Source/WebCore/page/FocusController.cpp

   1 /*
   2  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
   3  * Copyright (C) 2008 Nuanti Ltd.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include "config.h"
  28 #include "FocusController.h"
  29
  30 #include "AXObjectCache.h"
  31 #include "Chrome.h"
  32 #include "ComposedShadowTreeWalker.h"
  33 #include "Document.h"
  34 #include "Editor.h"
  35 #include "EditorClient.h"
  36 #include "Element.h"
  37 #include "ElementShadow.h"
  38 #include "Event.h"
  39 #include "EventHandler.h"
  40 #include "EventNames.h"
  41 #include "ExceptionCode.h"
  42 #include "Frame.h"
  43 #include "FrameSelection.h"
  44 #include "FrameTree.h"
  45 #include "FrameView.h"
  46 #include "HTMLAreaElement.h"
  47 #include "HTMLImageElement.h"
  48 #include "HTMLNames.h"
  49 #include "HitTestResult.h"
  50 #include "KeyboardEvent.h"
  51 #include "Page.h"
  52 #include "Range.h"
  53 #include "RenderObject.h"
  54 #include "RenderWidget.h"
  55 #include "ScrollAnimator.h"
  56 #include "Settings.h"
  57 #include "ShadowRoot.h"
  58 #include "SpatialNavigation.h"
  59 #include "Widget.h"
  60 #include "htmlediting.h" // For firstPositionInOrBeforeNode
  61 #include <limits>
  62
  63 namespace WebCore {
  64
  65 using namespace HTMLNames;
  66 using namespace std;
  67
  68 static inline ComposedShadowTreeWalker walkerFrom(const Node* node)
  69 {
  70     return ComposedShadowTreeWalker(node, ComposedShadowTreeWalker::DoNotCrossUpperBoundary);
  71 }
  72
  73 static inline ComposedShadowTreeWalker walkerFromNext(const Node* node)
  74 {
  75     ComposedShadowTreeWalker walker = ComposedShadowTreeWalker(node, ComposedShadowTreeWalker::DoNotCrossUpperBoundary);
  76     walker.next();
  77     return walker;
  78 }
  79
  80 static inline ComposedShadowTreeWalker walkerFromPrevious(const Node* node)
  81 {
  82     ComposedShadowTreeWalker walker = ComposedShadowTreeWalker(node, ComposedShadowTreeWalker::DoNotCrossUpperBoundary);
  83     walker.previous();
  84     return walker;
  85 }
  86
  87 static inline Node* nextNode(const Node* node)
  88 {
  89     return walkerFromNext(node).get();
  90 }
  91
  92 static inline Node* previousNode(const Node* node)
  93 {
  94     return walkerFromPrevious(node).get();
  95 }
  96
  97 FocusNavigationScope::FocusNavigationScope(TreeScope* treeScope)
  98     : m_rootTreeScope(treeScope)
  99 {
 100     ASSERT(treeScope);
 101     ASSERT(!treeScope->rootNode()->isShadowRoot() || toShadowRoot(treeScope->rootNode())->isYoungest());
 102 }
 103
 104 Node* FocusNavigationScope::rootNode() const
 105 {
 106     return m_rootTreeScope->rootNode();
 107 }
 108
 109 Element* FocusNavigationScope::owner() const
 110 {
 111     Node* root = rootNode();
 112     if (root->isShadowRoot())
 113         return toShadowRoot(root)->host();
 114     if (Frame* frame = root->document()->frame())
 115         return frame->ownerElement();
 116     return 0;
 117 }
 118
 119 FocusNavigationScope FocusNavigationScope::focusNavigationScopeOf(Node* node)
 120 {
 121     ASSERT(node);
 122     ComposedShadowTreeWalker walker(node, ComposedShadowTreeWalker::DoNotCrossUpperBoundary);
 123     Node* root = node;
 124     while (walker.get()) {
 125         root = walker.get();
 126         walker.parent();
 127     }
 128     // The result is not always a ShadowRoot nor a DocumentNode since
 129     // a starting node is in an orphaned tree in composed shadow tree.
 130     return FocusNavigationScope(root->treeScope());
 131 }
 132
 133 FocusNavigationScope FocusNavigationScope::focusNavigationScopeOwnedByShadowHost(Node* node)
 134 {
 135     ASSERT(isShadowHost(node));
 136     return FocusNavigationScope(toElement(node)->shadow()->youngestShadowRoot());
 137 }
 138
 139 FocusNavigationScope FocusNavigationScope::focusNavigationScopeOwnedByIFrame(HTMLFrameOwnerElement* frame)
 140 {
 141     ASSERT(frame && frame->contentFrame());
 142     return FocusNavigationScope(frame->contentFrame()->document());
 143 }
 144
 145 static inline void dispatchEventsOnWindowAndFocusedNode(Document* document, bool focused)
 146 {
 147     // If we have a focused node we should dispatch blur on it before we blur the window.
 148     // If we have a focused node we should dispatch focus on it after we focus the window.
