diff options
Diffstat (limited to '')
| -rw-r--r-- | accessible/base/nsAccUtils.cpp | 519 |
1 files changed, 519 insertions, 0 deletions
diff --git a/accessible/base/nsAccUtils.cpp b/accessible/base/nsAccUtils.cpp new file mode 100644 index 0000000000..49d0af6bd3 --- /dev/null +++ b/accessible/base/nsAccUtils.cpp @@ -0,0 +1,519 @@ +/* -*- 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 "Accessible-inl.h" +#include "ARIAMap.h" +#include "nsAccessibilityService.h" +#include "nsCoreUtils.h" +#include "DocAccessible.h" +#include "HyperTextAccessible.h" +#include "nsIAccessibleTypes.h" +#include "Role.h" +#include "States.h" +#include "TextLeafAccessible.h" + +#include "nsIDOMXULContainerElement.h" +#include "nsIPersistentProperties2.h" +#include "nsISimpleEnumerator.h" +#include "mozilla/a11y/PDocAccessibleChild.h" +#include "mozilla/dom/Document.h" +#include "mozilla/dom/Element.h" +#include "nsAccessibilityService.h" + +using namespace mozilla; +using namespace mozilla::a11y; + +void nsAccUtils::GetAccAttr(nsIPersistentProperties* aAttributes, + nsAtom* aAttrName, nsAString& aAttrValue) { + aAttrValue.Truncate(); + + aAttributes->GetStringProperty(nsAtomCString(aAttrName), aAttrValue); +} + +void nsAccUtils::SetAccAttr(nsIPersistentProperties* aAttributes, + nsAtom* aAttrName, const nsAString& aAttrValue) { + nsAutoString oldValue; + aAttributes->SetStringProperty(nsAtomCString(aAttrName), aAttrValue, + oldValue); +} + +void nsAccUtils::SetAccAttr(nsIPersistentProperties* aAttributes, + nsAtom* aAttrName, nsAtom* aAttrValue) { + nsAutoString oldValue; + aAttributes->SetStringProperty(nsAtomCString(aAttrName), + nsAtomString(aAttrValue), oldValue); +} + +void nsAccUtils::SetAccGroupAttrs(nsIPersistentProperties* aAttributes, + int32_t aLevel, int32_t aSetSize, + int32_t aPosInSet) { + nsAutoString value; + + if (aLevel) { + value.AppendInt(aLevel); + SetAccAttr(aAttributes, nsGkAtoms::level, value); + } + + if (aSetSize && aPosInSet) { + value.Truncate(); + value.AppendInt(aPosInSet); + SetAccAttr(aAttributes, nsGkAtoms::posinset, value); + + value.Truncate(); + value.AppendInt(aSetSize); + SetAccAttr(aAttributes, nsGkAtoms::setsize, value); + } +} + +int32_t nsAccUtils::GetDefaultLevel(const Accessible* aAccessible) { + roles::Role role = aAccessible->Role(); + + if (role == roles::OUTLINEITEM) return 1; + + if (role == roles::ROW) { + Accessible* parent = aAccessible->Parent(); + // It is a row inside flatten treegrid. Group level is always 1 until it + // is overriden by aria-level attribute. + if (parent && parent->Role() == roles::TREE_TABLE) return 1; + } + + return 0; +} + +int32_t nsAccUtils::GetARIAOrDefaultLevel(const Accessible* aAccessible) { + int32_t level = 0; + nsCoreUtils::GetUIntAttr(aAccessible->GetContent(), nsGkAtoms::aria_level, + &level); + + if (level != 0) return level; + + return GetDefaultLevel(aAccessible); +} + +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( + nsIPersistentProperties* aAttributes, nsIContent* aStartContent) { + nsAutoString live, relevant, busy; + dom::Document* doc = aStartContent->GetComposedDoc(); + if (!doc) { + return; + } + dom::Element* topEl = doc->GetRootElement(); + nsIContent* ancestor = aStartContent; + while (ancestor) { + // container-relevant attribute + if (relevant.IsEmpty() && + HasDefinedARIAToken(ancestor, nsGkAtoms::aria_relevant) && + ancestor->AsElement()->GetAttr(kNameSpaceID_None, + nsGkAtoms::aria_relevant, relevant)) + SetAccAttr(aAttributes, nsGkAtoms::containerRelevant, relevant); + + // container-live, and container-live-role attributes + if (live.IsEmpty()) { + const nsRoleMapEntry* role = nullptr; + if (ancestor->IsElement()) { + role = aria::GetRoleMap(ancestor->AsElement()); + } + if (HasDefinedARIAToken(ancestor, nsGkAtoms::aria_live)) { + ancestor->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::aria_live, + live); + } else