diff options
Diffstat (limited to 'accessible/base/nsAccUtils.cpp')
| -rw-r--r-- | accessible/base/nsAccUtils.cpp | 621 |
1 files changed, 621 insertions, 0 deletions
diff --git a/accessible/base/nsAccUtils.cpp b/accessible/base/nsAccUtils.cpp new file mode 100644 index 0000000000..313b825648 --- /dev/null +++ b/accessible/base/nsAccUtils.cpp @@ -0,0 +1,621 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 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/. */ + +#include "nsAccUtils.h" + +#include "LocalAccessible-inl.h" +#include "AccAttributes.h" +#include "ARIAMap.h" +#include "nsAccessibilityService.h" +#include "nsCoreUtils.h" +#include "nsGenericHTMLElement.h" +#include "DocAccessible.h" +#include "DocAccessibleParent.h" +#include "HyperTextAccessible.h" +#include "nsIAccessibleTypes.h" +#include "Role.h" +#include "States.h" +#include "TextLeafAccessible.h" + +#include "nsIBaseWindow.h" +#include "nsIDocShellTreeOwner.h" +#include "nsIDOMXULContainerElement.h" +#include "nsISimpleEnumerator.h" +#include "mozilla/a11y/PDocAccessibleChild.h" +#include "mozilla/a11y/RemoteAccessible.h" +#include "mozilla/dom/Document.h" +#include "mozilla/dom/Element.h" +#include "mozilla/dom/ElementInternals.h" +#include "mozilla/StaticPrefs_accessibility.h" +#include "nsAccessibilityService.h" + +using namespace mozilla; +using namespace mozilla::a11y; + +void nsAccUtils::SetAccGroupAttrs(AccAttributes* aAttributes, int32_t aLevel, + int32_t aSetSize, int32_t aPosInSet) { + nsAutoString value; + + if (aLevel) { + aAttributes->SetAttribute(nsGkAtoms::level, aLevel); + } + + if (aSetSize && aPosInSet) { + aAttributes->SetAttribute(nsGkAtoms::posinset, aPosInSet); + aAttributes->SetAttribute(nsGkAtoms::setsize, aSetSize); + } +} + +int32_t nsAccUtils::GetLevelForXULContainerItem(nsIContent* aContent) { + nsCOMPtr<nsIDOMXULContainerItemElement> item = + aContent->AsElement()->AsXULContainerItem(); + if (!item) return 0; + + nsCOMPtr<dom::Element> containerElement; + item->GetParentContainer(getter_AddRefs(containerElement)); + nsCOMPtr<nsIDOMXULContainerElement> container = + containerElement ? containerElement->AsXULContainer() : nullptr; + if (!container) return 0; + + // Get level of the item. + int32_t level = -1; + while (container) { + level++; + + container->GetParentContainer(getter_AddRefs(containerElement)); + container = containerElement ? containerElement->AsXULContainer() : nullptr; + } + + return level; +} + +void nsAccUtils::SetLiveContainerAttributes(AccAttributes* aAttributes, + Accessible* aStartAcc) { + nsAutoString live, relevant, busy; + nsStaticAtom* role = nullptr; + Maybe<bool> atomic; + for (Accessible* acc = aStartAcc; acc; acc = acc->Parent()) { + // We only want the nearest value for each attribute. If we already got a + // value, don't bother fetching it from further ancestors. + const bool wasLiveEmpty = live.IsEmpty(); + acc->LiveRegionAttributes(wasLiveEmpty ? &live : nullptr, + relevant.IsEmpty() ? &relevant : nullptr, + atomic ? nullptr : &atomic, + busy.IsEmpty() ? &busy : nullptr); + if (wasLiveEmpty) { + const nsRoleMapEntry* roleMap = acc->ARIARoleMap(); + if (live.IsEmpty()) { + // aria-live wasn't explicitly set. See if an aria-live value is implied + // by an ARIA role or markup element. + if (roleMap) { + GetLiveAttrValue(roleMap->liveAttRule, live); + } else if (nsStaticAtom* value = GetAccService()->MarkupAttribute( + acc, nsGkAtoms::aria_live)) { + value->ToString(live); + } + } + if (!live.IsEmpty() && roleMap && + roleMap->roleAtom != nsGkAtoms::_empty) { + role = roleMap->roleAtom; + } + } + if (acc->IsDoc()) { + break; + } + } + if (!live.IsEmpty()) { + aAttributes->SetAttribute(nsGkAtoms::containerLive, std::move(live)); + } + if (role) { + aAttributes->SetAttribute(nsGkAtoms::containerLiveRole, std::move(role)); + } + if (!relevant.IsEmpty()) { + aAttributes->SetAttribute(nsGkAtoms::containerRelevant, + std::move(relevant)); + } + if (atomic) { + aAttributes->SetAttribute(nsGkAtoms::containerAtomic, *atomic); + } + if (!busy.IsEmpty()) { + aAttributes->SetAttribute(nsGkAtoms::containerBusy, std::move(busy)); + } +} + +bool nsAccUtils::HasDefinedARIAToken(nsIContent* aContent, nsAtom* aAtom) { + NS_ASSERTION(aContent, "aContent is null in call to HasDefinedARIAToken!"); + + if (!aContent->IsElement()) return false; + + dom::Element* element = aContent->AsElement(); + if (auto* htmlElement = nsGenericHTMLElement::FromNode(element); + htmlElement && !element->HasAttr(aAtom)) { + const auto* defaults = GetARIADefaults(htmlElement); + if (!defaults) { + return false; + } + return HasDefinedARIAToken(defaults, aAtom); + } + return HasDefinedARIAToken(&element->GetAttrs(), aAtom); +} + +bool nsAccUtils::HasDefinedARIAToken(const AttrArray* aAttrs, nsAtom* aAtom) { + return aAttrs->HasAttr(kNameSpaceID_None, aAtom) && + !aAttrs->AttrValueIs(kNameSpaceID_None, aAtom, nsGkAtoms::_empty, + eCaseMatters) && + !aAttrs->AttrValueIs(kNameSpaceID_None, aAtom, nsGkAtoms::_undefined, + eCaseMatters); +} + +nsStaticAtom* nsAccUtils::NormalizeARIAToken(const AttrArray* aAttrs, + nsAtom* aAttr) { + if (!HasDefinedARIAToken(aAttrs, aAttr)) { + return nsGkAtoms::_empty; + } + + if (aAttr == nsGkAtoms::aria_current) { + static AttrArray::AttrValuesArray tokens[] = { + nsGkAtoms::page, nsGkAtoms::step, nsGkAtoms::location_, + nsGkAtoms::date, nsGkAtoms::time, nsGkAtoms::_true, + nullptr}; + int32_t idx = + aAttrs->FindAttrValueIn(kNameSpaceID_None, aAttr, tokens, eCaseMatters); + // If the token is present, return it, otherwise TRUE as per spec. + return (idx >= 0) ? tokens[idx] : nsGkAtoms::_true; + } + + static AttrArray::AttrValuesArray tokens[] = { + nsGkAtoms::_false, nsGkAtoms::_true, nsGkAtoms::mixed, nullptr}; + int32_t idx = + aAttrs->FindAttrValueIn(kNameSpaceID_None, aAttr, tokens, eCaseMatters); + if (idx >= 0) { + return tokens[idx]; + } + + return nullptr; +} + +nsStaticAtom* nsAccUtils::NormalizeARIAToken(dom::Element* aElement, + nsAtom* aAttr) { + if (auto* htmlElement = nsGenericHTMLElement::FromNode(aElement); + htmlElement && !aElement->HasAttr(aAttr)) { + const auto* defaults = GetARIADefaults(htmlElement); + if (!defaults) { + return nsGkAtoms::_empty; + } + return NormalizeARIAToken(defaults, aAttr); + } + return NormalizeARIAToken(&aElement->GetAttrs(), aAttr); +} + +Accessible* nsAccUtils::GetSelectableContainer(const Accessible* aAccessible, + uint64_t aState) { + if (!aAccessible) return nullptr; + + if (!(aState & states::SELECTABLE)) return nullptr; + MOZ_ASSERT(!aAccessible->IsDoc()); + + const Accessible* parent = aAccessible; + while ((parent = parent->Parent()) && !parent->IsSelect()) { + if (parent->IsDoc() || parent->Role() == roles::PANE) { + return nullptr; + } + } + return const_cast<Accessible*>(parent); +} + +LocalAccessible* nsAccUtils::GetSelectableContainer( + LocalAccessible* aAccessible, uint64_t aState) { + Accessible* selectable = + GetSelectableContainer(static_cast<Accessible*>(aAccessible), aState); + return selectable ? selectable->AsLocal() : nullptr; +} + +bool nsAccUtils::IsDOMAttrTrue(const LocalAccessible* aAccessible, + nsAtom* aAttr) { + dom::Element* el = aAccessible->Elm(); + return el && ARIAAttrValueIs(el, aAttr, nsGkAtoms::_true, eCaseMatters); +} + +Accessible* nsAccUtils::TableFor(Accessible* aAcc) { + if (!aAcc || + (!aAcc->IsTable() && !aAcc->IsTableRow() && !aAcc->IsTableCell())) { + return nullptr; + } + Accessible* table = aAcc; + for (; table && !table->IsTable(); table = table->Parent()) { + } + // We don't assert (table && table->IsTable()) here because + // it's possible for this tree walk to yield no table at all + // ex. because a table part has been moved in the tree + // using aria-owns. + return table; +} + +LocalAccessible* nsAccUtils::TableFor(LocalAccessible* aRow) { + Accessible* table = TableFor(static_cast<Accessible*>(aRow)); + return table ? table->AsLocal() : nullptr; +} + +HyperTextAccessible* nsAccUtils::GetTextContainer(nsINode* aNode) { + // Get text accessible containing the result node. + DocAccessible* doc = GetAccService()->GetDocAccessible(aNode->OwnerDoc()); + LocalAccessible* accessible = + doc ? doc->GetAccessibleOrContainer(aNode) : nullptr; + if (!accessible) return nullptr; + + do { + HyperTextAccessible* textAcc = accessible->AsHyperText(); + if (textAcc) return textAcc; + + accessible = accessible->LocalParent(); + } while (accessible); + + return nullptr; +} + +LayoutDeviceIntPoint nsAccUtils::ConvertToScreenCoords( + int32_t aX, int32_t aY, uint32_t aCoordinateType, Accessible* aAccessible) { + LayoutDeviceIntPoint coords(aX, aY); + + switch (aCoordinateType) { + // Regardless of coordinate type, the coords returned + // are in dev pixels. + case nsIAccessibleCoordinateType::COORDTYPE_SCREEN_RELATIVE: + break; + + case nsIAccessibleCoordinateType::COORDTYPE_WINDOW_RELATIVE: { + coords += GetScreenCoordsForWindow(aAccessible); + break; + } + + case nsIAccessibleCoordinateType::COORDTYPE_PARENT_RELATIVE: { + coords += GetScreenCoordsForParent(aAccessible); + break; + } + + default: + MOZ_ASSERT_UNREACHABLE("invalid coord type!"); + } + + return coords; +} + +void nsAccUtils::ConvertScreenCoordsTo(int32_t* aX, int32_t* aY, + uint32_t aCoordinateType, + Accessible* aAccessible) { + switch (aCoordinateType) { + // Regardless of coordinate type, the values returned for + // aX and aY are in dev pixels. + case nsIAccessibleCoordinateType::COORDTYPE_SCREEN_RELATIVE: + break; + + case nsIAccessibleCoordinateType::COORDTYPE_WINDOW_RELATIVE: { + LayoutDeviceIntPoint coords = GetScreenCoordsForWindow(aAccessible); + *aX -= coords.x; + *aY -= coords.y; + break; + } + + case nsIAccessibleCoordinateType::COORDTYPE_PARENT_RELATIVE: { + LayoutDeviceIntPoint coords = GetScreenCoordsForParent(aAccessible); + *aX -= coords.x; + *aY -= coords.y; + break; + } + + default: + MOZ_ASSERT_UNREACHABLE("invalid coord type!"); + } +} + +LayoutDeviceIntPoint nsAccUtils::GetScreenCoordsForParent( + Accessible* aAccessible) { + if (!aAccessible) return LayoutDeviceIntPoint(); + + if (Accessible* parent = aAccessible->Parent()) { + LayoutDeviceIntRect parentBounds = parent->Bounds(); + // The rect returned from Bounds() is already in dev + // pixels, so we don't need to do any conversion here. + return parentBounds.TopLeft(); + } + + return LayoutDeviceIntPoint(); +} + +LayoutDeviceIntPoint nsAccUtils::GetScreenCoordsForWindow( + Accessible* aAccessible) { + a11y::LocalAccessible* localAcc = aAccessible->AsLocal(); + if (!localAcc) { + localAcc = aAccessible->AsRemote()->OuterDocOfRemoteBrowser(); + } + + LayoutDeviceIntPoint coords(0, 0); + nsCOMPtr<nsIDocShellTreeItem> treeItem( + nsCoreUtils::GetDocShellFor(localAcc->GetNode())); + if (!treeItem) return coords; + + nsCOMPtr<nsIDocShellTreeOwner> treeOwner; + treeItem->GetTreeOwner(getter_AddRefs(treeOwner)); + if (!treeOwner) return coords; + + nsCOMPtr<nsIBaseWindow> baseWindow = do_QueryInterface(treeOwner); + if (baseWindow) { + baseWindow->GetPosition(&coords.x.value, + &coords.y.value); // in device pixels + } + + return coords; +} + +bool nsAccUtils::GetLiveAttrValue(uint32_t aRule, nsAString& aValue) { + switch (aRule) { + case eOffLiveAttr: + aValue = u"off"_ns; + return true; + case ePoliteLiveAttr: + aValue = u"polite"_ns; + return true; + case eAssertiveLiveAttr: + aValue = u"assertive"_ns; + return true; + } + + return false; +} + +#ifdef DEBUG + +bool nsAccUtils::IsTextInterfaceSupportCorrect(LocalAccessible* aAccessible) { + // Don't