 149     // https://bugs.webkit.org/show_bug.cgi?id=27105
 150
 151     // Do not fire events while modal dialogs are up.  See https://bugs.webkit.org/show_bug.cgi?id=33962
 152     if (Page* page = document->page()) {
 153         if (page->defersLoading())
 154             return;
 155     }
 156
 157     if (!focused && document->focusedNode())
 158         document->focusedNode()->dispatchBlurEvent(0);
 159     document->dispatchWindowEvent(Event::create(focused ? eventNames().focusEvent : eventNames().blurEvent, false, false));
 160     if (focused && document->focusedNode())
 161         document->focusedNode()->dispatchFocusEvent(0);
 162 }
 163
 164 static inline bool hasCustomFocusLogic(Node* node)
 165 {
 166     return node->hasTagName(inputTag) || node->hasTagName(textareaTag) || node->hasTagName(videoTag) || node->hasTagName(audioTag);
 167 }
 168
 169 static inline bool isNonFocusableShadowHost(Node* node, KeyboardEvent* event)
 170 {
 171     ASSERT(node);
 172     return !node->isKeyboardFocusable(event) && isShadowHost(node) && !hasCustomFocusLogic(node);
 173 }
 174
 175 static inline bool isFocusableShadowHost(Node* node, KeyboardEvent* event)
 176 {
 177     ASSERT(node);
 178     return node->isKeyboardFocusable(event) && isShadowHost(node) && !hasCustomFocusLogic(node);
 179 }
 180
 181 static inline int adjustedTabIndex(Node* node, KeyboardEvent* event)
 182 {
 183     ASSERT(node);
 184     return isNonFocusableShadowHost(node, event) ? 0 : node->tabIndex();
 185 }
 186
 187 static inline bool shouldVisit(Node* node, KeyboardEvent* event)
 188 {
 189     ASSERT(node);
 190     return node->isKeyboardFocusable(event) || isNonFocusableShadowHost(node, event);
 191 }
 192
 193 FocusController::FocusController(Page* page)
 194     : m_page(page)
 195     , m_isActive(false)
 196     , m_isFocused(false)
 197     , m_isChangingFocusedFrame(false)
 198     , m_containingWindowIsVisible(false)
 199 {
 200 }
 201
 202 PassOwnPtr<FocusController> FocusController::create(Page* page)
 203 {
 204     return adoptPtr(new FocusController(page));
 205 }
 206
 207 void FocusController::setFocusedFrame(PassRefPtr<Frame> frame)
 208 {
 209     ASSERT(!frame || frame->page() == m_page);
 210     if (m_focusedFrame == frame || m_isChangingFocusedFrame)
 211         return;
 212
 213     m_isChangingFocusedFrame = true;
 214
 215     RefPtr<Frame> oldFrame = m_focusedFrame;
 216     RefPtr<Frame> newFrame = frame;
 217
 218     m_focusedFrame = newFrame;
 219
 220     // Now that the frame is updated, fire events and update the selection focused states of both frames.
 221     if (oldFrame && oldFrame->view()) {
 222         oldFrame->selection()->setFocused(false);
 223         oldFrame->document()->dispatchWindowEvent(Event::create(eventNames().blurEvent, false, false));
 224     }
 225
 226     if (newFrame && newFrame->view() && isFocused()) {
 227         newFrame->selection()->setFocused(true);
 228         newFrame->document()->dispatchWindowEvent(Event::create(eventNames().focusEvent, false, false));
 229     }
 230
 231     m_page->chrome()->focusedFrameChanged(newFrame.get());
 232
 233     m_isChangingFocusedFrame = false;
 234 }
 235
 236 Frame* FocusController::focusedOrMainFrame() const
 237 {
 238     if (Frame* frame = focusedFrame())
 239         return frame;
 240     return m_page->mainFrame();
 241 }
 242
 243 void FocusController::setFocused(bool focused)
 244 {
 245     if (isFocused() == focused)
 246         return;
 247
 248     m_isFocused = focused;
 249
 250     if (!m_isFocused)
 251         focusedOrMainFrame()->eventHandler()->stopAutoscrollTimer();
 252
 253     if (!m_focusedFrame)
 254         setFocusedFrame(m_page->mainFrame());
 255
 256     if (m_focusedFrame->view()) {
 257         m_focusedFrame->selection()->setFocused(focused);
 258         dispatchEventsOnWindowAndFocusedNode(m_focusedFrame->document(), focused);
 259     }
 260 }
 261
 262 Node* FocusController::findFocusableNodeDecendingDownIntoFrameDocument(FocusDirection direction, Node* node, KeyboardEvent* event)
 263 {
 264     // The node we found might be a HTMLFrameOwnerElement, so descend down the tree until we find either:
 265     // 1) a focusable node, or
 266     // 2) the deepest-nested HTMLFrameOwnerElement.
