gecko-dev/xpfe/appshell/nsContentTreeOwner.cpp

/* -*- Mode: C++; tab-width: 3; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: set ts=2 sw=2 et 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/. */

// Local Includes
#include "nsContentTreeOwner.h"
#include "AppWindow.h"

// Interfaces needed to be included
#include "nsGlobalWindowOuter.h"
#include "nsIDOMWindow.h"
#include "nsIBrowserDOMWindow.h"
#include "nsIOpenWindowInfo.h"
#include "nsIPrompt.h"
#include "nsIAuthPrompt.h"
#include "nsIXULBrowserWindow.h"
#include "nsIPrincipal.h"
#include "nsIURIFixup.h"
#include "nsIWebNavigation.h"
#include "nsDocShellCID.h"
#include "nsIMIMEInfo.h"
#include "nsIWidget.h"
#include "nsWindowWatcher.h"
#include "nsIWindowMediator.h"
#include "mozilla/Components.h"
#include "mozilla/NullPrincipal.h"
#include "nsDocShell.h"
#include "nsDocShellLoadState.h"
#include "nsQueryActor.h"

#include "nsIScriptObjectPrincipal.h"
#include "nsIURI.h"
#include "mozilla/dom/Document.h"
#if defined(XP_MACOSX)
#  include "nsThreadUtils.h"
#endif

#include "mozilla/Preferences.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/ScriptSettings.h"

using namespace mozilla;

//*****************************************************************************
//***    nsContentTreeOwner: Object Management
//*****************************************************************************

nsContentTreeOwner::nsContentTreeOwner(bool fPrimary)
    : mAppWindow(nullptr), mPrimary(fPrimary) {}

//*****************************************************************************
// nsContentTreeOwner::nsISupports
//*****************************************************************************

NS_IMPL_ADDREF(nsContentTreeOwner)
NS_IMPL_RELEASE(nsContentTreeOwner)

NS_INTERFACE_MAP_BEGIN(nsContentTreeOwner)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDocShellTreeOwner)
  NS_INTERFACE_MAP_ENTRY(nsIDocShellTreeOwner)
  NS_INTERFACE_MAP_ENTRY(nsIBaseWindow)
  NS_INTERFACE_MAP_ENTRY(nsIWebBrowserChrome)
  NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
  NS_INTERFACE_MAP_ENTRY(nsIWindowProvider)
NS_INTERFACE_MAP_END

//*****************************************************************************
// nsContentTreeOwner::nsIInterfaceRequestor
//*****************************************************************************

NS_IMETHODIMP nsContentTreeOwner::GetInterface(const nsIID& aIID,
                                               void** aSink) {
  NS_ENSURE_ARG_POINTER(aSink);
  *aSink = nullptr;

  if (aIID.Equals(NS_GET_IID(nsIPrompt))) {
    NS_ENSURE_STATE(mAppWindow);
    return mAppWindow->GetInterface(aIID, aSink);
  }
  if (aIID.Equals(NS_GET_IID(nsIAuthPrompt))) {
    NS_ENSURE_STATE(mAppWindow);
    return mAppWindow->GetInterface(aIID, aSink);
  }
  if (aIID.Equals(NS_GET_IID(nsIDocShellTreeItem))) {
    NS_ENSURE_STATE(mAppWindow);
    nsCOMPtr<nsIDocShell> shell;
    mAppWindow->GetDocShell(getter_AddRefs(shell));
    if (shell) return shell->QueryInterface(aIID, aSink);
    return NS_ERROR_FAILURE;
  }

  if (aIID.Equals(NS_GET_IID(nsIDOMWindow)) ||
      aIID.Equals(NS_GET_IID(nsPIDOMWindowOuter))) {
    NS_ENSURE_STATE(mAppWindow);
    nsCOMPtr<nsIDocShellTreeItem> shell;
    mAppWindow->GetPrimaryContentShell(getter_AddRefs(shell));
    if (shell) {
      nsCOMPtr<nsIInterfaceRequestor> thing(do_QueryInterface(shell));
      if (thing) return thing->GetInterface(aIID, aSink);
    }
    return NS_ERROR_FAILURE;
  }

  if (aIID.Equals(NS_GET_IID(nsIAppWindow))) {
    NS_ENSURE_STATE(mAppWindow);
    return mAppWindow->QueryInterface(aIID, aSink);
  }

  return QueryInterface(aIID, aSink);
}

//*****************************************************************************
// nsContentTreeOwner::nsIDocShellTreeOwner
//*****************************************************************************

