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 SkPdfTokenLooper_DEFINED
9#define SkPdfTokenLooper_DEFINED
10
11#include "SkPdfNativeTokenizer.h"
12// For SkPdfResult
13#include "SkPdfUtils.h"
14
15class SkCanvas;
16class SkPdfContext;
17
18/**
19 *  An object which reads tokens from a tokenizer and draws it to an SkCanvas.
20 *  FIXME (scroggo): Can this be an interface? See http://goo.gl/AXQtkH
21 */
22class SkPdfTokenLooper {
23public:
24    /**
25     *  Create a looper with no parent.
26     *  @param tokenizer SkPdfNativeTokenizer for reading tokens.
27     *  @param pdfContext Context for drawing state.
28     *  @param canvas Target SkCanvas for drawing.
29     */
30    SkPdfTokenLooper(SkPdfNativeTokenizer* tokenizer,
31                     SkPdfContext* pdfContext,
32                     SkCanvas* canvas)
33        : fParent(NULL)
34        , fTokenizer(tokenizer)
35        , fPdfContext(pdfContext)
36        , fCanvas(canvas) {}
37
38    /**
39     *  Create a looper as a child of parent. It will share the
40     *  SkPdfContext, SkPdfTokenizer, and SkCanvas with its parent.
41     */
42    explicit SkPdfTokenLooper(SkPdfTokenLooper* parent)
43        : fParent(parent)
44        , fTokenizer(parent->fTokenizer)
45        , fPdfContext(parent->fPdfContext)
46        , fCanvas(parent->fCanvas) {}
47
48    virtual ~SkPdfTokenLooper() {}
49
50    /**
51     *  Consume a token, and draw to fCanvas as directed.
52     */
53    virtual SkPdfResult consumeToken(PdfToken& token) = 0;
54
55    /**
56     *  Consume all the tokens this looper can handle.
57     */
58    virtual void loop() = 0;
59
60protected:
61    // All are unowned pointers.
62    SkPdfTokenLooper*       fParent;
63    SkPdfNativeTokenizer*   fTokenizer;
64    SkPdfContext*           fPdfContext;
65    SkCanvas*               fCanvas;
66};
67
68#endif // SkPdfTokenLooper_DEFINED
69