1 #ifndef DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H
2 #define DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H
5 * Copyright (c) 2017 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
22 #include <dali/public-api/common/dali-vector.h>
23 #include <dali/public-api/images/buffer-image.h>
24 #include <dali/public-api/images/pixel-data.h>
25 #include <dali/public-api/object/base-handle.h>
26 #include <dali/devel-api/text-abstraction/font-list.h>
27 #include <dali/devel-api/text-abstraction/text-abstraction-definitions.h>
32 namespace TextAbstraction
38 namespace Internal DALI_INTERNAL
44 * @brief FontClient provides access to font information and resources.
46 * <h3>Querying the System Fonts</h3>
48 * A "system font" is described by a "path" to a font file on the native filesystem, along with a "family" and "style".
49 * For example on the Ubuntu system a "Regular" style font from the "Ubuntu Mono" family can be accessed from "/usr/share/fonts/truetype/ubuntu-font-family/UbuntuMono-R.ttf".
51 * <h3>Accessing Fonts</h3>
53 * A "font" is created from the system for a specific point size in 26.6 fractional points. A "FontId" is used to identify each font.
54 * For example two different fonts with point sizes 10 & 12 can be created from the "Ubuntu Mono" family:
56 * FontClient fontClient = FontClient::Get();
57 * FontId ubuntuMonoTen = fontClient.GetFontId( "/usr/share/fonts/truetype/ubuntu-font-family/UbuntuMono-R.ttf", 10*64 );
58 * FontId ubuntuMonoTwelve = fontClient.GetFontId( "/usr/share/fonts/truetype/ubuntu-font-family/UbuntuMono-R.ttf", 12*64 );
60 * Glyph metrics and bitmap resources can then be retrieved using the FontId.
62 class DALI_IMPORT_API FontClient : public BaseHandle
65 static const PointSize26Dot6 DEFAULT_POINT_SIZE; ///< The default point size.
68 * @brief Struct used to retrieve the glyph's bitmap.
70 struct GlyphBufferData
75 * Initializes struct members to their defaults.
84 unsigned char* buffer; ///< The glyph's bitmap buffer data.
85 unsigned int width; ///< The width of the bitmap.
86 unsigned int height; ///< The height of the bitmap.
87 Pixel::Format format; ///< The pixel's format of the bitmap.
93 * @brief Retrieve a handle to the FontClient instance.
95 * @return A handle to the FontClient
97 static FontClient Get();
100 * @brief Create an uninitialized TextAbstraction handle.
107 * This is non-virtual since derived Handle types must not contain data or virtual methods.
112 * @brief This copy constructor is required for (smart) pointer semantics.
114 * @param[in] handle A reference to the copied handle.
116 FontClient( const FontClient& handle );
119 * @brief This assignment operator is required for (smart) pointer semantics.
121 * @param [in] handle A reference to the copied handle.
122 * @return A reference to this.
124 FontClient& operator=( const FontClient& handle );
126 ////////////////////////////////////////
127 // Font management and validation.
128 ////////////////////////////////////////
131 * @brief Set the DPI of the target window.
133 * @note Multiple windows are not currently supported.
134 * @param[in] horizontalDpi The horizontal resolution in DPI.
135 * @param[in] verticalDpi The vertical resolution in DPI.
137 void SetDpi( unsigned int horizontalDpi, unsigned int verticalDpi );
140 * @brief Retrieves the DPI previously set to the target window.
142 * @note Multiple windows are not currently supported.
143 * @param[out] horizontalDpi The horizontal resolution in DPI.
144 * @param[out] verticalDpi The vertical resolution in DPI.
146 void GetDpi( unsigned int& horizontalDpi, unsigned int& verticalDpi );
149 * @brief Called by Dali to retrieve the default font size for the platform.
151 * This is an accessibility size, which is mapped to a UI Control specific point-size in stylesheets.
152 * For example if zero the smallest size, this could potentially map to TextLabel point-size 8.
153 * @return The default font size.
155 int GetDefaultFontSize();
158 * @brief Called when the user changes the system defaults.
160 * @post Previously cached system defaults are removed.
