Merge "Add initial View's APIs for auto translation"

core/java/android/text/method/TranslationTransformationMethod.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2020 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.text.method;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.graphics.Rect;
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.View;
+import android.view.translation.TranslationRequest;
+import android.widget.TextView;
+
+import java.util.regex.Pattern;
+
+/**
+ * Transforms source text into an translated string.
+ *
+ * @hide
+ */
+public class TranslationTransformationMethod implements TransformationMethod2 {
+
+    private static final String TAG = "TranslationTransformationMethod";
+    private static final Pattern PATTERN_WHITESPACE = Pattern.compile("\\s+");
+
+    @NonNull
+    private TranslationRequest mTranslationRequest;
+    @Nullable
+    private TransformationMethod mOriginalTranslationMethod;
+    private boolean mAllowLengthChanges;
+
+    /**
+     * @param request the translated result from translation service.
+     * @param method the {@link TextView}'s original {@link TransformationMethod}
+     */
+    public TranslationTransformationMethod(@NonNull TranslationRequest request,
+            @Nullable TransformationMethod method) {
+        mTranslationRequest = request;
+        mOriginalTranslationMethod = method;
+    }
+
+    /**
+     * Returns the {@link TextView}'s original {@link TransformationMethod}. This can be used to
+     * restore to show if the user pauses or finish the ui translation.
+     */
+    public TransformationMethod getOriginalTransformationMethod() {
+        return mOriginalTranslationMethod;
+    }
+
+    @Override
+    public CharSequence getTransformation(CharSequence source, View view) {
+        if (!mAllowLengthChanges) {
+            Log.w(TAG, "Caller did not enable length changes; not transforming to translated text");
+            return source;
+        }
+        CharSequence translatedText = mTranslationRequest.getTranslationText();
+        if (TextUtils.isEmpty(translatedText) || isWhitespace(translatedText.toString())) {
+            return source;
+        } else {
+            // TODO(b/174283799): apply the spans to the text
+            return translatedText;
+        }
+    }
+
+    @Override
+    public void onFocusChanged(View view, CharSequence sourceText,
+            boolean focused, int direction,
+            Rect previouslyFocusedRect) {
+        // do nothing
+    }
+
+    @Override
+    public void setLengthChangesAllowed(boolean allowLengthChanges) {
+        mAllowLengthChanges = allowLengthChanges;
+    }
+
+    private boolean isWhitespace(String text) {
+        return PATTERN_WHITESPACE.matcher(text.substring(0, text.length())).matches();
+    }
+}

core/java/android/view/View.java

@@ -139,6 +139,7 @@ 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.TranslationRequest;
 import android.widget.Checkable;
 import android.widget.FrameLayout;
 import android.widget.ScrollBarDrawable;
@@ -30630,4 +30631,72 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
             mPrivateFlags4 &= ~PFLAG4_DETACHED;
         }
     }
+
+    /**
+     * Returns a {@link TranslationRequest} to the {@link onStartUiTranslation} which represents
+     * the content to be translated.
+     *
+     * <p>The default implementation does nothing and return null.</p>
+     *
+     * @hide
+     *
+     * @return the {@link TranslationRequest} which contains the information to be translated.
+     */
+    @Nullable
+    //TODO(b/178046780): initial version for demo. Will mark public when the design is reviewed.
+    public TranslationRequest onCreateTranslationRequest() {
+        return null;
+    }
+
+    /**
+     * Called when the user wants to show the original text instead of the translated text.
+     *
+     * @hide
+     *
+     * <p> The default implementation does nothing.
+     */
+    //TODO(b/178046780): initial version for demo. Will mark public when the design is reviewed.
+    public void onPauseUiTranslation() {
+        // no-op
+    }
+
+    /**
+     * User can switch back to show the original text, this method called when the user wants to
+     * re-show the translated text again.
+     *
+     * @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 onRestoreUiTranslation() {
+        // no-op
+    }
+
+    /**
+     * 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
+     *
+     * <p> The default implementation does nothing.</p>
+     *
+     * @param request 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 TranslationRequest request) {
+        // no-op
+    }
 }

core/java/android/widget/TextView.java

@@ -129,6 +129,7 @@ import android.text.method.TextKeyListener;
 import android.text.method.TimeKeyListener;
 import android.text.method.TransformationMethod;
 import android.text.method.TransformationMethod2;
+import android.text.method.TranslationTransformationMethod;
 import android.text.method.WordIterator;
 import android.text.style.CharacterStyle;
 import android.text.style.ClickableSpan;
@@ -193,6 +194,7 @@ import android.view.textclassifier.TextClassifier;
 import android.view.textclassifier.TextLinks;
 import android.view.textservice.SpellCheckerSubtype;
 import android.view.textservice.TextServicesManager;
+import android.view.translation.TranslationRequest;
 import android.widget.RemoteViews.RemoteView;
 
 import com.android.internal.annotations.VisibleForTesting;
@@ -732,6 +734,7 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     private MovementMethod mMovement;
 
     private TransformationMethod mTransformation;
+    private TranslationTransformationMethod mTranslationTransformation;
     @UnsupportedAppUsage
     private boolean mAllowTransformationLengthChange;
     @UnsupportedAppUsage
@@ -13814,4 +13817,121 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
             Log.d(LOG_TAG, location + ": " + String.format(msgFormat, msgArgs));
         }
     }
+
+    /**
+     * Provides a {@link TranslationRequest} that represents the content to be translated via
+     * translation service.
+     *
+     * <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.
+     *
+     * @hide
+     */
+    @Nullable
+    @Override
+    public TranslationRequest onCreateTranslationRequest() {
+        if (mText == null || mText.length() == 0) {
+            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()) {
+            return null;
+        }
+        // TODO(b/176488462): apply the view's important for translation property
+        // TODO(b/174283799): remove the spans from the mText and save the spans informatopn
+        TranslationRequest request =
+                new TranslationRequest.Builder()
+                        .setAutofillId(getAutofillId())
+                        .setTranslationText(mText)
+                        .build();
+        return request;
+    }
+
+    /**
+     * 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.
+     *
+     * <p>NOTE: If this method is overridden, other translation related methods such as
+     * {@link onRestoreUiTranslation}, {@link onFinishUiTranslation}, {@link onTranslationComplete}
+     * should also be overridden.
+     *
+     * @hide
+     */
+    @Override
+    public void onPauseUiTranslation() {
+        // Restore to original text content.
+        if (mTranslationTransformation != null) {
+            setTransformationMethod(mTranslationTransformation.getOriginalTransformationMethod());
+        }
+    }
+
+    /**
+     * 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.
+     *
+     * @hide
+     */
+    @Override
+    public void onRestoreUiTranslation() {
+        if (mTranslationTransformation != null) {
+            setTransformationMethod(mTranslationTransformation);
+        } else {
+            Log.w(LOG_TAG, "onResumeTranslatedText(): 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;
+        }
+    }
+
+    /**
+     * 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 TranslationRequest data) {
+        // Show the translated text.
+        TransformationMethod originalTranslationMethod = mTranslationTransformation != null
+                ? mTranslationTransformation.getOriginalTransformationMethod() : mTransformation;
+        mTranslationTransformation =
+                new TranslationTransformationMethod(data, originalTranslationMethod);
+        // TODO(b/178353965): well-handle setTransformationMethod.
+        setTransformationMethod(mTranslationTransformation);
+    }
 }