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Diffstat (limited to 'accessible/base/AccGroupInfo.cpp')
| -rw-r--r-- | accessible/base/AccGroupInfo.cpp | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/accessible/base/AccGroupInfo.cpp b/accessible/base/AccGroupInfo.cpp new file mode 100644 index 0000000000..3b536b1aa4 --- /dev/null +++ b/accessible/base/AccGroupInfo.cpp @@ -0,0 +1,397 @@ +/* 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 "AccGroupInfo.h" +#include "mozilla/a11y/Accessible.h" +#include "mozilla/a11y/TableAccessible.h" + +#include "nsAccUtils.h" +#include "nsIAccessiblePivot.h" + +#include "Pivot.h" +#include "States.h" + +using namespace mozilla::a11y; + +static role BaseRole(role aRole); + +// This rule finds candidate siblings for compound widget children. +class CompoundWidgetSiblingRule : public PivotRule { + public: + CompoundWidgetSiblingRule() = delete; + explicit CompoundWidgetSiblingRule(role aRole) : mRole(aRole) {} + + uint16_t Match(Accessible* aAcc) override { + // If the acc has a matching role, that's a valid sibling. If the acc is + // separator then the group is ended. Return a match for separators with + // the assumption that the caller will check for the role of the returned + // accessible. + const role accRole = aAcc->Role(); + if (BaseRole(accRole) == mRole || accRole == role::SEPARATOR) { + return nsIAccessibleTraversalRule::FILTER_MATCH | + nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE; + } + + // Ignore generic accessibles, but keep searching through the subtree for + // siblings. + if (aAcc->IsGeneric()) { + return nsIAccessibleTraversalRule::FILTER_IGNORE; + } + + return nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE; + } + + private: + role mRole = role::NOTHING; +}; + +AccGroupInfo::AccGroupInfo(const Accessible* aItem, role aRole) + : mPosInSet(0), mSetSize(0), mParentId(0), mItem(aItem), mRole(aRole) { + MOZ_COUNT_CTOR(AccGroupInfo); + Update(); +} + +void AccGroupInfo::Update() { + mParentId = 0; + + Accessible* parent = mItem->GetNonGenericParent(); + if (!parent) { + return; + } + + const int32_t level = GetARIAOrDefaultLevel(mItem); + + // Compute position in set. + mPosInSet = 1; + + // Search backwards through the tree for candidate siblings. + Accessible* candidateSibling = const_cast<Accessible*>(mItem); + Pivot pivot{parent}; + CompoundWidgetSiblingRule widgetSiblingRule{mRole}; + while ((candidateSibling = pivot.Prev(candidateSibling, widgetSiblingRule)) && + candidateSibling != parent) { + // If the sibling is separator then the group is ended. + if (candidateSibling->Role() == roles::SEPARATOR) { + break; + } + + const AccGroupInfo* siblingGroupInfo = candidateSibling->GetGroupInfo(); + // Skip invisible siblings. + // If the sibling has calculated group info, that means it's visible. + if (!siblingGroupInfo && candidateSibling->State() & states::INVISIBLE) { + continue; + } + + // Check if it's hierarchical flatten structure, i.e. if the sibling + // level is lesser than this one then group is ended, if the sibling level + // is greater than this one then the group is split by some child elements + // (group will be continued). + const int32_t siblingLevel = GetARIAOrDefaultLevel(candidateSibling); + if (siblingLevel < level) { + mParentId = candidateSibling->ID(); + break; + } + + // Skip subset. + if (siblingLevel > level) { + continue; + } + + // If the previous item in the group has calculated group information then + // build group information for this item based on found one. + if (siblingGroupInfo) { + mPosInSet += siblingGroupInfo->mPosInSet; + mParentId = siblingGroupInfo->mParentId; + mSetSize = siblingGroupInfo->mSetSize; + return; + } + + mPosInSet++; + } + + // Compute set size. + mSetSize = mPosInSet; + + candidateSibling = const_cast<Accessible*>(mItem); + while ((candidateSibling = pivot.Next(candidateSibling, widgetSiblingRule)) && + candidateSibling != parent) { + // If the sibling is separator then the group is ended. + if (candidateSibling->Role() == roles::SEPARATOR) { + break; + } + + const AccGroupInfo* siblingGroupInfo = candidateSibling->GetGroupInfo(); + // Skip