1 #ifndef DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H
2 #define DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H
5 * Copyright (c) 2018 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>
28 #include <dali/public-api/dali-adaptor-common.h>
33 namespace TextAbstraction
39 namespace Internal DALI_INTERNAL
45 * @brief FontClient provides access to font information and resources.
47 * <h3>Querying the System Fonts</h3>
49 * A "system font" is described by a "path" to a font file on the native filesystem, along with a "family" and "style".
50 * 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".
52 * <h3>Accessing Fonts</h3>
54 * 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.
55 * For example two different fonts with point sizes 10 & 12 can be created from the "Ubuntu Mono" family:
57 * FontClient fontClient = FontClient::Get();
58 * FontId ubuntuMonoTen = fontClient.GetFontId( "/usr/share/fonts/truetype/ubuntu-font-family/UbuntuMono-R.ttf", 10*64 );
59 * FontId ubuntuMonoTwelve = fontClient.GetFontId( "/usr/share/fonts/truetype/ubuntu-font-family/UbuntuMono-R.ttf", 12*64 );
61 * Glyph metrics and bitmap resources can then be retrieved using the FontId.
63 class DALI_ADAPTOR_API FontClient : public BaseHandle
66 static const PointSize26Dot6 DEFAULT_POINT_SIZE; ///< The default point size.
69 * @brief Struct used to retrieve the glyph's bitmap.
71 struct DALI_ADAPTOR_API GlyphBufferData
76 * Initializes struct members to their defaults.
85 unsigned char* buffer; ///< The glyph's bitmap buffer data.
86 unsigned int width; ///< The width of the bitmap.
87 unsigned int height; ///< The height of the bitmap.
88 Pixel::Format format; ///< The pixel's format of the bitmap.
94 * @brief Retrieve a handle to the FontClient instance.
96 * @return A handle to the FontClient
98 static FontClient Get();
101 * @brief Create an uninitialized TextAbstraction handle.
108 * This is non-virtual since derived Handle types must not contain data or virtual methods.
113 * @brief This copy constructor is required for (smart) pointer semantics.
115 * @param[in] handle A reference to the copied handle.
117 FontClient( const FontClient& handle );
120 * @brief This assignment operator is required for (smart) pointer semantics.
122 * @param [in] handle A reference to the copied handle.
123 * @return A reference to this.
125 FontClient& operator=( const FontClient& handle );
127 ////////////////////////////////////////
128 // Font management and validation.
129 ////////////////////////////////////////
132 * @brief Set the DPI of the target window.
134 * @note Multiple windows are not currently supported.
135 * @param[in] horizontalDpi The horizontal resolution in DPI.
136 * @param[in] verticalDpi The vertical resolution in DPI.
138 void SetDpi( unsigned int horizontalDpi, unsigned int verticalDpi );
141 * @brief Retrieves the DPI previously set to the target window.
143 * @note Multiple windows are not currently supported.
144 * @param[out] horizontalDpi The horizontal resolution in DPI.
145 * @param[out] verticalDpi The vertical resolution in DPI.
147 void GetDpi( unsigned int& horizontalDpi, unsigned int& verticalDpi );
150 * @brief Called by Dali to retrieve the default font size for the platform.
152 * This is an accessibility size, which is mapped to a UI Control specific point-size in stylesheets.
153 * For example if zero the smallest size, this could potentially map to TextLabel point-size 8.
154 * @return The default font size.
156 int GetDefaultFontSize();
159 * @brief Called when the user changes the system defaults.
161 * @post Previously cached system defaults are removed.
163 void ResetSystemDefaults();
166 * @brief Retrieve the list of default fonts supported by the system.
168 * @param[out] defaultFonts A list of default font paths, family, width, weight and slant.
170 void GetDefaultFonts( FontList& defaultFonts );
173 * @brief Retrieve the active default font from the system.
175 * @param[out] fontDescription font structure describing the default font.
