Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 996 insertions, 0 deletions

diff --git a/dom/base/nsFocusManager.h b/dom/base/nsFocusManager.h
new file mode 100644
index 0000000000..8d6b7bc043
--- /dev/null
+++ b/dom/base/nsFocusManager.h
@@ -0,0 +1,996 @@
+/* -*- 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 nsFocusManager_h___
+#define nsFocusManager_h___
+
+#include "nsCycleCollectionParticipant.h"
+#include "nsIContent.h"
+#include "mozilla/dom/Document.h"
+#include "nsIFocusManager.h"
+#include "nsIObserver.h"
+#include "nsWeakReference.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/StaticPtr.h"
+
+#define FOCUSMETHOD_MASK 0xF000
+#define FOCUSMETHODANDRING_MASK 0xF0F000
+
+#define FOCUSMANAGER_CONTRACTID "@mozilla.org/focus-manager;1"
+
+class nsIContent;
+class nsPIDOMWindowOuter;
+
+namespace mozilla {
+class PresShell;
+namespace dom {
+class Element;
+struct FocusOptions;
+class BrowserParent;
+class ContentChild;
+class ContentParent;
+}  // namespace dom
+}  // namespace mozilla
+
+struct nsDelayedBlurOrFocusEvent;
+
+/**
+ * The focus manager keeps track of where the focus is, that is, the node
+ * which receives key events.
+ */
+
+class nsFocusManager final : public nsIFocusManager,
+                             public nsIObserver,
+                             public nsSupportsWeakReference {
+  typedef mozilla::widget::InputContextAction InputContextAction;
+  typedef mozilla::dom::Document Document;
+  friend class mozilla::dom::ContentChild;
+  friend class mozilla::dom::ContentParent;
+
+ public:
+  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsFocusManager, nsIFocusManager)
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSIFOCUSMANAGER
+
+  // called to initialize and stop the focus manager at startup and shutdown
+  static nsresult Init();
+  static void Shutdown();
+
+  // Simple helper to call SetFocusedWindow on the instance.
+  //
+  // This raises the window and switches to the tab as needed.
+  static void FocusWindow(nsPIDOMWindowOuter* aWindow,
+                          mozilla::dom::CallerType aCallerType);
+
+  static void PrefChanged(const char* aPref, void* aSelf);
+  void PrefChanged(const char* aPref);
+
+  /**
+   * Retrieve the single focus manager.
+   */
+  static nsFocusManager* GetFocusManager() { return sInstance; }
+
+  /**
+   * A faster version of nsIFocusManager::GetFocusedElement, returning a
+   * raw Element pointer (instead of having AddRef-ed Element
+   * pointer filled in to an out-parameter).
+   */
+  mozilla::dom::Element* GetFocusedElement() { return mFocusedElement; }
+
+  /**
+   * Returns true if aContent currently has focus.
+   */
+  bool IsFocused(nsIContent* aContent);
+
+  /**
+   * Returns true if test mode is enabled.
+   */
+  bool IsTestMode();
+
+  /**
+   * Return a focused window. Version of nsIFocusManager::GetFocusedWindow.
+   */
+  nsPIDOMWindowOuter* GetFocusedWindow() const { return mFocusedWindow; }
+
+  /**
+   * In the chrome process, retrieves the BrowsingContext corresponding
+   * to GetFocusedWindow(). In a content process, retrieves the
+   * focused BrowsingContext, which may not belong to this process.
+   */
+  mozilla::dom::BrowsingContext* GetFocusedBrowsingContext() const {
+    if (XRE_IsParentProcess()) {
+      if (mFocusedWindow) {
+        return mFocusedWindow->GetBrowsingContext();
+      }
+      return nullptr;
+    }
+    return mFocusedBrowsingContextInContent;
+  }
+
+  /**
+   * Returns whether the given browsing context is in the active window.
+   */
+  bool IsInActiveWindow(mozilla::dom::BrowsingContext*) const;
+
+  /**
+   * Return an active window. Version of nsIFocusManager::GetActiveWindow.
+   */
+  nsPIDOMWindowOuter* GetActiveWindow() const { return mActiveWindow; }
+
+  /**
+   * In the chrome process, retrieves the BrowsingContext corresponding
+   * to GetActiveWindow(). In a content process, retrieves the
+   * BrowsingContext of the top-level Web content in the active tab if
+   * in the same process as the caller or nullptr otherwise.
+   */
+  mozilla::dom::BrowsingContext* GetActiveBrowsingContext() const {
+    if (XRE_IsParentProcess()) {
+      if (mActiveWindow) {
+        return mActiveWindow->GetBrowsingContext();
+      }
+      return nullptr;
+    }
+    return mActiveBrowsingContextInContent;
+  }
+
+  /**
+   * Called when content has been removed.
