/*

 * 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 "include/core/SkRefCnt.h"

#include "include/core/SkScalar.h"

#include "include/private/base/SkAPI.h"

class SkCanvas;

class SkWStream;

struct SkRect;

/** SK_ScalarDefaultDPI is 72 dots per inch. */

static constexpr SkScalar 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 SK_API SkDocument : public SkRefCnt {

public:

    /**

     *  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.

     *  This will call endPage() if there is a currently active page.

     */

    SkCanvas* beginPage(SkScalar width, SkScalar height, const SkRect* content = nullptr);

    /**

     *  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.

     */

    void 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*);

    // note: subclasses must call close() in their destructor, as the base class

    // cannot do this for them.

    ~SkDocument() override;

    virtual SkCanvas* onBeginPage(SkScalar width, SkScalar height) = 0;

    virtual void onEndPage() = 0;

    virtual void onClose(SkWStream*) = 0;

    virtual void onAbort() = 0;

    // Allows subclasses to write to the stream as pages are written.

    SkWStream* getStream() { return fStream; }

    enum State {

        kBetweenPages_State,

        kInPage_State,

        kClosed_State

    };

    State getState() const { return fState; }

private:

    SkWStream* fStream;

    State      fState;

    using INHERITED = SkRefCnt;

};

#endif