162 void ResetSystemDefaults();
165 * @brief Retrieve the list of default fonts supported by the system.
167 * @param[out] defaultFonts A list of default font paths, family, width, weight and slant.
169 void GetDefaultFonts( FontList& defaultFonts );
172 * @brief Retrieve the active default font from the system.
174 * @param[out] fontDescription font structure describing the default font.
176 void GetDefaultPlatformFontDescription( FontDescription& fontDescription );
179 * @brief Retrieve the list of fonts supported by the system.
181 * @param[out] systemFonts A list of font paths, family, width, weight and slant.
183 void GetSystemFonts( FontList& systemFonts );
186 * @brief Retrieves the font description of a given font @p id.
188 * @param[in] id The font identifier.
189 * @param[out] fontDescription The path, family & style (width, weight and slant) describing the font.
191 void GetDescription( FontId id, FontDescription& fontDescription );
194 * @brief Retrieves the font point size of a given font @p id.
196 * @param[in] id The font identifier.
198 * @return The point size in 26.6 fractional points.
200 PointSize26Dot6 GetPointSize( FontId id );
203 * @brief Whether the given @p character is supported by the font.
205 * @param[in] fontId The id of the font.
206 * @param[in] character The character.
208 * @return @e true if the character is supported by the font.
210 bool IsCharacterSupportedByFont( FontId fontId, Character character );
213 * @brief Find the default font for displaying a UTF-32 character.
215 * This is useful when localised strings are provided for multiple languages
216 * i.e. when a single default font does not work for all languages.
218 * @param[in] charcode The character for which a font is needed.
219 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
220 * @param[in] preferColor @e true if a color font is preferred.
222 * @return A valid font identifier, or zero if the font does not exist.
224 FontId FindDefaultFont( Character charcode,
225 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
226 bool preferColor = false );
229 * @brief Find a fallback-font for displaying a UTF-32 character.
231 * This is useful when localised strings are provided for multiple languages
232 * i.e. when a single default font does not work for all languages.
234 * @param[in] charcode The character for which a font is needed.
235 * @param[in] preferredFontDescription Description of the preferred font which may not provide a glyph for @p charcode.
236 * The fallback-font will be the closest match to @p preferredFontDescription, which does support the required glyph.
237 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
238 * @param[in] preferColor @e true if a color font is preferred.
240 * @return A valid font identifier, or zero if the font does not exist.
242 FontId FindFallbackFont( Character charcode,
243 const FontDescription& preferredFontDescription,
244 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
245 bool preferColor = false );
248 * @brief Retrieve the unique identifier for a font.
250 * @param[in] path The path to a font file.
251 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
252 * @param[in] faceIndex The index of the font face (optional).
254 * @return A valid font identifier, or zero if the font does not exist.
256 FontId GetFontId( const FontPath& path,
257 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
258 FaceIndex faceIndex = 0 );
261 * @brief Retrieves a unique font identifier for a given description.
263 * @param[in] preferredFontDescription Description of the preferred font.
264 * The font will be the closest match to @p preferredFontDescription.
265 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
266 * @param[in] faceIndex The index of the font face (optional).
268 * @return A valid font identifier, or zero if no font is found.
270 FontId GetFontId( const FontDescription& preferredFontDescription,
271 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
272 FaceIndex faceIndex = 0 );
275 * @brief Check to see if a font is scalable.
277 * @param[in] path The path to a font file.
278 * @return true if scalable.
280 bool IsScalable( const FontPath& path );
283 * @brief Check to see if a font is scalable.
285 * @note It the font style is not empty, it will be used instead the font weight and font slant slant.
287 * @param[in] fontDescription A font description.
289 * @return true if scalable
291 bool IsScalable( const FontDescription& fontDescription );
294 * @brief Get a list of sizes available for a fixed size font.
296 * @param[in] path The path to a font file.
297 * @param[out] sizes A list of the available sizes, if no sizes available will return empty.
299 void GetFixedSizes( const FontPath& path, Dali::Vector< PointSize26Dot6>& sizes );
302 * @brief Get a list of sizes available for a fixed size font.
304 * @note It the font style is not empty, it will be used instead the font weight and font slant slant.