 267     while (node && node->isFrameOwnerElement()) {
 268         HTMLFrameOwnerElement* owner = static_cast<HTMLFrameOwnerElement*>(node);
 269         if (!owner->contentFrame())
 270             break;
 271         Node* foundNode = findFocusableNode(direction, FocusNavigationScope::focusNavigationScopeOwnedByIFrame(owner), 0, event);
 272         if (!foundNode)
 273             break;
 274         ASSERT(node != foundNode);
 275         node = foundNode;
 276     }
 277     return node;
 278 }
 279
 280 bool FocusController::setInitialFocus(FocusDirection direction, KeyboardEvent* event)
 281 {
 282     bool didAdvanceFocus = advanceFocus(direction, event, true);
 283
 284     // If focus is being set initially, accessibility needs to be informed that system focus has moved
 285     // into the web area again, even if focus did not change within WebCore. PostNotification is called instead
 286     // of handleFocusedUIElementChanged, because this will send the notification even if the element is the same.
 287     if (AXObjectCache::accessibilityEnabled())
 288         focusedOrMainFrame()->document()->axObjectCache()->postNotification(focusedOrMainFrame()->document()->renderer(), AXObjectCache::AXFocusedUIElementChanged, true);
 289
 290     return didAdvanceFocus;
 291 }
 292
 293 bool FocusController::advanceFocus(FocusDirection direction, KeyboardEvent* event, bool initialFocus)
 294 {
 295     switch (direction) {
 296     case FocusDirectionForward:
 297     case FocusDirectionBackward:
 298         return advanceFocusInDocumentOrder(direction, event, initialFocus);
 299     case FocusDirectionLeft:
 300     case FocusDirectionRight:
 301     case FocusDirectionUp:
 302     case FocusDirectionDown:
 303         return advanceFocusDirectionally(direction, event);
 304     default:
 305         ASSERT_NOT_REACHED();
 306     }
 307
 308     return false;
 309 }
 310
 311 bool FocusController::advanceFocusInDocumentOrder(FocusDirection direction, KeyboardEvent* event, bool initialFocus)
 312 {
 313     Frame* frame = focusedOrMainFrame();
 314     ASSERT(frame);
 315     Document* document = frame->document();
 316
 317     Node* currentNode = document->focusedNode();
 318     // FIXME: Not quite correct when it comes to focus transitions leaving/entering the WebView itself
 319     bool caretBrowsing = frame->settings() && frame->settings()->caretBrowsingEnabled();
 320
 321     if (caretBrowsing && !currentNode)
 322         currentNode = frame->selection()->start().deprecatedNode();
 323
 324     document->updateLayoutIgnorePendingStylesheets();
 325
 326     RefPtr<Node> node = findFocusableNodeAcrossFocusScope(direction, FocusNavigationScope::focusNavigationScopeOf(currentNode ? currentNode : document), currentNode, event);
 327
 328     if (!node) {
 329         // We didn't find a node to focus, so we should try to pass focus to Chrome.
 330         if (!initialFocus && m_page->chrome()->canTakeFocus(direction)) {
 331             document->setFocusedNode(0);
 332             setFocusedFrame(0);
 333             m_page->chrome()->takeFocus(direction);
 334             return true;
 335         }
 336
 337         // Chrome doesn't want focus, so we should wrap focus.
 338         node = findFocusableNodeRecursively(direction, FocusNavigationScope::focusNavigationScopeOf(m_page->mainFrame()->document()), 0, event);
 339         node = findFocusableNodeDecendingDownIntoFrameDocument(direction, node.get(), event);
 340
 341         if (!node)
 342             return false;
 343     }
 344
 345     ASSERT(node);
 346
 347     if (node == document->focusedNode())
 348         // Focus wrapped around to the same node.
 349         return true;
 350
 351     if (!node->isElementNode())
 352         // FIXME: May need a way to focus a document here.
 353         return false;
 354
 355     if (node->isFrameOwnerElement()) {
 356         // We focus frames rather than frame owners.
 357         // FIXME: We should not focus frames that have no scrollbars, as focusing them isn't useful to the user.
 358         HTMLFrameOwnerElement* owner = static_cast<HTMLFrameOwnerElement*>(node.get());
 359         if (!owner->contentFrame())
 360             return false;
 361
 362         document->setFocusedNode(0);
 363         setFocusedFrame(owner->contentFrame());
 364         return true;
 365     }
 366
 367     // FIXME: It would be nice to just be able to call setFocusedNode(node) here, but we can't do
 368     // that because some elements (e.g. HTMLInputElement and HTMLTextAreaElement) do extra work in
 369     // their focus() methods.
 370
 371     Document* newDocument = node->document();
 372
 373     if (newDocument != document)
 374         // Focus is going away from this document, so clear the focused node.
