import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

accessible/base/AccGroupInfo.cpp

@@ -0,0 +1,227 @@
+/* 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 "nsAccUtils.h"
+
+#include "Role.h"
+#include "States.h"
+
+using namespace mozilla::a11y;
+
+AccGroupInfo::AccGroupInfo(Accessible* aItem, role aRole) :
+  mPosInSet(0), mSetSize(0), mParent(nullptr), mItem(aItem), mRole(aRole)
+{
+  MOZ_COUNT_CTOR(AccGroupInfo);
+  Update();
+}
+
+void
+AccGroupInfo::Update()
+{
+  Accessible* parent = mItem->Parent();
+  if (!parent)
+    return;
+
+  int32_t indexInParent = mItem->IndexInParent();
+  uint32_t siblingCount = parent->ChildCount();
+  if (indexInParent == -1 ||
+      indexInParent >= static_cast<int32_t>(siblingCount)) {
+    NS_ERROR("Wrong index in parent! Tree invalidation problem.");
+    return;
+  }
+
+  int32_t level = nsAccUtils::GetARIAOrDefaultLevel(mItem);
+
+  // Compute position in set.
+  mPosInSet = 1;
+  for (int32_t idx = indexInParent - 1; idx >= 0 ; idx--) {
+    Accessible* sibling = parent->GetChildAt(idx);
+    roles::Role siblingRole = sibling->Role();
+
+    // If the sibling is separator then the group is ended.
+    if (siblingRole == roles::SEPARATOR)
+      break;
+
+    // If sibling is not visible and hasn't the same base role.
+    if (BaseRole(siblingRole) != mRole || sibling->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).
+    int32_t siblingLevel = nsAccUtils::GetARIAOrDefaultLevel(sibling);
+    if (siblingLevel < level) {
+      mParent = sibling;
+      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 (sibling->mBits.groupInfo) {
+      mPosInSet += sibling->mBits.groupInfo->mPosInSet;
+      mParent = sibling->mBits.groupInfo->mParent;
+      mSetSize = sibling->mBits.groupInfo->mSetSize;
+      return;
+    }
+
+    mPosInSet++;
+  }
+
+  // Compute set size.
+  mSetSize = mPosInSet;
+
+  for (uint32_t idx = indexInParent + 1; idx < siblingCount; idx++) {
+    Accessible* sibling = parent->GetChildAt(idx);
+
+    roles::Role siblingRole = sibling->Role();
+
+    // If the sibling is separator then the group is ended.
+    if (siblingRole == roles::SEPARATOR)
+      break;
+
+    // If sibling is visible and has the same base role
+    if (BaseRole(siblingRole) != mRole || sibling->State() & states::INVISIBLE)
+      continue;
+
+    // and check if it's hierarchical flatten structure.
+    int32_t siblingLevel = nsAccUtils::GetARIAOrDefaultLevel(sibling);
+    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 (sibling->mBits.groupInfo) {
+      mParent = sibling->mBits.groupInfo->mParent;
+      mSetSize = sibling->mBits.groupInfo->mSetSize;
+      return;
+    }
+
+    mSetSize++;
+  }
+
+  if (mParent)
+    return;
+
+  roles::Role parentRole = parent->Role();
+  if (ShouldReportRelations(mRole, parentRole))
+    mParent = parent;
+
+  // 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) {
+    Accessible* parentPrevSibling = parent->PrevSibling();
+    if (parentPrevSibling && parentPrevSibling->Role() == mRole) {
+      mParent = parentPrevSibling;
+      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->Parent();
+    if (grandParent && grandParent->Role() == mRole)
+      mParent = grandParent;
+  }
+}
+
+Accessible*
+AccGroupInfo::FirstItemOf(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->GetGroupInfo();
+      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->GetGroupInfo();
+      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;
+}
+
+Accessible*
+AccGroupInfo::NextItemTo(Accessible* aItem)
+{
+  AccGroupInfo* groupInfo = aItem->GetGroupInfo();
+  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->GetChildAt(idx);
+    AccGroupInfo* nextGroupInfo = nextItem->GetGroupInfo();
+    if (nextGroupInfo &&
+        nextGroupInfo->ConceptualParent() == groupInfo->ConceptualParent()) {
+      return nextItem;
+    }
+  }
+
+  NS_NOTREACHED("Item in the middle of the group but there's no next item!");
+  return nullptr;
+}
+
+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;
+}