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Diffstat (limited to '')
| -rw-r--r-- | accessible/base/ARIAMap.h | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/accessible/base/ARIAMap.h b/accessible/base/ARIAMap.h new file mode 100644 index 0000000000..4034a11fe5 --- /dev/null +++ b/accessible/base/ARIAMap.h @@ -0,0 +1,330 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim:expandtab:shiftwidth=2:tabstop=2: + */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef mozilla_a11y_aria_ARIAMap_h_ +#define mozilla_a11y_aria_ARIAMap_h_ + +#include "ARIAStateMap.h" +#include "mozilla/a11y/AccTypes.h" +#include "mozilla/a11y/Role.h" + +#include "nsAtom.h" +#include "nsIContent.h" +#include "nsTHashSet.h" + +class nsINode; + +namespace mozilla::dom { +class Element; +} + +//////////////////////////////////////////////////////////////////////////////// +// Value constants + +/** + * Used to define if role requires to expose Value interface. + */ +enum EValueRule { + /** + * Value interface isn't exposed. + */ + eNoValue, + + /** + * Value interface is implemented, supports value, min and max from + * aria-valuenow, aria-valuemin and aria-valuemax. + */ + eHasValueMinMax, + + /** + * Value interface is implemented, but only if the element is focusable. + * For instance, in ARIA 1.1 the ability for authors to create adjustable + * splitters was provided by supporting the value interface on separators + * that are focusable. Non-focusable separators expose no value information. + */ + eHasValueMinMaxIfFocusable +}; + +//////////////////////////////////////////////////////////////////////////////// +// Action constants + +/** + * Used to define if the role requires to expose action. + */ +enum EActionRule { + eNoAction, + eActivateAction, + eClickAction, + ePressAction, + eCheckUncheckAction, + eExpandAction, + eJumpAction, + eOpenCloseAction, + eSelectAction, + eSortAction, + eSwitchAction +}; + +//////////////////////////////////////////////////////////////////////////////// +// Live region constants + +/** + * Used to define if role exposes default value of aria-live attribute. + */ +enum ELiveAttrRule { + eNoLiveAttr, + eOffLiveAttr, + ePoliteLiveAttr, + eAssertiveLiveAttr +}; + +//////////////////////////////////////////////////////////////////////////////// +// Role constants + +/** + * ARIA role overrides role from native markup. + */ +const bool kUseMapRole = true; + +/** + * ARIA role doesn't override the role from native markup. + */ +const bool kUseNativeRole = false; + +//////////////////////////////////////////////////////////////////////////////// +// ARIA attribute characteristic masks + +/** + * This mask indicates the attribute should not be exposed as an object + * attribute via the catch-all logic in Accessible::Attributes(). + * This means it either isn't mean't to be exposed as an object attribute, or + * that it should, but is already handled in other code. + */ +const uint8_t ATTR_BYPASSOBJ = 0x1 << 0; +const uint8_t ATTR_BYPASSOBJ_IF_FALSE = 0x1 << 1; + +/** + * This mask indicates the attribute is expected to have an NMTOKEN or bool + * value. (See for example usage in Accessible::Attributes()) + */ +const uint8_t ATTR_VALTOKEN = 0x1 << 2; + +/** + * Indicate the attribute is global state or property (refer to + * http://www.w3.org/TR/wai-aria/states_and_properties#global_states). + */ +const uint8_t ATTR_GLOBAL = 0x1 << 3; + +/** + * Indicates that the attribute should have an integer value. + */ +const uint8_t ATTR_VALINT = 0x1 << 4; + +//////////////////////////////////////////////////////////////////////////////// +// State map entry + +/** + * Used in nsRoleMapEntry.state if no nsIAccessibleStates are automatic for + * a given role. + */ +#define kNoReqStates 0 + +//////////////////////////////////////////////////////////////////////////////// +// Role map entry + +/** + * For each ARIA role, this maps the nsIAccessible information. + */ +struct nsRoleMapEntry { + /** + * Return true if matches to the given ARIA role. + */ + bool Is(nsAtom* aARIARole) const { return roleAtom == aARIARole; } + + /** + * Return true if ARIA role has the given accessible type. + */ + bool IsOfType(mozilla::a11y::AccGenericType aType) const { + return accTypes & aType; + } + + /** + * Return ARIA role. + */ + const nsDependentAtomString ARIARoleString() const { + return nsDependentAtomString(roleAtom); + } + + // ARIA role: string representation such as "button" + nsStaticAtom* const roleAtom; + + // Role mapping rule: maps to enum Role + mozilla::a11y::role role; + + // Role rule: whether to use mapped role or native semantics + bool roleRule; + + // Value mapping rule: how to compute accessible value + EValueRule valueRule; + + // Action mapping rule, how to expose accessible action + EActionRule actionRule; + + // 'live' and 'container-live' object attributes mapping rule: how to expose + // these