 375         document->setFocusedNode(0);
 376
 377     if (newDocument)
 378         setFocusedFrame(newDocument->frame());
 379
 380     if (caretBrowsing) {
 381         Position position = firstPositionInOrBeforeNode(node.get());
 382         VisibleSelection newSelection(position, position, DOWNSTREAM);
 383         if (frame->selection()->shouldChangeSelection(newSelection))
 384             frame->selection()->setSelection(newSelection);
 385     }
 386
 387     static_cast<Element*>(node.get())->focus(false);
 388     return true;
 389 }
 390
 391 Node* FocusController::findFocusableNodeAcrossFocusScope(FocusDirection direction, FocusNavigationScope scope, Node* currentNode, KeyboardEvent* event)
 392 {
 393     ASSERT(!currentNode || !isNonFocusableShadowHost(currentNode, event));
 394     Node* found;
 395     if (currentNode && direction == FocusDirectionForward && isFocusableShadowHost(currentNode, event)) {
 396         Node* foundInInnerFocusScope = findFocusableNodeRecursively(direction, FocusNavigationScope::focusNavigationScopeOwnedByShadowHost(currentNode), 0, event);
 397         found = foundInInnerFocusScope ? foundInInnerFocusScope : findFocusableNodeRecursively(direction, scope, currentNode, event);
 398     } else
 399         found = findFocusableNodeRecursively(direction, scope, currentNode, event);
 400
 401     // If there's no focusable node to advance to, move up the focus scopes until we find one.
 402     while (!found) {
 403         Node* owner = scope.owner();
 404         if (!owner)
 405             break;
 406         scope = FocusNavigationScope::focusNavigationScopeOf(owner);
 407         if (direction == FocusDirectionBackward && isFocusableShadowHost(owner, event)) {
 408             found = owner;
 409             break;
 410         }
 411         found = findFocusableNodeRecursively(direction, scope, owner, event);
 412     }
 413     found = findFocusableNodeDecendingDownIntoFrameDocument(direction, found, event);
 414     return found;
 415 }
 416
 417 Node* FocusController::findFocusableNodeRecursively(FocusDirection direction, FocusNavigationScope scope, Node* start, KeyboardEvent* event)
 418 {
 419     // Starting node is exclusive.
 420     Node* found = findFocusableNode(direction, scope, start, event);
 421     if (!found)
 422         return 0;
 423     if (direction == FocusDirectionForward) {
 424         if (!isNonFocusableShadowHost(found, event))
 425             return found;
 426         Node* foundInInnerFocusScope = findFocusableNodeRecursively(direction, FocusNavigationScope::focusNavigationScopeOwnedByShadowHost(found), 0, event);
 427         return foundInInnerFocusScope ? foundInInnerFocusScope : findFocusableNodeRecursively(direction, scope, found, event);
 428     }
 429     ASSERT(direction == FocusDirectionBackward);
 430     if (isFocusableShadowHost(found, event)) {
 431         Node* foundInInnerFocusScope = findFocusableNodeRecursively(direction, FocusNavigationScope::focusNavigationScopeOwnedByShadowHost(found), 0, event);
 432         return foundInInnerFocusScope ? foundInInnerFocusScope : found;
 433     }
 434     if (isNonFocusableShadowHost(found, event)) {
 435         Node* foundInInnerFocusScope = findFocusableNodeRecursively(direction, FocusNavigationScope::focusNavigationScopeOwnedByShadowHost(found), 0, event);
 436         return foundInInnerFocusScope ? foundInInnerFocusScope :findFocusableNodeRecursively(direction, scope, found, event);
 437     }
 438     return found;
 439 }
 440
 441 Node* FocusController::findFocusableNode(FocusDirection direction, FocusNavigationScope scope, Node* node, KeyboardEvent* event)
 442 {
 443     return (direction == FocusDirectionForward)
 444         ? nextFocusableNode(scope, node, event)
 445         : previousFocusableNode(scope, node, event);
 446 }
 447
 448 Node* FocusController::findNodeWithExactTabIndex(Node* start, int tabIndex, KeyboardEvent* event, FocusDirection direction)
 449 {
 450     // Search is inclusive of start
 451     for (ComposedShadowTreeWalker walker = walkerFrom(start); walker.get(); direction == FocusDirectionForward ? walker.next() : walker.previous()) {
 452         if (shouldVisit(walker.get(), event) && adjustedTabIndex(walker.get(), event) == tabIndex)
 453             return walker.get();
 454     }
 455     return 0;
 456 }
 457
 458 static Node* nextNodeWithGreaterTabIndex(Node* start, int tabIndex, KeyboardEvent* event)
 459 {
 460     // Search is inclusive of start
 461     int winningTabIndex = std::numeric_limits<short>::max() + 1;
 462     Node* winner = 0;
 463     for (ComposedShadowTreeWalker walker = walkerFrom(start); walker.get(); walker.next()) {
 464         Node* node = walker.get();
 465         if (shouldVisit(node, event) && node->tabIndex() > tabIndex && node->tabIndex() < winningTabIndex) {
 466             winner = node;
 467             winningTabIndex = node->tabIndex();
 468         }
 469     }
 470
 471     return winner;
 472 }
 473
 474 static Node* previousNodeWithLowerTabIndex(Node* start, int tabIndex, KeyboardEvent* event)
 475 {
 476     // Search is inclusive of start
 477     int winningTabIndex = 0;
 478     Node* winner = 0;
 479     for (ComposedShadowTreeWalker walker = walkerFrom(start); walker.get(); walker.previous()) {
 480         Node* node = walker.get();
 481         int currentTabIndex = adjustedTabIndex(node, event);
 482         if ((shouldVisit(node, event) || isNonFocusableShadowHost(node, event)) && currentTabIndex < tabIndex && currentTabIndex > winningTabIndex) {
 483             winner = node;
 484             winningTabIndex = currentTabIndex;
 485         }
 486     }
 487     return winner;
 488 }
 489
 490 Node* FocusController::nextFocusableNode(FocusNavigationScope scope, Node* start, KeyboardEvent* event)
 491 {
 492     if (start) {
 493         int tabIndex = adjustedTabIndex(start, event);
 494         // If a node is excluded from the normal tabbing cycle, the next focusable node is determined by tree order
 495         if (tabIndex < 0) {
 496             for (ComposedShadowTreeWalker walker = walkerFromNext(start); walker.get(); walker.next()) {
 497                 if (shouldVisit(walker.get(), event) && adjustedTabIndex(walker.get(), event) >= 0)
 498                     return walker.get();
 499             }
 500         }
 501
 502         // First try to find a node with the same tabindex as start that comes after start in the scope.
