1 #ifndef DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H
2 #define DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H
5 * Copyright (c) 2020 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/pixel-data.h>
24 #include <dali/public-api/object/base-handle.h>
25 #include <dali/devel-api/text-abstraction/font-list.h>
26 #include <dali/devel-api/text-abstraction/text-abstraction-definitions.h>
27 #include <dali/public-api/dali-adaptor-common.h>
32 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.
67 static const float DEFAULT_ITALIC_ANGLE; ///< The default software italic angle in radians.
70 * @brief Struct used to retrieve the glyph's bitmap.
72 struct DALI_ADAPTOR_API GlyphBufferData
77 * Initializes struct members to their defaults.
86 unsigned char* buffer; ///< The glyph's bitmap buffer data.
87 unsigned int width; ///< The width of the bitmap.
88 unsigned int height; ///< The height of the bitmap.
89 int outlineOffsetX; ///< The additional horizontal offset to be added for the glyph's position for outline.
90 int outlineOffsetY; ///< The additional vertical offset to be added for the glyph's position for outline.
91 Pixel::Format format; ///< The pixel's format of the bitmap.
92 bool isColorEmoji:1; ///< Whether the glyph is an emoji.
93 bool isColorBitmap:1; ///< Whether the glyph is a color bitmap.
97 * @brief Used to load an embedded item into the font client.
99 struct EmbeddedItemDescription
101 std::string url; ///< The url path of the image.
102 unsigned int width; ///< The width of the item.
103 unsigned int height; ///< The height of the item.
104 ColorBlendingMode colorblendingMode; ///< Whether the color of the image is multiplied by the color of the text.
110 * @brief Retrieve a handle to the FontClient instance.
112 * @return A handle to the FontClient
114 static FontClient Get();
117 * @brief Create an uninitialized TextAbstraction handle.
124 * This is non-virtual since derived Handle types must not contain data or virtual methods.
129 * @brief This copy constructor is required for (smart) pointer semantics.
131 * @param[in] handle A reference to the copied handle.
133 FontClient( const FontClient& handle );
136 * @brief This assignment operator is required for (smart) pointer semantics.
138 * @param [in] handle A reference to the copied handle.
139 * @return A reference to this.
141 FontClient& operator=( const FontClient& handle );
143 ////////////////////////////////////////
144 // Font management and validation.
145 ////////////////////////////////////////
148 * @brief Clear all caches in FontClient
154 * @brief Set the DPI of the target window.
156 * @note Multiple windows are not currently supported.
157 * @param[in] horizontalDpi The horizontal resolution in DPI.
158 * @param[in] verticalDpi The vertical resolution in DPI.
160 void SetDpi( unsigned int horizontalDpi, unsigned int verticalDpi );
163 * @brief Retrieves the DPI previously set to the target window.
165 * @note Multiple windows are not currently supported.
166 * @param[out] horizontalDpi The horizontal resolution in DPI.
167 * @param[out] verticalDpi The vertical resolution in DPI.
169 void GetDpi( unsigned int& horizontalDpi, unsigned int& verticalDpi );
172 * @brief Called by Dali to retrieve the default font size for the platform.
174 * This is an accessibility size, which is mapped to a UI Control specific point-size in stylesheets.
175 * For example if zero the smallest size, this could potentially map to TextLabel point-size 8.
176 * @return The default font size.
178 int GetDefaultFontSize();
181 * @brief Called when the user changes the system defaults.
183 * @post Previously cached system defaults are removed.
185 void ResetSystemDefaults();
188 * @brief Retrieve the list of default fonts supported by the system.
190 * @param[out] defaultFonts A list of default font paths, family, width, weight and slant.
192 void GetDefaultFonts( FontList& defaultFonts );
195 * @brief Retrieve the active default font from the system.
197 * @param[out] fontDescription font structure describing the default font.
199 void GetDefaultPlatformFontDescription( FontDescription& fontDescription );
202 * @brief Retrieve the list of fonts supported by the system.
204 * @param[out] systemFonts A list of font paths, family, width, weight and slant.
206 void GetSystemFonts( FontList& systemFonts );
209 * @brief Retrieves the font description of a given font @p id.
211 * @param[in] id The font identifier.
212 * @param[out] fontDescription The path, family & style (width, weight and slant) describing the font.
214 void GetDescription( FontId id, FontDescription& fontDescription );
217 * @brief Retrieves the font point size of a given font @p id.
219 * @param[in] id The font identifier.
221 * @return The point size in 26.6 fractional points.
