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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /layout/svg/SVGObserverUtils.h
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef LAYOUT_SVG_SVGOBSERVERUTILS_H_
+#define LAYOUT_SVG_SVGOBSERVERUTILS_H_
+
+#include "mozilla/Attributes.h"
+#include "mozilla/dom/IDTracker.h"
+#include "FrameProperties.h"
+#include "nsID.h"
+#include "nsIFrame.h" // only for LayoutFrameType
+#include "nsIMutationObserver.h"
+#include "nsISupports.h"
+#include "nsISupportsImpl.h"
+#include "nsIReferrerInfo.h"
+#include "nsStringFwd.h"
+#include "nsStubMutationObserver.h"
+#include "nsStyleStruct.h"
+#include "nsCycleCollectionParticipant.h"
+
+class nsAtom;
+class nsIFrame;
+class nsIURI;
+
+namespace mozilla {
+class SVGClipPathFrame;
+class SVGFilterFrame;
+class SVGMarkerFrame;
+class SVGMaskFrame;
+class SVGPaintServerFrame;
+
+namespace dom {
+class CanvasRenderingContext2D;
+class Element;
+class SVGGeometryElement;
+} // namespace dom
+} // namespace mozilla
+
+namespace mozilla {
+
+/*
+ * This class contains URL and referrer information (referrer and referrer
+ * policy).
+ * We use it to pass to svg system instead of nsIURI. The object brings referrer
+ * and referrer policy so we can send correct Referer headers.
+ */
+class URLAndReferrerInfo {
+ public:
+ URLAndReferrerInfo(nsIURI* aURI, nsIReferrerInfo* aReferrerInfo)
+ : mURI(aURI), mReferrerInfo(aReferrerInfo) {
+ MOZ_ASSERT(aURI);
+ }
+
+ URLAndReferrerInfo(nsIURI* aURI, const URLExtraData& aExtraData)
+ : mURI(aURI), mReferrerInfo(aExtraData.ReferrerInfo()) {
+ MOZ_ASSERT(aURI);
+ }
+
+ NS_INLINE_DECL_REFCOUNTING(URLAndReferrerInfo)
+
+ nsIURI* GetURI() const { return mURI; }
+ nsIReferrerInfo* GetReferrerInfo() const { return mReferrerInfo; }
+
+ bool operator==(const URLAndReferrerInfo& aRHS) const;
+
+ private:
+ ~URLAndReferrerInfo() = default;
+
+ nsCOMPtr<nsIURI> mURI;
+ nsCOMPtr<nsIReferrerInfo> mReferrerInfo;
+};
+
+/**
+ * This interface allows us to be notified when a piece of SVG content is
+ * re-rendered.
+ *
+ * Concrete implementations of this base class need to implement
+ * GetReferencedElementWithoutObserving to specify the SVG element that
+ * they'd like to monitor for rendering changes, and they need to implement
+ * OnRenderingChange to specify how we'll react when that content gets
+ * re-rendered. They also need to implement a constructor and destructor,
+ * which should call StartObserving and StopObserving, respectively.
+ *
+ * The referenced element is generally looked up and stored during
+ * construction. If the referenced element is in an extenal SVG resource
+ * document, the lookup code will initiate loading of the external resource and
+ * OnRenderingChange will be called once the element in the external resource
+ * is available.
+ *
+ * Although the referenced element may be found and stored during construction,
+ * observing for rendering changes does not start until requested.
+ */
+class SVGRenderingObserver : public nsStubMutationObserver {
+ protected:
+ virtual ~SVGRenderingObserver() = default;
+
+ public:
+ using Element = dom::Element;
+
+ SVGRenderingObserver() : mInObserverSet(false) {}
+
+ // nsIMutationObserver
+ NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
+ NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
+ NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
+ NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
+
+ /**
+ * Called when non-DOM-mutation changes to the observed element should likely
+ * cause the rendering of our observer to change. This includes changes to
+ * CSS computed values, but also changes to rendering observers that the
+ * observed element itself may have (for example, when we're being used to
+ * observe an SVG pattern, and an element in that pattern references and
+ * observes a gradient that has changed).
