Adding upstream version 86.0.1.upstream/86.0.1upstream

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

1 files changed, 633 insertions, 0 deletions

diff --git a/dom/base/nsImageLoadingContent.h b/dom/base/nsImageLoadingContent.h
new file mode 100644
index 0000000000..ec4286bed9
--- /dev/null
+++ b/dom/base/nsImageLoadingContent.h
@@ -0,0 +1,633 @@
+/* -*- 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/. */
+
+/*
+ * A base class which implements nsIImageLoadingContent and can be
+ * subclassed by various content nodes that want to provide image
+ * loading functionality (eg <img>, <object>, etc).
+ */
+
+#ifndef nsImageLoadingContent_h__
+#define nsImageLoadingContent_h__
+
+#include "imgINotificationObserver.h"
+#include "mozilla/CORSMode.h"
+#include "mozilla/EventStates.h"
+#include "mozilla/TimeStamp.h"
+#include "nsCOMPtr.h"
+#include "nsIContentPolicy.h"
+#include "nsIImageLoadingContent.h"
+#include "nsIRequest.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/Promise.h"
+#include "nsAttrValue.h"
+#include "Units.h"
+
+class nsINode;
+class nsIURI;
+class nsPresContext;
+class nsIContent;
+class imgRequestProxy;
+
+namespace mozilla {
+class AsyncEventDispatcher;
+class ErrorResult;
+
+namespace dom {
+struct BindContext;
+class Document;
+class Element;
+}  // namespace dom
+}  // namespace mozilla
+
+#ifdef LoadImage
+// Undefine LoadImage to prevent naming conflict with Windows.
+#  undef LoadImage
+#endif
+
+class nsImageLoadingContent : public nsIImageLoadingContent {
+ protected:
+  template <typename T>
+  using Maybe = mozilla::Maybe<T>;
+  using Nothing = mozilla::Nothing;
+  using OnNonvisible = mozilla::OnNonvisible;
+  using Visibility = mozilla::Visibility;
+
+  /* METHODS */
+ public:
+  nsImageLoadingContent();
+  virtual ~nsImageLoadingContent();
+
+  NS_DECL_IMGINOTIFICATIONOBSERVER
+  NS_DECL_NSIIMAGELOADINGCONTENT
+
+  // Web IDL binding methods.
+  // Note that the XPCOM SetLoadingEnabled, ForceImageState methods are OK for
+  // Web IDL bindings to use as well, since none of them throw when called via
+  // the Web IDL bindings.
+
+  bool LoadingEnabled() const { return mLoadingEnabled; }
+  void AddObserver(imgINotificationObserver* aObserver);
+  void RemoveObserver(imgINotificationObserver* aObserver);
+  already_AddRefed<imgIRequest> GetRequest(int32_t aRequestType,
+                                           mozilla::ErrorResult& aError);
+  int32_t GetRequestType(imgIRequest* aRequest, mozilla::ErrorResult& aError);
+  already_AddRefed<nsIURI> GetCurrentURI();
+  already_AddRefed<nsIURI> GetCurrentRequestFinalURI();
+  void ForceReload(bool aNotify, mozilla::ErrorResult& aError);
+
+  mozilla::dom::Element* FindImageMap();
+
+  /**
+   * Toggle whether or not to synchronously decode an image on draw.
+   */
+  void SetSyncDecodingHint(bool aHint);
+
+  /**
+   * Notify us that the document state has changed. Called by nsDocument so that
+   * we may reject any promises which require the document to be active.
+   */
+  void NotifyOwnerDocumentActivityChanged();
+
+ protected:
+  enum ImageLoadType {
+    // Most normal image loads
+    eImageLoadType_Normal,
+    // From a <img srcset> or <picture> context. Affects type given to content
+    // policy.
+    eImageLoadType_Imageset
+  };
+
+  /**
+   * LoadImage is called by subclasses when the appropriate
+   * attributes (eg 'src' for <img> tags) change.  The string passed
+   * in is the new uri string; this consolidates the code for getting
+   * the charset, constructing URI objects, and any other incidentals
+   * into this superclass.