NS_IMETHODIMP
nsContentTreeOwner::ContentShellAdded(nsIDocShellTreeItem* aContentShell,
                                      bool aPrimary) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->ContentShellAdded(aContentShell, aPrimary);
}

NS_IMETHODIMP
nsContentTreeOwner::ContentShellRemoved(nsIDocShellTreeItem* aContentShell) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->ContentShellRemoved(aContentShell);
}

NS_IMETHODIMP
nsContentTreeOwner::GetPrimaryContentShell(nsIDocShellTreeItem** aShell) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetPrimaryContentShell(aShell);
}

NS_IMETHODIMP
nsContentTreeOwner::RemoteTabAdded(nsIRemoteTab* aTab, bool aPrimary) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->RemoteTabAdded(aTab, aPrimary);
}

NS_IMETHODIMP
nsContentTreeOwner::RemoteTabRemoved(nsIRemoteTab* aTab) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->RemoteTabRemoved(aTab);
}

NS_IMETHODIMP
nsContentTreeOwner::GetPrimaryRemoteTab(nsIRemoteTab** aTab) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetPrimaryRemoteTab(aTab);
}

NS_IMETHODIMP
nsContentTreeOwner::GetPrimaryContentBrowsingContext(
    mozilla::dom::BrowsingContext** aBc) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetPrimaryContentBrowsingContext(aBc);
}

NS_IMETHODIMP
nsContentTreeOwner::GetPrimaryContentSize(int32_t* aWidth, int32_t* aHeight) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetPrimaryContentSize(aWidth, aHeight);
}

NS_IMETHODIMP
nsContentTreeOwner::SetPrimaryContentSize(int32_t aWidth, int32_t aHeight) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->SetPrimaryContentSize(aWidth, aHeight);
}

NS_IMETHODIMP
nsContentTreeOwner::GetRootShellSize(int32_t* aWidth, int32_t* aHeight) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetRootShellSize(aWidth, aHeight);
}

NS_IMETHODIMP
nsContentTreeOwner::SetRootShellSize(int32_t aWidth, int32_t aHeight) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->SetRootShellSize(aWidth, aHeight);
}

NS_IMETHODIMP nsContentTreeOwner::SizeShellTo(nsIDocShellTreeItem* aShellItem,
                                              int32_t aCX, int32_t aCY) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->SizeShellTo(aShellItem, aCX, aCY);
}

NS_IMETHODIMP
nsContentTreeOwner::SetPersistence(bool aPersistPosition, bool aPersistSize,
                                   bool aPersistSizeMode) {
  NS_ENSURE_STATE(mAppWindow);
  nsCOMPtr<dom::Element> docShellElement = mAppWindow->GetWindowDOMElement();
  if (!docShellElement) return NS_ERROR_FAILURE;

  nsAutoString persistString;
  docShellElement->GetAttr(nsGkAtoms::persist, persistString);

  bool saveString = false;
  int32_t index;

