gecko-dev/embedding/browser/nsCommandHandler.cpp

/* -*- 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/. */

#include "nsCommandHandler.h"
#include "nsWebBrowser.h"
#include "nsDocShellTreeOwner.h"

#include "nsMemory.h"
#include "nsPIDOMWindow.h"

nsCommandHandler::nsCommandHandler()
  : mWindow(nullptr)
{
}

nsCommandHandler::~nsCommandHandler()
{
}

nsresult
nsCommandHandler::GetCommandHandler(nsICommandHandler** aCommandHandler)
{
  NS_ENSURE_ARG_POINTER(aCommandHandler);

  *aCommandHandler = nullptr;
  if (!mWindow) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsPIDOMWindow> window(do_QueryInterface(mWindow));
  if (!window) {
    return NS_ERROR_FAILURE;
  }

  // Get the document tree owner

  nsCOMPtr<nsIDocShellTreeItem> docShellAsTreeItem =
    do_QueryInterface(window->GetDocShell());
  nsIDocShellTreeOwner* treeOwner = nullptr;
  docShellAsTreeItem->GetTreeOwner(&treeOwner);

  // Make sure the tree owner is an an nsDocShellTreeOwner object
  // by QI'ing for a hidden interface. If it doesn't have the interface
  // then it's not safe to do the casting.

  nsCOMPtr<nsICDocShellTreeOwner> realTreeOwner(do_QueryInterface(treeOwner));
  if (realTreeOwner) {
    nsDocShellTreeOwner* tree = static_cast<nsDocShellTreeOwner*>(treeOwner);
    if (tree->mTreeOwner) {
      nsresult rv;
      rv = tree->mTreeOwner->QueryInterface(NS_GET_IID(nsICommandHandler),
                                            (void**)aCommandHandler);
      NS_RELEASE(treeOwner);
      return rv;
    }

    NS_RELEASE(treeOwner);
  }

  *aCommandHandler = nullptr;

  return NS_OK;
}

NS_IMPL_ADDREF(nsCommandHandler)
NS_IMPL_RELEASE(nsCommandHandler)

NS_INTERFACE_MAP_BEGIN(nsCommandHandler)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsICommandHandler)
  NS_INTERFACE_MAP_ENTRY(nsICommandHandlerInit)
  NS_INTERFACE_MAP_ENTRY(nsICommandHandler)
NS_INTERFACE_MAP_END

///////////////////////////////////////////////////////////////////////////////
// nsICommandHandlerInit implementation

NS_IMETHODIMP
nsCommandHandler::GetWindow(nsIDOMWindow** aWindow)
{
  *aWindow = nullptr;
  return NS_OK;
}

NS_IMETHODIMP
nsCommandHandler::SetWindow(nsIDOMWindow* aWindow)
{
  if (!aWindow) {
    return NS_ERROR_FAILURE;
  }
  mWindow = aWindow;
  return NS_OK;
}

///////////////////////////////////////////////////////////////////////////////
// nsICommandHandler implementation

NS_IMETHODIMP
nsCommandHandler::Exec(const char* aCommand, const char* aStatus,
                       char** aResult)
{
  NS_ENSURE_ARG_POINTER(aCommand);
  NS_ENSURE_ARG_POINTER(aResult);

  nsCOMPtr<nsICommandHandler> commandHandler;
  GetCommandHandler(getter_AddRefs(commandHandler));

  // Call the client's command handler to deal with this command
  if (commandHandler) {
    *aResult = nullptr;
    return commandHandler->Exec(aCommand, aStatus, aResult);
  }

  // Return an empty string
  const char szEmpty[] = "";
  *aResult = (char*)nsMemory::Clone(szEmpty, sizeof(szEmpty));

  return NS_OK;
}

NS_IMETHODIMP
nsCommandHandler::Query(const char* aCommand, const char* aStatus,
                        char** aResult)
{
  NS_ENSURE_ARG_POINTER(aCommand);
  NS_ENSURE_ARG_POINTER(aResult);

  nsCOMPtr<nsICommandHandler> commandHandler;
  GetCommandHandler(getter_AddRefs(commandHandler));

  // Call the client's command handler to deal with this command
  if (commandHandler) {
    *aResult = nullptr;
    return commandHandler->Query(aCommand, aStatus, aResult);
  }

  // Return an empty string
  const char szEmpty[] = "";
  *aResult = (char*)nsMemory::Clone(szEmpty, sizeof(szEmpty));

  return NS_OK;
}