO(b/178046780): initial version for demo. Will mark public when the design is reviewed.
-    public void onRestoreUiTranslation() {
-        // no-op
+    public void setViewTranslationCallback(@NonNull ViewTranslationCallback callback) {
+        mViewTranslationCallback = callback;
     }
 
     /**
-     * Called when the user finish the Ui translation and no longer to show the translated text.
-     *
-     * @hide
-     *
-     * <p> The default implementation does nothing.</p>
-     */
-    //TODO(b/178046780): initial version for demo. Will mark public when the design is reviewed.
-    public void onFinishUiTranslation() {
-        // no-op
-    }
-
-    /**
-     * Called when the request from {@link onStartUiTranslation} is completed by the translation
-     * service so that the translation result can be shown.
-     *
-     * @hide
+     * Called when the content from {@link #createTranslationRequest} had been translated by the
+     * TranslationService.
      *
      * <p> The default implementation does nothing.</p>
      *
-     * @param response the translated information which can be shown in the view.
+     * @param response a {@link ViewTranslationResponse} that contains the translated information
+     * which can be shown in the view.
      */
-    //TODO(b/178046780): initial version for demo. Will mark public when the design is reviewed.
-    public void onTranslationComplete(@NonNull ViewTranslationResponse response) {
+    public void onTranslationResponse(@NonNull ViewTranslationResponse response) {
         // no-op
     }
 

core/java/android/view/translation/UiTranslationController.java

@@ -46,7 +46,7 @@ import java.io.PrintWriter;
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.function.Consumer;
+import java.util.function.BiConsumer;
 
 /**
  * A controller to manage the ui translation requests for the {@link Activity}.
@@ -77,6 +77,7 @@ public class UiTranslationController {
     private final HandlerThread mWorkerThread;
     @NonNull
     private final Handler mWorkerHandler;
+    private int mCurrentState;
 
     public UiTranslationController(Activity activity, Context context) {
         mActivity = activity;
@@ -101,6 +102,9 @@ public class UiTranslationController {
         }
         Log.i(TAG, "updateUiTranslationState state: " + stateToString(state)
                 + (DEBUG ? ", views: " + views : ""));
+        synchronized (mLock) {
+            mCurrentState = state;
+        }
         switch (state) {
             case STATE_UI_TRANSLATION_STARTED:
                 final Pair<TranslationSpec, TranslationSpec> specs =
@@ -114,14 +118,14 @@ public class UiTranslationController {
                 }
                 break;
             case STATE_UI_TRANSLATION_PAUSED:
-                runForEachView(View::onPauseUiTranslation);
+                runForEachView((view, callback) -> callback.onHideTranslation(view));
                 break;
             case STATE_UI_TRANSLATION_RESUMED:
-                runForEachView(View::onRestoreUiTranslation);
+                runForEachView((view, callback) -> callback.onShowTranslation(view));
                 break;
             case STATE_UI_TRANSLATION_FINISHED:
                 destroyTranslators();
-                runForEachView(View::onFinishUiTranslation);
+                runForEachView((view, callback) -> callback.onClearTranslation(view));
                 synchronized (mLock) {
                     mViews.clear();
                 }
@@ -232,11 +236,16 @@ public class UiTranslationController {
         }
         final SparseArray<ViewTranslationResponse> translatedResult =
                 response.getViewTranslationResponses();
+        // TODO(b/177960696): handle virtual views. Check the result if the AutofillId is virtual
+        // AutofillId?
         onTranslationCompleted(translatedResult);
     }
 
