gecko-dev/layout/svg/base/src/nsSVGGFrame.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 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 "nsIDOMSVGTransformable.h"
#include "nsSVGDefsFrame.h"
#include "nsISVGRenderer.h"
#include "nsISVGRendererSurface.h"
#include "nsISVGOuterSVGFrame.h"
#include "nsISVGRendererCanvas.h"
#include "nsIFrame.h"
#include <math.h>

typedef nsSVGDefsFrame nsSVGGFrameBase;

class nsSVGGFrame : public nsSVGGFrameBase
{
  friend nsresult
  NS_NewSVGGFrame(nsIPresShell* aPresShell, nsIContent* aContent, nsIFrame** aNewFrame);

  // nsISVGChildFrame interface:
  NS_IMETHOD Paint(nsISVGRendererCanvas* canvas, const nsRect& dirtyRectTwips);
  NS_IMETHOD GetFrameForPoint(float x, float y, nsIFrame** hit);  
  NS_IMETHOD_(already_AddRefed<nsISVGRendererRegion>) GetCoveredRegion();
};

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

nsresult
NS_NewSVGGFrame(nsIPresShell* aPresShell, nsIContent* aContent, nsIFrame** aNewFrame)
{
  *aNewFrame = nsnull;
  
  nsCOMPtr<nsIDOMSVGTransformable> transformable = do_QueryInterface(aContent);
  if (!transformable) {
#ifdef DEBUG
    printf("warning: trying to construct an SVGGFrame for a content element that doesn't support the right interfaces\n");
#endif
    return NS_ERROR_FAILURE;
  }
  
  nsSVGGFrame* it = new (aPresShell) nsSVGGFrame;
  if (nsnull == it)
    return NS_ERROR_OUT_OF_MEMORY;

  *aNewFrame = it;

  return NS_OK;
}

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

NS_IMETHODIMP
nsSVGGFrame::Paint(nsISVGRendererCanvas* canvas, const nsRect& dirtyRectTwips)
{
  nsCOMPtr<nsISVGRendererSurface> surface;

  const nsStyleDisplay *display = mStyleContext->GetStyleDisplay();
  if (display->mOpacity == 0.0)
    return NS_OK;

  if (display->mOpacity != 1.0) {
    nsISVGOuterSVGFrame* outerSVGFrame = GetOuterSVGFrame();
    if (outerSVGFrame) {
      nsIFrame *frame = nsnull;
      CallQueryInterface(outerSVGFrame, &frame);

      if (frame) {
        nsSize size = frame->GetSize();
        float p2t = GetPresContext()->ScaledPixelsToTwips();
        PRUint32 width = (PRUint32)ceil(size.width/p2t);
        PRUint32 height = (PRUint32)ceil(size.height/p2t);
        
        nsCOMPtr<nsISVGRenderer> renderer;
        outerSVGFrame->GetRenderer(getter_AddRefs(renderer));
        if (renderer)
          renderer->CreateSurface(width, height, getter_AddRefs(surface));
        if (surface) {
          if (NS_FAILED(canvas->PushSurface(surface)))
            surface = nsnull;
        }
      }
    }
  }

  for (nsIFrame* kid = mFrames.FirstChild(); kid;
       kid = kid->GetNextSibling()) {
    nsISVGChildFrame* SVGFrame=nsnull;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame)
      SVGFrame->Paint(canvas, dirtyRectTwips);
  }

  if (surface) {
    canvas->PopSurface();
    canvas->CompositeSurface(surface, 0, 0, display->mOpacity);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsSVGGFrame::GetFrameForPoint(float x, float y, nsIFrame** hit)
{
  *hit = nsnull;
  for (nsIFrame* kid = mFrames.FirstChild(); kid;
       kid = kid->GetNextSibling()) {
    nsISVGChildFrame* SVGFrame=nsnull;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame) {
      nsIFrame* temp=nsnull;
      nsresult rv = SVGFrame->GetFrameForPoint(x, y, &temp);
      if (NS_SUCCEEDED(rv) && temp) {
        *hit = temp;
        // return NS_OK; can't return. we need reverse order but only
        // have a singly linked list...
      }
    }
  }
  
  return *hit ? NS_OK : NS_ERROR_FAILURE;
}

NS_IMETHODIMP_(already_AddRefed<nsISVGRendererRegion>)
nsSVGGFrame::GetCoveredRegion()
{
  nsISVGRendererRegion *accu_region=nsnull;
  
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGChildFrame* SVGFrame=0;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame) {
      nsCOMPtr<nsISVGRendererRegion> dirty_region = SVGFrame->GetCoveredRegion();
      if (dirty_region) {
        if (accu_region) {
          nsCOMPtr<nsISVGRendererRegion> temp = dont_AddRef(accu_region);
          dirty_region->Combine(temp, &accu_region);
        }
        else {
          accu_region = dirty_region;
          NS_IF_ADDREF(accu_region);
        }
      }
    }
    kid = kid->GetNextSibling();
  }
  
  return accu_region;
}