1 #ifndef DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H
2 #define DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H
5 * Copyright (c) 2019 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
40 namespace Internal DALI_INTERNAL
46 * @brief FontClient provides access to font information and resources.
48 * <h3>Querying the System Fonts</h3>
50 * A "system font" is described by a "path" to a font file on the native filesystem, along with a "family" and "style".
51 * 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".
53 * <h3>Accessing Fonts</h3>
55 * 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.
56 * For example two different fonts with point sizes 10 & 12 can be created from the "Ubuntu Mono" family:
58 * FontClient fontClient = FontClient::Get();
59 * FontId ubuntuMonoTen = fontClient.GetFontId( "/usr/share/fonts/truetype/ubuntu-font-family/UbuntuMono-R.ttf", 10*64 );
60 * FontId ubuntuMonoTwelve = fontClient.GetFontId( "/usr/share/fonts/truetype/ubuntu-font-family/UbuntuMono-R.ttf", 12*64 );
62 * Glyph metrics and bitmap resources can then be retrieved using the FontId.
64 class DALI_ADAPTOR_API FontClient : public BaseHandle
67 static const PointSize26Dot6 DEFAULT_POINT_SIZE; ///< The default point size.
68 static const float DEFAULT_ITALIC_ANGLE; ///< The default software italic angle in radians.
71 * @brief Struct used to retrieve the glyph's bitmap.
73 struct DALI_ADAPTOR_API GlyphBufferData
78 * Initializes struct members to their defaults.
87 unsigned char* buffer; ///< The glyph's bitmap buffer data.
88 unsigned int width; ///< The width of the bitmap.
89 unsigned int height; ///< The height of the bitmap.
90 Pixel::Format format; ///< The pixel's format of the bitmap.
94 * @brief Used to load an embedded item into the font client.
96 struct EmbeddedItemDescription
98 std::string url; ///< The url path of the image.
99 unsigned int width; ///< The width of the item.
100 unsigned int height; ///< The height of the item.
101 ColorBlendingMode colorblendingMode; ///< Whether the color of the image is multiplied by the color of the text.
107 * @brief Retrieve a handle to the FontClient instance.
109 * @return A handle to the FontClient
111 static FontClient Get();
114 * @brief Create an uninitialized TextAbstraction handle.
121 * This is non-virtual since derived Handle types must not contain data or virtual methods.
126 * @brief This copy constructor is required for (smart) pointer semantics.
128 * @param[in] handle A reference to the copied handle.
130 FontClient( const FontClient& handle );
133 * @brief This assignment operator is required for (smart) pointer semantics.
135 * @param [in] handle A reference to the copied handle.
136 * @return A reference to this.
138 FontClient& operator=( const FontClient& handle );
140 ////////////////////////////////////////
141 // Font management and validation.
142 ////////////////////////////////////////
145 * @brief Clear all caches in FontClient
151 * @brief Set the DPI of the target window.
153 * @note Multiple windows are not currently supported.
154 * @param[in] horizontalDpi The horizontal resolution in DPI.
155 * @param[in] verticalDpi The vertical resolution in DPI.
157 void SetDpi( unsigned int horizontalDpi, unsigned int verticalDpi );
160 * @brief Retrieves the DPI previously set to the target window.
162 * @note Multiple windows are not currently supported.
163 * @param[out] horizontalDpi The horizontal resolution in DPI.
164 * @param[out] verticalDpi The vertical resolution in DPI.
166 void GetDpi( unsigned int& horizontalDpi, unsigned int& verticalDpi );
169 * @brief Called by Dali to retrieve the default font size for the platform.
171 * This is an accessibility size, which is mapped to a UI Control specific point-size in stylesheets.
172 * For example if zero the smallest size, this could potentially map to TextLabel point-size 8.
173 * @return The default font size.
175 int GetDefaultFontSize();
178 * @brief Called when the user changes the system defaults.
180 * @post Previously cached system defaults are removed.
182 void ResetSystemDefaults();
185 * @brief Retrieve the list of default fonts supported by the system.
187 * @param[out] defaultFonts A list of default font paths, family, width, weight and slant.
189 void GetDefaultFonts( FontList& defaultFonts );
192 * @brief Retrieve the active default font from the system.
194 * @param[out] fontDescription font structure describing the default font.
196 void GetDefaultPlatformFontDescription( FontDescription& fontDescription );
199 * @brief Retrieve the list of fonts supported by the system.
201 * @param[out] systemFonts A list of font paths, family, width, weight and slant.
203 void GetSystemFonts( FontList& systemFonts );
206 * @brief Retrieves the font description of a given font @p id.