 503         if (Node* winner = findNodeWithExactTabIndex(nextNode(start), tabIndex, event, FocusDirectionForward))
 504             return winner;
 505
 506         if (!tabIndex)
 507             // We've reached the last node in the document with a tabindex of 0. This is the end of the tabbing order.
 508             return 0;
 509     }
 510
 511     // Look for the first node in the scope that:
 512     // 1) has the lowest tabindex that is higher than start's tabindex (or 0, if start is null), and
 513     // 2) comes first in the scope, if there's a tie.
 514     if (Node* winner = nextNodeWithGreaterTabIndex(scope.rootNode(), start ? adjustedTabIndex(start, event) : 0, event))
 515         return winner;
 516
 517     // There are no nodes with a tabindex greater than start's tabindex,
 518     // so find the first node with a tabindex of 0.
 519     return findNodeWithExactTabIndex(scope.rootNode(), 0, event, FocusDirectionForward);
 520 }
 521
 522 Node* FocusController::previousFocusableNode(FocusNavigationScope scope, Node* start, KeyboardEvent* event)
 523 {
 524     Node* last = 0;
 525     for (ComposedShadowTreeWalker walker = walkerFrom(scope.rootNode()); walker.get(); walker.lastChild())
 526         last = walker.get();
 527     ASSERT(last);
 528
 529     // First try to find the last node in the scope that comes before start and has the same tabindex as start.
 530     // If start is null, find the last node in the scope with a tabindex of 0.
 531     Node* startingNode;
 532     int startingTabIndex;
 533     if (start) {
 534         startingNode = previousNode(start);
 535         startingTabIndex = adjustedTabIndex(start, event);
 536     } else {
 537         startingNode = last;
 538         startingTabIndex = 0;
 539     }
 540
 541     // However, if a node is excluded from the normal tabbing cycle, the previous focusable node is determined by tree order
 542     if (startingTabIndex < 0) {
 543         for (ComposedShadowTreeWalker walker = walkerFrom(startingNode); walker.get(); walker.previous()) {
 544             if (shouldVisit(walker.get(), event) && adjustedTabIndex(walker.get(), event) >= 0)
 545                 return walker.get();
 546         }
 547     }
 548
 549     if (Node* winner = findNodeWithExactTabIndex(startingNode, startingTabIndex, event, FocusDirectionBackward))
 550         return winner;
 551
 552     // There are no nodes before start with the same tabindex as start, so look for a node that:
 553     // 1) has the highest non-zero tabindex (that is less than start's tabindex), and
 554     // 2) comes last in the scope, if there's a tie.
 555     startingTabIndex = (start && startingTabIndex) ? startingTabIndex : std::numeric_limits<short>::max();
 556     return previousNodeWithLowerTabIndex(last, startingTabIndex, event);
 557 }
 558
 559 static bool relinquishesEditingFocus(Node *node)
 560 {
 561     ASSERT(node);
 562     ASSERT(node->rendererIsEditable());
 563
 564     Node* root = node->rootEditableElement();
 565     Frame* frame = node->document()->frame();
 566     if (!frame || !root)
 567         return false;
 568
 569     return frame->editor()->shouldEndEditing(rangeOfContents(root).get());
 570 }
 571
 572 static void clearSelectionIfNeeded(Frame* oldFocusedFrame, Frame* newFocusedFrame, Node* newFocusedNode)
 573 {
 574     if (!oldFocusedFrame || !newFocusedFrame)
 575         return;
 576
 577     if (oldFocusedFrame->document() != newFocusedFrame->document())
 578         return;
 579
 580     FrameSelection* s = oldFocusedFrame->selection();
 581     if (s->isNone())
 582         return;
 583
 584     bool caretBrowsing = oldFocusedFrame->settings()->caretBrowsingEnabled();
 585     if (caretBrowsing)
 586         return;
 587
 588     Node* selectionStartNode = s->selection().start().deprecatedNode();
 589     if (selectionStartNode == newFocusedNode || selectionStartNode->isDescendantOf(newFocusedNode) || selectionStartNode->shadowAncestorNode() == newFocusedNode)
 590         return;
 591
 592     if (Node* mousePressNode = newFocusedFrame->eventHandler()->mousePressNode()) {
 593         if (mousePressNode->renderer() && !mousePressNode->canStartSelection()) {
 594             // Don't clear the selection for contentEditable elements, but do clear it for input and textarea. See bug 38696.
