DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (5216dd412535)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozila.org code.
 *
 * The Initial Developer of the Original Code is Mozilla Foundation
 * Portions created by the Initial Developer are Copyright (C) 2008
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef nsFocusManager_h___
#define nsFocusManager_h___

#include "nsIFocusManager.h"
#include "nsWeakReference.h"
#include "nsIObserver.h"
#include "nsIContent.h"

#define FOCUSMETHOD_MASK 0xF000
#define FOCUSMETHODANDRING_MASK 0xF0F000

#define FOCUSMANAGER_CONTRACTID "@mozilla.org/focus-manager;1"

class nsIDocShellTreeItem;
class nsPIDOMWindow;
struct nsDelayedBlurOrFocusEvent;

/**
 * The focus manager keeps track of where the focus is, that is, the node
 * which receives key events.
 */

class nsFocusManager : public nsIFocusManager,
                       public nsIFocusManager_MOZILLA_2_0_BRANCH,
                       public nsIObserver,
                       public nsSupportsWeakReference
{
public:

  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsFocusManager, nsIFocusManager)
  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  NS_DECL_NSIOBSERVER
  NS_DECL_NSIFOCUSMANAGER
  NS_DECL_NSIFOCUSMANAGER_MOZILLA_2_0_BRANCH

  // called to initialize and stop the focus manager at startup and shutdown
  static nsresult Init();
  static void Shutdown();

  /**
   * Retrieve the single focus manager.
   */
  static nsFocusManager* GetFocusManager() { return sInstance; }

  /**
   * A faster version of nsIFocusManager::GetFocusedElement, returning a
   * raw nsIContent pointer (instead of having AddRef-ed nsIDOMElement
   * pointer filled in to an out-parameter).
   */
  nsIContent* GetFocusedContent() { return mFocusedContent; }

  /**
   * Called when content has been removed.
   */
  nsresult ContentRemoved(nsIDocument* aDocument, nsIContent* aContent);

  /**
   * Called when mouse button down event handling is started and finished.
   */
  void SetMouseButtonDownHandlingDocument(nsIDocument* aDocument)
  {
    NS_ASSERTION(!aDocument || !mMouseDownEventHandlingDocument,
                 "Some mouse button down events are nested?");
    mMouseDownEventHandlingDocument = aDocument;
  }

  /**
   * 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 and aFocusedWindow must both be non-null.
   */
  static nsIContent* GetFocusedDescendant(nsPIDOMWindow* aWindow, PRBool aDeep,
                                          nsPIDOMWindow** aFocusedWindow);

  /**
   * 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 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 nsIContent* GetRedirectedFocus(nsIContent* aContent);

  static PRBool sMouseFocusesFormControl;

protected:

  nsFocusManager();
  ~nsFocusManager();

  /**
   * Ensure that the widget associated with the currently focused window is
   * focused at the widget level.
   */
  void EnsureCurrentWidgetFocused();

  /**
   * 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).
   */
  void SetFocusInner(nsIContent* aNewContent, PRInt32 aFlags,
                     PRBool aFocusChanged, PRBool aAdjustWidget);

  /**
   * Returns true if aPossibleAncestor is the same as aWindow or an
   * ancestor of aWindow.
   */
  PRBool IsSameOrAncestor(nsPIDOMWindow* aPossibleAncestor,
                          nsPIDOMWindow* aWindow);

  /**
   * Returns the window that is the lowest common ancestor of both aWindow1
   * and aWindow2, or null if they share no common ancestor.
   */
  already_AddRefed<nsPIDOMWindow> GetCommonAncestor(nsPIDOMWindow* aWindow1,
                                                    nsPIDOMWindow* aWindow2);

  /**
   * When aNewWindow is focused, adjust the ancestors of aNewWindow 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 aNewWindow.
   */
  void AdjustWindowFocus(nsPIDOMWindow* aNewWindow, PRBool aCheckPermission);

  /**
   * Returns true if aWindow is visible.
   */
  PRBool IsWindowVisible(nsPIDOMWindow* 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.
   */
  PRBool IsNonFocusableRoot(nsIContent* aContent);

  /**
   * Checks and returns aContent if it may be focused, another content 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
   * CheckIfFocusable method returns true. For <area> elements, there is no
   * frame, so only the IsFocusable method on the content node must be
   * true.
   */
  nsIContent* CheckIfFocusable(nsIContent* aContent, PRUint32 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 aWindowToClear will be cleared.
   * aWindowToClear 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.
   *
   * aAncestorWindowToFocus 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.
   */
  PRBool Blur(nsPIDOMWindow* aWindowToClear,
              nsPIDOMWindow* aAncestorWindowToFocus,
              PRBool aIsLeavingDocument,
              PRBool aAdjustWidget);

  /**
   * 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.
   */
  void Focus(nsPIDOMWindow* aWindow,
             nsIContent* aContent,
             PRUint32 aFlags,
             PRBool aIsNewDocument,
             PRBool aFocusChanged,
             PRBool aWindowRaised,
             PRBool aAdjustWidget);

  /**
   * Fires a focus or blur event at aTarget.
   *
   * aType should be either NS_FOCUS_CONTENT or NS_BLUR_CONTENT. For blur
   * events, aFocusMethod should normally be non-zero.
   *
   * aWindowRaised should only be true if called from WindowRaised.
   */
  void SendFocusOrBlurEvent(PRUint32 aType,
                            nsIPresShell* aPresShell,
                            nsIDocument* aDocument,
                            nsISupports* aTarget,
                            PRUint32 aFocusMethod,
                            PRBool aWindowRaised,
                            PRBool aIsRefocus = PR_FALSE);

