RichTextView.java revision d832154e333a3a45b5faecd518b664ddd297183c 
1/*
2 * Copyright (C) 2016 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.setupwizardlib.view;
18
19import android.content.Context;
20import android.support.v4.view.ViewCompat;
21import android.text.Annotation;
22import android.text.SpannableString;
23import android.text.Spanned;
24import android.text.method.LinkMovementMethod;
25import android.text.style.TextAppearanceSpan;
26import android.util.AttributeSet;
27import android.util.Log;
28import android.view.MotionEvent;
29import android.widget.TextView;
30
31import com.android.setupwizardlib.span.LinkSpan;
32import com.android.setupwizardlib.span.SpanHelper;
33import com.android.setupwizardlib.util.LinkAccessibilityHelper;
34
35/**
36 * An extension of TextView that automatically replaces the annotation tags as specified in
37 * {@link SpanHelper#replaceSpan(android.text.Spannable, Object, Object)}
38 */
39public class RichTextView extends TextView {
40
41    /* static section */
42
43    private static final String TAG = "RichTextView";
44
45    private static final String ANNOTATION_LINK = "link";
46    private static final String ANNOTATION_TEXT_APPEARANCE = "textAppearance";
47
48    /**
49     * Replace <annotation> tags in strings to become their respective types. Currently 2
50     * types are supported:
51     * <ol>
52     *     <li>&lt;annotation link="foobar"&gt; will create a
53     *     {@link com.android.setupwizardlib.span.LinkSpan} that broadcasts with the key
54     *     "foobar"</li>
55     *     <li>&lt;annotation textAppearance="TextAppearance.FooBar"&gt; will create a
56     *     {@link android.text.style.TextAppearanceSpan} with @style/TextAppearance.FooBar</li>
57     * </ol>
58     */
59    public static CharSequence getRichText(Context context, CharSequence text) {
60        if (text instanceof Spanned) {
61            final SpannableString spannable = new SpannableString(text);
62            final Annotation[] spans = spannable.getSpans(0, spannable.length(), Annotation.class);
63            for (Annotation span : spans) {
64                final String key = span.getKey();
65                if (ANNOTATION_TEXT_APPEARANCE.equals(key)) {
66                    String textAppearance = span.getValue();
67                    final int style = context.getResources()
68                            .getIdentifier(textAppearance, "style", context.getPackageName());
69                    if (style == 0) {
70                        Log.w(TAG, "Cannot find resource: " + style);
71                    }
72                    final TextAppearanceSpan textAppearanceSpan =
73                            new TextAppearanceSpan(context, style);
74                    SpanHelper.replaceSpan(spannable, span, textAppearanceSpan);
75                } else if (ANNOTATION_LINK.equals(key)) {
76                    LinkSpan link = new LinkSpan(span.getValue());
77                    SpanHelper.replaceSpan(spannable, span, link);
78                }
79            }
80            return spannable;
81        }
82        return text;
83    }
84
85    /* non-static section */
86
87    private LinkAccessibilityHelper mAccessibilityHelper;
88
89    public RichTextView(Context context) {
90        super(context);
91        init();
92    }
93
94    public RichTextView(Context context, AttributeSet attrs) {
95        super(context, attrs);
96        init();
97    }
98
99    private void init() {
100        mAccessibilityHelper = new LinkAccessibilityHelper(this);
101        ViewCompat.setAccessibilityDelegate(this, mAccessibilityHelper);
102        setMovementMethod(LinkMovementMethod.getInstance());
103    }
104
105    @Override
106    public void setText(CharSequence text, BufferType type) {
107        text = getRichText(getContext(), text);
108        super.setText(text, type);
109    }
110
111    @Override
112    protected boolean dispatchHoverEvent(MotionEvent event) {
113        if (mAccessibilityHelper != null && mAccessibilityHelper.dispatchHoverEvent(event)) {
114            return true;
115        }
116        return super.dispatchHoverEvent(event);
117    }
118}
119