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

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * 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
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * 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
 * Crocodile Clips Ltd..
 * Portions created by the Initial Developer are Copyright (C) 2001
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Alex Fritze <alex.fritze@crocodile-clips.com> (original author)
 *
 * Alternatively, the contents of this file may be used under the terms of
 * 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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 * ***** END LICENSE BLOCK ***** */

#include "nsSVGInnerSVGFrame.h"
#include "nsIFrame.h"
#include "nsISVGChildFrame.h"
#include "nsSVGOuterSVGFrame.h"
#include "nsIDOMSVGAnimatedRect.h"
#include "nsSVGMatrix.h"
#include "nsSVGSVGElement.h"
#include "nsSVGContainerFrame.h"
#include "gfxContext.h"

nsIFrame*
NS_NewSVGInnerSVGFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
  return new (aPresShell) nsSVGInnerSVGFrame(aContext);
}

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

NS_QUERYFRAME_HEAD(nsSVGInnerSVGFrame)
  NS_QUERYFRAME_ENTRY(nsSVGInnerSVGFrame)
  NS_QUERYFRAME_ENTRY(nsISVGSVGFrame)
NS_QUERYFRAME_TAIL_INHERITING(nsSVGInnerSVGFrameBase)

#ifdef DEBUG
NS_IMETHODIMP
nsSVGInnerSVGFrame::Init(nsIContent* aContent,
                         nsIFrame* aParent,
                         nsIFrame* aPrevInFlow)
{
  nsCOMPtr<nsIDOMSVGSVGElement> svg = do_QueryInterface(aContent);
  NS_ASSERTION(svg, "Content is not an SVG 'svg' element!");

  return nsSVGInnerSVGFrameBase::Init(aContent, aParent, aPrevInFlow);
}
#endif /* DEBUG */

nsIAtom *
nsSVGInnerSVGFrame::GetType() const
{
  return nsGkAtoms::svgInnerSVGFrame;
}

//----------------------------------------------------------------------
// nsISVGChildFrame methods

NS_IMETHODIMP
nsSVGInnerSVGFrame::PaintSVG(nsSVGRenderState *aContext,
                             const nsIntRect *aDirtyRect)
{
  gfxContextAutoSaveRestore autoSR;

  if (GetStyleDisplay()->IsScrollableOverflow()) {
    float x, y, width, height;
    static_cast<nsSVGSVGElement*>(mContent)->
      GetAnimatedLengthValues(&x, &y, &width, &height, nsnull);

    if (width <= 0 || height <= 0) {
      return NS_OK;
    }

    nsSVGContainerFrame *parent = static_cast<nsSVGContainerFrame*>(mParent);
    gfxMatrix clipTransform = parent->GetCanvasTM();

    gfxContext *gfx = aContext->GetGfxContext();
    autoSR.SetContext(gfx);
    gfxRect clipRect =
      nsSVGUtils::GetClipRectForFrame(this, x, y, width, height);
    nsSVGUtils::SetClipRect(gfx, clipTransform, clipRect);
  }

  return nsSVGInnerSVGFrameBase::PaintSVG(aContext, aDirtyRect);
}

void
nsSVGInnerSVGFrame::NotifySVGChanged(PRUint32 aFlags)
{
  if (aFlags & COORD_CONTEXT_CHANGED) {

    nsSVGSVGElement *svg = static_cast<nsSVGSVGElement*>(mContent);

    // Coordinate context changes affect mCanvasTM if we have a
    // percentage 'x' or 'y', or if we have a percentage 'width' or 'height' AND
    // a 'viewBox'.

    if (!(aFlags & TRANSFORM_CHANGED) &&
        (svg->mLengthAttributes[nsSVGSVGElement::X].IsPercentage() ||
         svg->mLengthAttributes[nsSVGSVGElement::Y].IsPercentage() ||
         (mContent->HasAttr(kNameSpaceID_None, nsGkAtoms::viewBox) &&
          (svg->mLengthAttributes[nsSVGSVGElement::WIDTH].IsPercentage() ||
           svg->mLengthAttributes[nsSVGSVGElement::HEIGHT].IsPercentage())))) {
    
