gecko-dev/dom/html/HTMLFormControlsCollection.h

/* -*- 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_HTMLFormControlsCollection_h
#define mozilla_dom_HTMLFormControlsCollection_h

#include "mozilla/dom/Element.h" // DOMProxyHandler::getOwnPropertyDescriptor
#include "nsIHTMLCollection.h"
#include "nsInterfaceHashtable.h"
#include "nsTArray.h"
#include "nsWrapperCache.h"

class nsGenericHTMLFormElement;
class nsIFormControl;

namespace mozilla {
namespace dom {
class HTMLFormElement;
class HTMLImageElement;
class OwningRadioNodeListOrElement;
template<typename> struct Nullable;

class HTMLFormControlsCollection final : public nsIHTMLCollection
                                       , public nsWrapperCache
{
public:
  explicit HTMLFormControlsCollection(HTMLFormElement* aForm);

  void DropFormReference();

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS

  // nsIDOMHTMLCollection interface
  NS_DECL_NSIDOMHTMLCOLLECTION

  virtual Element* GetElementAt(uint32_t index) override;
  virtual nsINode* GetParentObject() override;

  virtual Element*
  GetFirstNamedElement(const nsAString& aName, bool& aFound) override;

  void
  NamedGetter(const nsAString& aName,
              bool& aFound,
              Nullable<OwningRadioNodeListOrElement>& aResult);
  void
  NamedItem(const nsAString& aName,
            Nullable<OwningRadioNodeListOrElement>& aResult)
  {
    bool dummy;
    NamedGetter(aName, dummy, aResult);
  }
  virtual void GetSupportedNames(nsTArray<nsString>& aNames) override;

  nsresult AddElementToTable(nsGenericHTMLFormElement* aChild,
                             const nsAString& aName);
  nsresult AddImageElementToTable(HTMLImageElement* aChild,
                                  const nsAString& aName);
  nsresult RemoveElementFromTable(nsGenericHTMLFormElement* aChild,
                                  const nsAString& aName);
  nsresult IndexOfControl(nsIFormControl* aControl,
                          int32_t* aIndex);

  nsISupports* NamedItemInternal(const nsAString& aName, bool aFlushContent);
  
  /**
   * Create a sorted list of form control elements. This list is sorted
   * in document order and contains the controls in the mElements and
   * mNotInElements list. This function does not add references to the
   * elements.
   *
   * @param aControls The list of sorted controls[out].
   * @return NS_OK or NS_ERROR_OUT_OF_MEMORY.
   */
  nsresult GetSortedControls(nsTArray<nsGenericHTMLFormElement*>& aControls) const;

  // nsWrapperCache
  using nsWrapperCache::GetWrapperPreserveColor;
  virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
protected:
  virtual ~HTMLFormControlsCollection();
  virtual JSObject* GetWrapperPreserveColorInternal() override
  {
    return nsWrapperCache::GetWrapperPreserveColor();
  }
public:

  static bool ShouldBeInElements(nsIFormControl* aFormControl);

  HTMLFormElement* mForm;  // WEAK - the form owns me

  nsTArray<nsGenericHTMLFormElement*> mElements;  // Holds WEAK references - bug 36639

  // This array holds on to all form controls that are not contained
  // in mElements (form.elements in JS, see ShouldBeInFormControl()).
  // This is needed to properly clean up the bi-directional references
  // (both weak and strong) between the form and its form controls.

  nsTArray<nsGenericHTMLFormElement*> mNotInElements; // Holds WEAK references

  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(HTMLFormControlsCollection)

protected:
  // Drop all our references to the form elements
  void Clear();

  // Flush out the content model so it's up to date.
  void FlushPendingNotifications();
  
  // A map from an ID or NAME attribute to the form control(s), this
  // hash holds strong references either to the named form control, or
  // to a list of named form controls, in the case where this hash
  // holds on to a list of named form controls the list has weak
  // references to the form control.

  nsInterfaceHashtable<nsStringHashKey,nsISupports> mNameLookupTable;
};

} // namespace dom
} // namespace mozilla

#endif // mozilla_dom_HTMLFormControlsCollection_h