177 void GetDefaultPlatformFontDescription( FontDescription& fontDescription );
180 * @brief Retrieve the list of fonts supported by the system.
182 * @param[out] systemFonts A list of font paths, family, width, weight and slant.
184 void GetSystemFonts( FontList& systemFonts );
187 * @brief Retrieves the font description of a given font @p id.
189 * @param[in] id The font identifier.
190 * @param[out] fontDescription The path, family & style (width, weight and slant) describing the font.
192 void GetDescription( FontId id, FontDescription& fontDescription );
195 * @brief Retrieves the font point size of a given font @p id.
197 * @param[in] id The font identifier.
199 * @return The point size in 26.6 fractional points.
201 PointSize26Dot6 GetPointSize( FontId id );
204 * @brief Whether the given @p character is supported by the font.
206 * @param[in] fontId The id of the font.
207 * @param[in] character The character.
209 * @return @e true if the character is supported by the font.
211 bool IsCharacterSupportedByFont( FontId fontId, Character character );
214 * @brief Find the default font for displaying a UTF-32 character.
216 * This is useful when localised strings are provided for multiple languages
217 * i.e. when a single default font does not work for all languages.
219 * @param[in] charcode The character for which a font is needed.
220 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
221 * @param[in] preferColor @e true if a color font is preferred.
223 * @return A valid font identifier, or zero if the font does not exist.
225 FontId FindDefaultFont( Character charcode,
226 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
227 bool preferColor = false );
230 * @brief Find a fallback-font for displaying a UTF-32 character.
232 * This is useful when localised strings are provided for multiple languages
233 * i.e. when a single default font does not work for all languages.
235 * @param[in] charcode The character for which a font is needed.
236 * @param[in] preferredFontDescription Description of the preferred font which may not provide a glyph for @p charcode.
237 * The fallback-font will be the closest match to @p preferredFontDescription, which does support the required glyph.
238 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
239 * @param[in] preferColor @e true if a color font is preferred.
241 * @return A valid font identifier, or zero if the font does not exist.
243 FontId FindFallbackFont( Character charcode,
244 const FontDescription& preferredFontDescription,
245 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
246 bool preferColor = false );
249 * @brief Retrieve the unique identifier for a font.
251 * @param[in] path The path to a font file.
252 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
253 * @param[in] faceIndex The index of the font face (optional).
255 * @return A valid font identifier, or zero if the font does not exist.
257 FontId GetFontId( const FontPath& path,
258 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
259 FaceIndex faceIndex = 0 );
262 * @brief Retrieves a unique font identifier for a given description.
264 * @param[in] preferredFontDescription Description of the preferred font.
265 * The font will be the closest match to @p preferredFontDescription.
266 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
267 * @param[in] faceIndex The index of the font face (optional).
269 * @return A valid font identifier, or zero if no font is found.
271 FontId GetFontId( const FontDescription& preferredFontDescription,
272 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
273 FaceIndex faceIndex = 0 );
276 * @brief Check to see if a font is scalable.
278 * @param[in] path The path to a font file.
279 * @return true if scalable.
281 bool IsScalable( const FontPath& path );
284 * @brief Check to see if a font is scalable.
286 * @note It the font style is not empty, it will be used instead the font weight and font slant slant.
288 * @param[in] fontDescription A font description.
290 * @return true if scalable
292 bool IsScalable( const FontDescription& fontDescription );
295 * @brief Get a list of sizes available for a fixed size font.
297 * @param[in] path The path to a font file.
298 * @param[out] sizes A list of the available sizes, if no sizes available will return empty.
300 void GetFixedSizes( const FontPath& path, Dali::Vector< PointSize26Dot6>& sizes );
303 * @brief Get a list of sizes available for a fixed size font.
305 * @note It the font style is not empty, it will be used instead the font weight and font slant slant.
307 * @param[in] fontDescription A font description.
308 * @param[out] sizes A list of the available sizes, if no sizes available will return empty.