invisible siblings. + // If the sibling has calculated group info, that means it's visible. + if (!siblingGroupInfo && candidateSibling->State() & states::INVISIBLE) { + continue; + } + + // and check if it's hierarchical flatten structure. + const int32_t siblingLevel = GetARIAOrDefaultLevel(candidateSibling); + if (siblingLevel < level) { + break; + } + + // Skip subset. + if (siblingLevel > level) { + continue; + } + + // If the next item in the group has calculated group information then + // build group information for this item based on found one. + if (siblingGroupInfo) { + mParentId = siblingGroupInfo->mParentId; + mSetSize = siblingGroupInfo->mSetSize; + return; + } + + mSetSize++; + } + + if (mParentId) { + return; + } + + roles::Role parentRole = parent->Role(); + if (ShouldReportRelations(mRole, parentRole)) { + mParentId = parent->ID(); + } + + // ARIA tree and list can be arranged by using ARIA groups to organize levels. + if (parentRole != roles::GROUPING) { + return; + } + + // Way #1 for ARIA tree (not ARIA treegrid): previous sibling of a group is a + // parent. In other words the parent of the tree item will be a group and + // the previous tree item of the group is a conceptual parent of the tree + // item. + if (mRole == roles::OUTLINEITEM) { + // Find the relevant grandparent of the item. Use that parent as the root + // and find the previous outline item sibling within that root. + Accessible* grandParent = parent->GetNonGenericParent(); + MOZ_ASSERT(grandParent); + Pivot pivot{grandParent}; + CompoundWidgetSiblingRule parentSiblingRule{mRole}; + Accessible* parentPrevSibling = pivot.Prev(parent, widgetSiblingRule); + if (parentPrevSibling && parentPrevSibling->Role() == mRole) { + mParentId = parentPrevSibling->ID(); + return; + } + } + + // Way #2 for ARIA list and tree: group is a child of an item. In other words + // the parent of the item will be a group and containing item of the group is + // a conceptual parent of the item. + if (mRole == roles::LISTITEM || mRole == roles::OUTLINEITEM) { + Accessible* grandParent = parent->GetNonGenericParent(); + if (grandParent && grandParent->Role() == mRole) { + mParentId = grandParent->ID(); + } + } +} + +AccGroupInfo* AccGroupInfo::CreateGroupInfo(const Accessible* aAccessible) { + mozilla::a11y::role role = aAccessible->Role(); + if (role != mozilla::a11y::roles::ROW && + role != mozilla::a11y::roles::OUTLINEITEM && + role != mozilla::a11y::roles::OPTION && + role != mozilla::a11y::roles::LISTITEM && + role != mozilla::a11y::roles::MENUITEM && + role != mozilla::a11y::roles::COMBOBOX_OPTION && + role != mozilla::a11y::roles::RICH_OPTION && + role != mozilla::a11y::roles::CHECK_RICH_OPTION && + role != mozilla::a11y::roles::PARENT_MENUITEM && + role != mozilla::a11y::roles::CHECK_MENU_ITEM && + role != mozilla::a11y::roles::RADIO_MENU_ITEM && + role != mozilla::a11y::roles::RADIOBUTTON && + role != mozilla::a11y::roles::PAGETAB && + role != mozilla::a11y::roles::COMMENT) { + return nullptr; + } + + AccGroupInfo* info = new AccGroupInfo(aAccessible, BaseRole(role)); + return info; +} + +Accessible* AccGroupInfo::FirstItemOf(const Accessible* aContainer) { + // ARIA tree can be arranged by ARIA groups case #1 (previous sibling of a + // group is a parent) or by aria-level. + a11y::role containerRole = aContainer->Role(); + Accessible* item = aContainer->NextSibling(); + if (item) { + if (containerRole == roles::OUTLINEITEM && + item->Role() == roles::GROUPING) { + item = item->FirstChild(); + } + + if (item) { + AccGroupInfo* itemGroupInfo = item->GetOrCreateGroupInfo(); + if (itemGroupInfo && itemGroupInfo->ConceptualParent() == aContainer) { + return item; + } + } + } + + // ARIA list and tree can be arranged by ARIA groups case #2 (group is + // a child of an item). + item = aContainer->LastChild(); + if (!item) return nullptr; + + if (item->Role() == roles::GROUPING && + (containerRole == roles::LISTITEM || + containerRole == roles::OUTLINEITEM)) { + item = item->FirstChild(); + if (item) { + AccGroupInfo* itemGroupInfo = item->GetOrCreateGroupInfo(); + if (itemGroupInfo && itemGroupInfo->ConceptualParent() == aContainer) { + return