208 * @param[in] id The font identifier.
209 * @param[out] fontDescription The path, family & style (width, weight and slant) describing the font.
211 void GetDescription( FontId id, FontDescription& fontDescription );
214 * @brief Retrieves the font point size of a given font @p id.
216 * @param[in] id The font identifier.
218 * @return The point size in 26.6 fractional points.
220 PointSize26Dot6 GetPointSize( FontId id );
223 * @brief Whether the given @p character is supported by the font.
225 * @param[in] fontId The id of the font.
226 * @param[in] character The character.
228 * @return @e true if the character is supported by the font.
230 bool IsCharacterSupportedByFont( FontId fontId, Character character );
233 * @brief Find the default font for displaying a UTF-32 character.
235 * This is useful when localised strings are provided for multiple languages
236 * i.e. when a single default font does not work for all languages.
238 * @param[in] charcode The character for which a font is needed.
239 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
240 * @param[in] preferColor @e true if a color font is preferred.
242 * @return A valid font identifier, or zero if the font does not exist.
244 FontId FindDefaultFont( Character charcode,
245 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
246 bool preferColor = false );
249 * @brief Find a fallback-font for displaying a UTF-32 character.
251 * This is useful when localised strings are provided for multiple languages
252 * i.e. when a single default font does not work for all languages.
254 * @param[in] charcode The character for which a font is needed.
255 * @param[in] preferredFontDescription Description of the preferred font which may not provide a glyph for @p charcode.
256 * The fallback-font will be the closest match to @p preferredFontDescription, which does support the required glyph.
257 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
258 * @param[in] preferColor @e true if a color font is preferred.
260 * @return A valid font identifier, or zero if the font does not exist.
262 FontId FindFallbackFont( Character charcode,
263 const FontDescription& preferredFontDescription,
264 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
265 bool preferColor = false );
268 * @brief Retrieve the unique identifier for a font.
270 * @param[in] path The path to a font file.
271 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
272 * @param[in] faceIndex The index of the font face (optional).
274 * @return A valid font identifier, or zero if the font does not exist.
276 FontId GetFontId( const FontPath& path,
277 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
278 FaceIndex faceIndex = 0 );
281 * @brief Retrieves a unique font identifier for a given description.
283 * @param[in] preferredFontDescription Description of the preferred font.
284 * The font will be the closest match to @p preferredFontDescription.
285 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
286 * @param[in] faceIndex The index of the font face (optional).
288 * @return A valid font identifier, or zero if no font is found.
290 FontId GetFontId( const FontDescription& preferredFontDescription,
291 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
292 FaceIndex faceIndex = 0 );
295 * @brief Retrieves a unique font identifier for a given bitmap font.
297 * @param[in] bitmapFont A bitmap font.
299 * @return A valid font identifier, or zero if no bitmap font is created.
301 FontId GetFontId( const BitmapFont& bitmapFont );
304 * @brief Check to see if a font is scalable.
306 * @param[in] path The path to a font file.
307 * @return true if scalable.
309 bool IsScalable( const FontPath& path );
312 * @brief Check to see if a font is scalable.
314 * @note It the font style is not empty, it will be used instead the font weight and font slant slant.
316 * @param[in] fontDescription A font description.
318 * @return true if scalable
320 bool IsScalable( const FontDescription& fontDescription );
323 * @brief Get a list of sizes available for a fixed size font.
325 * @param[in] path The path to a font file.
326 * @param[out] sizes A list of the available sizes, if no sizes available will return empty.
328 void GetFixedSizes( const FontPath& path, Dali::Vector< PointSize26Dot6>& sizes );
331 * @brief Get a list of sizes available for a fixed size font.
333 * @note It the font style is not empty, it will be used instead the font weight and font slant slant.
335 * @param[in] fontDescription A font description.
336 * @param[out] sizes A list of the available sizes, if no sizes available will return empty.
338 void GetFixedSizes( const FontDescription& fontDescription,
339 Dali::Vector< PointSize26Dot6 >& sizes );
342 * @brief Whether the font has Italic style.
344 * @param[in] fontId The font identifier.
346 * @return true if the font has italic style.
348 bool HasItalicStyle( FontId fontId ) const;
350 ////////////////////////////////////////
351 // Font metrics, glyphs and bitmaps.
352 ////////////////////////////////////////
355 * @brief Query the metrics for a font.
357 * @param[in] fontId The identifier of the font for the required glyph.
358 * @param[out] metrics The font metrics.
