BulletSpan.java revision a70d4a90a029910f788c3e7f8715cf3b842b1e2b 
1/*
2 * Copyright (C) 2006 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 android.text.style;
18
19import android.graphics.Canvas;
20import android.graphics.Paint;
21import android.graphics.Path;
22import android.graphics.Path.Direction;
23import android.os.Parcel;
24import android.text.Layout;
25import android.text.ParcelableSpan;
26import android.text.Spanned;
27import android.text.TextUtils;
28
29public class BulletSpan implements LeadingMarginSpan, ParcelableSpan {
30    private final int mGapWidth;
31    private final boolean mWantColor;
32    private final int mColor;
33
34    private static final int BULLET_RADIUS = 3;
35    private static Path sBulletPath = null;
36    public static final int STANDARD_GAP_WIDTH = 2;
37
38    public BulletSpan() {
39        mGapWidth = STANDARD_GAP_WIDTH;
40        mWantColor = false;
41        mColor = 0;
42    }
43
44    public BulletSpan(int gapWidth) {
45        mGapWidth = gapWidth;
46        mWantColor = false;
47        mColor = 0;
48    }
49
50    public BulletSpan(int gapWidth, int color) {
51        mGapWidth = gapWidth;
52        mWantColor = true;
53        mColor = color;
54    }
55
56    public BulletSpan(Parcel src) {
57        mGapWidth = src.readInt();
58        mWantColor = src.readInt() != 0;
59        mColor = src.readInt();
60    }
61
62    public int getSpanTypeId() {
63        return getSpanTypeIdInternal();
64    }
65
66    /** @hide */
67    public int getSpanTypeIdInternal() {
68        return TextUtils.BULLET_SPAN;
69    }
70
71    public int describeContents() {
72        return 0;
73    }
74
75    public void writeToParcel(Parcel dest, int flags) {
76        writeToParcelInternal(dest, flags);
77    }
78
79    /** @hide */
80    public void writeToParcelInternal(Parcel dest, int flags) {
81        dest.writeInt(mGapWidth);
82        dest.writeInt(mWantColor ? 1 : 0);
83        dest.writeInt(mColor);
84    }
85
86    public int getLeadingMargin(boolean first) {
87        return 2 * BULLET_RADIUS + mGapWidth;
88    }
89
90    public void drawLeadingMargin(Canvas c, Paint p, int x, int dir,
91                                  int top, int baseline, int bottom,
92                                  CharSequence text, int start, int end,
93                                  boolean first, Layout l) {
94        if (((Spanned) text).getSpanStart(this) == start) {
95            Paint.Style style = p.getStyle();
96            int oldcolor = 0;
97
98            if (mWantColor) {
99                oldcolor = p.getColor();
100                p.setColor(mColor);
101            }
102
103            p.setStyle(Paint.Style.FILL);
104
105            if (c.isHardwareAccelerated()) {
106                if (sBulletPath == null) {
107                    sBulletPath = new Path();
108                    // Bullet is slightly better to avoid aliasing artifacts on mdpi devices.
109                    sBulletPath.addCircle(0.0f, 0.0f, 1.2f * BULLET_RADIUS, Direction.CW);
110                }
111
112                c.save();
113                c.translate(x + dir * BULLET_RADIUS, (top + bottom) / 2.0f);
114                c.drawPath(sBulletPath, p);
115                c.restore();
116            } else {
117                c.drawCircle(x + dir * BULLET_RADIUS, (top + bottom) / 2.0f, BULLET_RADIUS, p);
118            }
119
120            if (mWantColor) {
121                p.setColor(oldcolor);
122            }
123
124            p.setStyle(style);
125        }
126    }
127}
128