skia2/include/core/SkDocument.h

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/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkDocument_DEFINED
#define SkDocument_DEFINED
#include "SkBitmap.h"
#include "SkPicture.h"
#include "SkRect.h"
#include "SkRefCnt.h"
class SkCanvas;
class SkWStream;
/** SK_ScalarDefaultDPI is 72 DPI.
*/
#define SK_ScalarDefaultRasterDPI 72.0f
/**
* High-level API for creating a document-based canvas. To use..
*
* 1. Create a document, specifying a stream to store the output.
* 2. For each "page" of content:
* a. canvas = doc->beginPage(...)
* b. draw_my_content(canvas);
* c. doc->endPage();
* 3. Close the document with doc->close().
*/
class SkDocument : public SkRefCnt {
public:
SK_DECLARE_INST_COUNT(SkDocument)
/**
* Create a PDF-backed document, writing the results into a file.
* If there is an error trying to create the doc, returns NULL.
* encoder sets the DCTEncoder for images, to encode a bitmap
* as JPEG (DCT).
* rasterDpi - the DPI at which features without native PDF support
* will be rasterized (e.g. draw image with perspective,
* draw text with perspective, ...)
* A larger DPI would create a PDF that reflects the original
* intent with better fidelity, but it can make for larger
* PDF files too, which would use more memory while rendering,
* and it would be slower to be processed or sent online or
* to printer.
*/
static SkDocument* CreatePDF(
const char filename[],
SkPicture::EncodeBitmap encoder = NULL,
SkScalar rasterDpi = SK_ScalarDefaultRasterDPI);
/**
* Create a PDF-backed document, writing the results into a stream.
* If there is an error trying to create the doc, returns NULL.
*
* The document may write to the stream at anytime during its lifetime,
* until either close() is called or the document is deleted. Once close()
* has been called, and all of the data has been written to the stream,
* if there is a Done proc provided, it will be called with the stream.
* The proc can delete the stream, or whatever it needs to do.
* encoder sets the DCTEncoder for images, to encode a bitmap
* as JPEG (DCT).
* Done - clean up method intended to allow deletion of the stream.
* Its aborted parameter is true if the cleanup is due to an abort
* call. It is false otherwise.
* rasterDpi - the DPI at which features without native PDF support
* will be rasterized (e.g. draw image with perspective,
* draw text with perspective, ...)
* A larger DPI would create a PDF that reflects the original
* intent with better fidelity, but it can make for larger
* PDF files too, which would use more memory while rendering,
* and it would be slower to be processed or sent online or
* to printer. */
static SkDocument* CreatePDF(
SkWStream*, void (*Done)(SkWStream*,bool aborted) = NULL,
SkPicture::EncodeBitmap encoder = NULL,
SkScalar rasterDpi = SK_ScalarDefaultRasterDPI);
/**
* Begin a new page for the document, returning the canvas that will draw
* into the page. The document owns this canvas, and it will go out of
* scope when endPage() or close() is called, or the document is deleted.
*/
SkCanvas* beginPage(SkScalar width, SkScalar height,
const SkRect* content = NULL);
/**
* Call endPage() when the content for the current page has been drawn
* (into the canvas returned by beginPage()). After this call the canvas
* returned by beginPage() will be out-of-scope.
*/
void endPage();
/**
* Call close() when all pages have been drawn. This will close the file
* or stream holding the document's contents. After close() the document
* can no longer add new pages. Deleting the document will automatically
* call close() if need be.
* Returns true on success or false on failure.
*/
bool close();
/**
* Call abort() to stop producing the document immediately.
* The stream output must be ignored, and should not be trusted.
*/
void abort();
protected:
SkDocument(SkWStream*, void (*)(SkWStream*, bool aborted));
// note: subclasses must call close() in their destructor, as the base class
// cannot do this for them.
virtual ~SkDocument();
virtual SkCanvas* onBeginPage(SkScalar width, SkScalar height,
const SkRect& content) = 0;
virtual void onEndPage() = 0;
virtual bool onClose(SkWStream*) = 0;
virtual void onAbort() = 0;
enum State {
kBetweenPages_State,
kInPage_State,
kClosed_State
};
State getState() const { return fState; }
private:
SkWStream* fStream;
void (*fDoneProc)(SkWStream*, bool aborted);
State fState;
typedef SkRefCnt INHERITED;
};
#endif