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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 /* From trusted/ppb_browser_font_trusted.idl,
      7  *   modified Thu Mar 28 10:14:27 2013.
      8  */
      9 
     10 #ifndef PPAPI_C_TRUSTED_PPB_BROWSER_FONT_TRUSTED_H_
     11 #define PPAPI_C_TRUSTED_PPB_BROWSER_FONT_TRUSTED_H_
     12 
     13 #include "ppapi/c/pp_bool.h"
     14 #include "ppapi/c/pp_instance.h"
     15 #include "ppapi/c/pp_macros.h"
     16 #include "ppapi/c/pp_point.h"
     17 #include "ppapi/c/pp_rect.h"
     18 #include "ppapi/c/pp_resource.h"
     19 #include "ppapi/c/pp_size.h"
     20 #include "ppapi/c/pp_stdint.h"
     21 #include "ppapi/c/pp_var.h"
     22 
     23 #define PPB_BROWSERFONT_TRUSTED_INTERFACE_1_0 "PPB_BrowserFont_Trusted;1.0"
     24 #define PPB_BROWSERFONT_TRUSTED_INTERFACE PPB_BROWSERFONT_TRUSTED_INTERFACE_1_0
     25 
     26 /**
     27  * @file
     28  * This file defines the <code>PPB_BrowserFont_Trusted</code> interface.
     29  */
     30 
     31 
     32 /**
     33  * @addtogroup Enums
     34  * @{
     35  */
     36 typedef enum {
     37   /**
     38    * Uses the user's default web page font (normally either the default serif
     39    * or sans serif font).
     40    */
     41   PP_BROWSERFONT_TRUSTED_FAMILY_DEFAULT = 0,
     42   /**
     43    * These families will use the default web page font corresponding to the
     44    * given family.
     45    */
     46   PP_BROWSERFONT_TRUSTED_FAMILY_SERIF = 1,
     47   PP_BROWSERFONT_TRUSTED_FAMILY_SANSSERIF = 2,
     48   PP_BROWSERFONT_TRUSTED_FAMILY_MONOSPACE = 3
     49 } PP_BrowserFont_Trusted_Family;
     50 PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_BrowserFont_Trusted_Family, 4);
     51 
     52 /**
     53  * Specifies the font weight. Normally users will only use NORMAL or BOLD.
     54  */
     55 typedef enum {
     56   PP_BROWSERFONT_TRUSTED_WEIGHT_100 = 0,
     57   PP_BROWSERFONT_TRUSTED_WEIGHT_200 = 1,
     58   PP_BROWSERFONT_TRUSTED_WEIGHT_300 = 2,
     59   PP_BROWSERFONT_TRUSTED_WEIGHT_400 = 3,
     60   PP_BROWSERFONT_TRUSTED_WEIGHT_500 = 4,
     61   PP_BROWSERFONT_TRUSTED_WEIGHT_600 = 5,
     62   PP_BROWSERFONT_TRUSTED_WEIGHT_700 = 6,
     63   PP_BROWSERFONT_TRUSTED_WEIGHT_800 = 7,
     64   PP_BROWSERFONT_TRUSTED_WEIGHT_900 = 8,
     65   PP_BROWSERFONT_TRUSTED_WEIGHT_NORMAL = PP_BROWSERFONT_TRUSTED_WEIGHT_400,
     66   PP_BROWSERFONT_TRUSTED_WEIGHT_BOLD = PP_BROWSERFONT_TRUSTED_WEIGHT_700
     67 } PP_BrowserFont_Trusted_Weight;
     68 PP_COMPILE_ASSERT_SIZE_IN_BYTES(PP_BrowserFont_Trusted_Weight, 4);
     69 /**
     70  * @}
     71  */
     72 
     73 /**
     74  * @addtogroup Structs
     75  * @{
     76  */
     77 struct PP_BrowserFont_Trusted_Description {
     78   /**
     79    * Font face name as a string. This can also be an undefined var, in which
     80    * case the generic family will be obeyed. If the face is not available on
     81    * the system, the browser will attempt to do font fallback or pick a default
     82    * font.
