Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 420 insertions, 0 deletions

diff --git a/layout/svg/SVGObserverUtils.h b/layout/svg/SVGObserverUtils.h
new file mode 100644
index 0000000000..17bd012078
--- /dev/null
+++ b/layout/svg/SVGObserverUtils.h
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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_