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 "modules/skparagraph/include/FontCollection.h" 10 #include "modules/skparagraph/include/Paragraph.h" 11 #include "modules/skparagraph/include/ParagraphStyle.h" 12 #include "modules/skparagraph/include/TextStyle.h" 13 14 namespace skia { 15 namespace textlayout { 16 17 class ParagraphBuilder { 18 public: ParagraphBuilder(const ParagraphStyle &,sk_sp<FontCollection>)19 ParagraphBuilder(const ParagraphStyle&, sk_sp<FontCollection>) { } 20 21 virtual ~ParagraphBuilder() = default; 22 23 // Push a style to the stack. The corresponding text added with AddText will 24 // use the top-most style. 25 virtual void pushStyle(const TextStyle& style) = 0; 26 27 // Remove a style from the stack. Useful to apply different styles to chunks 28 // of text such as bolding. 29 // Example: 30 // builder.PushStyle(normal_style); 31 // builder.AddText("Hello this is normal. "); 32 // 33 // builder.PushStyle(bold_style); 34 // builder.AddText("And this is BOLD. "); 35 // 36 // builder.Pop(); 37 // builder.AddText(" Back to normal again."); 38 virtual void pop() = 0; 39 40 virtual TextStyle peekStyle() = 0; 41 42 // Adds text to the builder. Forms the proper runs to use the upper-most style 43 // on the style_stack 44 virtual void addText(const std::u16string& text) = 0; 45 46 // Adds text to the builder, using the top-most style on on the style_stack. 47 virtual void addText(const char* text) = 0; // Don't use this one - going away soon 48 virtual void addText(const char* text, size_t len) = 0; 49 50 // Pushes the information required to leave an open space, where Flutter may 51 // draw a custom placeholder into. 52 // Internally, this method adds a single object replacement character (0xFFFC) 53 virtual void addPlaceholder(const PlaceholderStyle& placeholderStyle) = 0; 54 55 virtual void setParagraphStyle(const ParagraphStyle& style) = 0; 56 57 // Constructs a SkParagraph object that can be used to layout and paint the text to a SkCanvas. 58 virtual std::unique_ptr<Paragraph> Build() = 0; 59 60 61 // Just until we fix all the google3 code 62 static std::unique_ptr<ParagraphBuilder> make(const ParagraphStyle& style, 63 sk_sp<FontCollection> fontCollection); 64 }; 65 } // namespace textlayout 66 } // namespace skia 67 68 #endif // ParagraphBuilder_DEFINED 69