     83    */
     84   struct PP_Var face;
     85   /**
     86    * When Create()ing a font and the face is an undefined var, the family
     87    * specifies the generic font family type to use. If the face is specified,
     88    * this will be ignored.
     89    *
     90    * When Describe()ing a font, the family will be the value you passed in when
     91    * the font was created. In other words, if you specify a face name, the
     92    * family will not be updated to reflect whether the font name you requested
     93    * is serif or sans serif.
     94    */
     95   PP_BrowserFont_Trusted_Family family;
     96   /**
     97    * Size in pixels.
     98    *
     99    * You can specify 0 to get the default font size. The default font size
    100    * may vary depending on the requested font. The typical example is that
    101    * the user may have a different font size for the default monospace font to
    102    * give it a similar optical size to the proportionally spaced fonts.
    103    */
    104   uint32_t size;
    105   /**
    106    * Normally you will use either normal or bold.
    107    */
    108   PP_BrowserFont_Trusted_Weight weight;
    109   PP_Bool italic;
    110   PP_Bool small_caps;
    111   /**
    112    * Adjustment to apply to letter and word spacing, respectively. Initialize
    113    * to 0 to get normal spacing. Negative values bring letters/words closer
    114    * together, positive values separate them.
    115    */
    116   int32_t letter_spacing;
    117   int32_t word_spacing;
    118   /**
    119    * Ensure that this struct is 48-bytes wide by padding the end.  In some
    120    * compilers, PP_Var is 8-byte aligned, so those compilers align this struct
    121    * on 8-byte boundaries as well and pad it to 16 bytes even without this
    122    * padding attribute.  This padding makes its size consistent across
    123    * compilers.
    124    */
    125   int32_t padding;
    126 };
    127 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_BrowserFont_Trusted_Description, 48);
    128 
    129 struct PP_BrowserFont_Trusted_Metrics {
    130   int32_t height;
    131   int32_t ascent;
    132   int32_t descent;
    133   int32_t line_spacing;
    134   int32_t x_height;
    135 };
    136 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_BrowserFont_Trusted_Metrics, 20);
    137 
    138 struct PP_BrowserFont_Trusted_TextRun {
    139   /**
    140    * This var must either be a string or a null/undefined var (which will be
    141    * treated as a 0-length string).
    142    */
    143   struct PP_Var text;
    144   /**
    145    * Set to PP_TRUE if the text is right-to-left.
    146    */
    147   PP_Bool rtl;
    148   /**
    149    * Set to PP_TRUE to force the directionality of the text regardless of
    150    * content
    151    */
    152   PP_Bool override_direction;
    153 };
    154 PP_COMPILE_ASSERT_STRUCT_SIZE_IN_BYTES(PP_BrowserFont_Trusted_TextRun, 24);
    155 /**
    156  * @}
    157  */
    158 
    159 /**
    160  * @addtogroup Interfaces
    161  * @{
    162  */
    163 /**
    164  * Provides an interface for native browser text rendering.
    165  *
    166  * This API is "trusted" not for security reasons, but because it can not be
    167  * implemented efficiently when running out-of-process in Browser Client. In
    168  * this case, WebKit is in another process and every text call would require a
    169  * synchronous IPC to the renderer. It is, however, available to native
    170  * (non-NaCl) out-of-process PPAPI plugins since WebKit is available in the
    171  * plugin process.
    172  */
    173 struct PPB_BrowserFont_Trusted_1_0 {
    174   /**
    175    * Returns a list of all available font families on the system. You can use
    176    * this list to decide whether to Create() a font.
    177    *
    178    * The return value will be a single string with null characters delimiting
    179    * the end of each font name. For example: "Arial\0Courier\0Times\0".
    180    *
    181    * Returns an undefined var on failure (this typically means you passed an
    182    * invalid instance).
    183    */
    184   struct PP_Var (*GetFontFamilies)(PP_Instance instance);
    185   /**
    186    * Returns a font which best matches the given description. The return value
    187    * will have a non-zero ID on success, or zero on failure.
    188    */
    189   PP_Resource (*Create)(
    190       PP_Instance instance,
    191       const struct PP_BrowserFont_Trusted_Description* description);
    192   /**
    193    * Returns PP_TRUE if the given resource is a Font. Returns PP_FALSE if the
    194    * resource is invalid or some type other than a Font.
