1/*
2 * Copyright (C) 2011 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.contacts.format;
18
19import android.text.SpannableString;
20import android.text.style.ForegroundColorSpan;
21import android.widget.TextView;
22
23/**
24 * Highlights the text in a text field.
25 */
26public class PrefixHighlighter {
27    private final int mPrefixHighlightColor;
28
29    private ForegroundColorSpan mPrefixColorSpan;
30
31    public PrefixHighlighter(int prefixHighlightColor) {
32        mPrefixHighlightColor = prefixHighlightColor;
33    }
34
35    /**
36     * Sets the text on the given text view, highlighting the word that matches the given prefix.
37     *
38     * @param view the view on which to set the text
39     * @param text the string to use as the text
40     * @param prefix the prefix to look for
41     */
42    public void setText(TextView view, String text, char[] prefix) {
43        view.setText(apply(text, prefix));
44    }
45
46    /**
47     * Returns a CharSequence which highlights the given prefix if found in the given text.
48     *
49     * @param text the text to which to apply the highlight
50     * @param prefix the prefix to look for
51     */
52    public CharSequence apply(CharSequence text, char[] prefix) {
53        int index = FormatUtils.indexOfWordPrefix(text, prefix);
54        if (index != -1) {
55            if (mPrefixColorSpan == null) {
56                mPrefixColorSpan = new ForegroundColorSpan(mPrefixHighlightColor);
57            }
58
59            SpannableString result = new SpannableString(text);
60            result.setSpan(mPrefixColorSpan, index, index + prefix.length, 0 /* flags */);
61            return result;
62        } else {
63            return text;
64        }
65    }
66}
67