+   *
+   * @param aNewURI the URI spec to be loaded (may be a relative URI)
+   * @param aForce If true, make sure to load the URI.  If false, only
+   *        load if the URI is different from the currently loaded URI.
+   * @param aNotify If true, nsIDocumentObserver state change notifications
+   *                will be sent as needed.
+   * @param aImageLoadType The ImageLoadType for this request
+   * @param aTriggeringPrincipal Optional parameter specifying the triggering
+   *        principal to use for the image load
+   */
+  nsresult LoadImage(const nsAString& aNewURI, bool aForce, bool aNotify,
+                     ImageLoadType aImageLoadType,
+                     nsIPrincipal* aTriggeringPrincipal = nullptr);
+
+  /**
+   * ImageState is called by subclasses that are computing their content state.
+   * The return value will have the NS_EVENT_STATE_BROKEN bit set as needed.
+   *
+   * Note that this state assumes that this node is "trying" to be an
+   * image (so for example complete lack of attempt to load an image will lead
+   * to NS_EVENT_STATE_BROKEN being set).  Subclasses that are not "trying" to
+   * be an image (eg an HTML <input> of type other than "image") should just
+   * not call this method when computing their intrinsic state.
+   */
+  mozilla::EventStates ImageState() const;
+
+  /**
+   * LoadImage is called by subclasses when the appropriate
+   * attributes (eg 'src' for <img> tags) change. If callers have an
+   * URI object already available, they should use this method.
+   *
+   * @param aNewURI the URI to be loaded
+   * @param aForce If true, make sure to load the URI.  If false, only
+   *        load if the URI is different from the currently loaded URI.
+   * @param aNotify If true, nsIDocumentObserver state change notifications
+   *                will be sent as needed.
+   * @param aImageLoadType The ImageLoadType for this request
+   * @param aLoadStart If true, dispatch "loadstart" event.
+   * @param aDocument Optional parameter giving the document this node is in.
+   *        This is purely a performance optimization.
+   * @param aLoadFlags Optional parameter specifying load flags to use for
+   *        the image load
+   * @param aTriggeringPrincipal Optional parameter specifying the triggering
+   *        principal to use for the image load
+   */
+  nsresult LoadImage(nsIURI* aNewURI, bool aForce, bool aNotify,
+                     ImageLoadType aImageLoadType, nsLoadFlags aLoadFlags,
+                     bool aLoadStart = true,
+                     mozilla::dom::Document* aDocument = nullptr,
+                     nsIPrincipal* aTriggeringPrincipal = nullptr);
+
+  nsresult LoadImage(nsIURI* aNewURI, bool aForce, bool aNotify,
+                     ImageLoadType aImageLoadType,
+                     nsIPrincipal* aTriggeringPrincipal) {
+    return LoadImage(aNewURI, aForce, aNotify, aImageLoadType, LoadFlags(),
+                     true, nullptr, aTriggeringPrincipal);
+  }
+
+  /**
+   * helpers to get the document for this content (from the nodeinfo
+   * and such).  Not named GetOwnerDoc/GetCurrentDoc to prevent ambiguous
+   * method names in subclasses
+   *
+   * @return the document we belong to
+   */
+  mozilla::dom::Document* GetOurOwnerDoc();
+  mozilla::dom::Document* GetOurCurrentDoc();
+
+  /**
+   * Helper function to get the frame associated with this content. Not named
+   * GetPrimaryFrame to prevent ambiguous method names in subclasses.
+   *
+   * @return The frame which we belong to, or nullptr if it doesn't exist.
+   */
+  nsIFrame* GetOurPrimaryFrame();
+
+  /**
+   * Helper function to get the PresContext associated with this content's
+   * frame. Not named GetPresContext to prevent ambiguous method names in
+   * subclasses.
+   *
+   * @return The nsPresContext associated with our frame, or nullptr if either
+   *         the frame doesn't exist, or the frame's prescontext doesn't exist.
+   */
+  nsPresContext* GetFramePresContext();
+
+  /**
+   * CancelImageRequests is called by subclasses when they want to
+   * cancel all image requests (for example when the subclass is
+   * somehow not an image anymore).