223 PointSize26Dot6 GetPointSize( FontId id );
226 * @brief Whether the given @p character is supported by the font.
228 * @param[in] fontId The id of the font.
229 * @param[in] character The character.
231 * @return @e true if the character is supported by the font.
233 bool IsCharacterSupportedByFont( FontId fontId, Character character );
236 * @brief Find the default font for displaying a UTF-32 character.
238 * This is useful when localised strings are provided for multiple languages
239 * i.e. when a single default font does not work for all languages.
241 * @param[in] charcode The character for which a font is needed.
242 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
243 * @param[in] preferColor @e true if a color font is preferred.
245 * @return A valid font identifier, or zero if the font does not exist.
247 FontId FindDefaultFont( Character charcode,
248 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
249 bool preferColor = false );
252 * @brief Find a fallback-font for displaying a UTF-32 character.
254 * This is useful when localised strings are provided for multiple languages
255 * i.e. when a single default font does not work for all languages.
257 * @param[in] charcode The character for which a font is needed.
258 * @param[in] preferredFontDescription Description of the preferred font which may not provide a glyph for @p charcode.
259 * The fallback-font will be the closest match to @p preferredFontDescription, which does support the required glyph.
260 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
261 * @param[in] preferColor @e true if a color font is preferred.
263 * @return A valid font identifier, or zero if the font does not exist.
265 FontId FindFallbackFont( Character charcode,
266 const FontDescription& preferredFontDescription,
267 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
268 bool preferColor = false );
271 * @brief Retrieve the unique identifier for a font.
273 * @param[in] path The path to a font file.
274 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
275 * @param[in] faceIndex The index of the font face (optional).
277 * @return A valid font identifier, or zero if the font does not exist.
279 FontId GetFontId( const FontPath& path,
280 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
281 FaceIndex faceIndex = 0 );
284 * @brief Retrieves a unique font identifier for a given description.
286 * @param[in] preferredFontDescription Description of the preferred font.
287 * The font will be the closest match to @p preferredFontDescription.
288 * @param[in] requestedPointSize The point size in 26.6 fractional points; the default point size is 12*64.
289 * @param[in] faceIndex The index of the font face (optional).
291 * @return A valid font identifier, or zero if no font is found.
293 FontId GetFontId( const FontDescription& preferredFontDescription,
294 PointSize26Dot6 requestedPointSize = DEFAULT_POINT_SIZE,
295 FaceIndex faceIndex = 0 );
298 * @brief Retrieves a unique font identifier for a given bitmap font.
300 * @param[in] bitmapFont A bitmap font.
302 * @return A valid font identifier, or zero if no bitmap font is created.
304 FontId GetFontId( const BitmapFont& bitmapFont );
307 * @brief Check to see if a font is scalable.
309 * @param[in] path The path to a font file.
310 * @return true if scalable.
312 bool IsScalable( const FontPath& path );
315 * @brief Check to see if a font is scalable.
317 * @note It the font style is not empty, it will be used instead the font weight and font slant slant.
319 * @param[in] fontDescription A font description.
321 * @return true if scalable
323 bool IsScalable( const FontDescription& fontDescription );
326 * @brief Get a list of sizes available for a fixed size font.
328 * @param[in] path The path to a font file.
329 * @param[out] sizes A list of the available sizes, if no sizes available will return empty.
331 void GetFixedSizes( const FontPath& path, Dali::Vector< PointSize26Dot6>& sizes );
334 * @brief Get a list of sizes available for a fixed size font.
336 * @note It the font style is not empty, it will be used instead the font weight and font slant slant.
338 * @param[in] fontDescription A font description.
339 * @param[out] sizes A list of the available sizes, if no sizes available will return empty.
341 void GetFixedSizes( const FontDescription& fontDescription,
342 Dali::Vector< PointSize26Dot6 >& sizes );
345 * @brief Whether the font has Italic style.
347 * @param[in] fontId The font identifier.
349 * @return true if the font has italic style.
351 bool HasItalicStyle( FontId fontId ) const;
353 ////////////////////////////////////////
354 // Font metrics, glyphs and bitmaps.
355 ////////////////////////////////////////
358 * @brief Query the metrics for a font.
360 * @param[in] fontId The identifier of the font for the required glyph.
361 * @param[out] metrics The font metrics.
363 void GetFontMetrics( FontId fontId, FontMetrics& metrics );
366 * @brief Retrieve the glyph index for a UTF-32 character code.
368 * @param[in] fontId The identifier of the font for the required glyph.
369 * @param[in] charcode The UTF-32 character code.