+   */
+  nsresult ContentRemoved(Document* aDocument, nsIContent* aContent);
+
+  void NeedsFlushBeforeEventHandling(mozilla::dom::Element* aElement) {
+    if (mFocusedElement == aElement) {
+      mEventHandlingNeedsFlush = true;
+    }
+  }
+
+  bool CanSkipFocus(nsIContent* aContent);
+
+  void FlushBeforeEventHandlingIfNeeded(nsIContent* aContent) {
+    if (mEventHandlingNeedsFlush) {
+      nsCOMPtr<Document> doc = aContent->GetComposedDoc();
+      if (doc) {
+        mEventHandlingNeedsFlush = false;
+        doc->FlushPendingNotifications(mozilla::FlushType::Layout);
+      }
+    }
+  }
+
+  /**
+   * Update the caret with current mode (whether in caret browsing mode or not).
+   */
+  void UpdateCaretForCaretBrowsingMode();
+
+  /**
+   * Returns the content node that would be focused if aWindow was in an
+   * active window. This will traverse down the frame hierarchy, starting at
+   * the given window aWindow. Sets aFocusedWindow to the window with the
+   * document containing aFocusedContent. If no element is focused,
+   * aFocusedWindow may be still be set -- this means that the document is
+   * focused but no element within it is focused.
+   *
+   * aWindow, aFocusIsOutOfProcess, aFocusedWindow must all be non-null.
+   */
+  enum SearchRange {
+    // Return focused content in aWindow.  So, aFocusedWindow is always aWindow.
+    eOnlyCurrentWindow,
+    // Return focused content in aWindow or one of all sub windows.
+    eIncludeAllDescendants,
+    // Return focused content in aWindow or one of visible sub windows.
+    eIncludeVisibleDescendants,
+  };
+  static mozilla::dom::Element* GetFocusedDescendant(
+      nsPIDOMWindowOuter* aWindow, SearchRange aSearchRange,
+      nsPIDOMWindowOuter** aFocusedWindow);
+
+  /**
+   * Helper function for MoveFocus which determines the next element
+   * to move the focus to and returns it in aNextContent.
+   *
+   * aWindow is the window to adjust the focus within, and aStart is
+   * the element to start navigation from. For tab key navigation,
+   * this should be the currently focused element.
+   *
+   * aType is the type passed to MoveFocus. If aNoParentTraversal is set,
+   * navigation is not done to parent documents and iteration returns to the
+   * beginning (or end) of the starting document.
+   *
+   * aNavigateByKey to move focus by keyboard as a side effect of computing the
+   * next target.
+   */
+  nsresult DetermineElementToMoveFocus(nsPIDOMWindowOuter* aWindow,
+                                       nsIContent* aStart, int32_t aType,
+                                       bool aNoParentTraversal,
+                                       bool aNavigateByKey,
+                                       nsIContent** aNextContent);
+
+  /**
+   * Setter for focusedWindow with CallerType
+   */
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY nsresult SetFocusedWindowWithCallerType(
+      mozIDOMWindowProxy* aWindowToFocus, mozilla::dom::CallerType aCallerType,
+      uint64_t aActionId);
+
+  /**
+   * Given an element, which must be the focused element, activate the remote
+   * frame it embeds, if any.
+   */
+  void ActivateRemoteFrameIfNeeded(mozilla::dom::Element&, uint64_t aActionId);
+
+  /**
+   * Raises the top-level window aWindow at the widget level.
+   */
+  void RaiseWindow(nsPIDOMWindowOuter* aWindow,
+                   mozilla::dom::CallerType aCallerType, uint64_t aActionId);
+
+  /**
+   * Called when a window has been raised.
+   */
+  void WindowRaised(mozIDOMWindowProxy* aWindow, uint64_t aActionId);
+
+  /**
+   * Called when a window has been lowered.
+   */
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY void WindowLowered(mozIDOMWindowProxy* aWindow,
+                                                 uint64_t aActionId);
+
+  /**
+   * Called when a new document in a window is shown.
+   *
+   * If aNeedsFocus is true, then focus events are expected to be fired on the
+   * window if this window is in the focused window chain.
+   */
+  void WindowShown(mozIDOMWindowProxy* aWindow, bool aNeedsFocus);
+
+  /**
+   * Called when a document in a window has been hidden or otherwise can no
+   * longer accept focus.
+   */
+  void WindowHidden(mozIDOMWindowProxy* aWindow, uint64_t aActionId);
+
+  /**
+   * Fire any events that have been delayed due to synchronized actions.
+   */
+  void FireDelayedEvents(Document* aDocument);
+
+  /**
+   * Indicate that a plugin wishes to take the focus. This is similar to a
+   * normal focus except that the widget focus is not changed. Updating the
+   * widget focus state is the responsibility of the caller.
+   */
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY nsresult
+  FocusPlugin(mozilla::dom::Element* aPlugin);
+
+  static uint32_t FocusOptionsToFocusManagerFlags(
+      const mozilla::dom::FocusOptions& aOptions);
+
+  /**
+   * Returns the content node that focus will be redirected to if aContent was
+   * focused. This is used for the special case of certain XUL elements such
+   * as textboxes or input number which redirect focus to an anonymous child.
+   *
+   * aContent must be non-null.
+   *
+   * XXXndeakin this should be removed eventually but I want to do that as
+   * followup work.
+   */
+  static mozilla::dom::Element* GetRedirectedFocus(nsIContent* aContent);
+
+  /**
+   * Returns an InputContextAction cause for aFlags.
+   */
+  static InputContextAction::Cause GetFocusMoveActionCause(uint32_t aFlags);
+
+  /**
+   * Notify of re-focus to same content.
