gecko/layout/svg/base/src/nsSVGImageFrame.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
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 *
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 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the Mozilla SVG project.
 *
 * The Initial Developer of the Original Code is IBM Corporation.
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 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *
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 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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#include "nsSVGPathGeometryFrame.h"
#include "imgIContainer.h"
#include "nsStubImageDecoderObserver.h"
#include "nsImageLoadingContent.h"
#include "nsIDOMSVGImageElement.h"
#include "nsLayoutUtils.h"
#include "nsSVGImageElement.h"
#include "nsSVGUtils.h"
#include "gfxContext.h"
#include "gfxMatrix.h"
#include "nsIInterfaceRequestorUtils.h"
#include "gfxPlatform.h"

class nsSVGImageFrame;

class nsSVGImageListener : public nsStubImageDecoderObserver
{
public:
  nsSVGImageListener(nsSVGImageFrame *aFrame);

  NS_DECL_ISUPPORTS
  // imgIDecoderObserver (override nsStubImageDecoderObserver)
  NS_IMETHOD OnStopDecode(imgIRequest *aRequest, nsresult status,
                          const PRUnichar *statusArg);
  // imgIContainerObserver (override nsStubImageDecoderObserver)
  NS_IMETHOD FrameChanged(imgIContainer *aContainer,
                          const nsIntRect *aDirtyRect);
  // imgIContainerObserver (override nsStubImageDecoderObserver)
  NS_IMETHOD OnStartContainer(imgIRequest *aRequest,
                              imgIContainer *aContainer);

  void SetFrame(nsSVGImageFrame *frame) { mFrame = frame; }

private:
  nsSVGImageFrame *mFrame;
};


class nsSVGImageFrame : public nsSVGPathGeometryFrame
{
  friend nsIFrame*
  NS_NewSVGImageFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);

protected:
  nsSVGImageFrame(nsStyleContext* aContext) : nsSVGPathGeometryFrame(aContext) {}
  virtual ~nsSVGImageFrame();

public:
  NS_DECL_FRAMEARENA_HELPERS

  // nsISVGChildFrame interface:
  NS_IMETHOD PaintSVG(nsSVGRenderState *aContext, const nsIntRect *aDirtyRect);
  NS_IMETHOD_(nsIFrame*) GetFrameForPoint(const nsPoint &aPoint);

  // nsSVGPathGeometryFrame methods:
  NS_IMETHOD UpdateCoveredRegion();
  virtual PRUint16 GetHittestMask();

  // nsIFrame interface:
  NS_IMETHOD  AttributeChanged(PRInt32         aNameSpaceID,
                               nsIAtom*        aAttribute,
                               PRInt32         aModType);
  NS_IMETHOD Init(nsIContent*      aContent,
                  nsIFrame*        aParent,
                  nsIFrame*        aPrevInFlow);

  /**
   * Get the "type" of the frame
   *
   * @see nsGkAtoms::svgImageFrame
   */
  virtual nsIAtom* GetType() const;

#ifdef DEBUG
  NS_IMETHOD GetFrameName(nsAString& aResult) const
  {
    return MakeFrameName(NS_LITERAL_STRING("SVGImage"), aResult);
  }
#endif

private:
  gfxMatrix GetImageTransform();

  nsCOMPtr<imgIDecoderObserver> mListener;

  nsCOMPtr<imgIContainer> mImageContainer;

  friend class nsSVGImageListener;
};

//----------------------------------------------------------------------
// Implementation

nsIFrame*
NS_NewSVGImageFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
  return new (aPresShell) nsSVGImageFrame(aContext);
}

NS_IMPL_FRAMEARENA_HELPERS(nsSVGImageFrame)

nsSVGImageFrame::~nsSVGImageFrame()
{
  // set the frame to null so we don't send messages to a dead object.
  if (mListener) {
    nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(mContent);
    if (imageLoader) {
      imageLoader->RemoveObserver(mListener);
    }
    reinterpret_cast<nsSVGImageListener*>(mListener.get())->SetFrame(nsnull);
  }
  mListener = nsnull;
}

NS_IMETHODIMP
nsSVGImageFrame::Init(nsIContent* aContent,
                      nsIFrame* aParent,
                      nsIFrame* aPrevInFlow)
{
#ifdef DEBUG
  nsCOMPtr<nsIDOMSVGImageElement> image = do_QueryInterface(aContent);
  NS_ASSERTION(image, "Content is not an SVG image!");
#endif

  nsresult rv = nsSVGPathGeometryFrame::Init(aContent, aParent, aPrevInFlow);
  if (NS_FAILED(rv)) return rv;
  
  mListener = new nsSVGImageListener(this);
  if (!mListener) return NS_ERROR_OUT_OF_MEMORY;
  nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(mContent);
  NS_ENSURE_TRUE(imageLoader, NS_ERROR_UNEXPECTED);
  imageLoader->AddObserver(mListener);

  return NS_OK; 
}

//----------------------------------------------------------------------
// nsIFrame methods:

