/* -*- 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 mozilla_dom_HTMLImageElement_h

#define mozilla_dom_HTMLImageElement_h

#include "mozilla/Attributes.h"

#include "nsGenericHTMLElement.h"

#include "nsImageLoadingContent.h"

#include "Units.h"

#include "nsCycleCollectionParticipant.h"

namespace mozilla {

class EventChainPreVisitor;

namespace dom {

class ImageLoadTask;

class ResponsiveImageSelector;

class HTMLImageElement final : public nsGenericHTMLElement,

                               public nsImageLoadingContent

{

  friend class HTMLSourceElement;

  friend class HTMLPictureElement;

  friend class ImageLoadTask;

public:

  explicit HTMLImageElement(already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);

  static already_AddRefed<HTMLImageElement>

    Image(const GlobalObject& aGlobal,

          const Optional<uint32_t>& aWidth,

          const Optional<uint32_t>& aHeight,

          ErrorResult& aError);

  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(HTMLImageElement,

                                           nsGenericHTMLElement)

  // nsISupports

  NS_DECL_ISUPPORTS_INHERITED

  virtual bool Draggable() const override;

  ResponsiveImageSelector* GetResponsiveImageSelector()

  {

    return mResponsiveSelector.get();

  }

  // Element

  virtual bool IsInteractiveHTMLContent(bool aIgnoreTabindex) const override;

  // EventTarget

  virtual void AsyncEventRunning(AsyncEventDispatcher* aEvent) override;

  NS_IMPL_FROMNODE_HTML_WITH_TAG(HTMLImageElement, img)

  // override from nsImageLoadingContent

  CORSMode GetCORSMode() override;

  // nsIContent

  virtual bool ParseAttribute(int32_t aNamespaceID,

                                nsAtom* aAttribute,

                                const nsAString& aValue,

                                nsIPrincipal* aMaybeScriptedPrincipal,

                                nsAttrValue& aResult) override;

  virtual nsChangeHint GetAttributeChangeHint(const nsAtom* aAttribute,

                                              int32_t aModType) const override;

  NS_IMETHOD_(bool) IsAttributeMapped(const nsAtom* aAttribute) const override;

  virtual nsMapRuleToAttributesFunc GetAttributeMappingFunction() const override;

  void GetEventTargetParent(EventChainPreVisitor& aVisitor) override;

  bool IsHTMLFocusable(bool aWithMouse, bool *aIsFocusable, int32_t *aTabIndex) override;

  virtual nsresult BindToTree(nsIDocument* aDocument, nsIContent* aParent,

                              nsIContent* aBindingParent) override;

  virtual void UnbindFromTree(bool aDeep, bool aNullParent) override;

  virtual EventStates IntrinsicState() const override;

  virtual nsresult Clone(dom::NodeInfo*, nsINode** aResult) const override;

  virtual void NodeInfoChanged(nsIDocument* aOldDoc) override;

  nsresult CopyInnerTo(HTMLImageElement* aDest);

  void MaybeLoadImage(bool aAlwaysForceLoad);

  // Overrides for nsImageLoadingContent's GetNaturalHeight/Width, since we

  // handle responsive scaling in the element's version of these methods.

  NS_IMETHOD GetNaturalHeight(uint32_t* aNaturalHeight) override;

  NS_IMETHOD GetNaturalWidth(uint32_t* aNaturalWidth) override;

  bool IsMap()

  {

    return GetBoolAttr(nsGkAtoms::ismap);

  }

  void SetIsMap(bool aIsMap, ErrorResult& aError)

  {

    SetHTMLBoolAttr(nsGkAtoms::ismap, aIsMap, aError);

  }

  MOZ_CAN_RUN_SCRIPT uint32_t Width()

  {

    return GetWidthHeightForImage(mCurrentRequest).width;

  }

  void SetWidth(uint32_t aWidth, ErrorResult& aError)

  {

    SetUnsignedIntAttr(nsGkAtoms::width, aWidth, 0, aError);

  }

  MOZ_CAN_RUN_SCRIPT uint32_t Height()

  {

    return GetWidthHeightForImage(mCurrentRequest).height;

  }

  void SetHeight(uint32_t aHeight, ErrorResult& aError)

  {

    SetUnsignedIntAttr(nsGkAtoms::height, aHeight, 0, aError);

