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
36namespace blink {
37
38struct FocusCandidate;
39class Element;
40class Frame;
41class HTMLFrameOwnerElement;
42class HTMLShadowElement;
43class Node;
44class Page;
45class TreeScope;
46
47class FocusNavigationScope {
48    STACK_ALLOCATED();
49public:
50    Node* rootNode() const;
51    Element* owner() const;
52    static FocusNavigationScope focusNavigationScopeOf(Node*);
53    static FocusNavigationScope ownedByNonFocusableFocusScopeOwner(Node*);
54    static FocusNavigationScope ownedByShadowHost(Node*);
55    static FocusNavigationScope ownedByShadowInsertionPoint(HTMLShadowElement*);
56    static FocusNavigationScope ownedByIFrame(HTMLFrameOwnerElement*);
57
58private:
59    explicit FocusNavigationScope(TreeScope*);
60    RawPtrWillBeMember<TreeScope> m_rootTreeScope;
61};
62
63class FocusController FINAL : public NoBaseWillBeGarbageCollectedFinalized<FocusController> {
64    WTF_MAKE_NONCOPYABLE(FocusController); WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
65public:
66    static PassOwnPtrWillBeRawPtr<FocusController> create(Page*);
67
68    void setFocusedFrame(PassRefPtrWillBeRawPtr<Frame>);
69    void focusDocumentView(PassRefPtrWillBeRawPtr<Frame>);
70    Frame* focusedFrame() const { return m_focusedFrame.get(); }
71    Frame* focusedOrMainFrame() const;
72
73    bool setInitialFocus(FocusType);
74    bool advanceFocus(FocusType type) { return advanceFocus(type, false); }
75
76    bool setFocusedElement(Element*, PassRefPtrWillBeRawPtr<Frame>, FocusType = FocusTypeNone);
77
78    void setActive(bool);
79    bool isActive() const { return m_isActive; }
80
81    void setFocused(bool);
82    bool isFocused() const { return m_isFocused; }
83
84    void trace(Visitor*);
85
86private:
87    explicit FocusController(Page*);
88
89    bool advanceFocus(FocusType, bool initialFocus);
90    bool advanceFocusDirectionally(FocusType);
91    bool advanceFocusInDocumentOrder(FocusType, bool initialFocus);
92
93    Node* findFocusableNodeAcrossFocusScope(FocusType, FocusNavigationScope startScope, Node* start);
94    Node* findFocusableNodeRecursively(FocusType, FocusNavigationScope, Node* start);
95    Node* findFocusableNodeDecendingDownIntoFrameDocument(FocusType, Node*);
96
97    // Searches through the given tree scope, starting from start node, for the next/previous selectable element that comes after/before start node.
98    // The order followed is as specified in section 17.11.1 of the HTML4 spec, which is elements with tab indexes
99    // first (from lowest to highest), and then elements without tab indexes (in document order).
100    //
101    // @param start The node from which to start searching. The node after this will be focused. May be null.
102    //
103    // @return The focus node that comes after/before start node.
104    //
105    // See http://www.w3.org/TR/html4/interact/forms.html#h-17.11.1
106    inline Node* findFocusableNode(FocusType, FocusNavigationScope, Node* start);
107
108    Node* nextFocusableNode(FocusNavigationScope, Node* start);
109    Node* previousFocusableNode(FocusNavigationScope, Node* start);
110
111    Node* findNodeWithExactTabIndex(Node* start, int tabIndex, FocusType);
112
113    bool advanceFocusDirectionallyInContainer(Node* container, const LayoutRect& startingRect, FocusType);
114    void findFocusCandidateInContainer(Node& container, const LayoutRect& startingRect, FocusType, FocusCandidate& closest);
115
116    RawPtrWillBeMember<Page> m_page;
117    RefPtrWillBeMember<Frame> m_focusedFrame;
118    bool m_isActive;
119    bool m_isFocused;
120    bool m_isChangingFocusedFrame;
121};
122
123} // namespace blink
124
125#endif // FocusController_h
126