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      1 /*
      2  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef FocusController_h
     27 #define FocusController_h
     28 
     29 #include "core/page/FocusType.h"
     30 #include "platform/geometry/LayoutRect.h"
     31 #include "platform/heap/Handle.h"
     32 #include "wtf/Forward.h"
     33 #include "wtf/Noncopyable.h"
     34 #include "wtf/RefPtr.h"
     35 
     36 namespace WebCore {
     37 
     38 struct FocusCandidate;
     39 class Document;
     40 class Element;
     41 class Frame;
     42 class HTMLFrameOwnerElement;
     43 class HTMLShadowElement;
     44 class IntRect;
     45 class KeyboardEvent;
     46 class Node;
     47 class Page;
     48 class TreeScope;
     49 
     50 class FocusNavigationScope {
     51     STACK_ALLOCATED();
     52 public:
     53     Node* rootNode() const;
     54     Element* owner() const;
     55     static FocusNavigationScope focusNavigationScopeOf(Node*);
     56     static FocusNavigationScope ownedByNonFocusableFocusScopeOwner(Node*);
     57     static FocusNavigationScope ownedByShadowHost(Node*);
     58     static FocusNavigationScope ownedByShadowInsertionPoint(HTMLShadowElement*);
     59     static FocusNavigationScope ownedByIFrame(HTMLFrameOwnerElement*);
     60 
     61 private:
     62     explicit FocusNavigationScope(TreeScope*);
     63     RawPtrWillBeMember<TreeScope> m_rootTreeScope;
     64 };
     65 
     66 class FocusController {
     67     WTF_MAKE_NONCOPYABLE(FocusController); WTF_MAKE_FAST_ALLOCATED;
     68 public:
     69     static PassOwnPtr<FocusController> create(Page*);
     70 
     71     void setFocusedFrame(PassRefPtr<Frame>);
     72     void focusDocumentView(PassRefPtr<Frame>);
     73     Frame* focusedFrame() const { return m_focusedFrame.get(); }
     74     Frame* focusedOrMainFrame() const;
     75 
     76     bool setInitialFocus(FocusType);
     77     bool advanceFocus(FocusType type) { return advanceFocus(type, false); }
     78 
     79     bool setFocusedElement(Element*, PassRefPtr<Frame>, FocusType = FocusTypeNone);
     80 
     81     void setActive(bool);
     82     bool isActive() const { return m_isActive; }
     83 
     84     void setFocused(bool);
     85     bool isFocused() const { return m_isFocused; }
     86 
     87 private:
     88     explicit FocusController(Page*);
     89 
     90     bool advanceFocus(FocusType, bool initialFocus);
     91     bool advanceFocusDirectionally(FocusType);
     92     bool advanceFocusInDocumentOrder(FocusType, bool initialFocus);
     93 
     94     Node* findFocusableNodeAcrossFocusScope(FocusType, FocusNavigationScope startScope, Node* start);
     95     Node* findFocusableNodeRecursively(FocusType, FocusNavigationScope, Node* start);
     96     Node* findFocusableNodeDecendingDownIntoFrameDocument(FocusType, Node*);
     97 
     98     // Searches through the given tree scope, starting from start node, for the next/previous selectable element that comes after/before start node.
     99     // The order followed is as specified in section 17.11.1 of the HTML4 spec, which is elements with tab indexes
    100     // first (from lowest to highest), and then elements without tab indexes (in document order).
    101     //
    102     // @param start The node from which to start searching. The node after this will be focused. May be null.
    103     //
    104     // @return The focus node that comes after/before start node.
    105     //
    106     // See http://www.w3.org/TR/html4/interact/forms.html#h-17.11.1
    107     inline Node* findFocusableNode(FocusType, FocusNavigationScope, Node* start);
    108 
    109     Node* nextFocusableNode(FocusNavigationScope, Node* start);
    110     Node* previousFocusableNode(FocusNavigationScope, Node* start);
    111 
    112     Node* findNodeWithExactTabIndex(Node* start, int tabIndex, FocusType);
    113 
    114     bool advanceFocusDirectionallyInContainer(Node* container, const LayoutRect& startingRect, FocusType);
    115     void findFocusCandidateInContainer(Node& container, const LayoutRect& startingRect, FocusType, FocusCandidate& closest);
    116 
    117     Page* m_page;
    118     RefPtr<Frame> m_focusedFrame;
    119     bool m_isActive;
    120     bool m_isFocused;
    121     bool m_isChangingFocusedFrame;
    122 };
    123 
    124 } // namespace WebCore
    125 
    126 #endif // FocusController_h
    127