      aFlags |= TRANSFORM_CHANGED;
    }

    // XXX We could clear the COORD_CONTEXT_CHANGED flag in some circumstances
    // if we have a non-percentage 'width' AND 'height, or if we have a 'viewBox'
    // rect. This is because, when we have a viewBox rect, the viewBox rect
    // is the coordinate context for our children, and it isn't changing.
    // Percentage lengths on our children will continue to resolve to the
    // same number of user units because they're relative to our viewBox rect. The
    // same is true if we have a non-percentage width and height and don't have a
    // viewBox. We (the <svg>) establish the coordinate context for our children. Our
    // children don't care about changes to our parent coordinate context unless that
    // change results in a change to the coordinate context that _we_ establish. Hence
    // we can (should, really) stop propagating COORD_CONTEXT_CHANGED in these cases.
    // We'd actually need to check that we have a viewBox rect and not just
    // that viewBox is set, since it could be set to none.
    // Take care not to break the testcase for bug 394463 when implementing this
  }

  if (aFlags & TRANSFORM_CHANGED) {
    // make sure our cached transform matrix gets (lazily) updated
    mCanvasTM = nsnull;
  }

  nsSVGInnerSVGFrameBase::NotifySVGChanged(aFlags);
}

NS_IMETHODIMP_(nsIFrame*)
nsSVGInnerSVGFrame::GetFrameForPoint(const nsPoint &aPoint)
{
  if (GetStyleDisplay()->IsScrollableOverflow()) {
    nsSVGElement *content = static_cast<nsSVGElement*>(mContent);
    nsSVGContainerFrame *parent = static_cast<nsSVGContainerFrame*>(mParent);

    float clipX, clipY, clipWidth, clipHeight;
    content->GetAnimatedLengthValues(&clipX, &clipY, &clipWidth, &clipHeight, nsnull);

    if (!nsSVGUtils::HitTestRect(parent->GetCanvasTM(),
                                 clipX, clipY, clipWidth, clipHeight,
                                 PresContext()->AppUnitsToDevPixels(aPoint.x),
                                 PresContext()->AppUnitsToDevPixels(aPoint.y))) {
      return nsnull;
    }
  }

  return nsSVGInnerSVGFrameBase::GetFrameForPoint(aPoint);
}

//----------------------------------------------------------------------
// nsISVGSVGFrame methods:

NS_IMETHODIMP
nsSVGInnerSVGFrame::SuspendRedraw()
{
  nsSVGOuterSVGFrame *outerSVGFrame = nsSVGUtils::GetOuterSVGFrame(this);
  if (!outerSVGFrame) {
    NS_ERROR("no outer svg frame");
    return NS_ERROR_FAILURE;
  }
  return outerSVGFrame->SuspendRedraw();
}

NS_IMETHODIMP
nsSVGInnerSVGFrame::UnsuspendRedraw()
{
  nsSVGOuterSVGFrame *outerSVGFrame = nsSVGUtils::GetOuterSVGFrame(this);
  if (!outerSVGFrame) {
    NS_ERROR("no outer svg frame");
    return NS_ERROR_FAILURE;
  }
  return outerSVGFrame->UnsuspendRedraw();
}

NS_IMETHODIMP
nsSVGInnerSVGFrame::NotifyViewportChange()
{
  PRUint32 flags = COORD_CONTEXT_CHANGED;

#if 1
  // XXX nsSVGSVGElement::InvalidateTransformNotifyFrame calls us for changes
  // to 'x' and 'y'. Until this is fixed, add TRANSFORM_CHANGED to flags
  // unconditionally.

  flags |= TRANSFORM_CHANGED;

  // make sure canvas transform matrix gets (lazily) recalculated:
  mCanvasTM = nsnull;
#else
  // viewport changes only affect our transform if we have a viewBox attribute
  if (mContent->HasAttr(kNameSpaceID_None, nsGkAtoms::viewBox)) {
    // make sure canvas transform matrix gets (lazily) recalculated:
    mCanvasTM = nsnull;

    flags |= TRANSFORM_CHANGED;
  }
#endif
  
  // inform children
  SuspendRedraw();
  nsSVGUtils::NotifyChildrenOfSVGChange(this, flags);
  UnsuspendRedraw();
  return NS_OK;
}

//----------------------------------------------------------------------
// nsSVGContainerFrame methods:

gfxMatrix
nsSVGInnerSVGFrame::GetCanvasTM()
{
  if (!mCanvasTM) {
    NS_ASSERTION(mParent, "null parent");

    nsSVGContainerFrame *parent = static_cast<nsSVGContainerFrame*>(mParent);
    nsSVGSVGElement *content = static_cast<nsSVGSVGElement*>(mContent);

    gfxMatrix tm = content->PrependLocalTransformTo(parent->GetCanvasTM());

    mCanvasTM = NS_NewSVGMatrix(tm);
  }
  return nsSVGUtils::ConvertSVGMatrixToThebes(mCanvasTM);
}