1 #ifndef DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H
2 #define DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H
5 * Copyright (c) 2016 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.
70 * @brief Retrieve a handle to the FontClient instance.
72 * @return A handle to the FontClient
74 static FontClient Get();
77 * @brief Create an uninitialized TextAbstraction handle.
84 * This is non-virtual since derived Handle types must not contain data or virtual methods.
89 * @brief This copy constructor is required for (smart) pointer semantics.
91 * @param[in] handle A reference to the copied handle.
93 FontClient( const FontClient& handle );
96 * @brief This assignment operator is required for (smart) pointer semantics.
98 * @param [in] handle A reference to the copied handle.
99 * @return A reference to this.
101 FontClient& operator=( const FontClient& handle );
103 ////////////////////////////////////////
104 // Font management and validation.
105 ////////////////////////////////////////
108 * @brief Set the DPI of the target window.
110 * @note Multiple windows are not currently supported.
111 * @param[in] horizontalDpi The horizontal resolution in DPI.
112 * @param[in] verticalDpi The vertical resolution in DPI.
114 void SetDpi( unsigned int horizontalDpi, unsigned int verticalDpi );
117 * @brief Retrieves the DPI previously set to the target window.
119 * @note Multiple windows are not currently supported.
120 * @param[out] horizontalDpi The horizontal resolution in DPI.
121 * @param[out] verticalDpi The vertical resolution in DPI.
123 void GetDpi( unsigned int& horizontalDpi, unsigned int& verticalDpi );
126 * @brief Called when the user changes the system defaults.
128 * @post Previously cached system defaults are removed.
130 void ResetSystemDefaults();
133 * @brief Retrieve the list of default fonts supported by the system.
135 * @param[out] defaultFonts A list of default font paths, family, width, weight and slant.
137 void GetDefaultFonts( FontList& defaultFonts );
140 * @brief Retrieve the active default font from the system.
142 * @param[out] fontDescription font structure describing the default font.
144 void GetDefaultPlatformFontDescription( FontDescription& fontDescription );
147 * @brief Retrieve the list of fonts supported by the system.
149 * @param[out] systemFonts A list of font paths, family, width, weight and slant.
151 void GetSystemFonts( FontList& systemFonts );
154 * @brief Retrieves the font description of a given font @p id.
156 * @param[in] id The font identifier.
157 * @param[out] fontDescription The path, family & style (width, weight and slant) describing the font.
159 void GetDescription( FontId id, FontDescription& fontDescription );
162 * @brief Retrieves the font point size of a given font @p id.
164 * @param[in] id The font identifier.
166 * @return The point size in 26.6 fractional points.
168 PointSize26Dot6 GetPointSize( FontId id );
171 * @brief Find the default font for displaying a UTF-32 character.
173 * This is useful when localised strings are provided for multiple languages
174 * i.e. when a single default font does not work for all languages.
176 * @param[in] charcode The character for which a font is needed.
177 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
178 * @param[in] preferColor @e true if a color font is preferred.
180 * @return A valid font identifier, or zero if the font does not exist.
182 FontId FindDefaultFont( Character charcode,
183 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
184 bool preferColor = false );
187 * @brief Find a fallback-font for displaying a UTF-32 character.
189 * This is useful when localised strings are provided for multiple languages
190 * i.e. when a single default font does not work for all languages.
192 * @param[in] charcode The character for which a font is needed.
193 * @param[in] preferredFontDescription Description of the preferred font which may not provide a glyph for @p charcode.
194 * The fallback-font will be the closest match to @p preferredFontDescription, which does support the required glyph.
195 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
196 * @param[in] preferColor @e true if a color font is preferred.
198 * @return A valid font identifier, or zero if the font does not exist.
200 FontId FindFallbackFont( Character charcode,
201 const FontDescription& preferredFontDescription,
202 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
203 bool preferColor = false );
206 * @brief Retrieve the unique identifier for a font.
208 * @param[in] path The path to a font file.
209 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
210 * @param[in] faceIndex The index of the font face (optional).
212 * @return A valid font identifier, or zero if the font does not exist.
214 FontId GetFontId( const FontPath& path,
215 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
216 FaceIndex faceIndex = 0 );
219 * @brief Retrieves a unique font identifier for a given description.
221 * @param[in] preferredFontDescription Description of the preferred font.
222 * The font will be the closest match to @p preferredFontDescription.