 595             Node * root = s->rootEditableElement();
 596             if (!root)
 597                 return;
 598
 599             if (Node* shadowAncestorNode = root->shadowAncestorNode()) {
 600                 if (!shadowAncestorNode->hasTagName(inputTag) && !shadowAncestorNode->hasTagName(textareaTag))
 601                     return;
 602             }
 603         }
 604     }
 605
 606     s->clear();
 607 }
 608
 609 bool FocusController::setFocusedNode(Node* node, PassRefPtr<Frame> newFocusedFrame)
 610 {
 611     RefPtr<Frame> oldFocusedFrame = focusedFrame();
 612     RefPtr<Document> oldDocument = oldFocusedFrame ? oldFocusedFrame->document() : 0;
 613
 614     Node* oldFocusedNode = oldDocument ? oldDocument->focusedNode() : 0;
 615 #if ENABLE(TIZEN_ISF_PORT)
 616     // A variable to remember a desingMode state before focusing/bluring will change it.
 617     bool oldDesignMode = false;
 618 #endif
 619
 620     if (oldFocusedNode == node)
 621         return true;
 622
 623     // FIXME: Might want to disable this check for caretBrowsing
 624     if (oldFocusedNode && oldFocusedNode->isRootEditableElement() && !relinquishesEditingFocus(oldFocusedNode))
 625         return false;
 626
 627     m_page->editorClient()->willSetInputMethodState();
 628
 629     clearSelectionIfNeeded(oldFocusedFrame.get(), newFocusedFrame.get(), node);
 630
 631     if (!node) {
 632         if (oldDocument)
 633             oldDocument->setFocusedNode(0);
 634         m_page->editorClient()->setInputMethodState(false);
 635         return true;
 636     }
 637
 638     RefPtr<Document> newDocument = node->document();
 639
 640     if (newDocument && newDocument->focusedNode() == node) {
 641         m_page->editorClient()->setInputMethodState(node->shouldUseInputMethod());
 642         return true;
 643     }
 644
 645     if (oldDocument && oldDocument != newDocument)
 646         oldDocument->setFocusedNode(0);
 647
 648     setFocusedFrame(newFocusedFrame);
 649
 650     // Setting the focused node can result in losing our last reft to node when JS event handlers fire.
 651     RefPtr<Node> protect = node;
 652     if (newDocument) {
 653 #if ENABLE(TIZEN_ISF_PORT)
 654         // Setting oldDesingMode befere focus/blur events.
 655         oldDesignMode = newDocument->inDesignMode();
 656 #endif
 657         bool successfullyFocused = newDocument->setFocusedNode(node);
 658         if (!successfullyFocused)
 659             return false;
 660     }
 661
 662 #if ENABLE(TIZEN_ISF_PORT)
 663     // If designMode during focusing/bluring was changed from true to false we do not allow to change
 664     // input method state.