  }

  uint32_t NaturalWidth();

  uint32_t NaturalHeight();

  bool Complete();

  uint32_t Hspace()

  {

    return GetUnsignedIntAttr(nsGkAtoms::hspace, 0);

  }

  void SetHspace(uint32_t aHspace, ErrorResult& aError)

  {

    SetUnsignedIntAttr(nsGkAtoms::hspace, aHspace, 0, aError);

  }

  uint32_t Vspace()

  {

    return GetUnsignedIntAttr(nsGkAtoms::vspace, 0);

  }

  void SetVspace(uint32_t aVspace, ErrorResult& aError)

  {

    SetUnsignedIntAttr(nsGkAtoms::vspace, aVspace, 0, aError);

  }

  void GetAlt(nsAString& aAlt)

  {

    GetHTMLAttr(nsGkAtoms::alt, aAlt);

  }

  void SetAlt(const nsAString& aAlt, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::alt, aAlt, aError);

  }

  void GetSrc(nsAString& aSrc)

  {

    GetURIAttr(nsGkAtoms::src, nullptr, aSrc);

  }

  void SetSrc(const nsAString& aSrc, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::src, aSrc, aError);

  }

  void SetSrc(const nsAString& aSrc, nsIPrincipal* aTriggeringPrincipal, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::src, aSrc, aTriggeringPrincipal, aError);

  }

  void GetSrcset(nsAString& aSrcset)

  {

    GetHTMLAttr(nsGkAtoms::srcset, aSrcset);

  }

  void SetSrcset(const nsAString& aSrcset, nsIPrincipal* aTriggeringPrincipal, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::srcset, aSrcset, aTriggeringPrincipal, aError);

  }

  void GetCrossOrigin(nsAString& aResult)

  {

    // Null for both missing and invalid defaults is ok, since we

    // always parse to an enum value, so we don't need an invalid

    // default, and we _want_ the missing default to be null.

    GetEnumAttr(nsGkAtoms::crossorigin, nullptr, aResult);

  }

  void SetCrossOrigin(const nsAString& aCrossOrigin, ErrorResult& aError)

  {

    SetOrRemoveNullableStringAttr(nsGkAtoms::crossorigin, aCrossOrigin, aError);

  }

  void GetUseMap(nsAString& aUseMap)

  {

    GetHTMLAttr(nsGkAtoms::usemap, aUseMap);

  }

  void SetUseMap(const nsAString& aUseMap, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::usemap, aUseMap, aError);

  }

  void GetName(nsAString& aName)

  {

    GetHTMLAttr(nsGkAtoms::name, aName);

  }

  void SetName(const nsAString& aName, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::name, aName, aError);

  }

  void GetAlign(nsAString& aAlign)

  {

    GetHTMLAttr(nsGkAtoms::align, aAlign);

  }

  void SetAlign(const nsAString& aAlign, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::align, aAlign, aError);

  }

  void GetLongDesc(nsAString& aLongDesc)

  {

    GetURIAttr(nsGkAtoms::longdesc, nullptr, aLongDesc);

  }

  void SetLongDesc(const nsAString& aLongDesc, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::longdesc, aLongDesc, aError);

  }

  void GetSizes(nsAString& aSizes)

  {

    GetHTMLAttr(nsGkAtoms::sizes, aSizes);

  }

  void SetSizes(const nsAString& aSizes, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::sizes, aSizes, aError);

  }

  void GetCurrentSrc(nsAString& aValue);

  void GetBorder(nsAString& aBorder)

  {

    GetHTMLAttr(nsGkAtoms::border, aBorder);

  }

  void SetBorder(const nsAString& aBorder, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::border, aBorder, aError);

  }

  void SetReferrerPolicy(const nsAString& aReferrer, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::referrerpolicy, aReferrer, aError);

  }

  void GetReferrerPolicy(nsAString& aReferrer)

  {

    GetEnumAttr(nsGkAtoms::referrerpolicy, EmptyCString().get(), aReferrer);

  }

  void SetDecoding(const nsAString& aDecoding, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::decoding, aDecoding, aError);

  }

  void GetDecoding(nsAString& aValue);

  net::ReferrerPolicy

  GetImageReferrerPolicy() override

  {

    return GetReferrerPolicyAsEnum();

  }

  MOZ_CAN_RUN_SCRIPT int32_t X();