360 void GetFontMetrics( FontId fontId, FontMetrics& metrics );
363 * @brief Retrieve the glyph index for a UTF-32 character code.
365 * @param[in] fontId The identifier of the font for the required glyph.
366 * @param[in] charcode The UTF-32 character code.
368 * @return The glyph index, or zero if the character code is undefined.
370 GlyphIndex GetGlyphIndex( FontId fontId, Character charcode );
373 * @brief Retrieve the metrics for a series of glyphs.
375 * @param[in,out] array An array of glyph-info structures with initialized FontId & GlyphIndex values.
376 * It may contain the advance and an offset set into the bearing from the shaping tool.
377 * 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.
378 * @param[in] size The size of the array.
379 * @param[in] type The type of glyphs used for rendering; either bitmaps or vectors.
380 * @param[in] horizontal True for horizontal layouts (set to false for vertical layouting).
382 * @return @e true if all of the requested metrics were found.
384 bool GetGlyphMetrics( GlyphInfo* array, uint32_t size, GlyphType type, bool horizontal = true );
387 * @brief Create a bitmap representation of a glyph.
389 * @note The caller is responsible for deallocating the bitmap data @p data.buffer using delete[].
391 * @param[in] fontId The identifier of the font.
392 * @param[in] glyphIndex The index of a glyph within the specified font.
393 * @param[in] isItalicRequired Whether the glyph requires italic style.
394 * @param[in] isBoldRequired Whether the glyph requires bold style.
395 * @param[out] data The bitmap data.
396 * @param[in] outlineWidth The width of the glyph outline in pixels.
398 void CreateBitmap( FontId fontId, GlyphIndex glyphIndex, bool isItalicRequired, bool isBoldRequired, GlyphBufferData& data, int outlineWidth );
401 * @brief Create a bitmap representation of a glyph.
403 * @param[in] fontId The identifier of the font.
404 * @param[in] glyphIndex The index of a glyph within the specified font.
405 * @param[in] outlineWidth The width of the glyph outline in pixels.
407 * @return A valid BufferImage, or an empty handle if the glyph could not be rendered.
409 PixelData CreateBitmap( FontId fontId, GlyphIndex glyphIndex, int outlineWidth );
412 * @brief Create a vector representation of a glyph.
414 * @note This feature requires highp shader support and is not available on all platforms
415 * @param[in] fontId The identifier of the font.
416 * @param[in] glyphIndex The index of a glyph within the specified font.
417 * @param[out] blob A blob of data; this is owned by FontClient and should be copied by the caller of CreateVectorData().
418 * @param[out] blobLength The length of the blob data, or zero if the blob creation failed.
419 * @param[out] nominalWidth The width of the blob.
420 * @param[out] nominalHeight The height of the blob.
422 void CreateVectorBlob( FontId fontId,
423 GlyphIndex glyphIndex,
425 unsigned int& blobLength,
426 unsigned int& nominalWidth,
427 unsigned int& nominalHeight );
430 * @brief Retrieves the ellipsis glyph for a requested point size.
432 * @param[in] requestedPointSize The requested point size.
434 * @return The ellipsis glyph.
436 const GlyphInfo& GetEllipsisGlyph( PointSize26Dot6 requestedPointSize );
439 * @brief Whether the given glyph @p glyphIndex is a color glyph.
441 * @param[in] fontId The font id.
442 * @param[in] glyphIndex The glyph index.
444 * @return @e true if the glyph is a color one.
446 bool IsColorGlyph( FontId fontId, GlyphIndex glyphIndex );
449 * @brief Add custom fonts directory
451 * @param[in] path to the fonts directory
453 * @return true if the fonts can be added.
455 bool AddCustomFontDirectory( const FontPath& path );
458 * @brief Creates and stores an embedded item and it's metrics.
460 * If in the @p description there is a non empty url, it calls Dali::LoadImageFromFile() internally.
461 * If in the @p description there is a url and @e width or @e height are zero it stores the default size. Otherwise the image is resized.
462 * If the url in the @p description is empty it stores the size.
464 * @param[in] description The description of the embedded item.
465 * @param[out] pixelFormat The pixel format of the image.
467 * return The index within the vector of embedded items.
469 GlyphIndex CreateEmbeddedItem( const EmbeddedItemDescription& description, Pixel::Format& pixelFormat);
472 public: // Not intended for application developers
474 * @brief This constructor is used by FontClient::Get().
476 * @param[in] fontClient A pointer to the internal fontClient object.
478 explicit DALI_INTERNAL FontClient( Internal::FontClient* fontClient );
481 } // namespace TextAbstraction
485 #endif // DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H