     private void onTranslationCompleted(SparseArray<ViewTranslationResponse> translatedResult) {
         if (!mActivity.isResumed()) {
+            if (DEBUG) {
+                Log.v(TAG, "onTranslationCompleted: Activity is not resumed.");
+            }
             return;
         }
         final int resultCount = translatedResult.size();
@@ -244,6 +253,11 @@ public class UiTranslationController {
             Log.v(TAG, "onTranslationCompleted: receive " + resultCount + " responses.");
         }
         synchronized (mLock) {
+            if (mCurrentState == STATE_UI_TRANSLATION_FINISHED) {
+                Log.w(TAG, "onTranslationCompleted: the translation state is finished now. "
+                        + "Skip to show the translated text.");
+                return;
+            }
             for (int i = 0; i < resultCount; i++) {
                 final ViewTranslationResponse response = translatedResult.get(i);
                 final AutofillId autofillId = response.getAutofillId();
@@ -256,18 +270,28 @@ public class UiTranslationController {
                             + " may be gone.");
                     continue;
                 }
-                mActivity.runOnUiThread(() -> view.onTranslationComplete(response));
+                mActivity.runOnUiThread(() -> {
+                    if (view.getViewTranslationCallback() == null) {
+                        if (DEBUG) {
+                            Log.d(TAG, view + " doesn't support showing translation because of "
+                                    + "null ViewTranslationCallback.");
+                        }
+                        return;
+                    }
+                    view.onTranslationResponse(response);
+                    view.getViewTranslationCallback().onShowTranslation(view);
+                });
             }
         }
     }
 
     /**
-     * Called when there is an ui translation request comes to request view translation.
+     * Creates a Translator for the given source and target translation specs and start the ui
+     * translation when the Translator is created successfully.
      */
     @WorkerThread
     private void createTranslatorAndStart(TranslationSpec sourceSpec, TranslationSpec destSpec,
             List<AutofillId> views) {
-        // Create Translator
         final Translator translator = createTranslatorIfNeeded(sourceSpec, destSpec);
         if (translator == null) {
             Log.w(TAG, "Can not create Translator for sourceSpec:" + sourceSpec + " destSpec:"
@@ -295,31 +319,51 @@ public class UiTranslationController {
      */
     private void onUiTranslationStarted(Translator translator, List<AutofillId> views) {
         synchronized (mLock) {
-            // Find Views collect the translation data
-            final ArrayList<ViewTranslationRequest> requests = new ArrayList<>();
-            final ArrayList<View> foundViews = new ArrayList<>();
-            findViewsTraversalByAutofillIds(views, foundViews);
-            for (int i = 0; i < foundViews.size(); i++) {
-                final View view = foundViews.get(i);
-                final int currentCount = i;
-                mActivity.runOnUiThread(() -> {
-                    final ViewTranslationRequest request = view.onCreateTranslationRequest();
-                    if (request != null
-                            && request.getKeys().size() > 0) {
-                        requests.add(request);
-                    }
-                    if (currentCount == (foundViews.size() - 1)) {
-                        Log.v(TAG, "onUiTranslationStarted: collect " + requests.size()
-                                + " requests.");
-                        mWorkerHandler.sendMessage(PooledLambda.obtainMessage(
-                                UiTranslationController::sendTranslationRequest,
-                                UiTranslationController.this, translator, requests));
-                    }
-                });
-            }
+            // TODO(b/177960696): handle virtual views. Need to check the requested view list is
+            //  virtual AutofillId or not
+            findViewsAndCollectViewTranslationRequest(translator, views);
         }
     }
 
+    /**
+     * If the translation requested views are not virtual view, we need to traverse the tree to
+     * find the views and get the View's ViewTranslationRequest.
+     */
+    private void findViewsAndCollectViewTranslationRequest(Translator translator,
+            List<AutofillId> views) {
+        // Find Views collect the translation data
+        final ArrayList<ViewTranslationRequest> requests = new ArrayList<>();
+            final ArrayList<View> foundViews = new ArrayList<>();
+        findViewsTraversalByAutofillIds(views, foundViews);
+        final int[] supportedFormats = getSupportedFormatsLocked();
+        for (int i = 0; i < foundViews.size(); i++) {
+            final View view = foundViews.get(i);
+            final int currentCount = i;
+            mActivity.runOnUiThread(() -> {
+                final ViewTranslationRequest request =
+                        view.createTranslationRequest(supportedFormats);
+                // TODO(b/177960696): handle null case, the developers may want to handle the
+                //  translation, call dispatchRequestTranslation() instead.
+                if (request != null
+                        && request.getKeys().size() > 0) {
+                    requests.add(request);
+                }
+                if (currentCount == (foundViews.size() - 1)) {
+                    Log.v(TAG, "onUiTranslationStarted: collect " + requests.size()
+                            + " requests.");
+                    mWorkerHandler.sendMessage(PooledLambda.obtainMessage(
+                            UiTranslationController::sendTranslationRequest,
+                            UiTranslationController.this, translator, requests));
+                }
+            });
+        }
+    }
+
+    private int[] getSupportedFormatsLocked() {
+        // We only support text now
+        return new int[] {TranslationSpec.DATA_FORMAT_TEXT};
+    }
+
     private void findViewsTraversalByAutofillIds(List<AutofillId> sourceViewIds,
             ArrayList<View> foundViews) {
         final ArrayList<ViewRootImpl> roots =
@@ -356,20 +400,21 @@ public class UiTranslationController {
         }
     }
 
