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      1 /*
      2  * Copyright (C) 2018 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 
     17 package com.android.incallui.rtt.impl;
     18 
     19 import android.support.annotation.NonNull;
     20 import android.support.annotation.Nullable;
     21 import android.text.TextWatcher;
     22 import com.android.incallui.rtt.protocol.Constants;
     23 import com.google.common.base.Splitter;
     24 import java.util.ArrayList;
     25 import java.util.Iterator;
     26 import java.util.List;
     27 
     28 /** Message class that holds one RTT chat content. */
     29 final class RttChatMessage {
     30 
     31   private static final Splitter SPLITTER = Splitter.on(Constants.BUBBLE_BREAKER);
     32 
     33   boolean isRemote;
     34   public boolean hasAvatar;
     35   private final StringBuilder content = new StringBuilder();
     36   private boolean isFinished;
     37 
     38   public boolean isFinished() {
     39     return isFinished;
     40   }
     41 
     42   public void finish() {
     43     isFinished = true;
     44   }
     45 
     46   public void append(String text) {
     47     for (int i = 0; i < text.length(); i++) {
     48       char c = text.charAt(i);
     49       if (c != '\b') {
     50         content.append(c);
     51       } else if (content.length() > 0) {
     52         content.deleteCharAt(content.length() - 1);
     53       }
     54     }
     55   }
     56 
     57   public String getContent() {
     58     return content.toString();
     59   }
     60 
     61   /**
     62    * Generates delta change to a text.
     63    *
     64    * <p>This is used to track text change of input. See more details in {@link
     65    * TextWatcher#onTextChanged}
     66    *
     67    * <p>e.g. "hello world" -> "hello" : "\b\b\b\b\b\b"
     68    *
     69    * <p>"hello world" -> "hello mom!" : "\b\b\b\b\bmom!"
     70    *
     71    * <p>"hello world" -> "hello d" : "\b\b\b\b\bd"
     72    *
     73    * <p>"hello world" -> "hello new world" : "\b\b\b\b\bnew world"
     74    */
     75   static String getChangedString(CharSequence s, int start, int before, int count) {
     76     StringBuilder modify = new StringBuilder();
     77     char c = '\b';
     78     int oldLength = s.length() - count + before;
     79     for (int i = 0; i < oldLength - start; i++) {
     80       modify.append(c);
     81     }
     82     modify.append(s, start, start + count);
     83     if (start + count < s.length()) {
     84       modify.append(s, start + count, s.length());
     85     }
     86     return modify.toString();
     87   }
     88 
     89   /** Convert remote input text into an array of {@code RttChatMessage}. */
     90   static RttChatMessage[] getRemoteRttChatMessage(
     91       @Nullable RttChatMessage currentMessage, @NonNull String text) {
     92     Iterator<String> splitText = SPLITTER.split(text).iterator();
     93     List<RttChatMessage> messageList = new ArrayList<>();
     94 
     95     String firstMessageContent = splitText.next();
     96     RttChatMessage firstMessage = currentMessage;
     97     if (firstMessage == null) {
     98       firstMessage = new RttChatMessage();
     99       firstMessage.isRemote = true;
    100     }
    101     firstMessage.append(firstMessageContent);
    102     if (splitText.hasNext() || text.endsWith(Constants.BUBBLE_BREAKER)) {
    103       firstMessage.finish();
    104     }
    105     messageList.add(firstMessage);
    106 
    107     while (splitText.hasNext()) {
    108       String singleMessageContent = splitText.next();
    109       if (singleMessageContent.isEmpty()) {
    110         continue;
    111       }
    112       RttChatMessage message = new RttChatMessage();
    113       message.append(singleMessageContent);
    114       message.isRemote = true;
    115       if (splitText.hasNext()) {
    116         message.finish();
    117       }
    118       messageList.add(message);
    119     }
    120 
    121     return messageList.toArray(new RttChatMessage[0]);
    122   }
    123 }
    124