item; + } + } + } + + // Otherwise, it can be a direct child if the container is a list or tree. + item = aContainer->FirstChild(); + if (ShouldReportRelations(item->Role(), containerRole)) return item; + + return nullptr; +} + +uint32_t AccGroupInfo::TotalItemCount(Accessible* aContainer, + bool* aIsHierarchical) { + uint32_t itemCount = 0; + switch (aContainer->Role()) { + case roles::TABLE: + if (auto val = aContainer->GetIntARIAAttr(nsGkAtoms::aria_rowcount)) { + if (*val >= 0) { + return *val; + } + } + if (TableAccessible* tableAcc = aContainer->AsTable()) { + return tableAcc->RowCount(); + } + break; + case roles::ROW: + if (Accessible* table = nsAccUtils::TableFor(aContainer)) { + if (auto val = table->GetIntARIAAttr(nsGkAtoms::aria_colcount)) { + if (*val >= 0) { + return *val; + } + } + if (TableAccessible* tableAcc = table->AsTable()) { + return tableAcc->ColCount(); + } + } + break; + case roles::OUTLINE: + case roles::LIST: + case roles::MENUBAR: + case roles::MENUPOPUP: + case roles::COMBOBOX: + case roles::GROUPING: + case roles::TREE_TABLE: + case roles::COMBOBOX_LIST: + case roles::LISTBOX: + case roles::DEFINITION_LIST: + case roles::EDITCOMBOBOX: + case roles::RADIO_GROUP: + case roles::PAGETABLIST: { + Accessible* childItem = AccGroupInfo::FirstItemOf(aContainer); + if (!childItem) { + childItem = aContainer->FirstChild(); + if (childItem && childItem->IsTextLeaf()) { + // First child can be a text leaf, check its sibling for an item. + childItem = childItem->NextSibling(); + } + } + + if (childItem) { + GroupPos groupPos = childItem->GroupPosition(); + itemCount = groupPos.setSize; + if (groupPos.level && aIsHierarchical) { + *aIsHierarchical = true; + } + } + break; + } + default: + break; + } + + return itemCount; +} + +Accessible* AccGroupInfo::NextItemTo(Accessible* aItem) { + AccGroupInfo* groupInfo = aItem->GetOrCreateGroupInfo(); + if (!groupInfo) return nullptr; + + // If the item in middle of the group then search next item in siblings. + if (groupInfo->PosInSet() >= groupInfo->SetSize()) return nullptr; + + Accessible* parent = aItem->Parent(); + uint32_t childCount = parent->ChildCount(); + for (uint32_t idx = aItem->IndexInParent() + 1; idx < childCount; idx++) { + Accessible* nextItem = parent->ChildAt(idx); + AccGroupInfo* nextGroupInfo = nextItem->GetOrCreateGroupInfo(); + if (nextGroupInfo && + nextGroupInfo->ConceptualParent() == groupInfo->ConceptualParent()) { + return nextItem; + } + } + + MOZ_ASSERT_UNREACHABLE( + "Item in the middle of the group but there's no next item!"); + return nullptr; +} + +size_t AccGroupInfo::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) { + // We don't count mParentId or mItem since they (should be) counted + // as part of the document. + return aMallocSizeOf(this); +} + +bool AccGroupInfo::ShouldReportRelations(role aRole, role aParentRole) { + // We only want to report hierarchy-based node relations for items in tree or + // list form. ARIA level/owns relations are always reported. + if (aParentRole == roles::OUTLINE && aRole == roles::OUTLINEITEM) return true; + if (aParentRole == roles::TREE_TABLE && aRole == roles::ROW) return true; + if (aParentRole == roles::LIST && aRole == roles::LISTITEM) return true; + + return false; +} + +int32_t AccGroupInfo::GetARIAOrDefaultLevel(const Accessible* aAccessible) { + int32_t level = 0; + aAccessible->ARIAGroupPosition(&level, nullptr, nullptr); + + if (level != 0) return level; + + return aAccessible->GetLevel(true); +} + +Accessible* AccGroupInfo::ConceptualParent() const { + if (!mParentId) { + // The conceptual parent can never be the document, so id 0 means none. + return nullptr; + } + if (Accessible* doc = + nsAccUtils::DocumentFor(const_cast<Accessible*>(mItem))) { + return nsAccUtils::GetAccessibleByID(doc, mParentId); + } + return nullptr; +} + +static role BaseRole(role aRole) { + if (aRole == roles::CHECK_MENU_ITEM || aRole == roles::PARENT_MENUITEM || + aRole == roles::RADIO_MENU_ITEM) { + return roles::MENUITEM; + } + + if (aRole == roles::CHECK_RICH_OPTION) { + return roles::RICH_OPTION; + } + + return aRole; +} |