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
17package com.android.settings;
18
19import android.text.Spannable;
20import android.text.TextPaint;
21import android.text.method.LinkMovementMethod;
22import android.text.style.ClickableSpan;
23import android.view.View;
24import android.widget.TextView;
25import android.widget.TextView.BufferType;
26
27/**
28 * Utility class to create clickable links inside {@link TextView TextViews}.
29 */
30public 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