+   *
+   * aContent is focused content.
+   */
+  void NotifyOfReFocus(nsIContent& aContent);
+
+  static bool sMouseFocusesFormControl;
+
+  static void MarkUncollectableForCCGeneration(uint32_t aGeneration);
+
+  struct BlurredElementInfo {
+    const mozilla::OwningNonNull<mozilla::dom::Element> mElement;
+    const bool mHadRing;
+
+    explicit BlurredElementInfo(mozilla::dom::Element&);
+    ~BlurredElementInfo();
+  };
+
+ protected:
+  nsFocusManager();
+  ~nsFocusManager();
+
+  /**
+   * Ensure that the widget associated with the currently focused window is
+   * focused at the widget level.
+   */
+  void EnsureCurrentWidgetFocused(mozilla::dom::CallerType aCallerType);
+
+  /**
+   * Activate or deactivate the window and send the activate/deactivate events.
+   */
+  void ActivateOrDeactivate(nsPIDOMWindowOuter* aWindow, bool aActive);
+
+  /**
+   * Blur whatever is currently focused and focus aNewContent. aFlags is a
+   * bitmask of the flags defined in nsIFocusManager. If aFocusChanged is
+   * true, then the focus has actually shifted and the caret position will be
+   * updated to the new focus, aNewContent will be scrolled into view (unless
+   * a flag disables this) and the focus method for the window will be updated.
+   * If aAdjustWidget is false, don't change the widget focus state.
+   *
+   * All actual focus changes must use this method to do so. (as opposed
+   * to those that update the focus in an inactive window for instance).
+   */
+  MOZ_CAN_RUN_SCRIPT void SetFocusInner(mozilla::dom::Element* aNewContent,
+                                        int32_t aFlags, bool aFocusChanged,
+                                        bool aAdjustWidget, uint64_t aActionId);
+
+  /**
+   * Returns true if aPossibleAncestor is the same as aWindow or an
+   * ancestor of aWindow.
+   */
+  bool IsSameOrAncestor(nsPIDOMWindowOuter* aPossibleAncestor,
+                        nsPIDOMWindowOuter* aWindow) const;
+  bool IsSameOrAncestor(nsPIDOMWindowOuter* aPossibleAncestor,
+                        mozilla::dom::BrowsingContext* aContext) const;
+  bool IsSameOrAncestor(mozilla::dom::BrowsingContext* aPossibleAncestor,
+                        nsPIDOMWindowOuter* aWindow) const;
+  bool IsSameOrAncestor(mozilla::dom::BrowsingContext* aPossibleAncestor,
+                        mozilla::dom::BrowsingContext* aContext) const;
+
+  /**
+   * Returns the window that is the lowest common ancestor of both aWindow
+   * and aContext, or null if they share no common ancestor.
+   */
+  mozilla::dom::BrowsingContext* GetCommonAncestor(
+      nsPIDOMWindowOuter* aWindow, mozilla::dom::BrowsingContext* aContext);
+
+  /**
+   * When aBrowsingContext is focused, adjust the ancestors of aBrowsingContext
+   * so that they also have their corresponding frames focused. Thus, one can
+   * start at the active top-level window and navigate down the currently
+   * focused elements for each frame in the tree to get to aBrowsingContext.
+   */
+  void AdjustWindowFocus(mozilla::dom::BrowsingContext* aBrowsingContext,
+                         bool aCheckPermission, bool aIsVisible);
+
+  /**
+   * Returns true if aWindow is visible.
+   */
+  bool IsWindowVisible(nsPIDOMWindowOuter* aWindow);
+
+  /**
+   * Returns true if aContent is a root element and not focusable.
+   * I.e., even if aContent is editable root element, this returns true when
+   * the document is in designMode.
+   *
+   * @param aContent must not be null and must be in a document.
+   */
+  bool IsNonFocusableRoot(nsIContent* aContent);
+
+  /**
+   * First flushes the pending notifications to ensure the PresShell and frames
+   * are updated.
+   * Checks and returns aElement if it may be focused, another element node if
+   * the focus should be retargeted at another node, or null if the node
+   * cannot be focused. aFlags are the flags passed to SetFocus and similar
+   * methods.
+   *
+   * An element is focusable if it is in a document, the document isn't in
+   * print preview mode and the element has an nsIFrame where the
+   * IsFocusable method returns true. For <area> elements, there is no
+   * frame, so only the IsFocusable method on the content node must be
+   * true.
+   */
+  mozilla::dom::Element* FlushAndCheckIfFocusable(
+      mozilla::dom::Element* aElement, uint32_t aFlags);
+
+  /**
+   * Blurs the currently focused element. Returns false if another element was
+   * focused as a result. This would mean that the caller should not proceed
+   * with a pending call to Focus. Normally, true would be returned.
+   *
+   * The currently focused element within aBrowsingContextToClear will be
+   * cleared. aBrowsingContextToClear may be null, which means that no window is
+   * cleared. This will be the case, for example, when lowering a window, as we
+   * want to fire a blur, but not actually change what element would be focused,
+   * so that the same element will be focused again when the window is raised.