  // Set X
  index = persistString.Find(u"screenX");
  if (!aPersistPosition && index >= 0) {
    persistString.Cut(index, 7);
    saveString = true;
  } else if (aPersistPosition && index < 0) {
    persistString.AppendLiteral(" screenX");
    saveString = true;
  }
  // Set Y
  index = persistString.Find(u"screenY");
  if (!aPersistPosition && index >= 0) {
    persistString.Cut(index, 7);
    saveString = true;
  } else if (aPersistPosition && index < 0) {
    persistString.AppendLiteral(" screenY");
    saveString = true;
  }
  // Set CX
  index = persistString.Find(u"width");
  if (!aPersistSize && index >= 0) {
    persistString.Cut(index, 5);
    saveString = true;
  } else if (aPersistSize && index < 0) {
    persistString.AppendLiteral(" width");
    saveString = true;
  }
  // Set CY
  index = persistString.Find(u"height");
  if (!aPersistSize && index >= 0) {
    persistString.Cut(index, 6);
    saveString = true;
  } else if (aPersistSize && index < 0) {
    persistString.AppendLiteral(" height");
    saveString = true;
  }
  // Set SizeMode
  index = persistString.Find(u"sizemode");
  if (!aPersistSizeMode && (index >= 0)) {
    persistString.Cut(index, 8);
    saveString = true;
  } else if (aPersistSizeMode && (index < 0)) {
    persistString.AppendLiteral(" sizemode");
    saveString = true;
  }

  ErrorResult rv;
  if (saveString) {
    docShellElement->SetAttribute(u"persist"_ns, persistString, rv);
  }

  return NS_OK;
}

NS_IMETHODIMP
nsContentTreeOwner::GetPersistence(bool* aPersistPosition, bool* aPersistSize,
                                   bool* aPersistSizeMode) {
  NS_ENSURE_STATE(mAppWindow);
  nsCOMPtr<dom::Element> docShellElement = mAppWindow->GetWindowDOMElement();
  if (!docShellElement) return NS_ERROR_FAILURE;

  nsAutoString persistString;
  docShellElement->GetAttr(nsGkAtoms::persist, persistString);

  // data structure doesn't quite match the question, but it's close enough
  // for what we want (since this method is never actually called...)
  if (aPersistPosition) {
    *aPersistPosition = persistString.Find(u"screenX") >= 0 ||
                        persistString.Find(u"screenY") >= 0;
  }
  if (aPersistSize) {
    *aPersistSize =
        persistString.Find(u"width") >= 0 || persistString.Find(u"height") >= 0;
  }
  if (aPersistSizeMode) {
    *aPersistSizeMode = persistString.Find(u"sizemode") >= 0;
  }

  return NS_OK;
}

NS_IMETHODIMP
nsContentTreeOwner::GetTabCount(uint32_t* aResult) {
  if (mAppWindow) {
    return mAppWindow->GetTabCount(aResult);
  }

  *aResult = 0;
  return NS_OK;
}

NS_IMETHODIMP
nsContentTreeOwner::GetHasPrimaryContent(bool* aResult) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetHasPrimaryContent(aResult);
}

//*****************************************************************************
// nsContentTreeOwner::nsIWebBrowserChrome
//*****************************************************************************

NS_IMETHODIMP nsContentTreeOwner::SetLinkStatus(const nsAString& aStatusText) {
  NS_ENSURE_STATE(mAppWindow);

  nsCOMPtr<nsIXULBrowserWindow> xulBrowserWindow;
  mAppWindow->GetXULBrowserWindow(getter_AddRefs(xulBrowserWindow));

  if (xulBrowserWindow) {
    xulBrowserWindow->SetOverLink(aStatusText);
  }

  return NS_OK;
}

NS_IMETHODIMP nsContentTreeOwner::SetChromeFlags(uint32_t aChromeFlags) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->SetChromeFlags(aChromeFlags);
}

NS_IMETHODIMP nsContentTreeOwner::GetChromeFlags(uint32_t* aChromeFlags) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetChromeFlags(aChromeFlags);
}

NS_IMETHODIMP nsContentTreeOwner::ShowAsModal() {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->ShowModal();
}

NS_IMETHODIMP nsContentTreeOwner::IsWindowModal(bool* _retval) {
  NS_ENSURE_STATE(mAppWindow);
  *_retval = mAppWindow->mContinueModalLoop;
  return NS_OK;
}

