1 // Copyright 2019 Google LLC. 2 #ifndef ParagraphBuilder_DEFINED 3 #define ParagraphBuilder_DEFINED 4 5 #include <memory> 6 #include <stack> 7 #include <string> 8 #include <tuple> 9 #include <vector> 10 #include "modules/skparagraph/include/FontCollection.h" 11 #include "modules/skparagraph/include/Paragraph.h" 12 #include "modules/skparagraph/include/ParagraphStyle.h" 13 #include "modules/skparagraph/include/TextStyle.h" 14 #include "modules/skunicode/include/SkUnicode.h" 15 16 namespace skia { 17 namespace textlayout { 18 19 class ParagraphBuilder { 20 protected: ParagraphBuilder()21 ParagraphBuilder() {} 22 23 public: 24 virtual ~ParagraphBuilder() = default; 25 26 // Push a style to the stack. The corresponding text added with AddText will 27 // use the top-most style. 28 virtual void pushStyle(const TextStyle& style) = 0; 29 30 // Remove a style from the stack. Useful to apply different styles to chunks 31 // of text such as bolding. 32 // Example: 33 // builder.PushStyle(normal_style); 34 // builder.AddText("Hello this is normal. "); 35 // 36 // builder.PushStyle(bold_style); 37 // builder.AddText("And this is BOLD. "); 38 // 39 // builder.Pop(); 40 // builder.AddText(" Back to normal again."); 41 virtual void pop() = 0; 42 43 virtual TextStyle peekStyle() = 0; 44 45 // Adds UTF16-encoded text to the builder. Forms the proper runs to use the upper-most style 46 // on the style_stack. 47 virtual void addText(const std::u16string& text) = 0; 48 49 // Adds UTF8-encoded text to the builder, using the top-most style on the style_stack. 50 virtual void addText(const char* text) = 0; 51 virtual void addText(const char* text, size_t len) = 0; 52 53 // Pushes the information required to leave an open space, where Flutter may 54 // draw a custom placeholder into. 55 // Internally, this method adds a single object replacement character (0xFFFC) 56 virtual void addPlaceholder(const PlaceholderStyle& placeholderStyle) = 0; 57 58 // Constructs a SkParagraph object that can be used to layout and paint the text to a SkCanvas. 59 virtual std::unique_ptr<Paragraph> Build() = 0; 60 61 virtual SkSpan<char> getText() = 0; 62 virtual const ParagraphStyle& getParagraphStyle() const = 0; 63 64 #if !defined(SK_DISABLE_LEGACY_CLIENT_UNICODE) && defined(SK_UNICODE_CLIENT_IMPLEMENTATION) 65 // Mainly, support for "Client" unicode 66 virtual void setWordsUtf8(std::vector<SkUnicode::Position> wordsUtf8) = 0; 67 virtual void setWordsUtf16(std::vector<SkUnicode::Position> wordsUtf16) = 0; 68 69 virtual void setGraphemeBreaksUtf8(std::vector<SkUnicode::Position> graphemesUtf8) = 0; 70 virtual void setGraphemeBreaksUtf16(std::vector<SkUnicode::Position> graphemesUtf16) = 0; 71 72 virtual void setLineBreaksUtf8(std::vector<SkUnicode::LineBreakBefore> lineBreaksUtf8) = 0; 73 virtual void setLineBreaksUtf16(std::vector<SkUnicode::LineBreakBefore> lineBreaksUtf16) = 0; 74 75 virtual std::tuple<std::vector<SkUnicode::Position>, 76 std::vector<SkUnicode::Position>, 77 std::vector<SkUnicode::LineBreakBefore>> 78 getClientICUData() const = 0; 79 80 virtual void SetUnicode(sk_sp<SkUnicode> unicode) = 0; 81 #endif 82 83 // Resets this builder to its initial state, discarding any text, styles, placeholders that have 84 // been added, but keeping the initial ParagraphStyle. 85 virtual void Reset() = 0; 86 87 // Just until we fix all the google3 code 88 static std::unique_ptr<ParagraphBuilder> make(const ParagraphStyle& style, 89 sk_sp<FontCollection> fontCollection, 90 sk_sp<SkUnicode> unicode); 91 92 #if !defined(SK_DISABLE_LEGACY_PARAGRAPH_UNICODE) 93 static std::unique_ptr<ParagraphBuilder> make(const ParagraphStyle& style, 94 sk_sp<FontCollection> fontCollection); 95 #endif 96 }; 97 } // namespace textlayout 98 } // namespace skia 99 100 #endif // ParagraphBuilder_DEFINED 101