-    private void runForEachView(Consumer<View> action) {
+    private void runForEachView(BiConsumer<View, ViewTranslationCallback> action) {
         synchronized (mLock) {
             final ArrayMap<AutofillId, WeakReference<View>> views = new ArrayMap<>(mViews);
             mActivity.runOnUiThread(() -> {
                 final int viewCounts = views.size();
                 for (int i = 0; i < viewCounts; i++) {
                     final View view = views.valueAt(i).get();
-                    if (view == null) {
+                    if (view == null || view.getViewTranslationCallback() == null) {
                         if (DEBUG) {
-                            Log.d(TAG, "View was gone for autofillid = " + views.keyAt(i));
+                            Log.d(TAG, "View was gone or ViewTranslationCallback for autofillid "
+                                    + "= " + views.keyAt(i));
                         }
                         continue;
                     }
-                    action.accept(view);
+                    action.accept(view, view.getViewTranslationCallback());
                 }
             });
         }

core/java/android/view/translation/ViewTranslationCallback.java

@@ -0,0 +1,51 @@
+/*
+ * 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.view.translation;
+
+import android.annotation.NonNull;
+import android.annotation.UiThread;
+import android.view.View;
+
+/**
+ * Callback for handling the translated information show or hide in the {@link View}. See {@link
+ * View#onTranslationResponse} for how to get the translated information.
+ */
+@UiThread
+public interface ViewTranslationCallback {
+    /**
+     * Called when the translated text is ready to show or if the user has requested to reshow the
+     * translated content after hiding it. This may be called before the translation results are
+     * returned through the {@link View#onTranslationResponse}.
+     *
+     * @return {@code true} if the View handles showing the translation.
+     */
+    boolean onShowTranslation(@NonNull View view);
+    /**
+     * Called when the user wants to show the original text instead of the translated text. This
+     * may be called before the translation results are returned through the
+     * {@link View#onTranslationResponse}.
+     *
+     * @return {@code true} if the View handles hiding the translation.
+     */
+    boolean onHideTranslation(@NonNull View view);
+    /**
+     * Called when the user finish the Ui translation and no longer to show the translated text.
+     *
+     * @return {@code true} if the View handles clearing the translation.
+     */
+    boolean onClearTranslation(@NonNull View view);
+}

core/java/android/widget/TextView.java

@@ -195,7 +195,9 @@ import android.view.textclassifier.TextLinks;
 import android.view.textservice.SpellCheckerSubtype;
 import android.view.textservice.TextServicesManager;
 import android.view.translation.TranslationRequestValue;
+import android.view.translation.TranslationSpec;
 import android.view.translation.UiTranslationController;
+import android.view.translation.ViewTranslationCallback;
 import android.view.translation.ViewTranslationRequest;
 import android.view.translation.ViewTranslationResponse;
 import android.widget.RemoteViews.RemoteView;
@@ -203,6 +205,7 @@ import android.widget.RemoteViews.RemoteView;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.logging.MetricsLogger;
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
+import com.android.internal.util.ArrayUtils;
 import com.android.internal.util.FastMath;
 import com.android.internal.util.Preconditions;
 import com.android.internal.widget.EditableInputConnection;
@@ -737,7 +740,7 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     private MovementMethod mMovement;
 
     private TransformationMethod mTransformation;
-    private TranslationTransformationMethod mTranslationTransformation;
+    private TextViewTranslationCallback mDefaultTranslationCallback;
     @UnsupportedAppUsage
     private boolean mAllowTransformationLengthChange;
     @UnsupportedAppUsage
@@ -13857,136 +13860,104 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     }
 
