experimental/tools/PageCachingDocument.cpp

   1 /*
   2  * Copyright 2014 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 #include "PageCachingDocument.h"
   9 #include "SkCanvas.h"
  10 #include "SkDocument.h"
  11 #include "SkPictureRecorder.h"
  12 #include "SkRect.h"
  13 #include "SkTDArray.h"
  14
  15 namespace {
  16
  17 typedef void (*DoneProc)(SkWStream*, bool);
  18 typedef SkData* (*Encoder)(size_t*, const SkBitmap&);
  19
  20 // This class allows us to compare the relative memory consumption of
  21 // the PDF and SkPicture backends.
  22 class PageCachingDocument : public SkDocument {
  23 public:
  24     PageCachingDocument(SkWStream*, DoneProc, Encoder, SkScalar rasterDpi);
  25     virtual ~PageCachingDocument();
  26     virtual SkCanvas* onBeginPage(SkScalar width,
  27                                   SkScalar height,
  28                                   const SkRect& content) SK_OVERRIDE;
  29     void onEndPage() SK_OVERRIDE;
  30     bool onClose(SkWStream*) SK_OVERRIDE;
  31     void onAbort() SK_OVERRIDE;
  32
  33 private:
  34     struct Page {
  35         SkScalar fWidth;
  36         SkScalar fHeight;
  37         SkAutoTUnref<SkPicture> fPic;
  38     };
  39     SkPictureRecorder fRecorder;
  40     SkTDArray<Page> fPages;
  41     Encoder fEncoder;
  42     SkScalar fRasterDpi;
  43 };
  44
  45 PageCachingDocument::PageCachingDocument(SkWStream* stream,
  46                                          DoneProc done,
  47                                          Encoder encoder,
  48                                          SkScalar rasterDpi)
  49     : SkDocument(stream, done), fEncoder(encoder), fRasterDpi(rasterDpi) {
  50 }
  51
  52 PageCachingDocument::~PageCachingDocument() {
  53     for (Page* p = fPages.begin(); p != fPages.end(); ++p) {
  54         p->~Page();
  55     }
  56 }
  57
  58 SkCanvas* PageCachingDocument::onBeginPage(SkScalar width,
  59                                            SkScalar height,
  60                                            const SkRect& content) {
  61     Page* page = fPages.push();
  62     sk_bzero(page, sizeof(*page));
  63     page->fWidth = width;
  64     page->fHeight = height;
  65     SkASSERT(!page->fPic.get());
  66     SkCanvas* canvas = fRecorder.beginRecording(content);
  67     return canvas;
  68 }
  69
  70 void PageCachingDocument::onEndPage() {
  71     SkASSERT(fPages.count() > 0);
  72     SkASSERT(!fPages[fPages.count() - 1].fPic);
  73     fPages[fPages.count() - 1].fPic.reset(fRecorder.endRecording());
  74 }
  75
  76 bool PageCachingDocument::onClose(SkWStream* stream) {
  77     SkAutoTUnref<SkDocument> doc(
  78         SkDocument::CreatePDF(stream, NULL, fEncoder, fRasterDpi));
  79     for (Page* page = fPages.begin(); page != fPages.end(); ++page) {
  80         SkRect cullRect = page->fPic->cullRect();
  81         SkCanvas* canvas =
  82             doc->beginPage(page->fWidth, page->fHeight, &cullRect);
  83         canvas->drawPicture(page->fPic);
  84         doc->endPage();
  85     }
  86     return doc->close();
  87 }
  88
  89 void PageCachingDocument::onAbort() {
  90 }
  91 }  // namespace
  92
  93 SkDocument* CreatePageCachingDocument(SkWStream* stream,
  94                                       DoneProc done,
  95                                       Encoder encoder,
  96                                       SkScalar rasterDpi) {
  97     return SkNEW_ARGS(PageCachingDocument, (stream, done, encoder, rasterDpi));
  98 }