+   *
+   * aAncestorBrowsingContextToFocus should be set to the common ancestor of the
+   * window that is being blurred and the window that is going to focused, when
+   * switching focus to a sibling window.
+   *
+   * aIsLeavingDocument should be set to true if the document/window is being
+   * blurred as well. Document/window blur events will be fired. It should be
+   * false if an element is the same document is about to be focused.
+   *
+   * If aAdjustWidget is false, don't change the widget focus state.
+   */
+  // MOZ_CAN_RUN_SCRIPT_BOUNDARY for now, until we annotate callers.
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY
+  bool Blur(mozilla::dom::BrowsingContext* aBrowsingContextToClear,
+            mozilla::dom::BrowsingContext* aAncestorBrowsingContextToFocus,
+            bool aIsLeavingDocument, bool aAdjustWidget, uint64_t aActionId,
+            mozilla::dom::Element* aElementToFocus = nullptr);
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY
+  void BlurFromOtherProcess(
+      mozilla::dom::BrowsingContext* aFocusedBrowsingContext,
+      mozilla::dom::BrowsingContext* aBrowsingContextToClear,
+      mozilla::dom::BrowsingContext* aAncestorBrowsingContextToFocus,
+      bool aIsLeavingDocument, bool aAdjustWidget, uint64_t aActionId);
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY
+  bool BlurImpl(mozilla::dom::BrowsingContext* aBrowsingContextToClear,
+                mozilla::dom::BrowsingContext* aAncestorBrowsingContextToFocus,
+                bool aIsLeavingDocument, bool aAdjustWidget,
+                mozilla::dom::Element* aElementToFocus, uint64_t aActionId);
+
+  /**
+   * Focus an element in the active window and child frame.
+   *
+   * aWindow is the window containing the element aContent to focus.
+   *
+   * aFlags is the flags passed to the various focus methods in
+   * nsIFocusManager.
+   *
+   * aIsNewDocument should be true if a new document is being focused.
+   * Document/window focus events will be fired.
+   *
+   * aFocusChanged should be true if a new content node is being focused, so
+   * the focused content will be scrolled into view and the caret position
+   * will be updated. If false is passed, then a window is simply being
+   * refocused, for instance, due to a window being raised, or a tab is being
+   * switched to.
+   *
+   * If aFocusChanged is true, then the focus has moved to a new location.
+   * Otherwise, the focus is just being updated because the window was
+   * raised.
+   *
+   * aWindowRaised should be true if the window is being raised. In this case,
+   * command updaters will not be called.
+   *
+   * If aAdjustWidget is false, don't change the widget focus state.
+   */
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY
+  void Focus(nsPIDOMWindowOuter* aWindow, mozilla::dom::Element* aContent,
+             uint32_t aFlags, bool aIsNewDocument, bool aFocusChanged,
+             bool aWindowRaised, bool aAdjustWidget, uint64_t aActionId,
+             const mozilla::Maybe<BlurredElementInfo>& = mozilla::Nothing());
+
+  /**
+   * Send a focus or blur event at aTarget. It may be added to the delayed
+   * event queue if the document is suppressing events.
+   *
+   * aEventMessage should be either eFocus or eBlur.
+   * For blur events, aFocusMethod should normally be non-zero.
+   *
+   * aWindowRaised should only be true if called from WindowRaised.
+   */
+  void SendFocusOrBlurEvent(
+      mozilla::EventMessage aEventMessage, mozilla::PresShell* aPresShell,
+      Document* aDocument, nsISupports* aTarget, uint32_t aFocusMethod,
+      bool aWindowRaised, bool aIsRefocus = false,
+      mozilla::dom::EventTarget* aRelatedTarget = nullptr);
+  /**
+   * Fire a focus or blur event at aTarget.
+   *
+   * aEventMessage should be either eFocus or eBlur.
+   * For blur events, aFocusMethod should normally be non-zero.
+   *
+   * aWindowRaised should only be true if called from WindowRaised.
+   */
+  void FireFocusOrBlurEvent(
+      mozilla::EventMessage aEventMessage, mozilla::PresShell* aPresShell,
+      nsISupports* aTarget, bool aWindowRaised, bool aIsRefocus = false,
+      mozilla::dom::EventTarget* aRelatedTarget = nullptr);
+
+  /**
+   *  Fire a focusin or focusout event
+   *
+   *  aEventMessage should be either eFocusIn or eFocusOut.
+   *
+   *  aTarget is the content the event will fire on (the object that gained
+   *  focus for focusin, the object blurred for focusout).
+   *
+   *  aCurrentFocusedWindow is the window focused before the focus/blur event
+   *  was fired.
+   *
+   *  aCurrentFocusedContent is the content focused before the focus/blur event
+   *  was fired.
+   *
+   *  aRelatedTarget is the content related to the event (the object
+   *  losing focus for focusin, the object getting focus for focusout).
+   */
+  void FireFocusInOrOutEvent(
+      mozilla::EventMessage aEventMessage, mozilla::PresShell* aPresShell,
+      nsISupports* aTarget, nsPIDOMWindowOuter* aCurrentFocusedWindow,
+      nsIContent* aCurrentFocusedContent,
+      mozilla::dom::EventTarget* aRelatedTarget = nullptr);
+
+  /**
+   * Scrolls aContent into view unless the FLAG_NOSCROLL flag is set.
