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
14namespace skia {
15namespace textlayout {
16
17class ParagraphBuilder {
18public:
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 static std::unique_ptr<ParagraphBuilder> make(const ParagraphStyle& style,
61 sk_sp<FontCollection> fontCollection);
62};
63} // namespace textlayout
64} // namespace skia
65
66#endif // ParagraphBuilder_DEFINED
67