//*****************************************************************************
// nsContentTreeOwner::nsIBaseWindow
//*****************************************************************************

NS_IMETHODIMP nsContentTreeOwner::InitWindow(nativeWindow aParentNativeWindow,
                                             nsIWidget* parentWidget, int32_t x,
                                             int32_t y, int32_t cx,
                                             int32_t cy) {
  // Ignore wigdet parents for now.  Don't think those are a vaild thing to
  // call.
  NS_ENSURE_SUCCESS(SetPositionAndSize(x, y, cx, cy, 0), NS_ERROR_FAILURE);

  return NS_OK;
}

NS_IMETHODIMP nsContentTreeOwner::Destroy() {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->Destroy();
}

double nsContentTreeOwner::GetWidgetCSSToDeviceScale() {
  return mAppWindow ? mAppWindow->GetWidgetCSSToDeviceScale() : 1.0;
}

NS_IMETHODIMP nsContentTreeOwner::GetDevicePixelsPerDesktopPixel(
    double* aScale) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetDevicePixelsPerDesktopPixel(aScale);
}

NS_IMETHODIMP nsContentTreeOwner::SetPositionDesktopPix(int32_t aX,
                                                        int32_t aY) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->SetPositionDesktopPix(aX, aY);
}

NS_IMETHODIMP nsContentTreeOwner::SetPosition(int32_t aX, int32_t aY) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->SetPosition(aX, aY);
}

NS_IMETHODIMP nsContentTreeOwner::GetPosition(int32_t* aX, int32_t* aY) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetPosition(aX, aY);
}

NS_IMETHODIMP nsContentTreeOwner::SetSize(int32_t aCX, int32_t aCY,
                                          bool aRepaint) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->SetSize(aCX, aCY, aRepaint);
}

NS_IMETHODIMP nsContentTreeOwner::GetSize(int32_t* aCX, int32_t* aCY) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetSize(aCX, aCY);
}

NS_IMETHODIMP nsContentTreeOwner::SetPositionAndSize(int32_t aX, int32_t aY,
                                                     int32_t aCX, int32_t aCY,
                                                     uint32_t aFlags) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->SetPositionAndSize(aX, aY, aCX, aCY, aFlags);
}

NS_IMETHODIMP nsContentTreeOwner::GetPositionAndSize(int32_t* aX, int32_t* aY,
                                                     int32_t* aCX,
                                                     int32_t* aCY) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetPositionAndSize(aX, aY, aCX, aCY);
}

NS_IMETHODIMP
nsContentTreeOwner::SetDimensions(DimensionRequest&& aRequest) {
  NS_ENSURE_STATE(mAppWindow);
  if (aRequest.mDimensionKind == DimensionKind::Outer) {
    return mAppWindow->SetDimensions(std::move(aRequest));
  }

  MOZ_TRY(aRequest.SupplementFrom(this));
  return aRequest.ApplyInnerTo(this, /* aAsRootShell */ false);
}

NS_IMETHODIMP
nsContentTreeOwner::GetDimensions(DimensionKind aDimensionKind, int32_t* aX,
                                  int32_t* aY, int32_t* aCX, int32_t* aCY) {
  NS_ENSURE_STATE(mAppWindow);
  if (aDimensionKind == DimensionKind::Outer) {
    return mAppWindow->GetDimensions(aDimensionKind, aX, aY, aCX, aCY);
  }
  if (aY || aX) {
    return NS_ERROR_NOT_IMPLEMENTED;
  }
  return GetPrimaryContentSize(aCX, aCY);
}

NS_IMETHODIMP nsContentTreeOwner::Repaint(bool aForce) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->Repaint(aForce);
}

NS_IMETHODIMP nsContentTreeOwner::GetParentWidget(nsIWidget** aParentWidget) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetParentWidget(aParentWidget);
}

