1 /*
2 * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies)
3 * Copyright (C) 2009 Antonio Gomes <tonikitoo@webkit.org>
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public License
16 * along with this library; see the file COPYING.LIB. If not, write to
17 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19 */
20
21 #ifndef SpatialNavigation_h
22 #define SpatialNavigation_h
23
24 #include "core/dom/Node.h"
25 #include "core/html/HTMLFrameOwnerElement.h"
26 #include "core/page/FocusDirection.h"
27 #include "platform/geometry/LayoutRect.h"
28
29 #include <limits>
30
31 namespace WebCore {
32
33 class Element;
34 class Frame;
35 class HTMLAreaElement;
36 class IntRect;
37 class RenderObject;
38
maxDistance()39 inline long long maxDistance()
40 {
41 return std::numeric_limits<long long>::max();
42 }
43
fudgeFactor()44 inline int fudgeFactor()
45 {
46 return 2;
47 }
48
49 bool isSpatialNavigationEnabled(const Frame*);
50
51 // Spatially speaking, two given elements in a web page can be:
52 // 1) Fully aligned: There is a full intersection between the rects, either
53 // vertically or horizontally.
54 //
55 // * Horizontally * Vertically
56 // _
57 // |_| _ _ _ _ _ _
58 // |_|...... _ |_|_|_|_|_|_|
59 // |_| |_| . .
60 // |_|......|_| OR . .
61 // |_| |_| . .
62 // |_|......|_| _ _ _ _
63 // |_| |_|_|_|_|
64 //
65 //
66 // 2) Partially aligned: There is a partial intersection between the rects, either
67 // vertically or horizontally.
68 //
69 // * Horizontally * Vertically
70 // _ _ _ _ _ _
71 // |_| |_|_|_|_|_|
72 // |_|.... _ OR . .
73 // |_| |_| . .
74 // |_|....|_| ._._ _
75 // |_| |_|_|_|
76 // |_|
77 //
78 // 3) Or, otherwise, not aligned at all.
79 //
80 // * Horizontally * Vertically
81 // _ _ _ _ _
82 // |_| |_|_|_|_|
83 // |_| .
84 // |_| .
85 // . OR .
86 // _ . ._ _ _ _ _
87 // |_| |_|_|_|_|_|
88 // |_|
89 // |_|
90 //
91 // "Totally Aligned" elements are preferable candidates to move
92 // focus to over "Partially Aligned" ones, that on its turns are
93 // more preferable than "Not Aligned".
94 enum RectsAlignment {
95 None = 0,
96 Partial,
97 Full
98 };
99
100 struct FocusCandidate {
FocusCandidateFocusCandidate101 FocusCandidate()
102 : visibleNode(0)
103 , focusableNode(0)
104 , enclosingScrollableBox(0)
105 , distance(maxDistance())
106 , parentDistance(maxDistance())
107 , alignment(None)
108 , parentAlignment(None)
109 , isOffscreen(true)
110 , isOffscreenAfterScrolling(true)
111 {
112 }
113
114 FocusCandidate(Node* n, FocusDirection);
115 explicit FocusCandidate(HTMLAreaElement* area, FocusDirection);
isNullFocusCandidate116 bool isNull() const { return !visibleNode; }
inScrollableContainerFocusCandidate117 bool inScrollableContainer() const { return visibleNode && enclosingScrollableBox; }
isFrameOwnerElementFocusCandidate118 bool isFrameOwnerElement() const { return visibleNode && visibleNode->isFrameOwnerElement(); }
documentFocusCandidate119 Document* document() const { return visibleNode ? &visibleNode->document() : 0; }
120
121 // We handle differently visibleNode and FocusableNode to properly handle the areas of imagemaps,
122 // where visibleNode would represent the image element and focusableNode would represent the area element.
123 // In all other cases, visibleNode and focusableNode are one and the same.
124 Node* visibleNode;
125 Node* focusableNode;
126 Node* enclosingScrollableBox;
127 long long distance;
128 long long parentDistance;
129 RectsAlignment alignment;
130 RectsAlignment parentAlignment;
131 LayoutRect rect;
132 bool isOffscreen;
133 bool isOffscreenAfterScrolling;
134 };
135
136 bool hasOffscreenRect(Node*, FocusDirection direction = FocusDirectionNone);
137 bool scrollInDirection(Frame*, FocusDirection);
138 bool scrollInDirection(Node* container, FocusDirection);
139 bool canScrollInDirection(const Node* container, FocusDirection);
140 bool canScrollInDirection(const Frame*, FocusDirection);
141 bool canBeScrolledIntoView(FocusDirection, const FocusCandidate&);
142 bool areElementsOnSameLine(const FocusCandidate& firstCandidate, const FocusCandidate& secondCandidate);
143 void distanceDataForNode(FocusDirection, const FocusCandidate& current, FocusCandidate& candidate);
144 Node* scrollableEnclosingBoxOrParentFrameForNodeInDirection(FocusDirection, Node*);
145 LayoutRect nodeRectInAbsoluteCoordinates(Node*, bool ignoreBorder = false);
146 LayoutRect frameRectInAbsoluteCoordinates(Frame*);
147 LayoutRect virtualRectForDirection(FocusDirection, const LayoutRect& startingRect, LayoutUnit width = 0);
148 LayoutRect virtualRectForAreaElementAndDirection(HTMLAreaElement*, FocusDirection);
149 HTMLFrameOwnerElement* frameOwnerElement(FocusCandidate&);
150
151 } // namspace WebCore
152
153 #endif // SpatialNavigation_h
154