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 "FocusDirection.h"
25 #include "HTMLFrameOwnerElement.h"
26 #include "IntRect.h"
27 #include "Node.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
39 using namespace std;
40
maxDistance()41 inline long long maxDistance()
42 {
43 return numeric_limits<long long>::max();
44 }
45
fudgeFactor()46 inline int fudgeFactor()
47 {
48 return 2;
49 }
50
51 bool isSpatialNavigationEnabled(const Frame*);
52
53 // Spatially speaking, two given elements in a web page can be:
54 // 1) Fully aligned: There is a full intersection between the rects, either
55 // vertically or horizontally.
56 //
57 // * Horizontally * Vertically
58 // _
59 // |_| _ _ _ _ _ _
60 // |_|...... _ |_|_|_|_|_|_|
61 // |_| |_| . .
62 // |_|......|_| OR . .
63 // |_| |_| . .
64 // |_|......|_| _ _ _ _
65 // |_| |_|_|_|_|
66 //
67 //
68 // 2) Partially aligned: There is a partial intersection between the rects, either
69 // vertically or horizontally.
70 //
71 // * Horizontally * Vertically
72 // _ _ _ _ _ _
73 // |_| |_|_|_|_|_|
74 // |_|.... _ OR . .
75 // |_| |_| . .
76 // |_|....|_| ._._ _
77 // |_| |_|_|_|
78 // |_|
79 //
80 // 3) Or, otherwise, not aligned at all.
81 //
82 // * Horizontally * Vertically
83 // _ _ _ _ _
84 // |_| |_|_|_|_|
85 // |_| .
86 // |_| .
87 // . OR .
88 // _ . ._ _ _ _ _
89 // |_| |_|_|_|_|_|
90 // |_|
91 // |_|
92 //
93 // "Totally Aligned" elements are preferable candidates to move
94 // focus to over "Partially Aligned" ones, that on its turns are
95 // more preferable than "Not Aligned".
96 enum RectsAlignment {
97 None = 0,
98 Partial,
99 Full
100 };
101
102 struct FocusCandidate {
FocusCandidateFocusCandidate103 FocusCandidate()
104 : visibleNode(0)
105 , focusableNode(0)
106 , enclosingScrollableBox(0)
107 , distance(maxDistance())
108 , parentDistance(maxDistance())
109 , alignment(None)
110 , parentAlignment(None)
111 , isOffscreen(true)
112 , isOffscreenAfterScrolling(true)
113 {
114 }
115
116 FocusCandidate(Node* n, FocusDirection);
117 explicit FocusCandidate(HTMLAreaElement* area, FocusDirection);
isNullFocusCandidate118 bool isNull() const { return !visibleNode; }
inScrollableContainerFocusCandidate119 bool inScrollableContainer() const { return visibleNode && enclosingScrollableBox; }
isFrameOwnerElementFocusCandidate120 bool isFrameOwnerElement() const { return visibleNode && visibleNode->isFrameOwnerElement(); }
documentFocusCandidate121 Document* document() const { return visibleNode ? visibleNode->document() : 0; }
122
123 // We handle differently visibleNode and FocusableNode to properly handle the areas of imagemaps,
124 // where visibleNode would represent the image element and focusableNode would represent the area element.
125 // In all other cases, visibleNode and focusableNode are one and the same.
126 Node* visibleNode;
127 Node* focusableNode;
128 Node* enclosingScrollableBox;
129 long long distance;
130 long long parentDistance;
131 RectsAlignment alignment;
132 RectsAlignment parentAlignment;
133 IntRect rect;
134 bool isOffscreen;
135 bool isOffscreenAfterScrolling;
136 };
137
138 bool hasOffscreenRect(Node*, FocusDirection direction = FocusDirectionNone);
139 bool scrollInDirection(Frame*, FocusDirection);
140 bool scrollInDirection(Node* container, FocusDirection);
141 bool canScrollInDirection(const Node* container, FocusDirection);
142 bool canScrollInDirection(const Frame*, FocusDirection);
143 bool canBeScrolledIntoView(FocusDirection, const FocusCandidate&);
144 bool areElementsOnSameLine(const FocusCandidate& firstCandidate, const FocusCandidate& secondCandidate);
145 void distanceDataForNode(FocusDirection, const FocusCandidate& current, FocusCandidate& candidate);
146 Node* scrollableEnclosingBoxOrParentFrameForNodeInDirection(FocusDirection, Node*);
147 IntRect nodeRectInAbsoluteCoordinates(Node*, bool ignoreBorder = false);
148 IntRect frameRectInAbsoluteCoordinates(Frame*);
149 IntRect virtualRectForDirection(FocusDirection, const IntRect& startingRect, int width = 0);
150 IntRect virtualRectForAreaElementAndDirection(HTMLAreaElement*, FocusDirection);
151 HTMLFrameOwnerElement* frameOwnerElement(FocusCandidate&);
152
153 } // namspace WebCore
154
155 #endif // SpatialNavigation_h
156