Font.java revision 11518acc8c416023d8c2192b441a1767205676d9 
1/*
2 * Copyright (C) 2008 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.renderscript;
18
19import java.io.File;
20import java.io.IOException;
21import java.io.InputStream;
22import java.util.HashMap;
23import java.util.Map;
24
25import android.os.Environment;
26
27import android.content.res.AssetManager;
28import android.content.res.Resources;
29import android.util.Log;
30import android.util.TypedValue;
31
32/**
33 * <p>This class gives users a simple way to draw hardware accelerated text.
34 * Internally, the glyphs are rendered using the Freetype library and an internal cache of
35 * rendered glyph bitmaps is maintained. Each font object represents a combination of a typeface,
36 * and point size. You can create multiple font objects to represent styles such as bold or italic text,
37 * faces, and different font sizes. During creation, the Android system quieries device's screen DPI to
38 * ensure proper sizing across multiple device configurations.</p>
39 * <p>Fonts are rendered using screen-space positions and no state setup beyond binding a
40 * font to the Renderscript is required. A note of caution on performance, though the state changes
41 * are transparent to the user, they do happen internally, and it is more efficient to
42 * render large batches of text in sequence. It is also more efficient to render multiple
43 * characters at once instead of one by one to improve draw call batching.</p>
44 * <p>Font color and transparency are not part of the font object and you can freely modify
45 * them in the script to suit the user's rendering needs. Font colors work as a state machine.
46 * Every new call to draw text uses the last color set in the script.</p>
47 **/
48public class Font extends BaseObj {
49
50    //These help us create a font by family name
51    private static final String[] sSansNames = {
52        "sans-serif", "arial", "helvetica", "tahoma", "verdana"
53    };
54
55    private static final String[] sSerifNames = {
56        "serif", "times", "times new roman", "palatino", "georgia", "baskerville",
57        "goudy", "fantasy", "cursive", "ITC Stone Serif"
58    };
59
60    private static final String[] sMonoNames = {
61        "monospace", "courier", "courier new", "monaco"
62    };
63
64    private static class FontFamily {
65        String[] mNames;
66        String mNormalFileName;
67        String mBoldFileName;
68        String mItalicFileName;
69        String mBoldItalicFileName;
70    }
71
72    private static Map<String, FontFamily> sFontFamilyMap;
73
74    public enum Style {
75        NORMAL,
76        BOLD,
77        ITALIC,
78        BOLD_ITALIC;
79    }
80
81    private static void addFamilyToMap(FontFamily family) {
82        for(int i = 0; i < family.mNames.length; i ++) {
83            sFontFamilyMap.put(family.mNames[i], family);
84        }
85    }
86
87    private static void initFontFamilyMap() {
88        sFontFamilyMap = new HashMap<String, FontFamily>();
89
90        FontFamily sansFamily = new FontFamily();
91        sansFamily.mNames = sSansNames;
92        sansFamily.mNormalFileName = "DroidSans.ttf";
93        sansFamily.mBoldFileName = "DroidSans-Bold.ttf";
94        sansFamily.mItalicFileName = "DroidSans.ttf";
95        sansFamily.mBoldItalicFileName = "DroidSans-Bold.ttf";
96        addFamilyToMap(sansFamily);
97
98        FontFamily serifFamily = new FontFamily();
99        serifFamily.mNames = sSerifNames;
100        serifFamily.mNormalFileName = "DroidSerif-Regular.ttf";
101        serifFamily.mBoldFileName = "DroidSerif-Bold.ttf";
102        serifFamily.mItalicFileName = "DroidSerif-Italic.ttf";
103        serifFamily.mBoldItalicFileName = "DroidSerif-BoldItalic.ttf";
104        addFamilyToMap(serifFamily);
105
106        FontFamily monoFamily = new FontFamily();
107        monoFamily.mNames = sMonoNames;
108        monoFamily.mNormalFileName = "DroidSansMono.ttf";
109        monoFamily.mBoldFileName = "DroidSansMono.ttf";
110        monoFamily.mItalicFileName = "DroidSansMono.ttf";
111        monoFamily.mBoldItalicFileName = "DroidSansMono.ttf";