NS_IMETHODIMP
nsSVGImageFrame::AttributeChanged(PRInt32         aNameSpaceID,
                                  nsIAtom*        aAttribute,
                                  PRInt32         aModType)
{
   if (aNameSpaceID == kNameSpaceID_None &&
       (aAttribute == nsGkAtoms::x ||
        aAttribute == nsGkAtoms::y ||
        aAttribute == nsGkAtoms::width ||
        aAttribute == nsGkAtoms::height ||
        aAttribute == nsGkAtoms::preserveAspectRatio)) {
     nsSVGUtils::UpdateGraphic(this);
     return NS_OK;
   }

   return nsSVGPathGeometryFrame::AttributeChanged(aNameSpaceID,
                                                   aAttribute, aModType);
}

gfxMatrix
nsSVGImageFrame::GetImageTransform()
{
  float x, y, width, height;
  nsSVGImageElement *element = static_cast<nsSVGImageElement*>(mContent);
  element->GetAnimatedLengthValues(&x, &y, &width, &height, nsnull);

  PRInt32 nativeWidth, nativeHeight;
  mImageContainer->GetWidth(&nativeWidth);
  mImageContainer->GetHeight(&nativeHeight);

  gfxMatrix viewBoxTM =
    nsSVGUtils::GetViewBoxTransform(element,
                                    width, height,
                                    0, 0, nativeWidth, nativeHeight,
                                    element->mPreserveAspectRatio);

  return viewBoxTM * gfxMatrix().Translate(gfxPoint(x, y)) * GetCanvasTM();
}

//----------------------------------------------------------------------
// nsISVGChildFrame methods:
NS_IMETHODIMP
nsSVGImageFrame::PaintSVG(nsSVGRenderState *aContext,
                          const nsIntRect *aDirtyRect)
{
  nsresult rv = NS_OK;

  if (!GetStyleVisibility()->IsVisible())
    return NS_OK;

  float x, y, width, height;
  nsSVGElement *element = static_cast<nsSVGElement*>(mContent);
  element->GetAnimatedLengthValues(&x, &y, &width, &height, nsnull);
  if (width <= 0 || height <= 0)
    return NS_OK;

  if (!mImageContainer) {
    nsCOMPtr<imgIRequest> currentRequest;
    nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(mContent);
    if (imageLoader)
      imageLoader->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
                              getter_AddRefs(currentRequest));

    if (currentRequest)
      currentRequest->GetImage(getter_AddRefs(mImageContainer));
  }

  if (mImageContainer) {
    if (mImageContainer->GetType() == imgIContainer::TYPE_VECTOR) {
      // <svg:image> not supported for SVG images yet.
      return NS_ERROR_FAILURE;
    }

    gfxContext* ctx = aContext->GetGfxContext();
    gfxContextAutoSaveRestore autoRestorer(ctx);

    if (GetStyleDisplay()->IsScrollableOverflow()) {
      gfxRect clipRect = nsSVGUtils::GetClipRectForFrame(this, x, y,
                                                         width, height);
      nsSVGUtils::SetClipRect(ctx, GetCanvasTM(), clipRect);
    }

    // NOTE: To ensure that |width| and |height| don't accidentally
    // scale the user-unit size in SVG images, we apply those attributes
    // via |destRect|, not via our gfxContext's transform.
    ctx->Multiply(GetImageTransform());

    // fill-opacity doesn't affect <image>, so if we're allowed to
    // optimize group opacity, the opacity used for compositing the
    // image into the current canvas is just the group opacity.
    float opacity = 1.0f;
    if (nsSVGUtils::CanOptimizeOpacity(this)) {
      opacity = GetStyleDisplay()->mOpacity;
    }

    if (opacity != 1.0f) {
      ctx->PushGroup(gfxASurface::CONTENT_COLOR_ALPHA);
    }

    nsRect dirtyRect; // only used if aDirtyRect is non-null
    if (aDirtyRect) {
      dirtyRect = aDirtyRect->ToAppUnits(PresContext()->AppUnitsPerDevPixel());
      // Adjust dirtyRect to match our local coordinate system.
      dirtyRect.MoveBy(-mRect.TopLeft());
    }