    195    */
    196   PP_Bool (*IsFont)(PP_Resource resource);
    197   /**
    198    * Loads the description and metrics of the font into the given structures.
    199    * The description will be different than the description the font was
    200    * created with since it will be filled with the real values from the font
    201    * that was actually selected.
    202    *
    203    * The PP_Var in the description should be of type Void on input. On output,
    204    * this will contain the string and will have a reference count of 1. The
    205    * plugin is responsible for calling Release on this var.
    206    *
    207    * Returns PP_TRUE on success, PP_FALSE if the font is invalid or if the Var
    208    * in the description isn't Null (to prevent leaks).
    209    */
    210   PP_Bool (*Describe)(PP_Resource font,
    211                       struct PP_BrowserFont_Trusted_Description* description,
    212                       struct PP_BrowserFont_Trusted_Metrics* metrics);
    213   /**
    214    * Draws the text to the image buffer.
    215    *
    216    * The given point represents the baseline of the left edge of the font,
    217    * regardless of whether it is left-to-right or right-to-left (in the case of
    218    * RTL text, this will actually represent the logical end of the text).
    219    *
    220    * The clip is optional and may be NULL. In this case, the text will be
    221    * clipped to the image.
    222    *
    223    * The image_data_is_opaque flag indicates whether subpixel antialiasing can
    224    * be performed, if it is supported. When the image below the text is
    225    * opaque, subpixel antialiasing is supported and you should set this to
    226    * PP_TRUE to pick up the user's default preferences. If your plugin is
    227    * partially transparent, then subpixel antialiasing is not possible and
    228    * grayscale antialiasing will be used instead (assuming the user has
    229    * antialiasing enabled at all).
    230    */
    231   PP_Bool (*DrawTextAt)(PP_Resource font,
    232                         PP_Resource image_data,
    233                         const struct PP_BrowserFont_Trusted_TextRun* text,
    234                         const struct PP_Point* position,
    235                         uint32_t color,
    236                         const struct PP_Rect* clip,
    237                         PP_Bool image_data_is_opaque);
    238   /**
    239    * Returns the width of the given string. If the font is invalid or the var
    240    * isn't a valid string, this will return -1.
    241    *
    242    * Note that this function handles complex scripts such as Arabic, combining
    243    * accents, etc. so that adding the width of substrings won't necessarily
    244    * produce the correct width of the entire string.
    245    *
    246    * Returns -1 on failure.
    247    */
    248   int32_t (*MeasureText)(PP_Resource font,
    249                          const struct PP_BrowserFont_Trusted_TextRun* text);
    250   /**
    251    * Returns the character at the given pixel X position from the beginning of
    252    * the string. This handles complex scripts such as Arabic, where characters
    253    * may be combined or replaced depending on the context. Returns (uint32)-1
    254    * on failure.
    255    *
    256    * TODO(brettw) this function may be broken. See the CharPosRTL test. It
    257    * seems to tell you "insertion point" rather than painting position. This
    258    * is useful but maybe not what we intended here.
    259    */
    260   uint32_t (*CharacterOffsetForPixel)(
    261       PP_Resource font,
    262       const struct PP_BrowserFont_Trusted_TextRun* text,
    263       int32_t pixel_position);
    264   /**
    265    * Returns the horizontal advance to the given character if the string was
    266    * placed at the given position. This handles complex scripts such as Arabic,
    267    * where characters may be combined or replaced depending on context. Returns
    268    * -1 on error.
    269    */
    270   int32_t (*PixelOffsetForCharacter)(
    271       PP_Resource font,
    272       const struct PP_BrowserFont_Trusted_TextRun* text,
    273       uint32_t char_offset);
    274 };
    275 
    276 typedef struct PPB_BrowserFont_Trusted_1_0 PPB_BrowserFont_Trusted;
    277 /**
    278  * @}
    279  */
    280 
    281 #endif  /* PPAPI_C_TRUSTED_PPB_BROWSER_FONT_TRUSTED_H_ */
    282 
    283