+ */
+ void OnNonDOMMutationRenderingChange();
+
+ // When a SVGRenderingObserver list gets forcibly cleared, it uses this
+ // callback to notify every observer that's cleared from it, so they can
+ // react.
+ void NotifyEvictedFromRenderingObserverSet();
+
+ nsIFrame* GetAndObserveReferencedFrame();
+ /**
+ * @param aOK this is only for the convenience of callers. We set *aOK to
+ * false if the frame is the wrong type
+ */
+ nsIFrame* GetAndObserveReferencedFrame(mozilla::LayoutFrameType aFrameType,
+ bool* aOK);
+
+ Element* GetAndObserveReferencedElement();
+
+ virtual bool ObservesReflow() { return false; }
+
+ protected:
+ void StartObserving();
+ void StopObserving();
+
+ /**
+ * Called whenever the rendering of the observed element may have changed.
+ *
+ * More specifically, this method is called whenever DOM mutation occurs in
+ * the observed element's subtree, or whenever
+ * SVGObserverUtils::InvalidateRenderingObservers or
+ * SVGObserverUtils::InvalidateDirectRenderingObservers is called for the
+ * observed element's frame.
+ *
+ * Subclasses should override this method to handle rendering changes
+ * appropriately.
+ */
+ virtual void OnRenderingChange() = 0;
+
+ virtual Element* GetReferencedElementWithoutObserving() = 0;
+
+#ifdef DEBUG
+ void DebugObserverSet();
+#endif
+
+ // Whether we're in our observed element's observer set at this time.
+ bool mInObserverSet;
+};
+
+class SVGObserverUtils {
+ public:
+ using CanvasRenderingContext2D = dom::CanvasRenderingContext2D;
+ using Element = dom::Element;
+ using SVGGeometryElement = dom::SVGGeometryElement;
+ using HrefToTemplateCallback = const std::function<void(nsAString&)>&;
+
+ /**
+ * Ensures that that if the given frame requires any resources that are in
+ * SVG resource documents that the loading of those documents is initiated.
+ * This does not make aFrame start to observe any elements that it
+ * references.
+ */
+ static void InitiateResourceDocLoads(nsIFrame* aFrame);
+
+ /**
+ * Called when changes to an element (e.g. CSS property changes) cause its
+ * frame to start/stop referencing (or reference different) SVG resource
+ * elements. (_Not_ called for changes to referenced resource elements.)
+ *
+ * This function handles such changes by discarding _all_ the frame's SVG
+ * effects frame properties (causing those properties to stop watching their
+ * target element). It also synchronously (re)creates the filter and marker
+ * frame properties (XXX why not the other properties?), which makes it
+ * useful for initializing those properties during first reflow.
+ *
+ * XXX rename to something more meaningful like RefreshResourceReferences?
+ */
+ static void UpdateEffects(nsIFrame* aFrame);
+
+ /**
+ * @param aFrame must be a first-continuation.
+ */
+ static void AddRenderingObserver(Element* aElement,
+ SVGRenderingObserver* aObserver);
+ /**
+ * @param aFrame must be a first-continuation.
+ */
+ static void RemoveRenderingObserver(Element* aElement,
+ SVGRenderingObserver* aObserver);
+
+ /**
+ * Removes all rendering observers from aElement.
+ */
+ static void RemoveAllRenderingObservers(Element* aElement);
+
+ /**
+ * This can be called on any frame. We invalidate the observers of aFrame's
+ * element, if any, or else walk up to the nearest observable SVG parent
+ * frame with observers and invalidate them instead.
+ *
+ * Note that this method is very different to e.g.
+ * MutationObservers::AttributeChanged which walks up the content node tree
+ * all the way to the root node (not stopping if it encounters a non-container
+ * SVG node) invalidating all mutation observers (not just
+ * SVGRenderingObservers) on all nodes along the way (not just the first
+ * node it finds with observers). In other words, by doing all the
+ * things in parentheses in the preceding sentence, this method uses
+ * knowledge about our implementation and what can be affected by SVG effects
+ * to make invalidation relatively lightweight when an SVG effect changes.
+ */
+ static void InvalidateRenderingObservers(nsIFrame* aFrame);
+
+ enum { INVALIDATE_REFLOW = 1 };
+
+ enum ReferenceState {
+ /// Has no references to SVG filters (may still have CSS filter functions!)