+   */
+  void CancelImageRequests(bool aNotify);
+
+  /**
+   * Derived classes of nsImageLoadingContent MUST call Destroy from their
+   * destructor, or earlier.  It does things that cannot be done in
+   * ~nsImageLoadingContent because they rely on being able to QueryInterface to
+   * other derived classes, which cannot happen once the derived class
+   * destructor has started calling the base class destructors.
+   */
+  void Destroy();
+
+  /**
+   * Returns the CORS mode that will be used for all future image loads. The
+   * default implementation returns CORS_NONE unconditionally.
+   */
+  virtual mozilla::CORSMode GetCORSMode();
+
+  // Subclasses are *required* to call BindToTree/UnbindFromTree.
+  void BindToTree(mozilla::dom::BindContext&, nsINode& aParent);
+  void UnbindFromTree(bool aNullParent);
+
+  void OnLoadComplete(imgIRequest* aRequest, nsresult aStatus);
+  void OnUnlockedDraw();
+  void OnImageIsAnimated(imgIRequest* aRequest);
+
+  // The nsContentPolicyType we would use for this ImageLoadType
+  static nsContentPolicyType PolicyTypeForLoad(ImageLoadType aImageLoadType);
+
+  void AsyncEventRunning(mozilla::AsyncEventDispatcher* aEvent);
+
+  // Get ourselves as an nsIContent*.  Not const because some of the callers
+  // want a non-const nsIContent.
+  virtual nsIContent* AsContent() = 0;
+
+  // Hooks for subclasses to call to get the intrinsic width and height.
+  uint32_t NaturalWidth();
+  uint32_t NaturalHeight();
+  /**
+   * Get width and height of the current request, using given image request if
+   * attributes are unset.
+   */
+  MOZ_CAN_RUN_SCRIPT mozilla::CSSIntSize GetWidthHeightForImage();
+
+  /**
+   * Create a promise and queue a microtask which will ensure the current
+   * request (after any pending loads are applied) has requested a full decode.
+   * The promise is fulfilled once the request has a fully decoded surface that
+   * is available for drawing, or an error condition occurrs (e.g. broken image,
+   * current request is updated, etc).
+   *
+   * https://html.spec.whatwg.org/multipage/embedded-content.html#dom-img-decode
+   */
+  already_AddRefed<mozilla::dom::Promise> QueueDecodeAsync(
+      mozilla::ErrorResult& aRv);
+
+  enum class ImageDecodingType : uint8_t {
+    Auto,
+    Async,
+    Sync,
+  };
+
+  static const nsAttrValue::EnumTable kDecodingTable[];
+  static const nsAttrValue::EnumTable* kDecodingTableDefault;
+
+ private:
+  /**
+   * Enqueue and/or fulfill a promise created by QueueDecodeAsync.
+   */
+  void DecodeAsync(RefPtr<mozilla::dom::Promise>&& aPromise,
+                   uint32_t aRequestGeneration);
+
+  /**
+   * Attempt to resolve all queued promises based on the state of the current
+   * request. If the current request does not yet have all of the encoded data,
+   * or the decoding has not yet completed, it will return without changing the
+   * promise states.
+   */
+  void MaybeResolveDecodePromises();
+
+  /**
+   * Reject all queued promises with the given status.
+   */
+  void RejectDecodePromises(nsresult aStatus);
+
+  /**
+   * Age the generation counter if we have a new current request with a
+   * different URI. If the generation counter is aged, then all queued promises
+   * will also be rejected.
+   */
+  void MaybeAgeRequestGeneration(nsIURI* aNewURI);
+
+  /**
+   * Deregister as an observer for the owner document's activity notifications
+   * if we have no outstanding decode promises.
+   */
+  void MaybeDeregisterActivityObserver();
+
+  /**
+   * Struct used to manage the native image observers.
+   */
+  struct ImageObserver {
+    explicit ImageObserver(imgINotificationObserver* aObserver);
+    ~ImageObserver();
+
+    nsCOMPtr<imgINotificationObserver> mObserver;
+    ImageObserver* mNext;
+  };
+
+  /**
+   * Struct used to manage the scripted/XPCOM image observers.