+   */
+  MOZ_CAN_RUN_SCRIPT
+  void ScrollIntoView(mozilla::PresShell* aPresShell, nsIContent* aContent,
+                      uint32_t aFlags);
+
+  /**
+   * Updates the caret positon and visibility to match the focus.
+   *
+   * aMoveCaretToFocus should be true to move the caret to aContent.
+   *
+   * aUpdateVisibility should be true to update whether the caret is
+   * visible or not.
+   */
+  void UpdateCaret(bool aMoveCaretToFocus, bool aUpdateVisibility,
+                   nsIContent* aContent);
+
+  /**
+   * Helper method to move the caret to the focused element aContent.
+   */
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY void MoveCaretToFocus(
+      mozilla::PresShell* aPresShell, nsIContent* aContent);
+
+  /**
+   * Makes the caret visible or not, depending on aVisible.
+   */
+  nsresult SetCaretVisible(mozilla::PresShell* aPresShell, bool aVisible,
+                           nsIContent* aContent);
+
+  // the remaining functions are used for tab key and document-navigation
+
+  /**
+   * Retrieves the start and end points of the current selection for
+   * aDocument and stores them in aStartContent and aEndContent.
+   */
+  nsresult GetSelectionLocation(Document* aDocument,
+                                mozilla::PresShell* aPresShell,
+                                nsIContent** aStartContent,
+                                nsIContent** aEndContent);
+
+  /**
+   * Retrieve the next tabbable element in scope owned by aOwner, using
+   * focusability and tabindex to determine the tab order.
+   *
+   * aOwner is the owner of scope to search in.
+   *
+   * aStartContent is the starting point for this call of this method.
+   *
+   * aOriginalStartContent is the initial starting point for sequential
+   * navigation.
+   *
+   * aForward should be true for forward navigation or false for backward
+   * navigation.
+   *
+   * aCurrentTabIndex is the current tabindex.
+   *
+   * aIgnoreTabIndex to ignore the current tabindex and find the element
+   * irrespective or the tab index.
+   *
+   * aForDocumentNavigation informs whether we're navigating only through
+   * documents.
+   *
+   * aSkipOwner to skip owner while searching. The flag is set when caller is
+   * |GetNextTabbableContent| in order to let caller handle owner.
+   *
+   * NOTE:
+   *   Consider the method searches downwards in flattened subtree
+   *   rooted at aOwner.
+   */
+  nsIContent* GetNextTabbableContentInScope(
+      nsIContent* aOwner, nsIContent* aStartContent,
+      nsIContent* aOriginalStartContent, bool aForward,
+      int32_t aCurrentTabIndex, bool aIgnoreTabIndex,
+      bool aForDocumentNavigation, bool aNavigateByKey, bool aSkipOwner);
+
+  /**
+   * Retrieve the next tabbable element in scope including aStartContent
+   * and the scope's ancestor scopes, using focusability and tabindex to
+   * determine the tab order.
+   *
+   * aStartOwner is the scope owner of the aStartContent.
+   *
+   * aStartContent an in/out paremeter. It as input is the starting point
+   * for this call of this method; as output it is the shadow host in
+   * light DOM if the next tabbable element is not found in shadow DOM,
+   * in order to continue searching in light DOM.
+   *
+   * aOriginalStartContent is the initial starting point for sequential
+   * navigation.
+   *
+   * aForward should be true for forward navigation or false for backward
+   * navigation.
+   *
+   * aCurrentTabIndex returns tab index of shadow host in light DOM if the
+   * next tabbable element is not found in shadow DOM, in order to continue
+   * searching in light DOM.
+   *
+   * aIgnoreTabIndex to ignore the current tabindex and find the element
+   * irrespective or the tab index.
+   *
+   * aForDocumentNavigation informs whether we're navigating only through
+   * documents.
+   *
+   * aNavigateByKey to move focus by keyboard as a side effect of computing the
+   * next target.
+   *
+   * NOTE:
+   *   Consider the method searches upwards in all shadow host- or slot-rooted
+   *   flattened subtrees that contains aStartContent as non-root, except
+   *   the flattened subtree rooted at shadow host in light DOM.
+   */
+  nsIContent* GetNextTabbableContentInAncestorScopes(
+      nsIContent* aStartOwner, nsIContent** aStartContent,
+      nsIContent* aOriginalStartContent, bool aForward,
+      int32_t* aCurrentTabIndex, bool aIgnoreTabIndex,
+      bool aForDocumentNavigation, bool aNavigateByKey);
+
+  /**
+   * Retrieve the next tabbable element within a document, using focusability
+   * and tabindex to determine the tab order. The element is returned in
+   * aResultContent.
+   *
+   * aRootContent is the root node -- nodes above this will not be examined.
+   * Typically this will be the root node of a document, but could also be
+   * a popup node.
+   *
+   * aOriginalStartContent is the content which was originally the starting
+   * node, in the case of recursive or looping calls.
+   *
+   * aStartContent is the starting point for this call of this method.
+   * If aStartContent doesn't have visual representation, the next content
+   * object, which does have a primary frame, will be used as a start.