    // XXXbholley - I don't think huge images in SVGs are common enough to
    // warrant worrying about the responsiveness impact of doing synchronous
    // decodes. The extra code complexity of determinining when we want to
    // force sync probably just isn't worth it, so always pass FLAG_SYNC_DECODE
    nsLayoutUtils::DrawSingleUnscaledImage(
      aContext->GetRenderingContext(this),
      mImageContainer,
      nsLayoutUtils::GetGraphicsFilterForFrame(this),
      nsPoint(0, 0),
      aDirtyRect ? &dirtyRect : nsnull,
      imgIContainer::FLAG_SYNC_DECODE);

    if (opacity != 1.0f) {
      ctx->PopGroupToSource();
      ctx->SetOperator(gfxContext::OPERATOR_OVER);
      ctx->Paint(opacity);
    }
    // gfxContextAutoSaveRestore goes out of scope & cleans up our gfxContext
  }

  return rv;
}

NS_IMETHODIMP_(nsIFrame*)
nsSVGImageFrame::GetFrameForPoint(const nsPoint &aPoint)
{
  if (GetStyleDisplay()->IsScrollableOverflow() && mImageContainer) {
    PRInt32 nativeWidth, nativeHeight;
    mImageContainer->GetWidth(&nativeWidth);
    mImageContainer->GetHeight(&nativeHeight);

    if (!nsSVGUtils::HitTestRect(GetImageTransform(),
                                 0, 0, nativeWidth, nativeHeight,
                                 PresContext()->AppUnitsToDevPixels(aPoint.x),
                                 PresContext()->AppUnitsToDevPixels(aPoint.y))) {
      return nsnull;
    }
  }

  return nsSVGPathGeometryFrame::GetFrameForPoint(aPoint);
}

nsIAtom *
nsSVGImageFrame::GetType() const
{
  return nsGkAtoms::svgImageFrame;
}

//----------------------------------------------------------------------
// nsSVGPathGeometryFrame methods:

// Lie about our fill/stroke so that covered region and hit detection work properly

NS_IMETHODIMP
nsSVGImageFrame::UpdateCoveredRegion()
{
  mRect.Empty();

  gfxContext context(gfxPlatform::GetPlatform()->ScreenReferenceSurface());

  GeneratePath(&context);
  context.IdentityMatrix();

  gfxRect extent = context.GetUserPathExtent();

  if (!extent.IsEmpty()) {
    mRect = nsSVGUtils::ToAppPixelRect(PresContext(), extent);
  }

  return NS_OK;
}

PRUint16
nsSVGImageFrame::GetHittestMask()
{
  PRUint16 mask = 0;

  switch(GetStyleVisibility()->mPointerEvents) {
    case NS_STYLE_POINTER_EVENTS_NONE:
      break;
    case NS_STYLE_POINTER_EVENTS_VISIBLEPAINTED:
    case NS_STYLE_POINTER_EVENTS_AUTO:
      if (GetStyleVisibility()->IsVisible()) {
        /* XXX: should check pixel transparency */
        mask |= HITTEST_MASK_FILL;
      }
      break;
    case NS_STYLE_POINTER_EVENTS_VISIBLEFILL:
    case NS_STYLE_POINTER_EVENTS_VISIBLESTROKE:
    case NS_STYLE_POINTER_EVENTS_VISIBLE:
      if (GetStyleVisibility()->IsVisible()) {
        mask |= HITTEST_MASK_FILL;
      }
      break;
    case NS_STYLE_POINTER_EVENTS_PAINTED:
      /* XXX: should check pixel transparency */
      mask |= HITTEST_MASK_FILL;
      break;
    case NS_STYLE_POINTER_EVENTS_FILL:
    case NS_STYLE_POINTER_EVENTS_STROKE:
    case NS_STYLE_POINTER_EVENTS_ALL:
      mask |= HITTEST_MASK_FILL;
      break;
    default:
      NS_ERROR("not reached");
      break;
  }

  return mask;
}

//----------------------------------------------------------------------
// nsSVGImageListener implementation

NS_IMPL_ISUPPORTS2(nsSVGImageListener,
                   imgIDecoderObserver,
                   imgIContainerObserver)

nsSVGImageListener::nsSVGImageListener(nsSVGImageFrame *aFrame) :  mFrame(aFrame)
{
}

NS_IMETHODIMP nsSVGImageListener::OnStopDecode(imgIRequest *aRequest,
                                               nsresult status,
                                               const PRUnichar *statusArg)
{
  if (!mFrame)
    return NS_ERROR_FAILURE;

  nsSVGUtils::UpdateGraphic(mFrame);
  return NS_OK;
}

NS_IMETHODIMP nsSVGImageListener::FrameChanged(imgIContainer *aContainer,
                                               const nsIntRect *aDirtyRect)
{
  if (!mFrame)
    return NS_ERROR_FAILURE;

  nsSVGUtils::UpdateGraphic(mFrame);
  return NS_OK;
}

NS_IMETHODIMP nsSVGImageListener::OnStartContainer(imgIRequest *aRequest,
                                                   imgIContainer *aContainer)
{
  if (!mFrame)
    return NS_ERROR_FAILURE;

  mFrame->mImageContainer = aContainer;
  nsSVGUtils::UpdateGraphic(mFrame);

  return NS_OK;
}