object attributes if ARIA 'live' attribute is missed. + ELiveAttrRule liveAttRule; + + // LocalAccessible types this role belongs to. + uint32_t accTypes; + + // Automatic state mapping rule: always include in states + uint64_t state; // or kNoReqStates if no default state for this role + + // ARIA properties supported for this role (in other words, the aria-foo + // attribute to accessible states mapping rules). + // Currently you cannot have unlimited mappings, because + // a variable sized array would not allow the use of + // C++'s struct initialization feature. + mozilla::a11y::aria::EStateRule attributeMap1; + mozilla::a11y::aria::EStateRule attributeMap2; + mozilla::a11y::aria::EStateRule attributeMap3; + mozilla::a11y::aria::EStateRule attributeMap4; +}; + +//////////////////////////////////////////////////////////////////////////////// +// ARIA map + +/** + * These provide the mappings for WAI-ARIA roles, states and properties using + * the structs defined in this file and ARIAStateMap files. + */ +namespace mozilla { +namespace a11y { +class AccAttributes; + +namespace aria { + +/** + * Empty role map entry. Used by accessibility service to create an accessible + * if the accessible can't use role of used accessible class. For example, + * it is used for table cells that aren't contained by table. + */ +extern nsRoleMapEntry gEmptyRoleMap; + +/** + * Constants for the role map entry index to indicate that the role map entry + * isn't in sWAIRoleMaps, but rather is a special entry: nullptr, + * gEmptyRoleMap, and sLandmarkRoleMap + */ +const uint8_t NO_ROLE_MAP_ENTRY_INDEX = UINT8_MAX - 2; +const uint8_t EMPTY_ROLE_MAP_ENTRY_INDEX = UINT8_MAX - 1; +const uint8_t LANDMARK_ROLE_MAP_ENTRY_INDEX = UINT8_MAX; + +/** + * Get the role map entry for a given DOM node. This will use the first + * ARIA role if the role attribute provides a space delimited list of roles. + * + * @param aEl [in] the DOM node to get the role map entry for + * @return a pointer to the role map entry for the ARIA role, or nullptr + * if none + */ +const nsRoleMapEntry* GetRoleMap(dom::Element* aEl); + +/** + * Get the role map entry pointer's index for a given DOM node. This will use + * the first ARIA role if the role attribute provides a space delimited list of + * roles. + * + * @param aEl [in] the DOM node to get the role map entry for + * @return the index of the pointer to the role map entry for the ARIA + * role, or NO_ROLE_MAP_ENTRY_INDEX if none + */ +uint8_t GetRoleMapIndex(dom::Element* aEl); + +/** + * Get the role map entry pointer for a given role map entry index. + * + * @param aRoleMapIndex [in] the role map index to get the role map entry + * pointer for + * @return a pointer to the role map entry for the ARIA role, + * or nullptr, if none + */ +const nsRoleMapEntry* GetRoleMapFromIndex(uint8_t aRoleMapIndex); + +/** + * Get the role map entry index for a given role map entry pointer. If the role + * map entry is within sWAIRoleMaps, return the index within that array, + * otherwise return one of the special index constants listed above. + * + * @param aRoleMap [in] the role map entry pointer to get the index for + * @return the index of the pointer to the role map entry, or + * NO_ROLE_MAP_ENTRY_INDEX if none + */ +uint8_t GetIndexFromRoleMap(const nsRoleMapEntry* aRoleMap); + +/** + * Return accessible state from ARIA universal states applied to the given + * element. + */ +uint64_t UniversalStatesFor(dom::Element* aElement); + +/** + * Get the ARIA attribute characteristics for a given ARIA attribute. + * + * @param aAtom ARIA attribute + * @return A bitflag representing the attribute characteristics + * (see above for possible bit masks, prefixed "ATTR_") + */ +uint8_t AttrCharacteristicsFor(nsAtom* aAtom); + +/** + * Return true if the element has defined aria-hidden. + */ +bool HasDefinedARIAHidden(nsIContent* aContent); + +/** + * Represents a simple enumerator for iterating through ARIA attributes + * exposed as object attributes on a given accessible. + */ +class AttrIterator { + public: + explicit AttrIterator(nsIContent* aContent); + + bool Next(); + + nsAtom* AttrName() const; + + void AttrValue(nsAString& aAttrValue) const; + + /** + * Expose this ARIA attribute in a specified AccAttributes. The appropriate + * type will be used for the attribute; e.g. an atom for a token value. + */ + bool ExposeAttr(AccAttributes* aTargetAttrs) const; + + private: + AttrIterator() = delete; + AttrIterator(const AttrIterator&) = delete; + AttrIterator& operator=(const AttrIterator&) = delete; + + dom::Element* mElement; + + bool mIteratingDefaults; + nsTHashSet<nsRefPtrHashKey<nsAtom>> mOverriddenAttrs; + + const AttrArray* mAttrs; + uint32_t mAttrIdx; + uint32_t mAttrCount; + RefPtr<nsAtom> mAttrAtom; + uint8_t mAttrCharacteristics; +}; + +} // namespace aria +} // namespace a11y +} // namespace mozilla + +#endif |