accessible/base/CacheConstants.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set expandtab shiftwidth=2 tabstop=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/. */
   6
   7 #ifndef _CacheConstants_h_
   8 #define _CacheConstants_h_
   9
  10 #include "nsGkAtoms.h"
  11 #include "mozilla/a11y/RelationType.h"
  12
  13 namespace mozilla {
  14 namespace a11y {
  15
  16 class CacheDomain {
  17  public:
  18   static constexpr uint64_t NameAndDescription = ((uint64_t)0x1) << 0;
  19   static constexpr uint64_t Value = ((uint64_t)0x1) << 1;
  20   static constexpr uint64_t Bounds = ((uint64_t)0x1) << 2;
  21   static constexpr uint64_t Resolution = ((uint64_t)0x1) << 3;
  22   static constexpr uint64_t Text = ((uint64_t)0x1) << 4;
  23   static constexpr uint64_t DOMNodeIDAndClass = ((uint64_t)0x1) << 5;
  24   static constexpr uint64_t State = ((uint64_t)0x1) << 6;
  25   static constexpr uint64_t GroupInfo = ((uint64_t)0x1) << 7;
  26   static constexpr uint64_t Actions = ((uint64_t)0x1) << 8;
  27   static constexpr uint64_t Style = ((uint64_t)0x1) << 9;
  28   static constexpr uint64_t TransformMatrix = ((uint64_t)0x1) << 10;
  29   static constexpr uint64_t ScrollPosition = ((uint64_t)0x1) << 11;
  30   static constexpr uint64_t Table = ((uint64_t)0x1) << 12;
  31   static constexpr uint64_t Spelling = ((uint64_t)0x1) << 13;
  32   static constexpr uint64_t Viewport = ((uint64_t)0x1) << 14;
  33   static constexpr uint64_t ARIA = ((uint64_t)0x1) << 15;
  34   static constexpr uint64_t Relations = ((uint64_t)0x1) << 16;
  35 #ifdef XP_WIN
  36   // Used for MathML.
  37   static constexpr uint64_t InnerHTML = ((uint64_t)0x1) << 17;
  38 #endif
  39   static constexpr uint64_t All = ~((uint64_t)0x0);
  40 };
  41
  42 enum class CacheUpdateType {
  43   /*
  44    * An initial cache push of a loaded document or inserted subtree.
  45    */
  46   Initial,
  47
  48   /*
  49    * An incremental cache push of one or more fields that have changed.
  50    */
  51   Update,
  52 };
  53
  54 struct RelationData {
  55   nsStaticAtom* const mAtom;
  56   nsStaticAtom* const mValidTag;
  57   RelationType mType;
  58   RelationType mReverseType;
  59 };
  60
  61 /**
  62  * This array of RelationData lists our relation types (explicit and reverse)
  63  * and the cache attribute atoms that store their targets. Attributes may
  64  * describe different kinds of relations, depending on the element they
  65  * originate on. For example, an <output> element's `for` attribute describes a
  66  * CONTROLLER_FOR relation, while the `for` attribute of a <label> describes a
  67  * LABEL_FOR relation. To ensure we process these attributes appropriately,
  68  * RelationData.mValidTag contains the atom for the tag this attribute/relation
  69  * type pairing is valid on. If the pairing is valid for all tag types, this
  70  * field is null.
  71  */
  72 static constexpr RelationData kRelationTypeAtoms[] = {
  73     {nsGkAtoms::aria_labelledby, nullptr, RelationType::LABELLED_BY,
  74      RelationType::LABEL_FOR},
  75     {nsGkAtoms::_for, nsGkAtoms::label, RelationType::LABEL_FOR,
  76      RelationType::LABELLED_BY},
  77     {nsGkAtoms::aria_controls, nullptr, RelationType::CONTROLLER_FOR,
  78      RelationType::CONTROLLED_BY},
  79     {nsGkAtoms::_for, nsGkAtoms::output, RelationType::CONTROLLED_BY,
  80      RelationType::CONTROLLER_FOR},
  81     {nsGkAtoms::aria_describedby, nullptr, RelationType::DESCRIBED_BY,
  82      RelationType::DESCRIPTION_FOR},
  83     {nsGkAtoms::aria_flowto, nullptr, RelationType::FLOWS_TO,
  84      RelationType::FLOWS_FROM},
  85     {nsGkAtoms::aria_details, nullptr, RelationType::DETAILS,
  86      RelationType::DETAILS_FOR},
  87     {nsGkAtoms::aria_errormessage, nullptr, RelationType::ERRORMSG,
  88      RelationType::ERRORMSG_FOR},
  89 };
  90
  91 // The count of numbers needed to serialize an nsRect. This is used when
  92 // flattening character rects into an array of ints.
  93 constexpr int32_t kNumbersInRect = 4;
  94
  95 /**
  96  * RemoteAccessible cache keys.
