third_party/WebKit/Source/core/html/canvas/CanvasImageSource.h

/*
 * Copyright (C) 2006, 2007, 2008 Apple Computer, Inc.  All rights reserved.
 * Copyright (C) 2007 Alp Toker <alp@atoker.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef CanvasImageSource_h
#define CanvasImageSource_h

#include "core/CoreExport.h"
#include "platform/graphics/GraphicsTypes.h"
#include "wtf/PassRefPtr.h"

namespace blink {

class Image;
class SecurityOrigin;

enum SourceImageStatus {
  NormalSourceImageStatus,
  UndecodableSourceImageStatus,     // Image element with a 'broken' image
  ZeroSizeCanvasSourceImageStatus,  // Source is a canvas with width or heigh of
                                    // zero
  IncompleteSourceImageStatus,      // Image element with no source media
  InvalidSourceImageStatus,
};

class CORE_EXPORT CanvasImageSource {
 public:
  virtual PassRefPtr<Image> getSourceImageForCanvas(SourceImageStatus*,
                                                    AccelerationHint,
                                                    SnapshotReason,
                                                    const FloatSize&) const = 0;

  // IMPORTANT: Result must be independent of whether destinationContext is
  // already tainted because this function may be used to determine whether
  // a CanvasPattern is "origin clean", and that pattern may be used on
  // another canvas, which may not be already tainted.
  virtual bool wouldTaintOrigin(
      SecurityOrigin* destinationSecurityOrigin) const = 0;

  virtual bool isCSSImageValue() const { return false; }
  virtual bool isVideoElement() const { return false; }
  virtual bool isCanvasElement() const { return false; }
  virtual bool isSVGSource() const { return false; }
  virtual bool isImageBitmap() const { return false; }
  virtual bool isOffscreenCanvas() const { return false; }

  // Adjusts the source and destination rectangles for cases where the actual
  // source image is a subregion of the image returned by
  // getSourceImageForCanvas.
  virtual void adjustDrawRects(FloatRect* srcRect, FloatRect* dstRect) const {}

  virtual FloatSize elementSize(const FloatSize& defaultObjectSize) const = 0;
  virtual FloatSize defaultDestinationSize(
      const FloatSize& defaultObjectSize) const {
    return elementSize(defaultObjectSize);
  }
  virtual const KURL& sourceURL() const { return blankURL(); }
  virtual bool isOpaque() const { return false; }
  virtual bool isAccelerated() const = 0;

  virtual int sourceWidth() = 0;
  virtual int sourceHeight() = 0;

 protected:
  virtual ~CanvasImageSource() {}
};

}  // namespace blink

#endif