112        addFamilyToMap(monoFamily);
113    }
114
115    static {
116        initFontFamilyMap();
117    }
118
119    static String getFontFileName(String familyName, Style style) {
120        FontFamily family = sFontFamilyMap.get(familyName);
121        if(family != null) {
122            switch(style) {
123                case NORMAL:
124                    return family.mNormalFileName;
125                case BOLD:
126                    return family.mBoldFileName;
127                case ITALIC:
128                    return family.mItalicFileName;
129                case BOLD_ITALIC:
130                    return family.mBoldItalicFileName;
131            }
132        }
133        // Fallback if we could not find the desired family
134        return "DroidSans.ttf";
135    }
136
137    Font(int id, RenderScript rs) {
138        super(id, rs);
139    }
140
141    /**
142     * Takes a specific file name as an argument
143     */
144    static public Font createFromFile(RenderScript rs, Resources res, String path, float pointSize) {
145        rs.validate();
146        int dpi = res.getDisplayMetrics().densityDpi;
147        int fontId = rs.nFontCreateFromFile(path, pointSize, dpi);
148
149        if(fontId == 0) {
150            throw new RSRuntimeException("Unable to create font from file " + path);
151        }
152        Font rsFont = new Font(fontId, rs);
153
154        return rsFont;
155    }
156
157    static public Font createFromFile(RenderScript rs, Resources res, File path, float pointSize) {
158        return createFromFile(rs, res, path.getAbsolutePath(), pointSize);
159    }
160
161    static public Font createFromAsset(RenderScript rs, Resources res, String path, float pointSize) {
162        rs.validate();
163        AssetManager mgr = res.getAssets();
164        int dpi = res.getDisplayMetrics().densityDpi;
165
166        int fontId = rs.nFontCreateFromAsset(mgr, path, pointSize, dpi);
167        if(fontId == 0) {
168            throw new RSRuntimeException("Unable to create font from asset " + path);
169        }
170        Font rsFont = new Font(fontId, rs);
171        return rsFont;
172    }
173
174    static public Font createFromResource(RenderScript rs, Resources res, int id, float pointSize) {
175        String name = "R." + Integer.toString(id);
176
177        rs.validate();
178        InputStream is = null;
179        try {
180            is = res.openRawResource(id);
181        } catch (Exception e) {
182            throw new RSRuntimeException("Unable to open resource " + id);
183        }
184
185        int dpi = res.getDisplayMetrics().densityDpi;
186
187        int fontId = 0;
188        if (is instanceof AssetManager.AssetInputStream) {
189            int asset = ((AssetManager.AssetInputStream) is).getAssetInt();
190            fontId = rs.nFontCreateFromAssetStream(name, pointSize, dpi, asset);
191        } else {
192            throw new RSRuntimeException("Unsupported asset stream created");
193        }
194
195        if(fontId == 0) {
196            throw new RSRuntimeException("Unable to create font from resource " + id);
197        }
198        Font rsFont = new Font(fontId, rs);
199        return rsFont;
200    }
201
202    /**
203     * Accepts one of the following family names as an argument
204     * and will attemp to produce the best match with a system font
205     * "sans-serif" "arial" "helvetica" "tahoma" "verdana"
206     * "serif" "times" "times new roman" "palatino" "georgia" "baskerville"
207     * "goudy" "fantasy" "cursive" "ITC Stone Serif"
208     * "monospace" "courier" "courier new" "monaco"
209     * Returns default font if no match could be found
210     */
211    static public Font create(RenderScript rs, Resources res, String familyName, Style fontStyle, float pointSize) {
212        String fileName = getFontFileName(familyName, fontStyle);
213        String fontPath = Environment.getRootDirectory().getAbsolutePath();
214        fontPath += "/fonts/" + fileName;
215        return createFromFile(rs, res, fontPath, pointSize);
216    }
217
218}
219