if (role) { + GetLiveAttrValue(role->liveAttRule, live); + } else if (nsStaticAtom* value = GetAccService()->MarkupAttribute( + ancestor, nsGkAtoms::live)) { + value->ToString(live); + } + + if (!live.IsEmpty()) { + SetAccAttr(aAttributes, nsGkAtoms::containerLive, live); + if (role) { + SetAccAttr(aAttributes, nsGkAtoms::containerLiveRole, + role->ARIARoleString()); + } + } + } + + // container-atomic attribute + if (ancestor->IsElement() && ancestor->AsElement()->AttrValueIs( + kNameSpaceID_None, nsGkAtoms::aria_atomic, + nsGkAtoms::_true, eCaseMatters)) { + SetAccAttr(aAttributes, nsGkAtoms::containerAtomic, u"true"_ns); + } + + // container-busy attribute + if (busy.IsEmpty() && HasDefinedARIAToken(ancestor, nsGkAtoms::aria_busy) && + ancestor->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::aria_busy, + busy)) + SetAccAttr(aAttributes, nsGkAtoms::containerBusy, busy); + + if (ancestor == topEl) { + break; + } + + ancestor = ancestor->GetParent(); + if (!ancestor) { + ancestor = topEl; // Use <body>/<frameset> + } + } +} + +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 (!element->HasAttr(kNameSpaceID_None, aAtom) || + element->AttrValueIs(kNameSpaceID_None, aAtom, nsGkAtoms::_empty, + eCaseMatters) || + element->AttrValueIs(kNameSpaceID_None, aAtom, nsGkAtoms::_undefined, + eCaseMatters)) { + return false; + } + return true; +} + +nsStaticAtom* nsAccUtils::GetARIAToken(dom::Element* aElement, nsAtom* aAttr) { + if (!HasDefinedARIAToken(aElement, aAttr)) return nsGkAtoms::_empty; + + static dom::Element::AttrValuesArray tokens[] = { + nsGkAtoms::_false, nsGkAtoms::_true, nsGkAtoms::mixed, nullptr}; + + int32_t idx = + aElement->FindAttrValueIn(kNameSpaceID_None, aAttr, tokens, eCaseMatters); + if (idx >= 0) return tokens[idx]; + + return nullptr; +} + +nsStaticAtom* nsAccUtils::NormalizeARIAToken(dom::Element* aElement, + nsAtom* aAttr) { + if (!HasDefinedARIAToken(aElement, aAttr)) { + return nsGkAtoms::_empty; + } + + if (aAttr == nsGkAtoms::aria_current) { + static dom::Element::AttrValuesArray tokens[] = { + nsGkAtoms::page, nsGkAtoms::step, nsGkAtoms::location_, + nsGkAtoms::date, nsGkAtoms::time, nsGkAtoms::_true, + nullptr}; + int32_t idx = aElement->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; + } + + return nullptr; +} + +Accessible* nsAccUtils::GetSelectableContainer(Accessible* aAccessible, + uint64_t aState) { + if (!aAccessible) return nullptr; + + if (!(aState & states::SELECTABLE)) return nullptr; + + Accessible* parent = aAccessible; + while ((parent = parent->Parent()) && !parent->IsSelect()) { + if (parent->Role() == roles::PANE) return nullptr; + } + return parent; +} + +bool nsAccUtils::IsDOMAttrTrue(const Accessible* aAccessible, nsAtom* aAttr) { + dom::Element* el = aAccessible->Elm(); + return el && el->AttrValueIs(kNameSpaceID_None, aAttr, nsGkAtoms::_true, + eCaseMatters); +} + +Accessible* nsAccUtils::TableFor(Accessible* aRow) { + if (aRow) { + Accessible* table = aRow->Parent(); + if (table) { + roles::Role tableRole = table->Role(); + const nsRoleMapEntry* roleMapEntry = table->ARIARoleMap(); + if (tableRole == roles::GROUPING || // if there's a rowgroup. + (table->IsGenericHyperText() && !roleMapEntry && + !table->IsTable())) { // or there is a wrapping text container + table = table->Parent(); + if (table) tableRole = table->Role(); + } + + return (tableRole == roles::TABLE || tableRole == roles::TREE_TABLE || + tableRole == roles::MATHML_TABLE) + ? table + : nullptr; + } + } + + return nullptr; +} + +HyperTextAccessible* nsAccUtils::GetTextContainer(nsINode* aNode) { + // Get text accessible containing the result node. + DocAccessible* doc = GetAccService()->GetDocAccessible(aNode->OwnerDoc()); + Accessible* accessible = doc ? doc->GetAccessibleOrContainer(aNode) : nullptr; + if (!accessible) return nullptr; + + do { + HyperTextAccessible* textAcc = accessible->AsHyperText(); + if (textAcc) return textAcc; + + accessible = accessible->Parent(); + } while (accessible); + + return nullptr; +} + +nsIntPoint nsAccUtils::ConvertToScreenCoords(int32_t aX, int32_t aY, + uint32_t aCoordinateType, + Accessible* aAccessible) { + nsIntPoint coords(aX, aY); + + switch (aCoordinateType) { + case nsIAccessibleCoordinateType::COORDTYPE_SCREEN_RELATIVE: + break; + + case nsIAccessibleCoordinateType::COORDTYPE_WINDOW_RELATIVE: { + coords += nsCoreUtils::GetScreenCoordsForWindow(aAccessible->GetNode()); + 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) { + case nsIAccessibleCoordinateType::COORDTYPE_SCREEN_RELATIVE: + break; + + case nsIAccessibleCoordinateType::COORDTYPE_WINDOW_RELATIVE: { + nsIntPoint coords = + nsCoreUtils::GetScreenCoordsForWindow(aAccessible->GetNode()); + *aX -= coords.x; + *aY -= coords.y; + break; + } + + case nsIAccessibleCoordinateType::COORDTYPE_PARENT_RELATIVE: { + nsIntPoint coords = GetScreenCoordsForParent(aAccessible); + *aX -= coords.x; + *aY -= coords.y; + break; + } + + default: + MOZ_ASSERT_UNREACHABLE("invalid coord type!"); + } +} + +nsIntPoint nsAccUtils::GetScreenCoordsForParent(Accessible* aAccessible) { + Accessible* parent = aAccessible->Parent(); + if (!parent) return nsIntPoint(0, 0); + + nsIFrame* parentFrame = parent->GetFrame(); + if (!parentFrame) return nsIntPoint(0, 0); + + nsRect rect = parentFrame->GetScreenRectInAppUnits(); + return nsPoint(rect.X(), rect.Y()) + .ToNearestPixels(parentFrame->PresContext()->AppUnitsPerDevPixel()); +} + +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(Accessible* 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++) { + Accessible* child = aAccessible->GetChildAt(childIdx); + if (child->IsText()) { + foundText = true; + break; + } + } + + return !foundText || aAccessible->IsHyperText(); +} +#endif + +uint32_t nsAccUtils::TextLength(Accessible* aAccessible) { + if (!aAccessible->IsText()) { + return 1; + } + + TextLeafAccessible* textLeaf = aAccessible->AsTextLeaf(); + if (textLeaf) return textLeaf->Text().Length(); + + // 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(AccessibleOrProxy aAccessible) { + MOZ_ASSERT(!aAccessible.IsNull()); + roles::Role role = aAccessible.Role(); + + if (role == roles::SLIDER) { + // Always prune the tree for sliders, as it doesn't make sense for a + // slider to have descendants and this confuses 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::PROGRESSBAR && + 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::PersistentPropertiesToArray(nsIPersistentProperties* aProps, + nsTArray<Attribute>* aAttributes) { + if (!aProps) { + return true; + } + nsCOMPtr<nsISimpleEnumerator> propEnum; + nsresult rv = aProps->Enumerate(getter_AddRefs(propEnum)); + NS_ENSURE_SUCCESS(rv, false); + + bool hasMore; + while (NS_SUCCEEDED(propEnum->HasMoreElements(&hasMore)) && hasMore) { + nsCOMPtr<nsISupports> sup; + rv = propEnum->GetNext(getter_AddRefs(sup)); + NS_ENSURE_SUCCESS(rv, false); + + nsCOMPtr<nsIPropertyElement> propElem(do_QueryInterface(sup)); + NS_ENSURE_TRUE(propElem, false); + + nsAutoCString name; + rv = propElem->GetKey(name); + NS_ENSURE_SUCCESS(rv, false); + + nsAutoString value; + rv = propElem->GetValue(value); + NS_ENSURE_SUCCESS(rv, false); + + aAttributes->AppendElement(Attribute(name, value)); + } + + return true; +} + +bool nsAccUtils::IsARIALive(const Accessible* 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)) { + ancestor->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::aria_live, + live); + } else if (role) { + GetLiveAttrValue(role->liveAttRule, live); + } else if (nsStaticAtom* value = GetAccService()->MarkupAttribute( + ancestor, nsGkAtoms::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; +} |