1 | /* |
2 | * Copyright 2013 Google Inc. |
3 | * |
4 | * Use of this source code is governed by a BSD-style license that can be |
5 | * found in the LICENSE file. |
6 | */ |
7 | |
8 | #ifndef SkDocument_DEFINED |
9 | #define SkDocument_DEFINED |
10 | |
11 | #include "include/core/SkRefCnt.h" |
12 | #include "include/core/SkScalar.h" |
13 | |
14 | class SkCanvas; |
15 | class SkWStream; |
16 | struct SkRect; |
17 | |
18 | /** SK_ScalarDefaultDPI is 72 dots per inch. */ |
19 | static constexpr SkScalar SK_ScalarDefaultRasterDPI = 72.0f; |
20 | |
21 | /** |
22 | * High-level API for creating a document-based canvas. To use.. |
23 | * |
24 | * 1. Create a document, specifying a stream to store the output. |
25 | * 2. For each "page" of content: |
26 | * a. canvas = doc->beginPage(...) |
27 | * b. draw_my_content(canvas); |
28 | * c. doc->endPage(); |
29 | * 3. Close the document with doc->close(). |
30 | */ |
31 | class SK_API SkDocument : public SkRefCnt { |
32 | public: |
33 | |
34 | /** |
35 | * Begin a new page for the document, returning the canvas that will draw |
36 | * into the page. The document owns this canvas, and it will go out of |
37 | * scope when endPage() or close() is called, or the document is deleted. |
38 | */ |
39 | SkCanvas* beginPage(SkScalar width, SkScalar height, const SkRect* content = nullptr); |
40 | |
41 | /** |
42 | * Call endPage() when the content for the current page has been drawn |
43 | * (into the canvas returned by beginPage()). After this call the canvas |
44 | * returned by beginPage() will be out-of-scope. |
45 | */ |
46 | void endPage(); |
47 | |
48 | /** |
49 | * Call close() when all pages have been drawn. This will close the file |
50 | * or stream holding the document's contents. After close() the document |
51 | * can no longer add new pages. Deleting the document will automatically |
52 | * call close() if need be. |
53 | */ |
54 | void close(); |
55 | |
56 | /** |
57 | * Call abort() to stop producing the document immediately. |
58 | * The stream output must be ignored, and should not be trusted. |
59 | */ |
60 | void abort(); |
61 | |
62 | protected: |
63 | SkDocument(SkWStream*); |
64 | |
65 | // note: subclasses must call close() in their destructor, as the base class |
66 | // cannot do this for them. |
67 | virtual ~SkDocument(); |
68 | |
69 | virtual SkCanvas* onBeginPage(SkScalar width, SkScalar height) = 0; |
70 | virtual void onEndPage() = 0; |
71 | virtual void onClose(SkWStream*) = 0; |
72 | virtual void onAbort() = 0; |
73 | |
74 | // Allows subclasses to write to the stream as pages are written. |
75 | SkWStream* getStream() { return fStream; } |
76 | |
77 | enum State { |
78 | kBetweenPages_State, |
79 | kInPage_State, |
80 | kClosed_State |
81 | }; |
82 | State getState() const { return fState; } |
83 | |
84 | private: |
85 | SkWStream* fStream; |
86 | State fState; |
87 | |
88 | typedef SkRefCnt INHERITED; |
89 | }; |
90 | |
91 | #endif |
92 | |