+ eHasNoRefs,
+ eHasRefsAllValid,
+ eHasRefsSomeInvalid,
+ };
+
+ /**
+ * This can be called on any element or frame. Only direct observers of this
+ * (frame's) element, if any, are invalidated.
+ */
+ static void InvalidateDirectRenderingObservers(Element* aElement,
+ uint32_t aFlags = 0);
+ static void InvalidateDirectRenderingObservers(nsIFrame* aFrame,
+ uint32_t aFlags = 0);
+
+ /**
+ * Get the paint server for aPaintedFrame.
+ */
+ static SVGPaintServerFrame* GetAndObservePaintServer(
+ nsIFrame* aPaintedFrame, mozilla::StyleSVGPaint nsStyleSVG::*aPaint);
+
+ /**
+ * Get the start/mid/end-markers for the given frame, and add the frame as
+ * an observer to those markers. Returns true if at least one marker type is
+ * found, false otherwise.
+ */
+ static bool GetAndObserveMarkers(nsIFrame* aMarkedFrame,
+ SVGMarkerFrame* (*aFrames)[3]);
+
+ /**
+ * Get the frames of the SVG filters applied to the given frame, and add the
+ * frame as an observer to those filter frames.
+ *
+ * NOTE! A return value of eHasNoRefs does NOT mean that there are no filters
+ * to be applied, only that there are no references to SVG filter elements.
+ *
+ * XXX Callers other than ComputePostEffectsInkOverflowRect and
+ * SVGUtils::GetPostFilterInkOverflowRect should not need to initiate
+ * observing. If we have a bug that causes invalidation (which would remove
+ * observers) between reflow and painting, then we don't really want to
+ * re-add abservers during painting. That has the potential to hide logic
+ * bugs, or cause later invalidation problems. However, let's not change
+ * that behavior just yet due to the regression potential.
+ */
+ static ReferenceState GetAndObserveFilters(
+ nsIFrame* aFilteredFrame, nsTArray<SVGFilterFrame*>* aFilterFrames);
+
+ /**
+ * If the given frame is already observing SVG filters, this function gets
+ * those filters. If the frame is not already observing filters this
+ * function assumes that it doesn't have anything to observe.
+ */
+ static ReferenceState GetFiltersIfObserving(
+ nsIFrame* aFilteredFrame, nsTArray<SVGFilterFrame*>* aFilterFrames);
+
+ /**
+ * Starts observing filters for a <canvas> element's CanvasRenderingContext2D.
+ *
+ * Returns a RAII object that the caller should make sure is released once
+ * the CanvasRenderingContext2D is no longer using them (that is, when the
+ * CanvasRenderingContext2D "drawing style state" on which the filters were
+ * set is destroyed or has its filter style reset).
+ *
+ * XXXjwatt: It's a bit unfortunate that both we and
+ * CanvasRenderingContext2D::UpdateFilter process the list of StyleFilter
+ * objects separately. It would be better to refactor things so that we only
+ * do that work once.
+ */
+ static already_AddRefed<nsISupports> ObserveFiltersForCanvasContext(
+ CanvasRenderingContext2D* aContext, Element* aCanvasElement,
+ Span<const StyleFilter> aFilters);
+
+ /**
+ * Called when cycle collecting CanvasRenderingContext2D, and requires the
+ * RAII object returned from ObserveFiltersForCanvasContext to be passed in.
+ *
+ * XXXjwatt: I don't think this is doing anything useful. All we do under
+ * this function is clear a raw C-style (i.e. not strong) pointer. That's
+ * clearly not helping in breaking any cycles. The fact that we MOZ_CRASH
+ * in OnRenderingChange if that pointer is null indicates that this isn't
+ * even doing anything useful in terms of preventing further invalidation
+ * from any observed filters.
+ */
+ static void DetachFromCanvasContext(nsISupports* aAutoObserver);
+
+ /**
+ * Get the frame of the SVG clipPath applied to aClippedFrame, if any, and
+ * set up aClippedFrame as a rendering observer of the clipPath's frame, to
+ * be invalidated if it changes.