 665     if (oldDesignMode && !newDocument->inDesignMode() && !node->shouldUseInputMethod())
 666         return true;
 667 #endif
 668
 669     if (newDocument->focusedNode() == node)
 670         m_page->editorClient()->setInputMethodState(node->shouldUseInputMethod());
 671
 672     return true;
 673 }
 674
 675 void FocusController::setActive(bool active)
 676 {
 677     if (m_isActive == active)
 678         return;
 679
 680     m_isActive = active;
 681
 682     if (FrameView* view = m_page->mainFrame()->view()) {
 683         if (!view->platformWidget()) {
 684             view->updateLayoutAndStyleIfNeededRecursive();
 685             view->updateControlTints();
 686         }
 687     }
 688
 689     focusedOrMainFrame()->selection()->pageActivationChanged();
 690
 691     if (m_focusedFrame && isFocused())
 692         dispatchEventsOnWindowAndFocusedNode(m_focusedFrame->document(), active);
 693 }
 694
 695 static void contentAreaDidShowOrHide(ScrollableArea* scrollableArea, bool didShow)
 696 {
 697     if (didShow)
 698         scrollableArea->contentAreaDidShow();
 699     else
 700         scrollableArea->contentAreaDidHide();
 701 }
 702
 703 void FocusController::setContainingWindowIsVisible(bool containingWindowIsVisible)
 704 {
 705     if (m_containingWindowIsVisible == containingWindowIsVisible)
 706         return;
 707
 708     m_containingWindowIsVisible = containingWindowIsVisible;
 709
 710     FrameView* view = m_page->mainFrame()->view();
 711     if (!view)
 712         return;
 713
 714     contentAreaDidShowOrHide(view, containingWindowIsVisible);
 715
 716     for (Frame* frame = m_page->mainFrame(); frame; frame = frame->tree()->traverseNext()) {
 717         FrameView* frameView = frame->view();
 718         if (!frameView)
 719             continue;
 720
 721         const HashSet<ScrollableArea*>* scrollableAreas = frameView->scrollableAreas();
 722         if (!scrollableAreas)
 723             continue;
 724
 725         for (HashSet<ScrollableArea*>::const_iterator it = scrollableAreas->begin(), end = scrollableAreas->end(); it != end; ++it) {
 726             ScrollableArea* scrollableArea = *it;
 727             ASSERT(scrollableArea->isOnActivePage());
 728
 729             contentAreaDidShowOrHide(scrollableArea, containingWindowIsVisible);
 730         }
 731     }
 732 }
 733
 734 static void updateFocusCandidateIfNeeded(FocusDirection direction, const FocusCandidate& current, FocusCandidate& candidate, FocusCandidate& closest)
 735 {
 736     ASSERT(candidate.visibleNode->isElementNode());
 737     ASSERT(candidate.visibleNode->renderer());
 738
 739     // Ignore iframes that don't have a src attribute
 740     if (frameOwnerElement(candidate) && (!frameOwnerElement(candidate)->contentFrame() || candidate.rect.isEmpty()))
 741         return;
 742
 743     // Ignore off screen child nodes of containers that do not scroll (overflow:hidden)
 744     if (candidate.isOffscreen && !canBeScrolledIntoView(direction, candidate))
 745         return;
 746
 747     distanceDataForNode(direction, current, candidate);
 748     if (candidate.distance == maxDistance())
 749         return;
 750
 751     if (candidate.isOffscreenAfterScrolling && candidate.alignment < Full)
 752         return;
 753
 754     if (closest.isNull()) {
 755         closest = candidate;
 756         return;
 757     }
 758
 759     LayoutRect intersectionRect = intersection(candidate.rect, closest.rect);
 760     if (!intersectionRect.isEmpty() && !areElementsOnSameLine(closest, candidate)) {
 761         // If 2 nodes are intersecting, do hit test to find which node in on top.
 762         LayoutUnit x = intersectionRect.x() + intersectionRect.width() / 2;
 763         LayoutUnit y = intersectionRect.y() + intersectionRect.height() / 2;
 764         HitTestResult result = candidate.visibleNode->document()->page()->mainFrame()->eventHandler()->hitTestResultAtPoint(IntPoint(x, y), false, true);
 765         if (candidate.visibleNode->contains(result.innerNode())) {
 766             closest = candidate;
 767             return;
 768         }
 769         if (closest.visibleNode->contains(result.innerNode()))
 770             return;
 771     }
 772
 773     if (candidate.alignment == closest.alignment) {
 774         if (candidate.distance < closest.distance)
 775             closest = candidate;
 776         return;
 777     }
 778
 779     if (candidate.alignment > closest.alignment)
 780         closest = candidate;
 781 }
 782
 783 void FocusController::findFocusCandidateInContainer(Node* container, const LayoutRect& startingRect, FocusDirection direction, KeyboardEvent* event, FocusCandidate& closest)
 784 {
 785     ASSERT(container);
 786     Node* focusedNode = (focusedFrame() && focusedFrame()->document()) ? focusedFrame()->document()->focusedNode() : 0;
 787
 788     Node* node = container->firstChild();
 789     FocusCandidate current;
 790     current.rect = startingRect;
 791     current.focusableNode = focusedNode;
 792     current.visibleNode = focusedNode;
 793
 794     for (; node; node = (node->isFrameOwnerElement() || canScrollInDirection(node, direction)) ? node->traverseNextSibling(container) : node->traverseNextNode(container)) {
 795         if (node == focusedNode)
 796             continue;
 797
 798         if (!node->isElementNode())
 799             continue;
 800
 801         if (!node->isKeyboardFocusable(event) && !node->isFrameOwnerElement() && !canScrollInDirection(node, direction))
 802             continue;
 803
 804         FocusCandidate candidate = FocusCandidate(node, direction);
 805         if (candidate.isNull())
 806             continue;
 807
 808         candidate.enclosingScrollableBox = container;
 809         updateFocusCandidateIfNeeded(direction, current, candidate, closest);
 810     }
 811 }
 812
 813 bool FocusController::advanceFocusDirectionallyInContainer(Node* container, const LayoutRect& startingRect, FocusDirection direction, KeyboardEvent* event)
 814 {
 815     if (!container || !container->document())
 816         return false;
 817
 818     LayoutRect newStartingRect = startingRect;
 819
 820     if (startingRect.isEmpty())
 821         newStartingRect = virtualRectForDirection(direction, nodeRectInAbsoluteCoordinates(container));
 822
 823     // Find the closest node within current container in the direction of the navigation.