     /**
-     * Provides a {@link ViewTranslationRequest} that represents the content to be translated via
-     * translation service.
+     * Returns a {@link ViewTranslationRequest} which represents the content to be translated.
      *
-     * <p>NOTE: When overriding the method, it should not translate the password. We also suggest
-     * that not translating the text is selectable or editable. We use the transformation method to
-     * implement showing the translated text. The TextView does not support the transformation
-     * method text length change. If the text is selectable or editable, it will crash while
-     * selecting the text. To support it, it needs broader changes to text APIs, we only allow to
-     * translate non selectable and editable text now.
+     * <p>NOTE: When overriding the method, it should not translate the password. If the subclass
+     * uses {@link TransformationMethod} to display the translated result, it's also not recommend
+     * to translate text is selectable or editable.
      *
-     * @hide
+     * @param supportedFormats the supported translation format. The value could be {@link
+     *                         android.view.translation.TranslationSpec#DATA_FORMAT_TEXT}.
+     * @return the {@link ViewTranslationRequest} which contains the information to be translated.
      */
     @Nullable
     @Override
-    public ViewTranslationRequest onCreateTranslationRequest() {
-        if (mText == null || mText.length() == 0) {
+    public ViewTranslationRequest createTranslationRequest(@NonNull int[] supportedFormats) {
+        if (supportedFormats == null || supportedFormats.length == 0) {
             // TODO(b/182433547): remove before S release
             if (UiTranslationController.DEBUG) {
-                Log.w(LOG_TAG, "Cannot create translation request for the empty text.");
+                Log.w(LOG_TAG, "Do not provide the support translation formats.");
             }
             return null;
         }
-        // Not translate password, editable text and not important for translation
-        // TODO(b/177214256): support selectable text translation. It needs to broader changes to
-        //  text selection apis, not support in S.
-        boolean isPassword = isAnyPasswordInputType() || hasPasswordTransformationMethod();
-        if (isTextEditable() || isPassword || isTextSelectable()) {
-            // TODO(b/182433547): remove before S release
-            if (UiTranslationController.DEBUG) {
-                Log.w(LOG_TAG, "Cannot create translation request. editable = " + isTextEditable()
-                        + ", isPassword = " + isPassword + ", selectable = " + isTextSelectable());
+        ViewTranslationRequest.Builder requestBuilder =
+                new ViewTranslationRequest.Builder(getAutofillId());
+        // Support Text translation
+        if (ArrayUtils.contains(supportedFormats, TranslationSpec.DATA_FORMAT_TEXT)) {
+            if (mText == null || mText.length() == 0) {
+                // TODO(b/182433547): remove before S release
+                if (UiTranslationController.DEBUG) {
+                    Log.w(LOG_TAG, "Cannot create translation request for the empty text.");
+                }
+                return null;
             }
-            return null;
+            boolean isPassword = isAnyPasswordInputType() || hasPasswordTransformationMethod();
+            // TODO(b/177214256): support selectable text translation.
+            //  We use the TransformationMethod to implement showing the translated text. The
+            //  TextView does not support the text length change for TransformationMethod. If the
+            //  text is selectable or editable, it will crash while selecting the text. To support
+            //  it, it needs broader changes to text APIs, we only allow to translate non selectable
+            //  and editable text in S.
+            if (isTextEditable() || isPassword || isTextSelectable()) {
+                // TODO(b/182433547): remove before S release
+                if (UiTranslationController.DEBUG) {
+                    Log.w(LOG_TAG, "Cannot create translation request. editable = "
+                            + isTextEditable() + ", isPassword = " + isPassword + ", selectable = "
+                            + isTextSelectable());
+                }
+                return null;
+            }
+            // TODO(b/176488462): apply the view's important for translation
+            requestBuilder.setValue(ViewTranslationRequest.ID_TEXT,
+                    TranslationRequestValue.forText(mText));
         }
-        // TODO(b/176488462): apply the view's important for translation property
-        // TODO(b/174283799): remove the spans from the mText and save the spans information
-        // TODO: use fixed ids for request texts.
-        ViewTranslationRequest request =
-                new ViewTranslationRequest.Builder(getAutofillId())
-                        .setValue(ViewTranslationRequest.ID_TEXT,
-                                TranslationRequestValue.forText(mText))
-                        .build();
-        return request;
+        return requestBuilder.build();
     }
 
