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1/* Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 */
5
6/**
7 * This file defines the <code>PPB_Font_Dev</code> interface.
8 */
9label Chrome {
10  M14 = 0.6
11};
12
13[assert_size(4)]
14enum PP_FontFamily_Dev {
15  /**
16   * Uses the user's default web page font (normally either the default serif
17   * or sans serif font).
18   */
19  PP_FONTFAMILY_DEFAULT = 0,
20
21  /**
22   * These families will use the default web page font corresponding to the
23   * given family.
24   */
25  PP_FONTFAMILY_SERIF = 1,
26  PP_FONTFAMILY_SANSSERIF = 2,
27  PP_FONTFAMILY_MONOSPACE = 3
28};
29
30/**
31 * Specifies the font weight. Normally users will only use NORMAL or BOLD.
32 */
33[assert_size(4)]
34enum PP_FontWeight_Dev {
35  PP_FONTWEIGHT_100 = 0,
36  PP_FONTWEIGHT_200 = 1,
37  PP_FONTWEIGHT_300 = 2,
38  PP_FONTWEIGHT_400 = 3,
39  PP_FONTWEIGHT_500 = 4,
40  PP_FONTWEIGHT_600 = 5,
41  PP_FONTWEIGHT_700 = 6,
42  PP_FONTWEIGHT_800 = 7,
43  PP_FONTWEIGHT_900 = 8,
44  PP_FONTWEIGHT_NORMAL = PP_FONTWEIGHT_400,
45  PP_FONTWEIGHT_BOLD = PP_FONTWEIGHT_700
46};
47
48[assert_size(48)]
49struct PP_FontDescription_Dev {
50  /**
51   * Font face name as a string. This can also be an undefined var, in which
52   * case the generic family will be obeyed. If the face is not available on
53   * the system, the browser will attempt to do font fallback or pick a default
54   * font.
55   */
56  PP_Var face;
57
58  /**
59   * When Create()ing a font and the face is an undefined var, the family
60   * specifies the generic font family type to use. If the face is specified,
61   * this will be ignored.
62   *
63   * When Describe()ing a font, the family will be the value you passed in when
64   * the font was created. In other words, if you specify a face name, the
65   * family will not be updated to reflect whether the font name you requested
66   * is serif or sans serif.
67   */
68  PP_FontFamily_Dev family;
69
70  /**
71   * Size in pixels.
72   *
73   * You can specify 0 to get the default font size. The default font size
74   * may vary depending on the requested font. The typical example is that
75   * the user may have a different font size for the default monospace font to
76   * give it a similar optical size to the proportionally spaced fonts.
77   */
78  uint32_t size;
79
80  /**
81   * Normally you will use either PP_FONTWEIGHT_NORMAL or PP_FONTWEIGHT_BOLD.
82   */
83  PP_FontWeight_Dev weight;
84
85  PP_Bool italic;
86  PP_Bool small_caps;
87
88  /**
89   * Adjustment to apply to letter and word spacing, respectively. Initialize
90   * to 0 to get normal spacing. Negative values bring letters/words closer
91   * together, positive values separate them.
92   */
93  int32_t letter_spacing;
94  int32_t word_spacing;
95
96  /**
97   * Ensure that this struct is 48-bytes wide by padding the end.  In some
98   * compilers, PP_Var is 8-byte aligned, so those compilers align this struct
99   * on 8-byte boundaries as well and pad it to 16 bytes even without this
100   * padding attribute.  This padding makes its size consistent across
101   * compilers.
102   */
103  int32_t padding;
104};
105
106[assert_size(20)]
107struct PP_FontMetrics_Dev {
108  int32_t height;
109  int32_t ascent;
110  int32_t descent;
111  int32_t line_spacing;
112  int32_t x_height;
113};
114
115[assert_size(24)]
116struct PP_TextRun_Dev {
117  /**
118   * This var must either be a string or a null/undefined var (which will be
119   * treated as a 0-length string).
120   */
121  PP_Var text;
122
123  /**
124   * Set to PP_TRUE if the text is right-to-left.
125   *
126   * When <code>override_direction</code> is false, the browser will perform
127   * the Unicode Bidirectional Algorithm (http://unicode.org/reports/tr9/) on
128   * the text. The value of the <code>rtl</code> flag specifies the
129   * directionality of the surrounding environment. This means that Hebrew
130   * word will always display right to left, even if <code>rtl</code> is false.
131   *
132   * When <code>override_direction</code> is true, no autodetection will be done
133   * and <code>rtl</code> specifies the direction of the text.