306 * @param[in] fontDescription A font description.
307 * @param[out] sizes A list of the available sizes, if no sizes available will return empty.
309 void GetFixedSizes( const FontDescription& fontDescription,
310 Dali::Vector< PointSize26Dot6 >& sizes );
312 ////////////////////////////////////////
313 // Font metrics, glyphs and bitmaps.
314 ////////////////////////////////////////
317 * @brief Query the metrics for a font.
319 * @param[in] fontId The identifier of the font for the required glyph.
320 * @param[out] metrics The font metrics.
322 void GetFontMetrics( FontId fontId, FontMetrics& metrics );
325 * @brief Retrieve the glyph index for a UTF-32 character code.
327 * @param[in] fontId The identifier of the font for the required glyph.
328 * @param[in] charcode The UTF-32 character code.
330 * @return The glyph index, or zero if the character code is undefined.
332 GlyphIndex GetGlyphIndex( FontId fontId, Character charcode );
335 * @brief Retrieve the metrics for a series of glyphs.
337 * @param[in,out] array An array of glyph-info structures with initialized FontId & GlyphIndex values.
338 * It may contain the advance and an offset set into the bearing from the shaping tool.
339 * On return, the glyph's size value will be initialized. The bearing value will be updated by adding the font's glyph bearing to the one set by the shaping tool.
340 * @param[in] size The size of the array.
341 * @param[in] type The type of glyphs used for rendering; either bitmaps or vectors.
342 * @param[in] horizontal True for horizontal layouts (set to false for vertical layouting).
344 * @return @e true if all of the requested metrics were found.
346 bool GetGlyphMetrics( GlyphInfo* array, uint32_t size, GlyphType type, bool horizontal = true );
349 * @brief Create a bitmap representation of a glyph.
351 * @note The caller is responsible for deallocating the bitmap data @p data.buffer using delete[].
353 * @param[in] fontId The identifier of the font.
354 * @param[in] glyphIndex The index of a glyph within the specified font.
355 * @param[out] data The bitmap data.
357 void CreateBitmap( FontId fontId, GlyphIndex glyphIndex, GlyphBufferData& data );
360 * @brief Create a bitmap representation of a glyph.
362 * @param[in] fontId The identifier of the font.
363 * @param[in] glyphIndex The index of a glyph within the specified font.
365 * @return A valid BufferImage, or an empty handle if the glyph could not be rendered.
367 PixelData CreateBitmap( FontId fontId, GlyphIndex glyphIndex );
370 * @brief Create a vector representation of a glyph.
372 * @note This feature requires highp shader support and is not available on all platforms
373 * @param[in] fontId The identifier of the font.
374 * @param[in] glyphIndex The index of a glyph within the specified font.
375 * @param[out] blob A blob of data; this is owned by FontClient and should be copied by the caller of CreateVectorData().
376 * @param[out] blobLength The length of the blob data, or zero if the blob creation failed.
377 * @param[out] nominalWidth The width of the blob.
378 * @param[out] nominalHeight The height of the blob.
380 void CreateVectorBlob( FontId fontId,
381 GlyphIndex glyphIndex,
383 unsigned int& blobLength,
384 unsigned int& nominalWidth,
385 unsigned int& nominalHeight );
388 * @brief Retrieves the ellipsis glyph for a requested point size.
390 * @param[in] requestedPointSize The requested point size.
392 * @return The ellipsis glyph.
394 const GlyphInfo& GetEllipsisGlyph( PointSize26Dot6 requestedPointSize );
397 * @brief Whether the given glyph @p glyphIndex is a color glyph.
399 * @param[in] fontId The font id.
400 * @param[in] glyphIndex The glyph index.
402 * @return @e true if the glyph is a color one.
404 bool IsColorGlyph( FontId fontId, GlyphIndex glyphIndex );
406 public: // Not intended for application developers
408 * @brief This constructor is used by FontClient::Get().
410 * @param[in] fontClient A pointer to the internal fontClient object.
412 explicit DALI_INTERNAL FontClient( Internal::FontClient* fontClient );
415 } // namespace TextAbstraction
419 #endif // DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H