  97  * Cache keys are nsAtoms, but this is mostly an implementation detail. Rather
  98  * than creating new atoms specific to the RemoteAccessible cache, we often
  99  * reuse existing atoms which are a reasonably close match for the value we're
 100  * caching, though the choices aren't always clear or intuitive. For clarity, we
 101  * alias the cache keys to atoms below. Code dealing with the RemoteAccessible
 102  * cache should generally use these aliases rather than using nsAtoms directly.
 103  * There are two exceptions:
 104  * 1. Some ARIA attributes are copied directly from the DOM node, so these
 105  * aren't aliased. Specifically,   aria-level, aria-posinset and aria-setsize
 106  * are copied as separate cache keys as part of CacheDomain::GroupInfo.
 107  * 2. Keys for relations are defined in kRelationTypeAtoms above.
 108  */
 109 class CacheKey {
 110  public:
 111   // uint64_t, CacheDomain::Actions
 112   // As returned by Accessible::AccessKey.
 113   static constexpr nsStaticAtom* AccessKey = nsGkAtoms::accesskey;
 114   // int32_t, no domain
 115   static constexpr nsStaticAtom* AppUnitsPerDevPixel =
 116       nsGkAtoms::_moz_device_pixel_ratio;
 117   // AccAttributes, CacheDomain::ARIA
 118   // ARIA attributes that are exposed as object attributes; i.e. returned in
 119   // Accessible::Attributes.
 120   static constexpr nsStaticAtom* ARIAAttributes = nsGkAtoms::aria;
 121   // nsString, CacheUpdateType::Initial
 122   // The ARIA role attribute if the role is unknown or if there are multiple
 123   // roles.
 124   static constexpr nsStaticAtom* ARIARole = nsGkAtoms::role;
 125   // bool, CacheDomain::State
 126   // The aria-selected attribute.
 127   static constexpr nsStaticAtom* ARIASelected = nsGkAtoms::aria_selected;
 128   // nsTArray<uint64_t>, CacheDomain::Table
 129   // The explicit headers of an HTML table cell.
 130   static constexpr nsStaticAtom* CellHeaders = nsGkAtoms::headers;
 131   // int32_t, CacheDomain::Table
 132   // The colspan of an HTML table cell.
 133   static constexpr nsStaticAtom* ColSpan = nsGkAtoms::colspan;
 134   // nsTArray<int32_t, 2>, CacheDomain::Bounds
 135   // The offset from an OuterDocAccessible (iframe) to its embedded document.
 136   static constexpr nsStaticAtom* CrossDocOffset = nsGkAtoms::crossorigin;
 137   // nsAtom, CacheDomain::Style
 138   // CSS display; block, inline, etc.
 139   static constexpr nsStaticAtom* CSSDisplay = nsGkAtoms::display;
 140   // nsAtom, CacheDomain::Style
 141   // CSS overflow; e.g. hidden.
 142   static constexpr nsStaticAtom* CSSOverflow = nsGkAtoms::overflow;
 143   // nsAtom, CacheDomain::Style
 144   // CSS position; e.g. fixed.
 145   static constexpr nsStaticAtom* CssPosition = nsGkAtoms::position;
 146   // nsString, CacheDomain::NameAndDescription
 147   static constexpr nsStaticAtom* Description = nsGkAtoms::description;
 148   // nsString, CacheDomain::Relations
 149   // The "name" DOM attribute.
 150   static constexpr nsStaticAtom* DOMName = nsGkAtoms::attributeName;
 151   // nsAtom, CacheDomain::DOMNodeIDAndClass
 152   // The "class" DOM attribute.
 153   static constexpr nsStaticAtom* DOMNodeClass = nsGkAtoms::_class;
 154   // nsAtom, CacheDomain::DOMNodeIDAndClass
 155   static constexpr nsStaticAtom* DOMNodeID = nsGkAtoms::id;
 156   // AccGroupInfo, no domain
 157   static constexpr nsStaticAtom* GroupInfo = nsGkAtoms::group;
 158   // nsTArray<int32_t>, no domain
 159   // As returned by HyperTextAccessibleBase::CachedHyperTextOffsets.
 160   static constexpr nsStaticAtom* HyperTextOffsets = nsGkAtoms::offset;
 161   // bool, CacheDomain::Actions
 162   // Whether this image has a longdesc.
 163   static constexpr nsStaticAtom* HasLongdesc = nsGkAtoms::longdesc;
 164   // nsString, CacheDomain::NameAndDescription
 165   static constexpr nsStaticAtom* HTMLPlaceholder = nsGkAtoms::placeholder;
 166 #ifdef XP_WIN
 167   // nsString, CacheDomain::InnerHTML
 168   static constexpr nsStaticAtom* InnerHTML = nsGkAtoms::html;
 169 #endif
 170   // nsAtom, CacheUpdateType::Initial
 171   // The type of an <input> element; tel, email, etc.
 172   static constexpr nsStaticAtom* InputType = nsGkAtoms::textInputType;
 173   // bool, CacheDomain::Bounds
 174   // Whether the Accessible is fully clipped.