310 void GetFixedSizes( const FontDescription& fontDescription,
311 Dali::Vector< PointSize26Dot6 >& sizes );
313 ////////////////////////////////////////
314 // Font metrics, glyphs and bitmaps.
315 ////////////////////////////////////////
318 * @brief Query the metrics for a font.
320 * @param[in] fontId The identifier of the font for the required glyph.
321 * @param[out] metrics The font metrics.
323 void GetFontMetrics( FontId fontId, FontMetrics& metrics );
326 * @brief Retrieve the glyph index for a UTF-32 character code.
328 * @param[in] fontId The identifier of the font for the required glyph.
329 * @param[in] charcode The UTF-32 character code.
331 * @return The glyph index, or zero if the character code is undefined.
333 GlyphIndex GetGlyphIndex( FontId fontId, Character charcode );
336 * @brief Retrieve the metrics for a series of glyphs.
338 * @param[in,out] array An array of glyph-info structures with initialized FontId & GlyphIndex values.
339 * It may contain the advance and an offset set into the bearing from the shaping tool.
340 * 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.
341 * @param[in] size The size of the array.
342 * @param[in] type The type of glyphs used for rendering; either bitmaps or vectors.
343 * @param[in] horizontal True for horizontal layouts (set to false for vertical layouting).
345 * @return @e true if all of the requested metrics were found.
347 bool GetGlyphMetrics( GlyphInfo* array, uint32_t size, GlyphType type, bool horizontal = true );
350 * @brief Create a bitmap representation of a glyph.
352 * @note The caller is responsible for deallocating the bitmap data @p data.buffer using delete[].
354 * @param[in] fontId The identifier of the font.
355 * @param[in] glyphIndex The index of a glyph within the specified font.
356 * @param[out] data The bitmap data.
357 * @param[in] outlineWidth The width of the glyph outline in pixels.
359 void CreateBitmap( FontId fontId, GlyphIndex glyphIndex, GlyphBufferData& data, int outlineWidth );
362 * @brief Create a bitmap representation of a glyph.
364 * @param[in] fontId The identifier of the font.
365 * @param[in] glyphIndex The index of a glyph within the specified font.
366 * @param[in] outlineWidth The width of the glyph outline in pixels.
368 * @return A valid BufferImage, or an empty handle if the glyph could not be rendered.
370 PixelData CreateBitmap( FontId fontId, GlyphIndex glyphIndex, int outlineWidth );
373 * @brief Create a vector representation of a glyph.
375 * @note This feature requires highp shader support and is not available on all platforms
376 * @param[in] fontId The identifier of the font.
377 * @param[in] glyphIndex The index of a glyph within the specified font.
378 * @param[out] blob A blob of data; this is owned by FontClient and should be copied by the caller of CreateVectorData().
379 * @param[out] blobLength The length of the blob data, or zero if the blob creation failed.
380 * @param[out] nominalWidth The width of the blob.
381 * @param[out] nominalHeight The height of the blob.
383 void CreateVectorBlob( FontId fontId,
384 GlyphIndex glyphIndex,
386 unsigned int& blobLength,
387 unsigned int& nominalWidth,
388 unsigned int& nominalHeight );
391 * @brief Retrieves the ellipsis glyph for a requested point size.
393 * @param[in] requestedPointSize The requested point size.
395 * @return The ellipsis glyph.
397 const GlyphInfo& GetEllipsisGlyph( PointSize26Dot6 requestedPointSize );
400 * @brief Whether the given glyph @p glyphIndex is a color glyph.
402 * @param[in] fontId The font id.
403 * @param[in] glyphIndex The glyph index.
405 * @return @e true if the glyph is a color one.
407 bool IsColorGlyph( FontId fontId, GlyphIndex glyphIndex );
409 public: // Not intended for application developers
411 * @brief This constructor is used by FontClient::Get().
413 * @param[in] fontClient A pointer to the internal fontClient object.
415 explicit DALI_INTERNAL FontClient( Internal::FontClient* fontClient );
418 } // namespace TextAbstraction
422 #endif // DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H