     /**
-     * Provides the implementation that pauses the ongoing Ui translation, it will show the original
-     * text instead of the translated text and restore the original transformation method.
+     * Returns a {@link ViewTranslationCallback} that is used to display the translated information.
+     * The default implementation will use a {@link TransformationMethod} that allow to replace the
+     * current {@link TransformationMethod} to transform the original text to the translated text
+     * display.
      *
-     * <p>NOTE: If this method is overridden, other translation related methods such as
-     * {@link onRestoreUiTranslation}, {@link onFinishUiTranslation}, {@link onTranslationComplete}
-     * should also be overridden.
-     *
-     * @hide
+     * @return a {@link ViewTranslationCallback} that is used to control how to display the
+     * translated information or {@code null} if this View doesn't support translation.
      */
+    @Nullable
     @Override
-    public void onPauseUiTranslation() {
-        // Restore to original text content.
-        if (mTranslationTransformation != null) {
-            setTransformationMethod(mTranslationTransformation.getOriginalTransformationMethod());
-        } else {
-            // TODO(b/182433547): remove before S release
-            Log.w(LOG_TAG, "onPauseUiTranslation(): no translated text.");
+    public ViewTranslationCallback getViewTranslationCallback() {
+        return getDefaultViewTranslationCallback();
+    }
+
+    private ViewTranslationCallback getDefaultViewTranslationCallback() {
+        if (mDefaultTranslationCallback == null) {
+            mDefaultTranslationCallback = new TextViewTranslationCallback();
         }
+        return mDefaultTranslationCallback;
     }
 
     /**
-     * Provides the implementation that restoes the paused Ui translation, it will show the
-     * translated text again if the text had been translated. This method will replace the current
-     * tansformation method with {@link TranslationTransformationMethod}.
      *
-     * <p>NOTE: If this method is overridden, other translation related methods such as
-     * {@link onPauseUiTranslation}, {@link onFinishUiTranslation}, {@link onTranslationComplete}
-     * should also be overridden.
+     * Called when the content from {@link #createTranslationRequest} had been translated by the
+     * TranslationService. The default implementation will replace the current
+     * {@link TransformationMethod} to transform the original text to the translated text display.
      *
-     * @hide
+     * @param response a {@link ViewTranslationResponse} that contains the translated information
+     * which can be shown in the view.
      */
     @Override
-    public void onRestoreUiTranslation() {
-        if (mTranslationTransformation != null) {
-            setTransformationMethod(mTranslationTransformation);
-        } else {
-            // TODO(b/182433547): remove before S release
-            Log.w(LOG_TAG, "onRestoreUiTranslation(): no translated text.");
-        }
-    }
-
-    /**
-     * Provides the implementation that finishes the current Ui translation and it's no longer to
-     * show the translated text. This method restores the original transformation method and resets
-     * the saved {@link TranslationTransformationMethod}.
-     *
-     * <p>NOTE: If this method is overridden, other translation related methods such as
-     * {@link onPauseUiTranslation}, {@link onRestoreUiTranslation}, {@link onTranslationComplete}
-     * should also be overridden.
-     *
-     * @hide
-     */
-    @Override
-    public void onFinishUiTranslation() {
-        // Restore to original text content and clear TranslationTransformation
-        if (mTranslationTransformation != null) {
-            setTransformationMethod(mTranslationTransformation.getOriginalTransformationMethod());
-            mTranslationTransformation = null;
-        } else {
-            // TODO(b/182433547): remove before S release
-            Log.w(LOG_TAG, "onFinishUiTranslation(): no translated text.");
-        }
-    }
-
-    /**
-     * Default {@link TextView} implementation after the translation request is done by the
-     * translation service, it's ok to show the translated text. This method will save the original
-     * transformation method and replace the current transformation method with
-     * {@link TranslationTransformationMethod}.
-     *
-     * <p>NOTE: If this method is overridden, other translation related methods such as
-     * {@link onPauseUiTranslation}, {@link onRestoreUiTranslation}, {@link onFinishUiTranslation}
-     * should also be overridden.
-     *
-     * @hide
-     */
-    @Override
-    public void onTranslationComplete(@NonNull ViewTranslationResponse response) {
-        // Show the translated text.
-        TransformationMethod originalTranslationMethod = mTranslationTransformation != null
-                ? mTranslationTransformation.getOriginalTransformationMethod() : mTransformation;
-        mTranslationTransformation =
+    public void onTranslationResponse(@NonNull ViewTranslationResponse response) {
+        // TODO(b/183467275): Use the overridden ViewTranslationCallback instead of our default
+        //  implementation if the view has overridden getViewTranslationCallback.
+        TextViewTranslationCallback callback =
+                (TextViewTranslationCallback) getDefaultViewTranslationCallback();
+        TranslationTransformationMethod oldTranslationMethod =
+                callback.getTranslationTransformation();
+        TransformationMethod originalTranslationMethod = oldTranslationMethod != null
+                ? oldTranslationMethod.getOriginalTransformationMethod() : mTransformation;
+        TranslationTransformationMethod newTranslationMethod =
                 new TranslationTransformationMethod(response, originalTranslationMethod);
         // TODO(b/178353965): well-handle setTransformationMethod.
-        setTransformationMethod(mTranslationTransformation);
+        callback.setTranslationTransformation(newTranslationMethod);
     }
 }

