layout/svg/SVGStopFrame.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 "nsContainerFrame.h"
   9 #include "nsIFrame.h"
  10 #include "nsGkAtoms.h"
  11 #include "mozilla/ComputedStyle.h"
  12 #include "mozilla/PresShell.h"
  13 #include "mozilla/SVGGradientFrame.h"
  14 #include "mozilla/SVGObserverUtils.h"
  15
  16 // This is a very simple frame whose only purpose is to capture style change
  17 // events and propagate them to the parent.  Most of the heavy lifting is done
  18 // within the SVGGradientFrame, which is the parent for this frame
  19
  20 nsIFrame* NS_NewSVGStopFrame(mozilla::PresShell* aPresShell,
  21                              mozilla::ComputedStyle* aStyle);
  22
  23 namespace mozilla {
  24
  25 class SVGStopFrame : public nsIFrame {
  26   friend nsIFrame* ::NS_NewSVGStopFrame(mozilla::PresShell* aPresShell,
  27                                         ComputedStyle* aStyle);
  28
  29  protected:
  30   explicit SVGStopFrame(ComputedStyle* aStyle, nsPresContext* aPresContext)
  31       : nsIFrame(aStyle, aPresContext, kClassID) {
  32     AddStateBits(NS_FRAME_SVG_LAYOUT | NS_FRAME_IS_NONDISPLAY);
  33   }
  34
  35  public:
  36   NS_DECL_FRAMEARENA_HELPERS(SVGStopFrame)
  37
  38   // nsIFrame interface:
  39 #ifdef DEBUG
  40   void Init(nsIContent* aContent, nsContainerFrame* aParent,
  41             nsIFrame* aPrevInFlow) override;
  42 #endif
  43
  44   void BuildDisplayList(nsDisplayListBuilder* aBuilder,
  45                         const nsDisplayListSet& aLists) override {}
  46
  47   nsresult AttributeChanged(int32_t aNameSpaceID, nsAtom* aAttribute,
  48                             int32_t aModType) override;
  49
  50 #ifdef DEBUG_FRAME_DUMP
  51   nsresult GetFrameName(nsAString& aResult) const override {
  52     return MakeFrameName(u"SVGStop"_ns, aResult);
  53   }
  54 #endif
  55 };
  56
  57 //----------------------------------------------------------------------
  58 // Implementation
  59
  60 NS_IMPL_FRAMEARENA_HELPERS(SVGStopFrame)
  61
  62 //----------------------------------------------------------------------
  63 // nsIFrame methods:
  64
  65 #ifdef DEBUG
  66 void SVGStopFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
  67                         nsIFrame* aPrevInFlow) {
  68   NS_ASSERTION(aContent->IsSVGElement(nsGkAtoms::stop),
  69                "Content is not a stop element");
  70
  71   nsIFrame::Init(aContent, aParent, aPrevInFlow);
  72 }
  73 #endif /* DEBUG */
  74
  75 nsresult SVGStopFrame::AttributeChanged(int32_t aNameSpaceID,
  76                                         nsAtom* aAttribute, int32_t aModType) {
  77   if (aNameSpaceID == kNameSpaceID_None && aAttribute == nsGkAtoms::offset) {
  78     MOZ_ASSERT(
  79         static_cast<SVGGradientFrame*>(do_QueryFrame(GetParent())),
  80         "Observers observe the gradient, so that's what we must invalidate");
  81     SVGObserverUtils::InvalidateRenderingObservers(GetParent());
  82   }
  83
  84   return nsIFrame::AttributeChanged(aNameSpaceID, aAttribute, aModType);
  85 }
  86
  87 }  // namespace mozilla
  88
  89 // -------------------------------------------------------------------------
  90 // Public functions
  91 // -------------------------------------------------------------------------
  92
  93 nsIFrame* NS_NewSVGStopFrame(mozilla::PresShell* aPresShell,
  94                              mozilla::ComputedStyle* aStyle) {
  95   return new (aPresShell)
  96       mozilla::SVGStopFrame(aStyle, aPresShell->GetPresContext());
  97 }