  /**
   * Scrolls aContent into view unless the FLAG_NOSCROLL flag is set.
   */
  void ScrollIntoView(nsIPresShell* aPresShell,
                      nsIContent* aContent,
                      PRUint32 aFlags);

  /**
   * Raises the top-level window aWindow at the widget level.
   */
  void RaiseWindow(nsPIDOMWindow* aWindow);

  /**
   * 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(PRBool aMoveCaretToFocus,
                   PRBool aUpdateVisibility,
                   nsIContent* aContent);

  /**
   * Helper method to move the caret to the focused element aContent.
   */
  void MoveCaretToFocus(nsIPresShell* aPresShell, nsIContent* aContent);

  /**
   * Makes the caret visible or not, depending on aVisible.
   */
  nsresult SetCaretVisible(nsIPresShell* aPresShell,
                           PRBool 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(nsIDocument* aDocument,
                                nsIPresShell* aPresShell,
                                nsIContent **aStartContent,
                                nsIContent **aEndContent);

  /**
   * 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.
   */
  nsresult DetermineElementToMoveFocus(nsPIDOMWindow* aWindow,
                                       nsIContent* aStart,
                                       PRInt32 aType,
                                       nsIContent** aNextContent);

  /**
   * 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.
   */
  nsresult GetNextTabbableContent(nsIPresShell* aPresShell,
                                  nsIContent* aRootContent,
                                  nsIContent* aOriginalStartContent,
                                  nsIContent* aStartContent,
                                  PRBool aForward,
                                  PRInt32 aCurrentTabIndex,
                                  PRBool aIgnoreTabIndex,
                                  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(PRBool aForward,
                                     PRInt32 aCurrentTabIndex,
                                     nsIContent* 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.
   */
  PRInt32 GetNextTabIndex(nsIContent* aParent,
                          PRInt32 aCurrentTabIndex,
                          PRBool aForward);

  /**
   * 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 aIsForDocNavigation is true, and aWindow is in an <iframe>.
   * - if aIsForDocNavigation is false, and aWindow is a chrome shell.
   * - if aCheckVisibility is true and the aWindow is not visible.
   * - if aDocument is a frameset document.
   */
  nsIContent* GetRootForFocus(nsPIDOMWindow* aWindow,
                              nsIDocument* aDocument,
                              PRBool aIsForDocNavigation,
                              PRBool aCheckVisibility);

  /**
   * Get the last docshell child of aItem and return it in aResult.
   */
  void GetLastDocShell(nsIDocShellTreeItem* aItem,
                       nsIDocShellTreeItem** aResult);

  /**
   * Get the next docshell child of aItem and return it in aResult.
   */
  void GetNextDocShell(nsIDocShellTreeItem* aItem,
                       nsIDocShellTreeItem** aResult);

  /**
   * Get the previous docshell child of aItem and return it in aResult.
   */
  void GetPreviousDocShell(nsIDocShellTreeItem* aItem,
                           nsIDocShellTreeItem** aResult);

  /**
   * Get the tabbable next document from the currently focused frame if
   * aForward is true, or the previously tabbable document if aForward is
   * false. If this document is a chrome or frameset document, returns
   * the first focusable element within this document, otherwise, returns
   * the root node of the document.
   *
   * This method would be used for document navigation, which is typically
   * invoked by pressing F6.
   */
  nsIContent* GetNextTabbableDocument(PRBool aForward);

  /**
   * 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(nsPIDOMWindow* aWindow,
                           nsIContent* aStartSelection,
                           nsIContent* aEndSelection,
                           nsIContent** aFocusedContent);

  // the currently active and front-most top-most window
  nsCOMPtr<nsPIDOMWindow> mActiveWindow;

  // the child or top-level window that is currently focused. This window will
  // either be the same window as mActiveWindow or a descendant of it.
  nsCOMPtr<nsPIDOMWindow> mFocusedWindow;

  // the currently focused content, which is always inside mFocusedWindow. This
  // is a cached copy of the mFocusedWindow's current content. This may be null
  // if no content is focused.
  nsCOMPtr<nsIContent> mFocusedContent;

  // 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.
  nsCOMPtr<nsIContent> mFirstBlurEvent;
  nsCOMPtr<nsIContent> mFirstFocusEvent;

  // keep track of a window while it is being lowered
  nsCOMPtr<nsPIDOMWindow> mWindowBeingLowered;

  // synchronized actions cannot be interrupted with events, so queue these up
  // and fire them later.
  nsTArray<nsDelayedBlurOrFocusEvent> mDelayedBlurFocusEvents;

  // A document which is handling a mouse button down event.
  // When a mouse down event process is finished, ESM sets focus to the target
  // content.  Therefore, while DOM event handlers are handling mouse down
  // events, the handlers should be able to steal focus from any elements even
  // if focus is in chrome content.  So, if this isn't NULL and the caller
  // can access the document node, the caller should succeed in moving focus.
  nsCOMPtr<nsIDocument> mMouseDownEventHandlingDocument;

  // the single focus manager
  static nsFocusManager* sInstance;
};

nsresult
NS_NewFocusManager(nsIFocusManager** aResult);

#endif