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1 /*
2  * Copyright (C) 2020 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package android.text.method;
17 
18 import android.annotation.NonNull;
19 import android.annotation.Nullable;
20 import android.graphics.Rect;
21 import android.text.TextUtils;
22 import android.util.Log;
23 import android.view.View;
24 import android.view.translation.TranslationResponseValue;
25 import android.view.translation.ViewTranslationRequest;
26 import android.view.translation.ViewTranslationResponse;
27 import android.widget.TextView;
28 
29 import java.util.regex.Pattern;
30 
31 /**
32  * Transforms source text into an translated string.
33  *
34  * @hide
35  */
36 @android.ravenwood.annotation.RavenwoodKeepWholeClass
37 public class TranslationTransformationMethod implements TransformationMethod2 {
38 
39     private static final String TAG = "TranslationTransformationMethod";
40     private static final Pattern PATTERN_WHITESPACE = Pattern.compile("\\s+");
41 
42     @NonNull
43     private final ViewTranslationResponse mTranslationResponse;
44     @Nullable
45     private TransformationMethod mOriginalTranslationMethod;
46     private boolean mAllowLengthChanges;
47 
48     /**
49      * @param response the translated result from translation service.
50      * @param method the {@link TextView}'s original {@link TransformationMethod}
51      */
TranslationTransformationMethod(@onNull ViewTranslationResponse response, @Nullable TransformationMethod method)52     public TranslationTransformationMethod(@NonNull ViewTranslationResponse response,
53             @Nullable TransformationMethod method) {
54         mTranslationResponse = response;
55         mOriginalTranslationMethod = method;
56     }
57 
58     /**
59      * Returns the {@link TextView}'s original {@link TransformationMethod}. This can be used to
60      * restore to show if the user pauses or finish the ui translation.
61      */
getOriginalTransformationMethod()62     public TransformationMethod getOriginalTransformationMethod() {
63         return mOriginalTranslationMethod;
64     }
65 
66     /**
67      * Returns the {@link TextView}'s {@link ViewTranslationResponse}.
68      */
getViewTranslationResponse()69     public ViewTranslationResponse getViewTranslationResponse() {
70         return mTranslationResponse;
71     }
72 
73     @Override
getTransformation(CharSequence source, View view)74     public CharSequence getTransformation(CharSequence source, View view) {
75         if (!mAllowLengthChanges) {
76             Log.w(TAG, "Caller did not enable length changes; not transforming to translated text");
77             return source;
78         }
79         TranslationResponseValue value = mTranslationResponse.getValue(
80                 ViewTranslationRequest.ID_TEXT);
81         CharSequence translatedText;
82         if (value.getStatusCode() == TranslationResponseValue.STATUS_SUCCESS) {
83             translatedText = value.getText();
84         } else {
85             translatedText = "";
86         }
87 
88         if (TextUtils.isEmpty(translatedText) || isWhitespace(translatedText.toString())) {
89             return source;
90         } else {
91             // TODO(b/174283799): apply the spans to the text
92             return translatedText;
93         }
94     }
95 
96     @Override
onFocusChanged(View view, CharSequence sourceText, boolean focused, int direction, Rect previouslyFocusedRect)97     public void onFocusChanged(View view, CharSequence sourceText,
98             boolean focused, int direction,
99             Rect previouslyFocusedRect) {
100         // do nothing
101     }
102 
103     @Override
setLengthChangesAllowed(boolean allowLengthChanges)104     public void setLengthChangesAllowed(boolean allowLengthChanges) {
105         mAllowLengthChanges = allowLengthChanges;
106     }
107 
isWhitespace(String text)108     private boolean isWhitespace(String text) {
109         return PATTERN_WHITESPACE.matcher(text.substring(0, text.length())).matches();
110     }
111 }
112