1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/base/public/DirectionalityUtils.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,150 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + *
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef DirectionalityUtils_h___
1.11 +#define DirectionalityUtils_h___
1.12 +
1.13 +#include "nscore.h"
1.14 +
1.15 +class nsIContent;
1.16 +class nsIDocument;
1.17 +class nsINode;
1.18 +class nsAString;
1.19 +class nsAttrValue;
1.20 +class nsTextNode;
1.21 +
1.22 +namespace mozilla {
1.23 +namespace dom {
1.24 +class Element;
1.25 +} // namespace dom
1.26 +} // namespace mozilla
1.27 +
1.28 +namespace mozilla {
1.29 +
1.30 +enum Directionality {
1.31 + eDir_NotSet,
1.32 + eDir_RTL,
1.33 + eDir_LTR,
1.34 + eDir_Auto
1.35 +};
1.36 +
1.37 +/**
1.38 + * Set the directionality of an element according to the algorithm defined at
1.39 + * http://www.whatwg.org/specs/web-apps/current-work/multipage/elements.html#the-directionality,
1.40 + * not including elements with auto direction.
1.41 + *
1.42 + * @return the directionality that the element was set to
1.43 + */
1.44 +Directionality RecomputeDirectionality(mozilla::dom::Element* aElement,
1.45 + bool aNotify = true);
1.46 +
1.47 +/**
1.48 + * Set the directionality of any descendants of a node that do not themselves
1.49 + * have a dir attribute.
1.50 + * For performance reasons we walk down the descendant tree in the rare case
1.51 + * of setting the dir attribute, rather than walking up the ancestor tree in
1.52 + * the much more common case of getting the element's directionality.
1.53 + */
1.54 +void SetDirectionalityOnDescendants(mozilla::dom::Element* aElement,
1.55 + Directionality aDir,
1.56 + bool aNotify = true);
1.57 +
1.58 +/**
1.59 + * Walk the descendants of a node in tree order and, for any text node
1.60 + * descendant that determines the directionality of some element and is not a
1.61 + * descendant of another descendant of the original node with dir=auto,
1.62 + * redetermine that element's directionality
1.63 + */
1.64 +void WalkDescendantsResetAutoDirection(mozilla::dom::Element* aElement);
1.65 +
1.66 +/**
1.67 + * After setting dir=auto on an element, walk its descendants in tree order.
1.68 + * If the node doesn't have the NODE_ANCESTOR_HAS_DIR_AUTO flag, set the
1.69 + * NODE_ANCESTOR_HAS_DIR_AUTO flag on all of its descendants.
1.70 + * Resolve the directionality of the element by the "downward propagation
1.71 + * algorithm" (defined in section 3 in the comments at the beginning of
1.72 + * DirectionalityUtils.cpp)
1.73 + */
1.74 +void WalkDescendantsSetDirAuto(mozilla::dom::Element* aElement,
1.75 + bool aNotify = true);
1.76 +
1.77 +/**
1.78 + * After unsetting dir=auto on an element, walk its descendants in tree order,
1.79 + * skipping any that have dir=auto themselves, and unset the
1.80 + * NODE_ANCESTOR_HAS_DIR_AUTO flag
1.81 + */
1.82 +void WalkDescendantsClearAncestorDirAuto(mozilla::dom::Element* aElement);
1.83 +
1.84 +/**
1.85 + * When the contents of a text node are about to change, retrieve the current
1.86 + * directionality of the text
1.87 + *
1.88 + * @return whether the text node affects the directionality of any element
1.89 + */
1.90 +bool TextNodeWillChangeDirection(nsIContent* aTextNode, Directionality* aOldDir,
1.91 + uint32_t aOffset);
1.92 +
1.93 +/**
1.94 + * After the contents of a text node have changed, change the directionality
1.95 + * of any elements whose directionality is determined by that node
1.96 + */
1.97 +void TextNodeChangedDirection(nsIContent* aTextNode, Directionality aOldDir,
1.98 + bool aNotify);
1.99 +
1.100 +/**
1.101 + * When a text node is appended to an element, find any ancestors with dir=auto
1.102 + * whose directionality will be determined by the text node
1.103 + */
1.104 +void SetDirectionFromNewTextNode(nsIContent* aTextNode);
1.105 +
1.106 +/**
1.107 + * When a text node is removed from a document, find any ancestors whose
1.108 + * directionality it determined and redetermine their directionality
1.109 + *
1.110 + * @param aTextNode the text node
1.111 + * @param aNullParent whether the the parent is also being removed
1.112 + * (passed from UnbindFromTree)
1.113 + */
1.114 +void ResetDirectionSetByTextNode(nsTextNode* aTextNode, bool aNullParent);
1.115 +
1.116 +/**
1.117 + * Set the directionality of an element according to the directionality of the
1.118 + * text in aValue
1.119 + */
1.120 +void SetDirectionalityFromValue(mozilla::dom::Element* aElement,
1.121 + const nsAString& aValue,
1.122 + bool aNotify);
1.123 +
1.124 +/**
1.125 + * Called when setting the dir attribute on an element, immediately after
1.126 + * AfterSetAttr. This is instead of using BeforeSetAttr or AfterSetAttr, because
1.127 + * in AfterSetAttr we don't know the old value, so we can't identify all cases
1.128 + * where we need to walk up or down the document tree and reset the direction;
1.129 + * and in BeforeSetAttr we can't do the walk because this element hasn't had the
1.130 + * value set yet so the results will be wrong.
1.131 + */
1.132 +void OnSetDirAttr(mozilla::dom::Element* aElement,
1.133 + const nsAttrValue* aNewValue,
1.134 + bool hadValidDir,
1.135 + bool hadDirAuto,
1.136 + bool aNotify);
1.137 +
1.138 +/**
1.139 + * Called when binding a new element to the tree, to set the
1.140 + * NodeAncestorHasDirAuto flag and set the direction of the element and its
1.141 + * ancestors if necessary
1.142 + */
1.143 +void SetDirOnBind(mozilla::dom::Element* aElement, nsIContent* aParent);
1.144 +
1.145 +/**
1.146 + * Called when unbinding an element from the tree, to recompute the
1.147 + * directionality of the element if it doesn't have autodirection, and to
1.148 + * clean up any entries in nsTextDirectionalityMap that refer to it.
1.149 + */
1.150 +void ResetDir(mozilla::dom::Element* aElement);
1.151 +} // end namespace mozilla
1.152 +
1.153 +#endif /* DirectionalityUtils_h___ */