+   */
+  class ScriptedImageObserver final {
+   public:
+    NS_INLINE_DECL_REFCOUNTING(ScriptedImageObserver)
+
+    ScriptedImageObserver(imgINotificationObserver* aObserver,
+                          RefPtr<imgRequestProxy>&& aCurrentRequest,
+                          RefPtr<imgRequestProxy>&& aPendingRequest);
+    bool CancelRequests();
+
+    nsCOMPtr<imgINotificationObserver> mObserver;
+    RefPtr<imgRequestProxy> mCurrentRequest;
+    RefPtr<imgRequestProxy> mPendingRequest;
+
+   private:
+    ~ScriptedImageObserver();
+  };
+
+  /**
+   * Struct to report state changes
+   */
+  struct AutoStateChanger {
+    AutoStateChanger(nsImageLoadingContent* aImageContent, bool aNotify)
+        : mImageContent(aImageContent), mNotify(aNotify) {
+      mImageContent->mStateChangerDepth++;
+    }
+    ~AutoStateChanger() {
+      mImageContent->mStateChangerDepth--;
+      mImageContent->UpdateImageState(mNotify);
+    }
+
+    nsImageLoadingContent* mImageContent;
+    bool mNotify;
+  };
+
+  friend struct AutoStateChanger;
+
+  /**
+   * Method to fire an event once we know what's going on with the image load.
+   *
+   * @param aEventType "loadstart", "loadend", "load", or "error" depending on
+   *                   how things went
+   * @param aIsCancelable true if event is cancelable.
+   */
+  nsresult FireEvent(const nsAString& aEventType, bool aIsCancelable = false);
+
+  /**
+   * Method to cancel and null-out pending event if they exist.
+   */
+  void CancelPendingEvent();
+
+  RefPtr<mozilla::AsyncEventDispatcher> mPendingEvent;
+
+ protected:
+  /**
+   * UpdateImageState recomputes the current state of this image loading
+   * content and updates what ImageState() returns accordingly.  It will also
+   * fire a ContentStatesChanged() notification as needed if aNotify is true.
+   */
+  void UpdateImageState(bool aNotify);
+
+  /**
+   * Method to create an nsIURI object from the given string (will
+   * handle getting the right charset, base, etc).  You MUST pass in a
+   * non-null document to this function.
+   *
+   * @param aSpec the string spec (from an HTML attribute, eg)
+   * @param aDocument the document we belong to
+   * @return the URI we want to be loading
+   */
+  nsresult StringToURI(const nsAString& aSpec,
+                       mozilla::dom::Document* aDocument, nsIURI** aURI);
+
+  /**
+   * Prepare and returns a reference to the "next request". If there's already
+   * a _usable_ current request (one with SIZE_AVAILABLE), this request is
+   * "pending" until it becomes usable. Otherwise, this becomes the current
+   * request.
+   *
+   * @param aImageLoadType The ImageLoadType for this request
+   */
+  RefPtr<imgRequestProxy>& PrepareNextRequest(ImageLoadType aImageLoadType);
+
+  /**
+   * Returns a COMPtr reference to the current/pending image requests, cleaning
+   * up and canceling anything that was there before. Note that if you just want
+   * to get rid of one of the requests, you should call
+   * Clear*Request(NS_BINDING_ABORTED) instead.
+   *
+   * @param aImageLoadType The ImageLoadType for this request
+   */
+  RefPtr<imgRequestProxy>& PrepareCurrentRequest(ImageLoadType aImageLoadType);
+  RefPtr<imgRequestProxy>& PreparePendingRequest(ImageLoadType aImageLoadType);
+
+  /**
+   * Switch our pending request to be our current request.
+   * mPendingRequest must be non-null!
+   */
+  void MakePendingRequestCurrent();
+
+  /**
+   * Cancels and nulls-out the "current" and "pending" requests if they exist.
+   *
+   * @param aNonvisibleAction An action to take if the image is no longer
+   *                          visible as a result; see |UntrackImage|.