 824     FocusCandidate focusCandidate;
 825     findFocusCandidateInContainer(container, newStartingRect, direction, event, focusCandidate);
 826
 827     if (focusCandidate.isNull()) {
 828         // Nothing to focus, scroll if possible.
 829         // NOTE: If no scrolling is performed (i.e. scrollInDirection returns false), the
 830         // spatial navigation algorithm will skip this container.
 831         return scrollInDirection(container, direction);
 832     }
 833
 834     if (HTMLFrameOwnerElement* frameElement = frameOwnerElement(focusCandidate)) {
 835         // If we have an iframe without the src attribute, it will not have a contentFrame().
 836         // We ASSERT here to make sure that
 837         // updateFocusCandidateIfNeeded() will never consider such an iframe as a candidate.
 838         ASSERT(frameElement->contentFrame());
 839
 840         if (focusCandidate.isOffscreenAfterScrolling) {
 841             scrollInDirection(focusCandidate.visibleNode->document(), direction);
 842             return true;
 843         }
 844         // Navigate into a new frame.
 845         LayoutRect rect;
 846         Node* focusedNode = focusedOrMainFrame()->document()->focusedNode();
 847         if (focusedNode && !hasOffscreenRect(focusedNode))
 848             rect = nodeRectInAbsoluteCoordinates(focusedNode, true /* ignore border */);
 849         frameElement->contentFrame()->document()->updateLayoutIgnorePendingStylesheets();
 850         if (!advanceFocusDirectionallyInContainer(frameElement->contentFrame()->document(), rect, direction, event)) {
 851             // The new frame had nothing interesting, need to find another candidate.
 852             return advanceFocusDirectionallyInContainer(container, nodeRectInAbsoluteCoordinates(focusCandidate.visibleNode, true), direction, event);
 853         }
 854         return true;
 855     }
 856
 857     if (canScrollInDirection(focusCandidate.visibleNode, direction)) {
 858         if (focusCandidate.isOffscreenAfterScrolling) {
 859             scrollInDirection(focusCandidate.visibleNode, direction);
 860             return true;
 861         }
 862         // Navigate into a new scrollable container.
 863         LayoutRect startingRect;
 864         Node* focusedNode = focusedOrMainFrame()->document()->focusedNode();
 865         if (focusedNode && !hasOffscreenRect(focusedNode))
 866             startingRect = nodeRectInAbsoluteCoordinates(focusedNode, true);
 867         return advanceFocusDirectionallyInContainer(focusCandidate.visibleNode, startingRect, direction, event);
 868     }
 869     if (focusCandidate.isOffscreenAfterScrolling) {
 870         Node* container = focusCandidate.enclosingScrollableBox;
 871         scrollInDirection(container, direction);
 872         return true;
 873     }
 874
 875     // We found a new focus node, navigate to it.
 876     Element* element = toElement(focusCandidate.focusableNode);
 877     ASSERT(element);
 878
 879     element->focus(false);
 880     return true;
 881 }
 882
 883 bool FocusController::advanceFocusDirectionally(FocusDirection direction, KeyboardEvent* event)
 884 {
 885     Frame* curFrame = focusedOrMainFrame();
 886     ASSERT(curFrame);
 887
 888     Document* focusedDocument = curFrame->document();
 889     if (!focusedDocument)
 890         return false;
 891
 892     Node* focusedNode = focusedDocument->focusedNode();
 893     Node* container = focusedDocument;
 894
 895     if (container->isDocumentNode())
 896         static_cast<Document*>(container)->updateLayoutIgnorePendingStylesheets();
 897
 898     // Figure out the starting rect.
 899     LayoutRect startingRect;
 900     if (focusedNode) {
 901         if (!hasOffscreenRect(focusedNode)) {
 902             container = scrollableEnclosingBoxOrParentFrameForNodeInDirection(direction, focusedNode);
 903             startingRect = nodeRectInAbsoluteCoordinates(focusedNode, true /* ignore border */);
 904         } else if (focusedNode->hasTagName(areaTag)) {
 905             HTMLAreaElement* area = static_cast<HTMLAreaElement*>(focusedNode);
 906             container = scrollableEnclosingBoxOrParentFrameForNodeInDirection(direction, area->imageElement());
 907             startingRect = virtualRectForAreaElementAndDirection(area, direction);
 908         }
 909     }
 910
 911     bool consumed = false;
 912     do {
 913         consumed = advanceFocusDirectionallyInContainer(container, startingRect, direction, event);
 914         startingRect = nodeRectInAbsoluteCoordinates(container, true /* ignore border */);
 915         container = scrollableEnclosingBoxOrParentFrameForNodeInDirection(direction, container);
 916         if (container && container->isDocumentNode())
 917             static_cast<Document*>(container)->updateLayoutIgnorePendingStylesheets();
 918     } while (!consumed && container);
 919
 920     return consumed;
 921 }
 922
 923 } // namespace WebCore