content/base/public/DirectionalityUtils.h@8bccb770b82d
content/base/public/DirectionalityUtils.h
Wed, 31 Dec 2014 13:27:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 13:27:57 +0100
- branch
- TOR_BUG_3246
- changeset 6
- 8bccb770b82d
- permissions
- -rw-r--r--
Ignore runtime configuration files generated during quality assurance.
1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
2 *
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
7 #ifndef DirectionalityUtils_h___
8 #define DirectionalityUtils_h___
10 #include "nscore.h"
12 class nsIContent;
13 class nsIDocument;
14 class nsINode;
15 class nsAString;
16 class nsAttrValue;
17 class nsTextNode;
19 namespace mozilla {
20 namespace dom {
21 class Element;
22 } // namespace dom
23 } // namespace mozilla
25 namespace mozilla {
27 enum Directionality {
28 eDir_NotSet,
29 eDir_RTL,
30 eDir_LTR,
31 eDir_Auto
32 };
34 /**
35 * Set the directionality of an element according to the algorithm defined at
36 * http://www.whatwg.org/specs/web-apps/current-work/multipage/elements.html#the-directionality,
37 * not including elements with auto direction.
38 *
39 * @return the directionality that the element was set to
40 */
41 Directionality RecomputeDirectionality(mozilla::dom::Element* aElement,
42 bool aNotify = true);
44 /**
45 * Set the directionality of any descendants of a node that do not themselves
46 * have a dir attribute.
47 * For performance reasons we walk down the descendant tree in the rare case
48 * of setting the dir attribute, rather than walking up the ancestor tree in
49 * the much more common case of getting the element's directionality.
50 */
51 void SetDirectionalityOnDescendants(mozilla::dom::Element* aElement,
52 Directionality aDir,
53 bool aNotify = true);
55 /**
56 * Walk the descendants of a node in tree order and, for any text node
57 * descendant that determines the directionality of some element and is not a
58 * descendant of another descendant of the original node with dir=auto,
59 * redetermine that element's directionality
60 */
61 void WalkDescendantsResetAutoDirection(mozilla::dom::Element* aElement);
63 /**
64 * After setting dir=auto on an element, walk its descendants in tree order.
65 * If the node doesn't have the NODE_ANCESTOR_HAS_DIR_AUTO flag, set the
66 * NODE_ANCESTOR_HAS_DIR_AUTO flag on all of its descendants.
67 * Resolve the directionality of the element by the "downward propagation
68 * algorithm" (defined in section 3 in the comments at the beginning of
69 * DirectionalityUtils.cpp)
70 */
71 void WalkDescendantsSetDirAuto(mozilla::dom::Element* aElement,
72 bool aNotify = true);
74 /**
75 * After unsetting dir=auto on an element, walk its descendants in tree order,
76 * skipping any that have dir=auto themselves, and unset the
77 * NODE_ANCESTOR_HAS_DIR_AUTO flag
78 */
79 void WalkDescendantsClearAncestorDirAuto(mozilla::dom::Element* aElement);
81 /**
82 * When the contents of a text node are about to change, retrieve the current
83 * directionality of the text
84 *
85 * @return whether the text node affects the directionality of any element
86 */
87 bool TextNodeWillChangeDirection(nsIContent* aTextNode, Directionality* aOldDir,
88 uint32_t aOffset);
90 /**
91 * After the contents of a text node have changed, change the directionality
92 * of any elements whose directionality is determined by that node
93 */
94 void TextNodeChangedDirection(nsIContent* aTextNode, Directionality aOldDir,
95 bool aNotify);
97 /**
98 * When a text node is appended to an element, find any ancestors with dir=auto
99 * whose directionality will be determined by the text node
100 */
101 void SetDirectionFromNewTextNode(nsIContent* aTextNode);
103 /**
104 * When a text node is removed from a document, find any ancestors whose
105 * directionality it determined and redetermine their directionality
106 *
107 * @param aTextNode the text node
108 * @param aNullParent whether the the parent is also being removed
109 * (passed from UnbindFromTree)
110 */
111 void ResetDirectionSetByTextNode(nsTextNode* aTextNode, bool aNullParent);
113 /**
114 * Set the directionality of an element according to the directionality of the
115 * text in aValue
116 */
117 void SetDirectionalityFromValue(mozilla::dom::Element* aElement,
118 const nsAString& aValue,
119 bool aNotify);
121 /**
122 * Called when setting the dir attribute on an element, immediately after
123 * AfterSetAttr. This is instead of using BeforeSetAttr or AfterSetAttr, because
124 * in AfterSetAttr we don't know the old value, so we can't identify all cases
125 * where we need to walk up or down the document tree and reset the direction;
126 * and in BeforeSetAttr we can't do the walk because this element hasn't had the
127 * value set yet so the results will be wrong.
128 */
129 void OnSetDirAttr(mozilla::dom::Element* aElement,
130 const nsAttrValue* aNewValue,
131 bool hadValidDir,
132 bool hadDirAuto,
133 bool aNotify);
135 /**
136 * Called when binding a new element to the tree, to set the
137 * NodeAncestorHasDirAuto flag and set the direction of the element and its
138 * ancestors if necessary
139 */
140 void SetDirOnBind(mozilla::dom::Element* aElement, nsIContent* aParent);
142 /**
143 * Called when unbinding an element from the tree, to recompute the
144 * directionality of the element if it doesn't have autodirection, and to
145 * clean up any entries in nsTextDirectionalityMap that refer to it.
146 */
147 void ResetDir(mozilla::dom::Element* aElement);
148 } // end namespace mozilla
150 #endif /* DirectionalityUtils_h___ */
