layout/svg/SVGFEImageFrame.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 // Keep in (case-insensitive) order:
   8 #include "mozilla/PresShell.h"
   9 #include "mozilla/SVGObserverUtils.h"
  10 #include "mozilla/dom/SVGFEImageElement.h"
  11 #include "mozilla/dom/MutationEventBinding.h"
  12 #include "nsContainerFrame.h"
  13 #include "nsIFrame.h"
  14 #include "nsGkAtoms.h"
  15 #include "nsLiteralString.h"
  16
  17 using namespace mozilla::dom;
  18
  19 nsIFrame* NS_NewSVGFEImageFrame(mozilla::PresShell* aPresShell,
  20                                 mozilla::ComputedStyle* aStyle);
  21
  22 namespace mozilla {
  23
  24 class SVGFEImageFrame final : public nsIFrame {
  25   friend nsIFrame* ::NS_NewSVGFEImageFrame(mozilla::PresShell* aPresShell,
  26                                            ComputedStyle* aStyle);
  27
  28  protected:
  29   explicit SVGFEImageFrame(ComputedStyle* aStyle, nsPresContext* aPresContext)
  30       : nsIFrame(aStyle, aPresContext, kClassID) {
  31     AddStateBits(NS_FRAME_SVG_LAYOUT | NS_FRAME_IS_NONDISPLAY);
  32
  33     // This frame isn't actually displayed, but it contains an image and we want
  34     // to use the nsImageLoadingContent machinery for managing images, which
  35     // requires visibility tracking, so we enable visibility tracking and
  36     // forcibly mark it visible below.
  37     EnableVisibilityTracking();
  38   }
  39
  40  public:
  41   NS_DECL_FRAMEARENA_HELPERS(SVGFEImageFrame)
  42
  43   void Init(nsIContent* aContent, nsContainerFrame* aParent,
  44             nsIFrame* aPrevInFlow) override;
  45   void Destroy(DestroyContext&) override;
  46
  47 #ifdef DEBUG_FRAME_DUMP
  48   nsresult GetFrameName(nsAString& aResult) const override {
  49     return MakeFrameName(u"SVGFEImage"_ns, aResult);
  50   }
  51 #endif
  52
  53   nsresult AttributeChanged(int32_t aNameSpaceID, nsAtom* aAttribute,
  54                             int32_t aModType) override;
  55
  56   void OnVisibilityChange(
  57       Visibility aNewVisibility,
  58       const Maybe<OnNonvisible>& aNonvisibleAction = Nothing()) override;
  59
  60   bool ComputeCustomOverflow(OverflowAreas& aOverflowAreas) override {
  61     // We don't maintain a ink overflow rect
  62     return false;
  63   }
  64 };
  65
  66 }  // namespace mozilla
  67
  68 nsIFrame* NS_NewSVGFEImageFrame(mozilla::PresShell* aPresShell,
  69                                 mozilla::ComputedStyle* aStyle) {
  70   return new (aPresShell)
  71       mozilla::SVGFEImageFrame(aStyle, aPresShell->GetPresContext());
  72 }
  73
  74 namespace mozilla {
  75
  76 NS_IMPL_FRAMEARENA_HELPERS(SVGFEImageFrame)
  77
  78 /* virtual */
  79 void SVGFEImageFrame::Destroy(DestroyContext& aContext) {
  80   DecApproximateVisibleCount();
  81
  82   nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(mContent);
  83   if (imageLoader) {
  84     imageLoader->FrameDestroyed(this);
  85   }
  86
  87   nsIFrame::Destroy(aContext);
  88 }
  89
  90 void SVGFEImageFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
  91                            nsIFrame* aPrevInFlow) {
  92   NS_ASSERTION(aContent->IsSVGElement(nsGkAtoms::feImage),
  93                "Trying to construct an SVGFEImageFrame for a "
  94                "content element that doesn't support the right interfaces");
  95
  96   nsIFrame::Init(aContent, aParent, aPrevInFlow);
  97
  98   // We assume that feImage's are always visible.
  99   // This call must happen before the FrameCreated. This is because the
 100   // primary frame pointer on our content node isn't set until after this
 101   // function ends, so there is no way for the resulting OnVisibilityChange
 102   // notification to get a frame. FrameCreated has a workaround for this in
 103   // that it passes our frame around so it can be accessed. OnVisibilityChange
 104   // doesn't have that workaround.
 105   IncApproximateVisibleCount();
 106
 107   nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(mContent);
 108   if (imageLoader) {
 109     imageLoader->FrameCreated(this);
 110   }
 111 }
 112
 113 nsresult SVGFEImageFrame::AttributeChanged(int32_t aNameSpaceID,
 114                                            nsAtom* aAttribute,
 115                                            int32_t aModType) {
 116   SVGFEImageElement* element = static_cast<SVGFEImageElement*>(GetContent());
 117   if (element->AttributeAffectsRendering(aNameSpaceID, aAttribute)) {
 118     MOZ_ASSERT(
 119         GetParent()->IsSVGFilterFrame(),
 120         "Observers observe the filter, so that's what we must invalidate");
 121     SVGObserverUtils::InvalidateRenderingObservers(GetParent());
 122   }
 123
 124   // Currently our SMIL implementation does not modify the DOM attributes. Once
 125   // we implement the SVG 2 SMIL behaviour this can be removed
 126   // SVGFEImageElement::AfterSetAttr's implementation will be sufficient.
 127   if (aModType == MutationEvent_Binding::SMIL &&
 128       aAttribute == nsGkAtoms::href &&
 129       (aNameSpaceID == kNameSpaceID_XLink ||
 130        aNameSpaceID == kNameSpaceID_None)) {
 131     bool hrefIsSet =
 132         element->mStringAttributes[SVGFEImageElement::HREF].IsExplicitlySet() ||
 133         element->mStringAttributes[SVGFEImageElement::XLINK_HREF]
 134             .IsExplicitlySet();
 135     if (hrefIsSet) {
 136       element->LoadSVGImage(true, true);
 137     } else {
 138       element->CancelImageRequests(true);
 139     }
 140   }
 141
 142   return nsIFrame::AttributeChanged(aNameSpaceID, aAttribute, aModType);
 143 }
 144
 145 void SVGFEImageFrame::OnVisibilityChange(
 146     Visibility aNewVisibility, const Maybe<OnNonvisible>& aNonvisibleAction) {
 147   nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(mContent);
 148   if (imageLoader) {
 149     imageLoader->OnVisibilityChange(aNewVisibility, aNonvisibleAction);
 150   }
 151
 152   nsIFrame::OnVisibilityChange(aNewVisibility, aNonvisibleAction);
 153 }
 154
 155 }  // namespace mozilla