371 * @return The glyph index, or zero if the character code is undefined.
373 GlyphIndex GetGlyphIndex( FontId fontId, Character charcode );
376 * @brief Retrieve the metrics for a series of glyphs.
378 * @param[in,out] array An array of glyph-info structures with initialized FontId & GlyphIndex values.
379 * It may contain the advance and an offset set into the bearing from the shaping tool.
380 * 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.
381 * @param[in] size The size of the array.
382 * @param[in] type The type of glyphs used for rendering; either bitmaps or vectors.
383 * @param[in] horizontal True for horizontal layouts (set to false for vertical layouting).
385 * @return @e true if all of the requested metrics were found.
387 bool GetGlyphMetrics( GlyphInfo* array, uint32_t size, GlyphType type, bool horizontal = true );
390 * @brief Create a bitmap representation of a glyph.
392 * @note The caller is responsible for deallocating the bitmap data @p data.buffer using delete[].
394 * @param[in] fontId The identifier of the font.
395 * @param[in] glyphIndex The index of a glyph within the specified font.
396 * @param[in] isItalicRequired Whether the glyph requires italic style.
397 * @param[in] isBoldRequired Whether the glyph requires bold style.
398 * @param[out] data The bitmap data.
399 * @param[in] outlineWidth The width of the glyph outline in pixels.
401 void CreateBitmap( FontId fontId, GlyphIndex glyphIndex, bool isItalicRequired, bool isBoldRequired, GlyphBufferData& data, int outlineWidth );
404 * @brief Create a bitmap representation of a glyph.
406 * @param[in] fontId The identifier of the font.
407 * @param[in] glyphIndex The index of a glyph within the specified font.
408 * @param[in] outlineWidth The width of the glyph outline in pixels.
410 * @return A valid PixelData, or an empty handle if the glyph could not be rendered.
412 PixelData CreateBitmap( FontId fontId, GlyphIndex glyphIndex, int outlineWidth );
415 * @brief Create a vector representation of a glyph.
417 * @note This feature requires highp shader support and is not available on all platforms
418 * @param[in] fontId The identifier of the font.
419 * @param[in] glyphIndex The index of a glyph within the specified font.
420 * @param[out] blob A blob of data; this is owned by FontClient and should be copied by the caller of CreateVectorData().
421 * @param[out] blobLength The length of the blob data, or zero if the blob creation failed.
422 * @param[out] nominalWidth The width of the blob.
423 * @param[out] nominalHeight The height of the blob.
425 void CreateVectorBlob( FontId fontId,
426 GlyphIndex glyphIndex,
428 unsigned int& blobLength,
429 unsigned int& nominalWidth,
430 unsigned int& nominalHeight );
433 * @brief Retrieves the ellipsis glyph for a requested point size.
435 * @param[in] requestedPointSize The requested point size.
437 * @return The ellipsis glyph.
439 const GlyphInfo& GetEllipsisGlyph( PointSize26Dot6 requestedPointSize );
442 * @brief Whether the given glyph @p glyphIndex is a color glyph.
444 * @param[in] fontId The font id.
445 * @param[in] glyphIndex The glyph index.
447 * @return @e true if the glyph is a color one.
449 bool IsColorGlyph( FontId fontId, GlyphIndex glyphIndex );
452 * @brief Add custom fonts directory
454 * @param[in] path to the fonts directory
456 * @return true if the fonts can be added.
458 bool AddCustomFontDirectory( const FontPath& path );
461 * @brief Creates and stores an embedded item and it's metrics.
463 * If in the @p description there is a non empty url, it calls Dali::LoadImageFromFile() internally.
464 * 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.
465 * If the url in the @p description is empty it stores the size.
467 * @param[in] description The description of the embedded item.
468 * @param[out] pixelFormat The pixel format of the image.
470 * return The index within the vector of embedded items.
472 GlyphIndex CreateEmbeddedItem( const EmbeddedItemDescription& description, Pixel::Format& pixelFormat);
475 public: // Not intended for application developers
477 * @brief This constructor is used by FontClient::Get().
479 * @param[in] fontClient A pointer to the internal fontClient object.
481 explicit DALI_INTERNAL FontClient( Internal::FontClient* fontClient );
485 * @brief This is used to improve application launch performance
487 * @return A pre-initialized FontClient
489 DALI_ADAPTOR_API FontClient FontClientPreInitialize();
491 } // namespace TextAbstraction
495 #endif // DALI_PLATFORM_TEXT_ABSTRACTION_FONT_CLIENT_H