  MOZ_CAN_RUN_SCRIPT int32_t Y();

  void GetLowsrc(nsAString& aLowsrc)

  {

    GetURIAttr(nsGkAtoms::lowsrc, nullptr, aLowsrc);

  }

  void SetLowsrc(const nsAString& aLowsrc, ErrorResult& aError)

  {

    SetHTMLAttr(nsGkAtoms::lowsrc, aLowsrc, aError);

  }

#ifdef DEBUG

  HTMLFormElement* GetForm() const;

#endif

  void SetForm(HTMLFormElement* aForm);

  void ClearForm(bool aRemoveFromForm);

  virtual void DestroyContent() override;

  void MediaFeatureValuesChanged();

  /**

   * Given a hypothetical <img> or <source> tag with the given parameters,

   * return what URI we would attempt to use, if any.  Used by the preloader to

   * resolve sources prior to DOM creation.

   *

   * @param aDocument The document this image would be for, for referencing

   *        viewport width and DPI/zoom

   * @param aIsSourceTag If these parameters are for a <source> tag (as in a

   *        <picture>) rather than an <img> tag. Note that some attrs are unused

   *        when this is true an vice versa

   * @param aSrcAttr [ignored if aIsSourceTag] The src attr for this image.

   * @param aSrcsetAttr The srcset attr for this image/source

   * @param aSizesAttr The sizes attr for this image/source

   * @param aTypeAttr [ignored if !aIsSourceTag] The type attr for this source.

   *                  Should be a void string to differentiate no type attribute

   *                  from an empty one.

   * @param aMediaAttr [ignored if !aIsSourceTag] The media attr for this

   *                   source.  Should be a void string to differentiate no

   *                   media attribute from an empty one.

   * @param aResult A reference to store the resulting URL spec in if we

   *                selected a source.  This value is not guaranteed to parse to

   *                a valid URL, merely the URL that the tag would attempt to

   *                resolve and load (which may be the empty string).  This

   *                parameter is not modified if return value is false.

   * @return True if we were able to select a final source, false if further

   *         sources would be considered.  It follows that this always returns

   *         true if !aIsSourceTag.

   *

   * Note that the return value may be true with an empty string as the result,

   * which implies that the parameters provided describe a tag that would select

   * no source.  This is distinct from a return of false which implies that

   * further <source> or <img> tags would be considered.

   */

  static bool

    SelectSourceForTagWithAttrs(nsIDocument *aDocument,

                                bool aIsSourceTag,

                                const nsAString& aSrcAttr,

                                const nsAString& aSrcsetAttr,

                                const nsAString& aSizesAttr,

                                const nsAString& aTypeAttr,

                                const nsAString& aMediaAttr,

                                nsAString& aResult);

  /**

   * If this image's src pointers to an SVG document, flush the SVG document's

   * use counters to telemetry.  Only used for testing purposes.

   */

  void FlushUseCounters();

protected:

  virtual ~HTMLImageElement();

  // Queues a task to run LoadSelectedImage pending stable state.

  //

  // Pending Bug 1076583 this is only used by the responsive image

  // algorithm (InResponsiveMode()) -- synchronous actions when just

  // using img.src will bypass this, and update source and kick off

  // image load synchronously.

  void QueueImageLoadTask(bool aAlwaysLoad);

  // True if we have a srcset attribute or a <picture> parent, regardless of if

  // any valid responsive sources were parsed from either.

  bool HaveSrcsetOrInPicture();

  // True if we are using the newer image loading algorithm. This will be the

  // only mode after Bug 1076583

  bool InResponsiveMode();

  // True if the given URL equals the last URL that was loaded by this element.

  bool SelectedSourceMatchesLast(nsIURI* aSelectedSource);

  // Resolve and load the current mResponsiveSelector (responsive mode) or src

  // attr image.

  nsresult LoadSelectedImage(bool aForce, bool aNotify, bool aAlwaysLoad);

  // True if this string represents a type we would support on <source type>

  static bool SupportedPictureSourceType(const nsAString& aType);

  // Update/create/destroy mResponsiveSelector

  void PictureSourceSrcsetChanged(nsIContent *aSourceNode,

                                  const nsAString& aNewValue, bool aNotify);

  void PictureSourceSizesChanged(nsIContent *aSourceNode,

                                 const nsAString& aNewValue, bool aNotify);