NS_IMETHODIMP nsContentTreeOwner::SetParentWidget(nsIWidget* aParentWidget) {
  NS_ASSERTION(false, "You can't call this");
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP nsContentTreeOwner::GetParentNativeWindow(
    nativeWindow* aParentNativeWindow) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetParentNativeWindow(aParentNativeWindow);
}

NS_IMETHODIMP nsContentTreeOwner::SetParentNativeWindow(
    nativeWindow aParentNativeWindow) {
  NS_ASSERTION(false, "You can't call this");
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP nsContentTreeOwner::GetNativeHandle(nsAString& aNativeHandle) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetNativeHandle(aNativeHandle);
}

NS_IMETHODIMP nsContentTreeOwner::GetVisibility(bool* aVisibility) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetVisibility(aVisibility);
}

NS_IMETHODIMP nsContentTreeOwner::SetVisibility(bool aVisibility) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->SetVisibility(aVisibility);
}

NS_IMETHODIMP nsContentTreeOwner::GetEnabled(bool* aEnabled) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->GetEnabled(aEnabled);
}

NS_IMETHODIMP nsContentTreeOwner::SetEnabled(bool aEnable) {
  NS_ENSURE_STATE(mAppWindow);
  return mAppWindow->SetEnabled(aEnable);
}

NS_IMETHODIMP nsContentTreeOwner::GetMainWidget(nsIWidget** aMainWidget) {
  NS_ENSURE_ARG_POINTER(aMainWidget);
  NS_ENSURE_STATE(mAppWindow);

  *aMainWidget = mAppWindow->mWindow;
  NS_IF_ADDREF(*aMainWidget);

  return NS_OK;
}

NS_IMETHODIMP nsContentTreeOwner::GetTitle(nsAString& aTitle) {
  NS_ENSURE_STATE(mAppWindow);

  return mAppWindow->GetTitle(aTitle);
}

NS_IMETHODIMP nsContentTreeOwner::SetTitle(const nsAString& aTitle) {
  return NS_OK;
}

//*****************************************************************************
// nsContentTreeOwner: nsIWindowProvider
//*****************************************************************************
NS_IMETHODIMP
nsContentTreeOwner::ProvideWindow(
    nsIOpenWindowInfo* aOpenWindowInfo, uint32_t aChromeFlags,
    bool aCalledFromJS, nsIURI* aURI, const nsAString& aName,
    const nsACString& aFeatures, bool aForceNoOpener, bool aForceNoReferrer,
    bool aIsPopupRequested, nsDocShellLoadState* aLoadState, bool* aWindowIsNew,
    dom::BrowsingContext** aReturn) {
  NS_ENSURE_ARG_POINTER(aOpenWindowInfo);

  RefPtr<dom::BrowsingContext> parent = aOpenWindowInfo->GetParent();

  *aReturn = nullptr;

  if (!mAppWindow) {
    // Nothing to do here
    return NS_OK;
  }

#ifdef DEBUG
  nsCOMPtr<nsIDocShell> docshell = parent->GetDocShell();
  nsCOMPtr<nsIDocShellTreeOwner> parentOwner = do_GetInterface(docshell);
  NS_ASSERTION(
      SameCOMIdentity(parentOwner, static_cast<nsIDocShellTreeOwner*>(this)),
      "Parent from wrong docshell tree?");
#endif

  int32_t openLocation = nsWindowWatcher::GetWindowOpenLocation(
      parent->GetDOMWindow(), aChromeFlags, aCalledFromJS,
      aOpenWindowInfo->GetIsForPrinting());

  if (openLocation != nsIBrowserDOMWindow::OPEN_NEWTAB &&
      openLocation != nsIBrowserDOMWindow::OPEN_CURRENTWINDOW &&
      openLocation != nsIBrowserDOMWindow::OPEN_PRINT_BROWSER) {
    // Just open a window normally
    return NS_OK;
  }

  nsCOMPtr<mozIDOMWindowProxy> domWin;
  mAppWindow->GetWindowDOMWindow(getter_AddRefs(domWin));
  if (!domWin || !nsGlobalWindowOuter::Cast(domWin)->IsChromeWindow()) {
    // Really odd... but whatever
    NS_WARNING("AppWindow's DOMWindow is not a chrome window");
    return NS_OK;
  }

  nsCOMPtr<nsIBrowserDOMWindow> browserDOMWin =
      nsGlobalWindowOuter::Cast(domWin)->GetBrowserDOMWindow();
  if (!browserDOMWin) {
    return NS_OK;
  }