+   * If that content object is focusable, the method may return it.
+   *
+   * aForward should be true for forward navigation or false for backward
+   * navigation.
+   *
+   * aCurrentTabIndex is the current tabindex.
+   *
+   * aIgnoreTabIndex to ignore the current tabindex and find the element
+   * irrespective or the tab index. This will be true when a selection is
+   * active, since we just want to focus the next element in tree order
+   * from where the selection is. Similarly, if the starting element isn't
+   * focusable, since it doesn't really have a defined tab index.
+   *
+   * aNavigateByKey to move focus by keyboard as a side effect of computing the
+   * next target.
+   */
+  nsresult GetNextTabbableContent(
+      mozilla::PresShell* aPresShell, nsIContent* aRootContent,
+      nsIContent* aOriginalStartContent, nsIContent* aStartContent,
+      bool aForward, int32_t aCurrentTabIndex, bool aIgnoreTabIndex,
+      bool aForDocumentNavigation, bool aNavigateByKey,
+      nsIContent** aResultContent);
+
+  /**
+   * Get the next tabbable image map area and returns it.
+   *
+   * aForward should be true for forward navigation or false for backward
+   * navigation.
+   *
+   * aCurrentTabIndex is the current tabindex.
+   *
+   * aImageContent is the image.
+   *
+   * aStartContent is the current image map area.
+   */
+  nsIContent* GetNextTabbableMapArea(bool aForward, int32_t aCurrentTabIndex,
+                                     mozilla::dom::Element* aImageContent,
+                                     nsIContent* aStartContent);
+
+  /**
+   * Return the next valid tabindex value after aCurrentTabIndex, if aForward
+   * is true, or the previous tabindex value if aForward is false. aParent is
+   * the node from which to start looking for tab indicies.
+   */
+  int32_t GetNextTabIndex(nsIContent* aParent, int32_t aCurrentTabIndex,
+                          bool aForward);
+
+  /**
+   * Focus the first focusable content within the document with a root node of
+   * aRootContent. For content documents, this will be aRootContent itself, but
+   * for chrome documents, this will locate the next focusable content.
+   */
+  nsresult FocusFirst(mozilla::dom::Element* aRootContent,
+                      nsIContent** aNextContent);
+
+  /**
+   * Retrieves and returns the root node from aDocument to be focused. Will
+   * return null if the root node cannot be focused. There are several reasons
+   * for this:
+   *
+   * - if aForDocumentNavigation is false and aWindow is a chrome shell.
+   * - if aCheckVisibility is true and the aWindow is not visible.
+   * - if aDocument is a frameset document.
+   */
+  mozilla::dom::Element* GetRootForFocus(nsPIDOMWindowOuter* aWindow,
+                                         Document* aDocument,
+                                         bool aForDocumentNavigation,
+                                         bool aCheckVisibility);
+
+  /**
+   * Retrieves and returns the root node as with GetRootForFocus but only if
+   * aContent is a frame with a valid child document.
+   */
+  mozilla::dom::Element* GetRootForChildDocument(nsIContent* aContent);
+
+  /**
+   * Retreives a focusable element within the current selection of aWindow.
+   * Currently, this only detects links.
+   *
+   * This is used when MoveFocus is called with a type of MOVEFOCUS_CARET,
+   * which is used, for example, to focus links as the caret is moved over
+   * them.
+   */
+  void GetFocusInSelection(nsPIDOMWindowOuter* aWindow,
+                           nsIContent* aStartSelection,
+                           nsIContent* aEndSelection,
+                           nsIContent** aFocusedContent);
+
+ private:
+  // Notify that the focus state of aElement has changed.  Note that we need to
+  // pass in whether the window should show a focus ring before the
+  // SetFocusedNode call on it happened when losing focus and after the
+  // SetFocusedNode call when gaining focus, which is why that information needs
+  // to be an explicit argument instead of just passing in the window and asking
+  // it whether it should show focus rings: in the losing focus case that
+  // information could be wrong.
+  static void NotifyFocusStateChange(
+      mozilla::dom::Element* aElement, mozilla::dom::Element* aElementToFocus,
+      bool aWindowShouldShowFocusRing, int32_t aFlags, bool aGettingFocus,
+      const mozilla::Maybe<BlurredElementInfo>& = mozilla::Nothing());
+
+  void SetFocusedWindowInternal(nsPIDOMWindowOuter* aWindow);
+
+  bool TryDocumentNavigation(nsIContent* aCurrentContent,
+                             bool* aCheckSubDocument,
+                             nsIContent** aResultContent);
+
+  bool TryToMoveFocusToSubDocument(nsIContent* aCurrentContent,
+                                   nsIContent* aOriginalStartContent,
+                                   bool aForward, bool aForDocumentNavigation,
+                                   bool aNavigateByKey,
+                                   nsIContent** aResultContent);
+
+  // Sets the focused BrowsingContext and, if appropriate, syncs it to
+  // other processes.
+  void SetFocusedBrowsingContext(mozilla::dom::BrowsingContext* aContext);
+
+  // Content-only
+  // Called when receiving an IPC message about another process setting
+  // the focused BrowsingContext.
