/* -*- 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 BrowsingContext_h

#define BrowsingContext_h

#include "mozilla/LinkedList.h"

#include "mozilla/Maybe.h"

#include "mozilla/RefPtr.h"

#include "mozilla/WeakPtr.h"

#include "nsCOMPtr.h"

#include "nsCycleCollectionParticipant.h"

#include "nsString.h"

#include "nsTArray.h"

#include "nsWrapperCache.h"

class nsIDocShell;

namespace mozilla {

class LogModule;

namespace dom {

// BrowsingContext, in this context, is the cross process replicated

// environment in which information about documents is stored. In

// particular the tree structure of nested browsing contexts is

// represented by the tree of BrowsingContexts.

//

// The tree of BrowsingContexts in created in step with its

// corresponding nsDocShell, and when nsDocShells are connected

// through a parent/child relationship, so are BrowsingContexts. The

// major difference is that BrowsingContexts are replicated (synced)

// to the parent process, making it possible to traverse the

// BrowsingContext tree for a tab, in both the parent and the child

// process.

class BrowsingContext

  : public nsWrapperCache

  , public SupportsWeakPtr<BrowsingContext>

  , public LinkedListElement<RefPtr<BrowsingContext>>

{

public:

  static void Init();

  static LogModule* GetLog();

  static void CleanupContexts(uint64_t aProcessId);

  static already_AddRefed<BrowsingContext> Get(uint64_t aId);

  static already_AddRefed<BrowsingContext> Create(nsIDocShell* aDocShell);

  // Attach the current BrowsingContext to its parent, in both the

  // child and the parent process. If 'aParent' is null, 'this' is

  // taken to be a root BrowsingContext.

  void Attach(BrowsingContext* aParent);

  // Detach the current BrowsingContext from its parent, in both the

  // child and the parent process.

  void Detach();

  // Remove all children from the current BrowsingContext and cache

  // them to allow them to be attached again.

  void CacheChildren();

  bool IsCached();

  void SetName(const nsAString& aName) { mName = aName; }

  void GetName(nsAString& aName) { aName = mName; }

  bool NameEquals(const nsAString& aName) { return mName.Equals(aName); }

  uint64_t Id() const { return mBrowsingContextId; }

  uint64_t OwnerProcessId() const;

  already_AddRefed<BrowsingContext> GetParent()

  {

    return do_AddRef(mParent.get());

  }

  void GetChildren(nsTArray<RefPtr<BrowsingContext>>& aChildren);

  static void GetRootBrowsingContexts(

    nsTArray<RefPtr<BrowsingContext>>& aBrowsingContexts);

  nsISupports* GetParentObject() const;

  virtual JSObject* WrapObject(JSContext* aCx,

                               JS::Handle<JSObject*> aGivenProto) override;

  MOZ_DECLARE_WEAKREFERENCE_TYPENAME(BrowsingContext)

  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(BrowsingContext)

  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(BrowsingContext)

  using Children = AutoCleanLinkedList<RefPtr<BrowsingContext>>;

protected:

  virtual ~BrowsingContext();

  // Create a new BrowsingContext for 'aDocShell'. The id will be

  // generated so that it is unique across all content child processes

  // and the content parent process.

  explicit BrowsingContext(nsIDocShell* aDocShell);

  BrowsingContext(uint64_t aBrowsingContextId,

                  const nsAString& aName);

private:

  const uint64_t mBrowsingContextId;

  WeakPtr<BrowsingContext> mParent;

  Children mChildren;

  nsCOMPtr<nsIDocShell> mDocShell;

  nsString mName;

};

} // namespace dom

} // namespace mozilla

#endif