core/java/android/widget/TextViewTranslationCallback.java

@@ -0,0 +1,120 @@
+/*
+ * 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.widget;
+
+import android.annotation.NonNull;
+import android.text.method.TranslationTransformationMethod;
+import android.util.Log;
+import android.view.View;
+import android.view.translation.UiTranslationManager;
+import android.view.translation.ViewTranslationCallback;
+import android.view.translation.ViewTranslationResponse;
+
+/**
+ * Default implementation for {@link ViewTranslationCallback} for {@link TextView} components.
+ * This class handles how to display the translated information for {@link TextView}.
+ *
+ * @hide
+ */
+public class TextViewTranslationCallback implements ViewTranslationCallback {
+
+    private static final String TAG = "TextViewTranslationCallback";
+
+    private static final boolean DEBUG = Log.isLoggable(UiTranslationManager.LOG_TAG, Log.DEBUG);
+
+    private TranslationTransformationMethod mTranslationTransformation;
+
+    /**
+     * Invoked by the platform when receiving the successful {@link ViewTranslationResponse} for the
+     * view that provides the translatable information by {@link View#createTranslationRequest} and
+     * sent by the platform.
+     */
+    void setTranslationTransformation(TranslationTransformationMethod method) {
+        if (method == null) {
+            if (DEBUG) {
+                Log.w(TAG, "setTranslationTransformation: should not set null "
+                        + "TranslationTransformationMethod");
+            }
+            return;
+        }
+        mTranslationTransformation = method;
+    }
+
+    TranslationTransformationMethod getTranslationTransformation() {
+        return mTranslationTransformation;
+    }
+
+    private void clearTranslationTransformation() {
+        if (DEBUG) {
+            Log.v(TAG, "clearTranslationTransformation: " + mTranslationTransformation);
+        }
+        mTranslationTransformation = null;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public boolean onShowTranslation(@NonNull View view) {
+        if (mTranslationTransformation != null) {
+            ((TextView) view).setTransformationMethod(mTranslationTransformation);
+        } else {
+            if (DEBUG) {
+                // TODO(b/182433547): remove before S release
+                Log.w(TAG, "onShowTranslation(): no translated text.");
+            }
+        }
+        return true;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public boolean onHideTranslation(@NonNull View view) {
+        // Restore to original text content.
+        if (mTranslationTransformation != null) {
+            ((TextView) view).setTransformationMethod(
+                    mTranslationTransformation.getOriginalTransformationMethod());
+        } else {
+            if (DEBUG) {
+                // TODO(b/182433547): remove before S release
+                Log.w(TAG, "onHideTranslation(): no translated text.");
+            }
+        }
+        return true;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public boolean onClearTranslation(@NonNull View view) {
+        // Restore to original text content and clear TranslationTransformation
+        if (mTranslationTransformation != null) {
+            ((TextView) view).setTransformationMethod(
+                    mTranslationTransformation.getOriginalTransformationMethod());
+            clearTranslationTransformation();
+        } else {
+            if (DEBUG) {
+                // TODO(b/182433547): remove before S release
+                Log.w(TAG, "onClearTranslation(): no translated text.");
+            }
+        }
+        return true;
+    }
+}