+  void SetFocusedBrowsingContextFromOtherProcess(
+      mozilla::dom::BrowsingContext* aContext);
+
+  // Chrome-only
+  // Sets the chrome process notion of what BrowsingContext is focused
+  // in content.
+  void SetFocusedBrowsingContextInChrome(
+      mozilla::dom::BrowsingContext* aContext);
+
+  void InsertNewFocusActionId(uint64_t aActionId);
+
+  bool ProcessPendingActiveBrowsingContextActionId(uint64_t aActionId,
+                                                   bool aSettingToNonNull);
+
+ public:
+  // Chrome-only
+  // Gets the chrome process notion of what BrowsingContext is focused
+  // in content.
+  mozilla::dom::BrowsingContext* GetFocusedBrowsingContextInChrome();
+
+  // Chrome-only
+  // Notifies the focus manager that BrowsingContext::Detach was called
+  // on a BrowsingContext so that pointers to it can be forgotten.
+  void BrowsingContextDetached(mozilla::dom::BrowsingContext* aContext);
+
+ private:
+  // Content-only
+  // Sets the BrowsingContext corresponding to top-level Web content
+  // in the frontmost tab if focus is in Web content.
+  void SetActiveBrowsingContextInContent(
+      mozilla::dom::BrowsingContext* aContext, uint64_t aActionId);
+
+  // Content-only
+  // Receives notification of another process setting the top-level Web
+  // content as being in the frontmost tab with focus in Web content.
+  void SetActiveBrowsingContextFromOtherProcess(
+      mozilla::dom::BrowsingContext* aContext);
+
+  // Content-only
+  // Receives notification that another process determined that focus
+  // moved to chrome so a particular BrowsingContext is no longer the
+  // "active" one.
+  void UnsetActiveBrowsingContextFromOtherProcess(
+      mozilla::dom::BrowsingContext* aContext);
+
+  // Content-only
+  // Receives a notification from parent that this content process's
+  // attempt to set the active browsing context was late and the
+  // prevailing browsing context is instead the first argument of
+  // this method call. This should be ignored if the second argument
+  // doesn't match the latest action id associated with setting the
+  // active browsing context in this process, because in that case,
+  // this revision is late.
+  void ReviseActiveBrowsingContext(mozilla::dom::BrowsingContext* aContext,
+                                   uint64_t aActionId);
+
+  // Chrome-only
+  // Sets the chrome process notion of what content believes to be
+  // the top-level BrowsingContext in the frontmost tab when focus
+  // is in Web content.
+  // Returns true if set and false if ignored.
+  bool SetActiveBrowsingContextInChrome(mozilla::dom::BrowsingContext* aContext,
+                                        uint64_t aActionId);
+
+ public:
+  // Chrome-only
+  // Gets the chrome process notion of what content believes to be
+  // the top-level BrowsingContext in the frontmost tab when focus
+  // is in Web content.
+  mozilla::dom::BrowsingContext* GetActiveBrowsingContextInChrome();
+
+  static uint64_t GenerateFocusActionId();
+
+ private:
+  // In the chrome process, the currently active and front-most top-most
+  // window. Not supposed to be used in a meaningful way in content
+  // processes. For legacy reasons, this exists as a separate field
+  // instead of being derived from mFocusedWindow when needed, because
+  // the defined relation that mActiveWindow is supposed to be the same
+  // as or ancestor of mFocusedWindow is temporarily broken when a
+  // window is being raised or lowered.
+  nsCOMPtr<nsPIDOMWindowOuter> mActiveWindow;
+
+  // In a content process, the BrowsingContext corresponding to top-level
+  // Web content in the active tab or nullptr if focus is not in a
+  // BrowsingContextGroup that this process participates in. Synced
+  // across processes in a BrowsingContextGroup. This field exists
+  // separately from mFocusedBrowsingContextInContent instead of being being
+  // derived from it, because for legacy reasons the relation
+  // mFocusedBrowsingContextInContent->Top() == mActiveBrowsingContextInContent
+  // is temporarily broken when a window is being raised or lowered.
+  // Not supposed to be used in a meaningful way in the chrome process.
+  RefPtr<mozilla::dom::BrowsingContext> mActiveBrowsingContextInContent;
+
+  // If this content process set mActiveBrowsingContextInContent, this
+  // field holds the corresponding actionId so that
+  // mActiveBrowsingContextInContent can be revised of the parent rejects
+  // the update. This field is used for accepting revisions only if nothing
+  // else has updated mActiveBrowsingContextInContent before the revision
+  // arrives.
+  uint64_t mActionIdForActiveBrowsingContextInContent;
+
+  // Whether or not mActiveBrowsingContextInContent was set from another process
+  // or from this process.
+  bool mActiveBrowsingContextInContentSetFromOtherProcess;
+
+  // This is the chrome process notion of content's
+  // mActiveBrowsingContextInContent. Avoiding field reuse for different
+  // semantics in different process types to make it easier to catch bugs.
+  RefPtr<mozilla::dom::BrowsingContext> mActiveBrowsingContextInChrome;
+
+  // the child or top-level window that is currently focused. In the chrome
+  // process, when a window isn't being raised or lowered, this window will
+  // either be the same window as mActiveWindow or a descendant of it.