  *aWindowIsNew = (openLocation != nsIBrowserDOMWindow::OPEN_CURRENTWINDOW);

  {
    dom::AutoNoJSAPI nojsapi;

    uint32_t flags = nsIBrowserDOMWindow::OPEN_NEW;
    if (aForceNoOpener) {
      flags |= nsIBrowserDOMWindow::OPEN_NO_OPENER;
    }
    if (aForceNoReferrer) {
      flags |= nsIBrowserDOMWindow::OPEN_NO_REFERRER;
    }

    // Get a new rendering area from the browserDOMWin.
    // Since we are not loading any URI, we follow the principle of least
    // privilege and use a nullPrincipal as the triggeringPrincipal.
    //
    // This method handles setting the opener for us, so we don't need to set it
    // ourselves.
    RefPtr<NullPrincipal> nullPrincipal =
        NullPrincipal::CreateWithoutOriginAttributes();
    return browserDOMWin->CreateContentWindow(aURI, aOpenWindowInfo,
                                              openLocation, flags,
                                              nullPrincipal, nullptr, aReturn);
  }
}

//*****************************************************************************
// nsContentTreeOwner: Accessors
//*****************************************************************************

void nsContentTreeOwner::AppWindow(mozilla::AppWindow* aAppWindow) {
  mAppWindow = aAppWindow;
}

mozilla::AppWindow* nsContentTreeOwner::AppWindow() { return mAppWindow; }

/* this implementation focuses another window. if there isn't another
   window to focus, we do nothing. */
NS_IMETHODIMP
nsContentTreeOwner::Blur() {
  NS_DEFINE_CID(kWindowMediatorCID, NS_WINDOWMEDIATOR_CID);

  nsCOMPtr<nsISimpleEnumerator> windowEnumerator;
  nsCOMPtr<nsIAppWindow> appWindow;
  bool more, foundUs;

  {
    nsCOMPtr<nsIWindowMediator> windowMediator(
        do_GetService(kWindowMediatorCID));
    if (windowMediator) {
      windowMediator->GetZOrderAppWindowEnumerator(
          nullptr, true, getter_AddRefs(windowEnumerator));
    }
  }

  if (!windowEnumerator) return NS_ERROR_FAILURE;

  // step through the top-level windows
  foundUs = false;
  windowEnumerator->HasMoreElements(&more);
  while (more) {
    nsCOMPtr<nsISupports> nextWindow;
    nsCOMPtr<nsIAppWindow> nextAppWindow;

    windowEnumerator->GetNext(getter_AddRefs(nextWindow));
    nextAppWindow = do_QueryInterface(nextWindow);

    // got it!(?)
    if (foundUs) {
      appWindow = nextAppWindow;
      break;
    }

    // remember the very first one, in case we have to wrap
    if (!appWindow) appWindow = nextAppWindow;

    // look for us
    if (nextAppWindow == mAppWindow) {
      foundUs = true;
    }

    windowEnumerator->HasMoreElements(&more);
  }

  // change focus to the window we just found
  if (appWindow) {
    nsCOMPtr<nsIDocShell> docshell;
    appWindow->GetDocShell(getter_AddRefs(docshell));
    if (!docshell) {
      return NS_OK;
    }

    nsCOMPtr<nsPIDOMWindowOuter> domWindow = docshell->GetWindow();
    if (domWindow) domWindow->Focus(mozilla::dom::CallerType::System);
  }
  return NS_OK;
}