+   */
+  void ClearCurrentRequest(
+      nsresult aReason,
+      const Maybe<OnNonvisible>& aNonvisibleAction = Nothing());
+  void ClearPendingRequest(
+      nsresult aReason,
+      const Maybe<OnNonvisible>& aNonvisibleAction = Nothing());
+
+  /**
+   * Retrieve a pointer to the 'registered with the refresh driver' flag for
+   * which a particular image request corresponds.
+   *
+   * @returns A pointer to the boolean flag for a given image request, or
+   *          |nullptr| if the request is not either |mPendingRequest| or
+   *          |mCurrentRequest|.
+   */
+  bool* GetRegisteredFlagForRequest(imgIRequest* aRequest);
+
+  /**
+   * Reset animation of the current request if
+   * |mNewRequestsWillNeedAnimationReset| was true when the request was
+   * prepared.
+   */
+  void ResetAnimationIfNeeded();
+
+  /**
+   * Static helper method to tell us if we have the size of a request. The
+   * image may be null.
+   */
+  static bool HaveSize(imgIRequest* aImage);
+
+  /**
+   * Adds/Removes a given imgIRequest from our document's tracker.
+   *
+   * No-op if aImage is null.
+   *
+   * @param aFrame If called from FrameCreated the frame passed to FrameCreated.
+   *               This is our frame, but at the time of the FrameCreated call
+   *               our primary frame pointer hasn't been set yet, so this is
+   *               only way to get our frame.
+   *
+   * @param aNonvisibleAction A requested action if the frame has become
+   *                          nonvisible. If Nothing(), no action is
+   *                          requested. If DISCARD_IMAGES is specified, the
+   *                          frame is requested to ask any images it's
+   *                          associated with to discard their surfaces if
+   *                          possible.
+   */
+  void TrackImage(imgIRequest* aImage, nsIFrame* aFrame = nullptr);
+  void UntrackImage(imgIRequest* aImage,
+                    const Maybe<OnNonvisible>& aNonvisibleAction = Nothing());
+
+  nsLoadFlags LoadFlags();
+
+  /* MEMBERS */
+  RefPtr<imgRequestProxy> mCurrentRequest;
+  RefPtr<imgRequestProxy> mPendingRequest;
+  uint32_t mCurrentRequestFlags;
+  uint32_t mPendingRequestFlags;
+
+  enum {
+    // Set if the request needs ResetAnimation called on it.
+    REQUEST_NEEDS_ANIMATION_RESET = 0x00000001U,
+    // Set if the request is currently tracked with the document.
+    REQUEST_IS_TRACKED = 0x00000004U,
+    // Set if this is an imageset request, such as from <img srcset> or
+    // <picture>
+    REQUEST_IS_IMAGESET = 0x00000008U
+  };
+
+  // If the image was blocked or if there was an error loading, it's nice to
+  // still keep track of what the URI was despite not having an imgIRequest.
+  // We only maintain this in those situations (in the common case, this is
+  // always null).
+  nsCOMPtr<nsIURI> mCurrentURI;
+
+ private:
+  /**
+   * Clones the given "current" or "pending" request for each scripted observer.
+   */
+  void CloneScriptedRequests(imgRequestProxy* aRequest);
+
+  /**
+   * Cancels and nulls-out the "current" or "pending" requests if they exist
+   * for each scripted observer.
+   */
+  void ClearScriptedRequests(int32_t aRequestType, nsresult aReason);
+
+  /**
+   * Moves the "pending" request into the "current" request for each scripted
+   * observer. If there is an existing "current" request, it will cancel it
+   * first.
+   */
+  void MakePendingScriptedRequestsCurrent();
+
+  /**
+   * Depending on the configured decoding hint, and/or how recently we updated
+   * the image request, force or stop the frame from decoding the image
+   * synchronously when it is drawn.
+   * @param aPrepareNextRequest True if this is when updating the image request.
+   * @param aFrame If called from FrameCreated the frame passed to FrameCreated.
+   *               This is our frame, but at the time of the FrameCreated call
+   *               our primary frame pointer hasn't been set yet, so this is
+   *               only way to get our frame.