+  // Except during shutdown use SetFocusedWindowInternal to set mFocusedWindow!
+  nsCOMPtr<nsPIDOMWindowOuter> mFocusedWindow;
+
+  // The focused BrowsingContext if this is a chrome process and focus is
+  // in chrome or if this is a content process and focus is in Web content
+  // in this BrowsingContextGroup. nullptr otherwise.
+  // Except during shutdown, must be set via SetFocusedWindowInternal which
+  // calls SetFocusedBrowsingContext or if the value is coming in via IPC
+  // via SetFocusedBrowsingContextFromOtherProcess.
+  RefPtr<mozilla::dom::BrowsingContext> mFocusedBrowsingContextInContent;
+
+  // This is the chrome process notion of content's
+  // mFocusedBrowsingContextInContent. Avoiding field reuse for different
+  // semantics in different process types to make it easier to catch bugs.
+  RefPtr<mozilla::dom::BrowsingContext> mFocusedBrowsingContextInChrome;
+
+  // the currently focused content if in-process or the XUL browser in which
+  // Web content focus resides. Always inside mFocusedWindow. When a window
+  // isn't being raised or lowered, this is a cached copy of the
+  // mFocusedWindow's current content. This may be null if no content is
+  // focused.
+  RefPtr<mozilla::dom::Element> mFocusedElement;
+
+  // these fields store a content node temporarily while it is being focused
+  // or blurred to ensure that a recursive call doesn't refire the same event.
+  // They will always be cleared afterwards.
+  RefPtr<mozilla::dom::Element> mFirstBlurEvent;
+  RefPtr<mozilla::dom::Element> mFirstFocusEvent;
+
+  // keep track of a window while it is being lowered
+  nsCOMPtr<nsPIDOMWindowOuter> mWindowBeingLowered;
+
+  // synchronized actions cannot be interrupted with events, so queue these up
+  // and fire them later.
+  nsTArray<nsDelayedBlurOrFocusEvent> mDelayedBlurFocusEvents;
+
+  // Array of focus action ids for which we haven't seen an active browsing
+  // context set yet. As set is allowed to overwrite an unset. Therefore,
+  // an unset removes earlier ids but not the matching id. A set removes
+  // earlier ids and the matching id.
+  //
+  // Conceptually, active browsing context shouldn't have to exist as a
+  // field, because it should be possible to always derive it from the
+  // focused browsing context. Unfortunately, for legacy reasons, this
+  // is not the case while a window is being raised or lowered.
+  //
+  // Conceptually, it should be possible for the parent to manage the
+  // active browsing context. Unfortunately, for legacy reasons, the
+  // code for setting the active browsing context needs to reside in
+  // the content process to retain the existing and test-passing code
+  // flow.
+  //
+  // This, obviously, raises the issue of content processes racing to
+  // set the active browsing context. In particular, there is a pattern
+  // that the parent initiates actions that cause multiple content
+  // processes to mutate the active browsing context at almost the
+  // same time. When two native browser windows change order, the
+  // lowering isn't distinguished from the case of lowering the
+  // entire app. For this reason, the owner of the previous active
+  // browsing context tries to unset it and at almost the same time
+  // the another content process sets a new active browsing context.
+  // If the IPC messages for these unset and set actions were to
+  // arrive in the wrong order, this could get in the wrong state.
+  //
+  // To address this issue, the parent manages an authortative order
+  // of attempts to (un)set the active browsing context using the
+  // array mPendingActiveBrowsingContextActions.
+  //
+  // A process reserves a slot in the order by calling
+  // GenerateFocusActionId(). Per one call to GenerateFocusActionId(),
+  // there may be at most one action to set the active browsing context
+  // to a new value. There may be logically prior attempts to unset it
+  // (i.e. set it to nullptr). That is, if there are both attempts to
+  // unset and set the active browsing context with the same action id,
+  // the attempt to set to a non-null value wins.
+  //
+  // The completion of an action from reserting the slot in the order
+  // and actually performing the setting of the active browsing context
+  // may span multiple processes and IPC messages.
+  //
+  // The at-most-once property is not asserted, because the process
+  // claiming the position in the order and the process setting the
+  // active browsing context with that actionId may be different, and
+  // the act of using an actionId to set the active browsing context
+  // is used to delete stale items from the array to avoid excessive
+  // growth of the array.
+  //
+  // This arrangement raises the obvious question: Shouldn't
+  // out-of-order attempts to set the focused browsing context
+  // also have an array of actionIds ensuring a coherent global
+  // ordering? Probably yes, but a concrete need has not been
+  // demonstrated, yet.
+  nsTArray<uint64_t> mPendingActiveBrowsingContextActions;
+
+  // If set to true, layout of the document of the event target should be
+  // flushed before handling focus depending events.
+  bool mEventHandlingNeedsFlush;
+
+  static bool sTestMode;
+
+  // Process-specific counter for maintaining the prosess-specific
+  // uniqueness of actionIds.
+  static uint64_t sFocusActionCounter;
+
+  // the single focus manager
+  static mozilla::StaticRefPtr<nsFocusManager> sInstance;
+};
+
+nsresult NS_NewFocusManager(nsIFocusManager** aResult);
+
+#endif