test for accessible docs, it makes us create accessibles too + // early and fire mutation events before we need to + if (aAccessible->IsDoc()) return true; + + bool foundText = false; + uint32_t childCount = aAccessible->ChildCount(); + for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) { + LocalAccessible* child = aAccessible->LocalChildAt(childIdx); + if (child && child->IsText()) { + foundText = true; + break; + } + } + + return !foundText || aAccessible->IsHyperText(); +} +#endif + +uint32_t nsAccUtils::TextLength(Accessible* aAccessible) { + if (!aAccessible->IsText()) { + return 1; + } + + if (LocalAccessible* localAcc = aAccessible->AsLocal()) { + TextLeafAccessible* textLeaf = localAcc->AsTextLeaf(); + if (textLeaf) { + return textLeaf->Text().Length(); + } + } else if (aAccessible->IsText()) { + MOZ_ASSERT(StaticPrefs::accessibility_cache_enabled_AtStartup(), + "Shouldn't be called on a RemoteAccessible unless the cache is " + "enabled"); + RemoteAccessible* remoteAcc = aAccessible->AsRemote(); + MOZ_ASSERT(remoteAcc); + return remoteAcc->GetCachedTextLength(); + } + + // For list bullets (or anything other accessible which would compute its own + // text. They don't have their own frame. + // XXX In the future, list bullets may have frame and anon content, so + // we should be able to remove this at that point + nsAutoString text; + aAccessible->AppendTextTo(text); // Get all the text + return text.Length(); +} + +bool nsAccUtils::MustPrune(Accessible* aAccessible) { + MOZ_ASSERT(aAccessible); + roles::Role role = aAccessible->Role(); + + if (role == roles::SLIDER || role == roles::PROGRESSBAR) { + // Always prune the tree for sliders and progressbars, as it doesn't make + // sense for either to have descendants. Per the ARIA spec, children of + // these elements are presentational. They also confuse NVDA. + return true; + } + + if (role != roles::MENUITEM && role != roles::COMBOBOX_OPTION && + role != roles::OPTION && role != roles::ENTRY && + role != roles::FLAT_EQUATION && role != roles::PASSWORD_TEXT && + role != roles::PUSHBUTTON && role != roles::TOGGLE_BUTTON && + role != roles::GRAPHIC && role != roles::SEPARATOR) { + // If it doesn't match any of these roles, don't prune its children. + return false; + } + + if (aAccessible->ChildCount() != 1) { + // If the accessible has more than one child, don't prune it. + return false; + } + + roles::Role childRole = aAccessible->FirstChild()->Role(); + // If the accessible's child is a text leaf, prune the accessible. + return childRole == roles::TEXT_LEAF || childRole == roles::STATICTEXT; +} + +bool nsAccUtils::IsARIALive(const LocalAccessible* aAccessible) { + // Get computed aria-live property based on the closest container with the + // attribute. Inner nodes override outer nodes within the same + // document. + // This should be the same as the container-live attribute, but we don't need + // the other container-* attributes, so we can't use the same function. + nsIContent* ancestor = aAccessible->GetContent(); + if (!ancestor) { + return false; + } + dom::Document* doc = ancestor->GetComposedDoc(); + if (!doc) { + return false; + } + dom::Element* topEl = doc->GetRootElement(); + while (ancestor) { + const nsRoleMapEntry* role = nullptr; + if (ancestor->IsElement()) { + role = aria::GetRoleMap(ancestor->AsElement()); + } + nsAutoString live; + if (HasDefinedARIAToken(ancestor, nsGkAtoms::aria_live)) { + GetARIAAttr(ancestor->AsElement(), nsGkAtoms::aria_live, live); + } else if (role) { + GetLiveAttrValue(role->liveAttRule, live); + } else if (nsStaticAtom* value = GetAccService()->MarkupAttribute( + ancestor, nsGkAtoms::aria_live)) { + value->ToString(live); + } + if (!live.IsEmpty() && !live.EqualsLiteral("off")) { + return true; + } + + if (ancestor == topEl) { + break; + } + + ancestor = ancestor->GetParent(); + if (!ancestor) { + ancestor = topEl; // Use <body>/<frameset> + } + } + + return false; +} + +Accessible* nsAccUtils::DocumentFor(Accessible* aAcc) { + if (!aAcc) { + return nullptr; + } + if (LocalAccessible* localAcc = aAcc->AsLocal()) { + return localAcc->Document(); + } + return aAcc->AsRemote()->Document(); +} + +Accessible* nsAccUtils::GetAccessibleByID(Accessible* aDoc, uint64_t aID) { + if (!aDoc) { + return nullptr; + } + if (LocalAccessible* localAcc = aDoc->AsLocal()) { + if (DocAccessible* doc = localAcc->AsDoc()) { + if (!aID) { + // GetAccessibleByUniqueID doesn't treat 0 as the document. + return aDoc; + } + return doc->GetAccessibleByUniqueID( + reinterpret_cast<void*>(static_cast<uintptr_t>(aID))); + } + } else if (DocAccessibleParent* doc = aDoc->AsRemote()->AsDoc()) { + return doc->GetAccessible(aID); + } + return nullptr; +} + +void nsAccUtils::DocumentURL(Accessible* aDoc, nsAString& aURL) { + MOZ_ASSERT(aDoc && aDoc->IsDoc()); + if (LocalAccessible* localAcc = aDoc->AsLocal()) { + return localAcc->AsDoc()->URL(aURL); + } + return aDoc->AsRemote()->AsDoc()->URL(aURL); +} + +// ARIA Accessibility Default Accessors +const AttrArray* nsAccUtils::GetARIADefaults(dom::Element* aElement) { + auto* element = nsGenericHTMLElement::FromNode(aElement); + if (!element) { + return nullptr; + } + auto* internals = element->GetInternals(); + if (!internals) { + return nullptr; + } + return &internals->GetAttrs(); +} + +bool nsAccUtils::HasARIAAttr(dom::Element* aElement, const nsAtom* aName) { + if (aElement->HasAttr(kNameSpaceID_None, aName)) { + return true; + } + const auto* defaults = GetARIADefaults(aElement); + if (!defaults) { + return false; + } + return defaults->HasAttr(kNameSpaceID_None, aName); +} + +bool nsAccUtils::GetARIAAttr(dom::Element* aElement, const nsAtom* aName, + nsAString& aResult) { + if (aElement->GetAttr(kNameSpaceID_None, aName, aResult)) { + return true; + } + const auto* defaults = GetARIADefaults(aElement); + if (!defaults) { + return false; + } + return defaults->GetAttr(kNameSpaceID_None, aName, aResult); +} + +const nsAttrValue* nsAccUtils::GetARIAAttr(dom::Element* aElement, + const nsAtom* aName) { + if (const auto* val = aElement->GetParsedAttr(aName, kNameSpaceID_None)) { + return val; + } + const auto* defaults = GetARIADefaults(aElement); + if (!defaults) { + return nullptr; + } + return defaults->GetAttr(aName, kNameSpaceID_None); +} + +bool nsAccUtils::ARIAAttrValueIs(dom::Element* aElement, const nsAtom* aName, + const nsAString& aValue, + nsCaseTreatment aCaseSensitive) { + if (aElement->AttrValueIs(kNameSpaceID_None, aName, aValue, aCaseSensitive)) { + return true; + } + const auto* defaults = GetARIADefaults(aElement); + if (!defaults) { + return false; + } + return defaults->AttrValueIs(kNameSpaceID_None, aName, aValue, + aCaseSensitive); +} + +bool nsAccUtils::ARIAAttrValueIs(dom::Element* aElement, const nsAtom* aName, + const nsAtom* aValue, + nsCaseTreatment aCaseSensitive) { + if (aElement->AttrValueIs(kNameSpaceID_None, aName, aValue, aCaseSensitive)) { + return true; + } + const auto* defaults = GetARIADefaults(aElement); + if (!defaults) { + return false; + } + return defaults->AttrValueIs(kNameSpaceID_None, aName, aValue, + aCaseSensitive); +} + +int32_t nsAccUtils::FindARIAAttrValueIn(dom::Element* aElement, + const nsAtom* aName, + AttrArray::AttrValuesArray* aValues, + nsCaseTreatment aCaseSensitive) { + int32_t index = aElement->FindAttrValueIn(kNameSpaceID_None, aName, aValues, + aCaseSensitive); + if (index == AttrArray::ATTR_MISSING) { + const auto* defaults = GetARIADefaults(aElement); + if (!defaults) { + return index; + } + index = defaults->FindAttrValueIn(kNameSpaceID_None, aName, aValues, + aCaseSensitive); + } + return index; +} |