134   *
135   * TODO(brettw) note that autodetection with rtl = true is currently
136   * unimplemented.
137   */
138  PP_Bool rtl;
139
140  /**
141   * Set to PP_TRUE to force the directionality of the text regardless of
142   * content.
143   *
144   * If this flag is set, the browser will skip autodetection of the content
145   * and will display all text in the direction specified by the
146   * <code>rtl</code> flag.
147   */
148  PP_Bool override_direction;
149};
150
151interface PPB_Font_Dev {
152  /**
153   * Returns a list of all available font families on the system. You can use
154   * this list to decide whether to Create() a font.
155   *
156   * The return value will be a single string with null characters delimiting
157   * the end of each font name. For example: "Arial\0Courier\0Times\0".
158   *
159   * Returns an undefined var on failure (this typically means you passed an
160   * invalid instance).
161   */
162  PP_Var GetFontFamilies(
163      [in] PP_Instance instance);
164
165  /**
166   * Returns a font which best matches the given description. The return value
167   * will have a non-zero ID on success, or zero on failure.
168   */
169  PP_Resource Create(
170      [in] PP_Instance instance,
171      [in] PP_FontDescription_Dev description);
172
173  /**
174   * Returns PP_TRUE if the given resource is a Font. Returns PP_FALSE if the
175   * resource is invalid or some type other than a Font.
176   */
177  PP_Bool IsFont(
178      [in] PP_Resource resource);
179
180  /**
181   * Loads the description and metrics of the font into the given structures.
182   * The description will be different than the description the font was
183   * created with since it will be filled with the real values from the font
184   * that was actually selected.
185   *
186   * The PP_Var in the description should be of type Void on input. On output,
187   * this will contain the string and will have a reference count of 1. The
188   * plugin is responsible for calling Release on this var.
189   *
190   * Returns PP_TRUE on success, PP_FALSE if the font is invalid or if the Var
191   * in the description isn't Null (to prevent leaks).
192   */
193  PP_Bool Describe(
194      [in] PP_Resource font,
195      [out] PP_FontDescription_Dev description,
196      [out] PP_FontMetrics_Dev metrics);
197
198  /**
199   * Draws the text to the image buffer.
200   *
201   * The given point represents the baseline of the left edge of the font,
202   * regardless of whether it is left-to-right or right-to-left (in the case of
203   * RTL text, this will actually represent the logical end of the text).
204   *
205   * The clip is optional and may be NULL. In this case, the text will be
206   * clipped to the image.
207   *
208   * The image_data_is_opaque flag indicates whether subpixel antialiasing can
209   * be performed, if it is supported. When the image below the text is
210   * opaque, subpixel antialiasing is supported and you should set this to
211   * PP_TRUE to pick up the user's default preferences. If your plugin is
212   * partially transparent, then subpixel antialiasing is not possible and
213   * grayscale antialiasing will be used instead (assuming the user has
214   * antialiasing enabled at all).
215   */
216  PP_Bool DrawTextAt(
217      [in] PP_Resource font,
218      [in] PP_Resource image_data,
219      [in] PP_TextRun_Dev text,
220      [in] PP_Point position,
221      [in] uint32_t color,
222      [in] PP_Rect clip,
223      [in] PP_Bool image_data_is_opaque);
224
225  /**
226   * Returns the width of the given string. If the font is invalid or the var
227   * isn't a valid string, this will return -1.
228   *
229   * Note that this function handles complex scripts such as Arabic, combining
230   * accents, etc. so that adding the width of substrings won't necessarily
231   * produce the correct width of the entire string.
232   *
233   * Returns -1 on failure.
234   */
235  int32_t MeasureText(
236      [in] PP_Resource font,
237      [in] PP_TextRun_Dev text);
238
239  /**
240   * Returns the character at the given pixel X position from the beginning of
241   * the string. This handles complex scripts such as Arabic, where characters
242   * may be combined or replaced depending on the context. Returns (uint32)-1
243   * on failure.
244   */
245  uint32_t CharacterOffsetForPixel(
246      [in] PP_Resource font,
247      [in] PP_TextRun_Dev text,
248      [in] int32_t pixel_position);
249
250  /**
251   * Returns the horizontal advance to the given character if the string was
252   * placed at the given position. This handles complex scripts such as Arabic,
253   * where characters may be combined or replaced depending on context. Returns
254   * -1 on error.
255   */
256  int32_t PixelOffsetForCharacter(
257      [in] PP_Resource font,
258      [in] PP_TextRun_Dev text,
259      [in] uint32_t char_offset);
260};
261
262