gecko/content/canvas/public/nsICanvasRenderingContextInternal.h

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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * 1.1 (the "License"); you may not use this file except in compliance with
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 * License.
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 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 *   Vladimir Vukicevic <vladimir@pobox.com>
 * Portions created by the Initial Developer are Copyright (C) 2005
 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *
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#ifndef nsICanvasRenderingContextInternal_h___
#define nsICanvasRenderingContextInternal_h___

#include "nsISupports.h"
#include "nsIInputStream.h"
#include "nsIDocShell.h"
#include "gfxPattern.h"

// {b96168fd-6f13-4ca7-b820-e96f22e71fe5}
#define NS_ICANVASRENDERINGCONTEXTINTERNAL_IID \
{ 0xb96168fd, 0x6f13, 0x4ca7, \
  { 0xb8, 0x20, 0xe9, 0x6f, 0x22, 0xe7, 0x1f, 0xe5 } }

class nsHTMLCanvasElement;
class gfxContext;
class gfxASurface;

namespace mozilla {
namespace layers {
class CanvasLayer;
class LayerManager;
}
namespace ipc {
class Shmem;
}
}

class nsICanvasRenderingContextInternal : public nsISupports {
public:
  typedef mozilla::layers::CanvasLayer CanvasLayer;
  typedef mozilla::layers::LayerManager LayerManager;

  NS_DECLARE_STATIC_IID_ACCESSOR(NS_ICANVASRENDERINGCONTEXTINTERNAL_IID)

  // This method should NOT hold a ref to aParentCanvas; it will be called
  // with nsnull when the element is going away.
  NS_IMETHOD SetCanvasElement(nsHTMLCanvasElement* aParentCanvas) = 0;

  // Sets the dimensions of the canvas, in pixels.  Called
  // whenever the size of the element changes.
  NS_IMETHOD SetDimensions(PRInt32 width, PRInt32 height) = 0;

  NS_IMETHOD InitializeWithSurface(nsIDocShell *docShell, gfxASurface *surface, PRInt32 width, PRInt32 height) = 0;

  // Render the canvas at the origin of the given gfxContext
  NS_IMETHOD Render(gfxContext *ctx, gfxPattern::GraphicsFilter aFilter) = 0;

  // Gives you a stream containing the image represented by this context.
  // The format is given in aMimeTime, for example "image/png".
  //
  // If the image format does not support transparency or aIncludeTransparency
  // is false, alpha will be discarded and the result will be the image
  // composited on black.
  NS_IMETHOD GetInputStream(const char *aMimeType,
                            const PRUnichar *aEncoderOptions,
                            nsIInputStream **aStream) = 0;

  // If this canvas context can be represented with a simple Thebes surface,
  // return the surface.  Otherwise returns an error.
  NS_IMETHOD GetThebesSurface(gfxASurface **surface) = 0;

  // If this context is opaque, the backing store of the canvas should
  // be created as opaque; all compositing operators should assume the
  // dst alpha is always 1.0.  If this is never called, the context
  // defaults to false (not opaque).
  NS_IMETHOD SetIsOpaque(PRBool isOpaque) = 0;

  // Return the CanvasLayer for this context, creating
  // one for the given layer manager if not available.
  virtual already_AddRefed<CanvasLayer> GetCanvasLayer(CanvasLayer *aOldLayer,
                                                       LayerManager *aManager) = 0;

  virtual void MarkContextClean() = 0;

  // Redraw the dirty rectangle of this canvas.
  NS_IMETHOD Redraw(const gfxRect &dirty) = 0;

  // If this context can be set to use Mozilla's Shmem segments as its backing
  // store, this will set it to that state. Note that if you have drawn
  // anything into this canvas before changing the shmem state, it will be
  // lost.
  NS_IMETHOD SetIsIPC(PRBool isIPC) = 0;

  // Swap this back buffer with the front, and copy its contents to the new
  // back. x, y, w, and h specify the area of |back| that is dirty.
  NS_IMETHOD Swap(mozilla::ipc::Shmem& back,
                  PRInt32 x, PRInt32 y, PRInt32 w, PRInt32 h) = 0;

  // Sync back and front buffer, move ownership of back buffer to parent
  NS_IMETHOD Swap(PRUint32 nativeID,
                  PRInt32 x, PRInt32 y, PRInt32 w, PRInt32 h) = 0;

};

NS_DEFINE_STATIC_IID_ACCESSOR(nsICanvasRenderingContextInternal,
                              NS_ICANVASRENDERINGCONTEXTINTERNAL_IID)

#endif /* nsICanvasRenderingContextInternal_h___ */