223 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
224 * @param[in] faceIndex The index of the font face (optional).
226 * @return A valid font identifier, or zero if no font is found.
228 FontId GetFontId( const FontDescription& preferredFontDescription,
229 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
230 FaceIndex faceIndex = 0 );
233 * @brief Check to see if a font is scalable.
235 * @param[in] path The path to a font file.
236 * @return true if scalable.
238 bool IsScalable( const FontPath& path );
241 * @brief Check to see if a font is scalable.
243 * @note It the font style is not empty, it will be used instead the font weight and font slant slant.
245 * @param[in] fontDescription A font description.
247 * @return true if scalable
249 bool IsScalable( const FontDescription& fontDescription );
252 * @brief Get a list of sizes available for a fixed size font.
254 * @param[in] path The path to a font file.
255 * @param[out] sizes A list of the available sizes, if no sizes available will return empty.
257 void GetFixedSizes( const FontPath& path, Dali::Vector< PointSize26Dot6>& sizes );
260 * @brief Get a list of sizes available for a fixed size font.
262 * @note It the font style is not empty, it will be used instead the font weight and font slant slant.
264 * @param[in] fontDescription A font description.
265 * @param[out] sizes A list of the available sizes, if no sizes available will return empty.
267 void GetFixedSizes( const FontDescription& fontDescription,
268 Dali::Vector< PointSize26Dot6 >& sizes );
270 ////////////////////////////////////////
271 // Font metrics, glyphs and bitmaps.
272 ////////////////////////////////////////
275 * @brief Query the metrics for a font.
277 * @param[in] fontId The identifier of the font for the required glyph.
278 * @param[out] metrics The font metrics.
280 void GetFontMetrics( FontId fontId, FontMetrics& metrics );
283 * @brief Retrieve the glyph index for a UTF-32 character code.
285 * @param[in] fontId The identifier of the font for the required glyph.
286 * @param[in] charcode The UTF-32 character code.
288 * @return The glyph index, or zero if the character code is undefined.
290 GlyphIndex GetGlyphIndex( FontId fontId, Character charcode );
293 * @brief Retrieve the metrics for a series of glyphs.
295 * @param[in,out] array An array of glyph-info structures with initialized FontId & GlyphIndex values.
296 * It may contain the advance and an offset set into the bearing from the shaping tool.
297 * 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.
298 * @param[in] size The size of the array.
299 * @param[in] type The type of glyphs used for rendering; either bitmaps or vectors.
300 * @param[in] horizontal True for horizontal layouts (set to false for vertical layouting).
302 * @return @e true if all of the requested metrics were found.
304 bool GetGlyphMetrics( GlyphInfo* array, uint32_t size, GlyphType type, bool horizontal = true );
307 * @brief Create a bitmap representation of a glyph.
309 * @param[in] fontId The identifier of the font.
310 * @param[in] glyphIndex The index of a glyph within the specified font.
312 * @return A valid BufferImage, or an empty handle if the glyph could not be rendered.
314 PixelData CreateBitmap( FontId fontId, GlyphIndex glyphIndex );
317 * @brief Create a vector representation of a glyph.
319 * @note This feature requires highp shader support and is not available on all platforms
320 * @param[in] fontId The identifier of the font.
321 * @param[in] glyphIndex The index of a glyph within the specified font.
322 * @param[out] blob A blob of data; this is owned by FontClient and should be copied by the caller of CreateVectorData().
323 * @param[out] blobLength The length of the blob data, or zero if the blob creation failed.
324 * @param[out] nominalWidth The width of the blob.
325 * @param[out] nominalHeight The height of the blob.
327 void CreateVectorBlob( FontId fontId,
328 GlyphIndex glyphIndex,
330 unsigned int& blobLength,
331 unsigned int& nominalWidth,
332 unsigned int& nominalHeight );
335 * @brief Retrieves the ellipsis glyph for a requested point size.
337 * @param[in] requestedPointSize The requested point size.
339 * @return The ellipsis glyph.
341 const GlyphInfo& GetEllipsisGlyph( PointSize26Dot6 requestedPointSize );
343 public: // Not intended for application developers
345 * @brief This constructor is used by FontClient::Get().
347 * @param[in] fontClient A pointer to the internal fontClient object.
349 explicit DALI_INTERNAL FontClient( Internal::FontClient* fontClient );
352 } // namespace TextAbstraction
356 #endif // DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H