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      1 /*
      2  * Copyright (C) 2015 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.settings;
     18 
     19 import android.text.Spannable;
     20 import android.text.TextPaint;
     21 import android.text.method.LinkMovementMethod;
     22 import android.text.style.ClickableSpan;
     23 import android.view.View;
     24 import android.widget.TextView;
     25 import android.widget.TextView.BufferType;
     26 
     27 /**
     28  * Utility class to create clickable links inside {@link TextView TextViews}.
     29  */
     30 public class LinkifyUtils {
     31     private static final String PLACE_HOLDER_LINK_BEGIN = "LINK_BEGIN";
     32     private static final String PLACE_HOLDER_LINK_END = "LINK_END";
     33 
     34     private LinkifyUtils() {
     35     }
     36 
     37     /** Interface that handles the click event of the link */
     38     public interface OnClickListener {
     39         void onClick();
     40     }
     41 
     42     /**
     43      * Applies the text into the {@link TextView} and part of it a clickable link.
     44      * The text surrounded with "LINK_BEGIN" and "LINK_END" will become a clickable link. Only
     45      * supports at most one link.
     46      * @return true if the link has been successfully applied, or false if the original text
     47      *         contains no link place holders.
     48      */
     49     public static boolean linkify(TextView textView, StringBuilder text,
     50             final OnClickListener listener) {
     51         // Remove place-holders from the string and record their positions
     52         final int beginIndex = text.indexOf(PLACE_HOLDER_LINK_BEGIN);
     53         if (beginIndex == -1) {
     54             textView.setText(text);
     55             return false;
     56         }
     57         text.delete(beginIndex, beginIndex + PLACE_HOLDER_LINK_BEGIN.length());
     58         final int endIndex = text.indexOf(PLACE_HOLDER_LINK_END);
     59         if (endIndex == -1) {
     60             textView.setText(text);
     61             return false;
     62         }
     63         text.delete(endIndex, endIndex + PLACE_HOLDER_LINK_END.length());
     64 
     65         textView.setText(text.toString(), BufferType.SPANNABLE);
     66         textView.setMovementMethod(LinkMovementMethod.getInstance());
     67         Spannable spannableContent = (Spannable) textView.getText();
     68         ClickableSpan spannableLink = new ClickableSpan() {
     69             @Override
     70             public void onClick(View widget) {
     71                 listener.onClick();
     72             }
     73 
     74             @Override
     75             public void updateDrawState(TextPaint ds) {
     76                 super.updateDrawState(ds);
     77                 ds.setUnderlineText(false);
     78             }
     79         };
     80         spannableContent.setSpan(spannableLink, beginIndex, endIndex,
     81                 Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
     82         return true;
     83     }
     84 }
     85