+ *
+ * Currently we only have support for 'clip-path' with a single item, but the
+ * spec. now says 'clip-path' can be set to an arbitrary number of items.
+ * Once we support that, aClipPathFrame will need to be an nsTArray as it
+ * is for 'filter' and 'mask'. Currently a return value of eHasNoRefs means
+ * that there is no clipping at all, but once we support more than one item
+ * then - as for filter and mask - we could still have basic shape clipping
+ * to apply even if there are no references to SVG clipPath elements.
+ *
+ * Note that, unlike for filters, a reference to an ID that doesn't exist
+ * is not invalid for clip-path or mask. We will return eHasNoRefs in that
+ * case.
+ */
+ static ReferenceState GetAndObserveClipPath(
+ nsIFrame* aClippedFrame, SVGClipPathFrame** aClipPathFrame);
+
+ /**
+ * If masking is applied to aMaskedFrame, gets an array of any SVG masks
+ * that are referenced, setting up aMaskFrames as a rendering observer of
+ * those masks (if any).
+ *
+ * NOTE! A return value of eHasNoRefs does NOT mean that there are no masks
+ * to be applied, only that there are no references to SVG mask elements.
+ *
+ * Note that, unlike for filters, a reference to an ID that doesn't exist
+ * is not invalid for clip-path or mask. We will return eHasNoRefs in that
+ * case.
+ */
+ static ReferenceState GetAndObserveMasks(
+ nsIFrame* aMaskedFrame, nsTArray<SVGMaskFrame*>* aMaskFrames);
+
+ /**
+ * Get the SVGGeometryElement that is referenced by aTextPathFrame, and make
+ * aTextPathFrame start observing rendering changes to that element.
+ */
+ static SVGGeometryElement* GetAndObserveTextPathsPath(
+ nsIFrame* aTextPathFrame);
+
+ /**
+ * Make aTextPathFrame stop observing rendering changes to the
+ * SVGGeometryElement that it references, if any.
+ */
+ static void RemoveTextPathObserver(nsIFrame* aTextPathFrame);
+
+ /**
+ * Gets the nsIFrame of a referenced SVG "template" element, if any, and
+ * makes aFrame start observing rendering changes to the template element.
+ *
+ * Template elements: some elements like gradients, pattern or filter can
+ * reference another element of the same type using their 'href' attribute,
+ * and use that element as a template that provides attributes or content
+ * that is missing from the referring element.
+ *
+ * The frames that this function is called for do not have a common base
+ * class, which is why it is necessary to pass in a function that can be
+ * used as a callback to lazily get the href value, if necessary.
+ */
+ static nsIFrame* GetAndObserveTemplate(nsIFrame* aFrame,
+ HrefToTemplateCallback aGetHref);
+
+ static void RemoveTemplateObserver(nsIFrame* aFrame);
+
+ /**
+ * Gets an arbitrary element and starts observing it. Used to implement
+ * '-moz-element'.
+ *
+ * Note that bug 1496065 has been filed to remove support for referencing
+ * arbitrary elements using '-moz-element'.
+ */
+ static Element* GetAndObserveBackgroundImage(nsIFrame* aFrame,
+ const nsAtom* aHref);
+
+ /**
+ * Gets an arbitrary element and starts observing it. Used to detect
+ * invalidation changes for background-clip:text.
+ */
+ static Element* GetAndObserveBackgroundClip(nsIFrame* aFrame);
+
+ /**
+ * A helper function to resolve filter URL.
+ */
+ static already_AddRefed<URLAndReferrerInfo> GetFilterURI(
+ nsIFrame* aFrame, const StyleFilter& aFilter);
+
+ /**
+ * Return a baseURL for resolving a local-ref URL.
+ *
+ * @param aContent an element which uses a local-ref property. Here are some
+ * examples:
+ * <rect fill=url(#foo)>
+ * <circle clip-path=url(#foo)>
+ * <use xlink:href="#foo">
+ */
+ static already_AddRefed<nsIURI> GetBaseURLForLocalRef(nsIContent* aContent,
+ nsIURI* aDocURI);
+};
+
+} // namespace mozilla
+
+#endif // LAYOUT_SVG_SVGOBSERVERUTILS_H_