 175   static constexpr nsStaticAtom* IsClipped = nsGkAtoms::clip_rule;
 176   // nsString, CacheUpdateType::Initial
 177   static constexpr nsStaticAtom* MimeType = nsGkAtoms::headerContentType;
 178   // double, CacheDomain::Value
 179   static constexpr nsStaticAtom* MaxValue = nsGkAtoms::max;
 180   // double, CacheDomain::Value
 181   static constexpr nsStaticAtom* MinValue = nsGkAtoms::min;
 182   // nsString, CacheDomain::NameAndDescription
 183   static constexpr nsStaticAtom* Name = nsGkAtoms::name;
 184   // ENameValueFlag, CacheDomain::NameAndDescription
 185   // Returned by Accessible::Name.
 186   static constexpr nsStaticAtom* NameValueFlag = nsGkAtoms::explicit_name;
 187   // double, CacheDomain::Value
 188   // The numeric value returned by Accessible::CurValue.
 189   static constexpr nsStaticAtom* NumericValue = nsGkAtoms::value;
 190   // float, CacheDomain::Style
 191   static constexpr nsStaticAtom* Opacity = nsGkAtoms::opacity;
 192   // nsTArray<int32_t, 4>, CacheDomain::Bounds
 193   // The screen bounds relative  to the parent Accessible
 194   // as returned by LocalAccessible::ParentRelativeBounds.
 195   static constexpr nsStaticAtom* ParentRelativeBounds =
 196       nsGkAtoms::relativeBounds;
 197   // nsAtom, CacheUpdateType::Initial
 198   // The type of a popup (used for HTML popover).
 199   static constexpr nsStaticAtom* PopupType = nsGkAtoms::ispopup;
 200   // nsAtom, CacheDomain::Actions
 201   static constexpr nsStaticAtom* PrimaryAction = nsGkAtoms::action;
 202   // float, no domain
 203   // Document resolution.
 204   static constexpr nsStaticAtom* Resolution = nsGkAtoms::resolution;
 205   // int32_t, CacheDomain::Table
 206   // The rowspan of an HTML table cell.
 207   static constexpr nsStaticAtom* RowSpan = nsGkAtoms::rowspan;
 208   // nsTArray<int32_t, 2>, CacheDomain::ScrollPosition
 209   static constexpr nsStaticAtom* ScrollPosition = nsGkAtoms::scrollPosition;
 210   // nsTArray<int32_t>, CacheDomain::Spelling | CacheDomain::Text
 211   // The offsets of spelling errors.
 212   static constexpr nsStaticAtom* SpellingErrors = nsGkAtoms::spelling;
 213   // nsString, CacheDomain::Value
 214   // The src URL of images.
 215   static constexpr nsStaticAtom* SrcURL = nsGkAtoms::src;
 216   // uint64_t, CacheDomain::State
 217   // As returned by Accessible::State.
 218   static constexpr nsStaticAtom* State = nsGkAtoms::state;
 219   // double, CacheDomain::Value
 220   // The value step returned by Accessible::Step.
 221   static constexpr nsStaticAtom* Step = nsGkAtoms::step;
 222   // nsAtom, CacheUpdateType::Initial
 223   // The tag name of the element.
 224   static constexpr nsStaticAtom* TagName = nsGkAtoms::tag;
 225   // bool, CacheDomain::Table
 226   // Whether this is a layout table.
 227   static constexpr nsStaticAtom* TableLayoutGuess = nsGkAtoms::layout_guess;
 228   // nsString, CacheDomain::Text
 229   // The text of TextLeafAccessibles.
 230   static constexpr nsStaticAtom* Text = nsGkAtoms::text;
 231   // AccAttributes, CacheDomain::Text
 232   // Text attributes; font, etc.
 233   static constexpr nsStaticAtom* TextAttributes = nsGkAtoms::style;
 234   // nsTArray<int32_t, 4 * n>, CacheDomain::Text | CacheDomain::Bounds
 235   // The bounds of each character in a text leaf.
 236   static constexpr nsStaticAtom* TextBounds = nsGkAtoms::characterData;
 237   // nsTArray<int32_t>, CacheDomain::Text | CacheDomain::Bounds
 238   // The text offsets where new lines start.
 239   static constexpr nsStaticAtom* TextLineStarts = nsGkAtoms::line;
 240   // nsString, CacheDomain::Value
 241   // The textual value returned by Accessible::Value (as opposed to
 242   // the numeric value returned by Accessible::CurValue).
 243   static constexpr nsStaticAtom* TextValue = nsGkAtoms::aria_valuetext;
 244   // gfx::Matrix4x4, CacheDomain::TransformMatrix
 245   static constexpr nsStaticAtom* TransformMatrix = nsGkAtoms::transform;
 246   // nsTArray<uint64_t>, CacheDomain::Viewport
 247   // The list of Accessibles in the viewport used for hit testing and on-screen
 248   // determination.
 249   static constexpr nsStaticAtom* Viewport = nsGkAtoms::viewport;
 250 };
 251
 252 }  // namespace a11y
 253 }  // namespace mozilla
 254
 255 #endif