  // As we re-run the source selection on these mutations regardless,

  // we don't actually care which changed or to what

  void PictureSourceMediaOrTypeChanged(nsIContent *aSourceNode, bool aNotify);

  void PictureSourceAdded(nsIContent *aSourceNode);

  // This should be called prior to the unbind, such that nextsibling works

  void PictureSourceRemoved(nsIContent *aSourceNode);

  // Re-evaluates all source nodes (picture <source>,<img>) and finds

  // the best source set for mResponsiveSelector. If a better source

  // is found, creates a new selector and feeds the source to it. If

  // the current ResponsiveSelector is not changed, runs

  // SelectImage(true) to re-evaluate its candidates.

  //

  // Because keeping the existing selector is the common case (and we

  // often do no-op reselections), this does not re-parse values for

  // the existing mResponsiveSelector, meaning you need to update its

  // parameters as appropriate before calling (or null it out to force

  // recreation)

  //

  // Returns true if the source has changed, and false otherwise.

  bool UpdateResponsiveSource();

  // Given a <source> node that is a previous sibling *or* ourselves, try to

  // create a ResponsiveSelector.

  // If the node's srcset/sizes make for an invalid selector, returns

  // false. This does not guarantee the resulting selector matches an image,

  // only that it is valid.

  bool TryCreateResponsiveSelector(Element* aSourceElement);

  MOZ_CAN_RUN_SCRIPT CSSIntPoint GetXY();

  virtual JSObject* WrapNode(JSContext *aCx, JS::Handle<JSObject*> aGivenProto) override;

  void UpdateFormOwner();

  virtual nsresult BeforeSetAttr(int32_t aNameSpaceID, nsAtom* aName,

                                 const nsAttrValueOrString* aValue,

                                 bool aNotify) override;

  virtual nsresult AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,

                                const nsAttrValue* aValue,

                                const nsAttrValue* aOldValue,

                                nsIPrincipal* aMaybeScriptedPrincipal,

                                bool aNotify) override;

  virtual nsresult OnAttrSetButNotChanged(int32_t aNamespaceID, nsAtom* aName,

                                          const nsAttrValueOrString& aValue,

                                          bool aNotify) override;

  // Override for nsImageLoadingContent.

  nsIContent* AsContent() override { return this; }

  // This is a weak reference that this element and the HTMLFormElement

  // cooperate in maintaining.

  HTMLFormElement* mForm;

  // Created when we're tracking responsive image state

  RefPtr<ResponsiveImageSelector> mResponsiveSelector;

private:

  bool SourceElementMatches(Element* aSourceElement);

  static void MapAttributesIntoRule(const nsMappedAttributes* aAttributes,

                                    MappedDeclarations&);

  /**

   * This function is called by AfterSetAttr and OnAttrSetButNotChanged.

   * It will not be called if the value is being unset.

   *

   * @param aNamespaceID the namespace of the attr being set

   * @param aName the localname of the attribute being set

   * @param aValue the value it's being set to represented as either a string or

   *        a parsed nsAttrValue.

   * @param aOldValue the value previously set. Will be null if no value was

   *        previously set. This value should only be used when

   *        aValueMaybeChanged is true; when aValueMaybeChanged is false,

   *        aOldValue should be considered unreliable.

   * @param aValueMaybeChanged will be false when this function is called from

   *        OnAttrSetButNotChanged to indicate that the value was not changed.

   * @param aNotify Whether we plan to notify document observers.

   */

  void AfterMaybeChangeAttr(int32_t aNamespaceID, nsAtom* aName,

                            const nsAttrValueOrString& aValue,

                            const nsAttrValue* aOldValue,

                            nsIPrincipal* aMaybeScriptedPrincipal,

                            bool aValueMaybeChanged, bool aNotify);

  bool mInDocResponsiveContent;

  RefPtr<ImageLoadTask> mPendingImageLoadTask;

  nsCOMPtr<nsIPrincipal> mSrcTriggeringPrincipal;

  nsCOMPtr<nsIPrincipal> mSrcsetTriggeringPrincipal;

  // Last URL that was attempted to load by this element.

  nsCOMPtr<nsIURI> mLastSelectedSource;

  // Last pixel density that was selected.

  double mCurrentDensity;

};

} // namespace dom

} // namespace mozilla

#endif /* mozilla_dom_HTMLImageElement_h */