+   */
+  void MaybeForceSyncDecoding(bool aPrepareNextRequest,
+                              nsIFrame* aFrame = nullptr);
+
+  /**
+   * Typically we will have only one observer (our frame in the screen
+   * prescontext), so we want to only make space for one and to
+   * heap-allocate anything past that (saves memory and malloc churn
+   * in the common case).  The storage is a linked list, we just
+   * happen to actually hold the first observer instead of a pointer
+   * to it.
+   */
+  ImageObserver mObserverList;
+
+  /**
+   * Typically we will have no scripted observers, as this is only used by
+   * chrome, legacy extensions, and some mochitests. An empty array reserves
+   * minimal memory.
+   */
+  nsTArray<RefPtr<ScriptedImageObserver>> mScriptedObservers;
+
+  /**
+   * Promises created by QueueDecodeAsync that are still waiting to be
+   * fulfilled by the image being fully decoded.
+   */
+  nsTArray<RefPtr<mozilla::dom::Promise>> mDecodePromises;
+
+  /**
+   * When mIsImageStateForced is true, this holds the ImageState that we'll
+   * return in ImageState().
+   */
+  mozilla::EventStates mForcedImageState;
+
+  mozilla::TimeStamp mMostRecentRequestChange;
+
+  /**
+   * Total number of outstanding decode promises, including those stored in
+   * mDecodePromises and those embedded in runnables waiting to be enqueued.
+   * This is used to determine whether we need to register as an observer for
+   * document activity notifications.
+   */
+  size_t mOutstandingDecodePromises;
+
+  /**
+   * An incrementing counter representing the current request generation;
+   * Each time mCurrentRequest is modified with a different URI, this will
+   * be incremented. Each QueueDecodeAsync call will cache the generation
+   * of the current request so that when it is processed, it knows if it
+   * should have rejected because the request changed.
+   */
+  uint32_t mRequestGeneration;
+
+  bool mLoadingEnabled : 1;
+
+  /**
+   * When true, we return mForcedImageState from ImageState().
+   */
+  bool mIsImageStateForced : 1;
+
+  /**
+   * The state we had the last time we checked whether we needed to notify the
+   * document of a state change.  These are maintained by UpdateImageState.
+   */
+  bool mLoading : 1;
+  bool mBroken : 1;
+
+ protected:
+  /**
+   * A hack to get animations to reset, see bug 594771. On requests
+   * that originate from setting .src, we mark them for needing their animation
+   * reset when they are ready. mNewRequestsWillNeedAnimationReset is set to
+   * true while preparing such requests (as a hack around needing to change an
+   * interface), and the other two booleans store which of the current
+   * and pending requests are of the sort that need their animation restarted.
+   */
+  bool mNewRequestsWillNeedAnimationReset : 1;
+
+  /**
+   * Flag to indicate whether the channel should be mark as urgent-start.
+   * It should be set in *Element and passed to nsContentUtils::LoadImage.
+   * True if we want to set nsIClassOfService::UrgentStart to the channel to
+   * get the response ASAP for better user responsiveness.
+   */
+  bool mUseUrgentStartForChannel : 1;
+
+  // Represents the image is deferred loading until this element gets visible.
+  bool mLazyLoading : 1;
+
+ private:
+  /* The number of nested AutoStateChangers currently tracking our state. */
+  uint8_t mStateChangerDepth;
+
+  // Flags to indicate whether each of the current and pending requests are
+  // registered with the refresh driver.
+  bool mCurrentRequestRegistered;
+  bool mPendingRequestRegistered;
+
+  // TODO:
+  // Bug 1353685: Should ServiceWorker call SetBlockedRequest?
+  //
+  // This member is used in SetBlockedRequest, if it's true, then this call is
+  // triggered from LoadImage.
+  // If this is false, it means this call is from other places like
+  // ServiceWorker, then we will ignore call to SetBlockedRequest for now.
+  //
+  // Also we use this variable to check if some evil code is reentering
+  // LoadImage.
+  bool mIsStartingImageLoad;
+
+  // If true, force frames to synchronously decode images on draw.
+  bool mSyncDecodingHint;
+};
+
+#endif  // nsImageLoadingContent_h__