1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/accessible/src/base/AccGroupInfo.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,227 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +#include "AccGroupInfo.h"
1.9 +#include "nsAccUtils.h"
1.10 +
1.11 +#include "Role.h"
1.12 +#include "States.h"
1.13 +
1.14 +using namespace mozilla::a11y;
1.15 +
1.16 +AccGroupInfo::AccGroupInfo(Accessible* aItem, role aRole) :
1.17 + mPosInSet(0), mSetSize(0), mParent(nullptr), mItem(aItem), mRole(aRole)
1.18 +{
1.19 + MOZ_COUNT_CTOR(AccGroupInfo);
1.20 + Update();
1.21 +}
1.22 +
1.23 +void
1.24 +AccGroupInfo::Update()
1.25 +{
1.26 + Accessible* parent = mItem->Parent();
1.27 + if (!parent)
1.28 + return;
1.29 +
1.30 + int32_t indexInParent = mItem->IndexInParent();
1.31 + uint32_t siblingCount = parent->ChildCount();
1.32 + if (indexInParent == -1 ||
1.33 + indexInParent >= static_cast<int32_t>(siblingCount)) {
1.34 + NS_ERROR("Wrong index in parent! Tree invalidation problem.");
1.35 + return;
1.36 + }
1.37 +
1.38 + int32_t level = nsAccUtils::GetARIAOrDefaultLevel(mItem);
1.39 +
1.40 + // Compute position in set.
1.41 + mPosInSet = 1;
1.42 + for (int32_t idx = indexInParent - 1; idx >= 0 ; idx--) {
1.43 + Accessible* sibling = parent->GetChildAt(idx);
1.44 + roles::Role siblingRole = sibling->Role();
1.45 +
1.46 + // If the sibling is separator then the group is ended.
1.47 + if (siblingRole == roles::SEPARATOR)
1.48 + break;
1.49 +
1.50 + // If sibling is not visible and hasn't the same base role.
1.51 + if (BaseRole(siblingRole) != mRole || sibling->State() & states::INVISIBLE)
1.52 + continue;
1.53 +
1.54 + // Check if it's hierarchical flatten structure, i.e. if the sibling
1.55 + // level is lesser than this one then group is ended, if the sibling level
1.56 + // is greater than this one then the group is split by some child elements
1.57 + // (group will be continued).
1.58 + int32_t siblingLevel = nsAccUtils::GetARIAOrDefaultLevel(sibling);
1.59 + if (siblingLevel < level) {
1.60 + mParent = sibling;
1.61 + break;
1.62 + }
1.63 +
1.64 + // Skip subset.
1.65 + if (siblingLevel > level)
1.66 + continue;
1.67 +
1.68 + // If the previous item in the group has calculated group information then
1.69 + // build group information for this item based on found one.
1.70 + if (sibling->mGroupInfo) {
1.71 + mPosInSet += sibling->mGroupInfo->mPosInSet;
1.72 + mParent = sibling->mGroupInfo->mParent;
1.73 + mSetSize = sibling->mGroupInfo->mSetSize;
1.74 + return;
1.75 + }
1.76 +
1.77 + mPosInSet++;
1.78 + }
1.79 +
1.80 + // Compute set size.
1.81 + mSetSize = mPosInSet;
1.82 +
1.83 + for (uint32_t idx = indexInParent + 1; idx < siblingCount; idx++) {
1.84 + Accessible* sibling = parent->GetChildAt(idx);
1.85 +
1.86 + roles::Role siblingRole = sibling->Role();
1.87 +
1.88 + // If the sibling is separator then the group is ended.
1.89 + if (siblingRole == roles::SEPARATOR)
1.90 + break;
1.91 +
1.92 + // If sibling is visible and has the same base role
1.93 + if (BaseRole(siblingRole) != mRole || sibling->State() & states::INVISIBLE)
1.94 + continue;
1.95 +
1.96 + // and check if it's hierarchical flatten structure.
1.97 + int32_t siblingLevel = nsAccUtils::GetARIAOrDefaultLevel(sibling);
1.98 + if (siblingLevel < level)
1.99 + break;
1.100 +
1.101 + // Skip subset.
1.102 + if (siblingLevel > level)
1.103 + continue;
1.104 +
1.105 + // If the next item in the group has calculated group information then
1.106 + // build group information for this item based on found one.
1.107 + if (sibling->mGroupInfo) {
1.108 + mParent = sibling->mGroupInfo->mParent;
1.109 + mSetSize = sibling->mGroupInfo->mSetSize;
1.110 + return;
1.111 + }
1.112 +
1.113 + mSetSize++;
1.114 + }
1.115 +
1.116 + if (mParent)
1.117 + return;
1.118 +
1.119 + roles::Role parentRole = parent->Role();
1.120 + if (ShouldReportRelations(mRole, parentRole))
1.121 + mParent = parent;
1.122 +
1.123 + // ARIA tree and list can be arranged by using ARIA groups to organize levels.
1.124 + if (parentRole != roles::GROUPING)
1.125 + return;
1.126 +
1.127 + // Way #1 for ARIA tree (not ARIA treegrid): previous sibling of a group is a
1.128 + // parent. In other words the parent of the tree item will be a group and
1.129 + // the previous tree item of the group is a conceptual parent of the tree
1.130 + // item.
1.131 + if (mRole == roles::OUTLINEITEM) {
1.132 + Accessible* parentPrevSibling = parent->PrevSibling();
1.133 + if (parentPrevSibling && parentPrevSibling->Role() == mRole) {
1.134 + mParent = parentPrevSibling;
1.135 + return;
1.136 + }
1.137 + }
1.138 +
1.139 + // Way #2 for ARIA list and tree: group is a child of an item. In other words
1.140 + // the parent of the item will be a group and containing item of the group is
1.141 + // a conceptual parent of the item.
1.142 + if (mRole == roles::LISTITEM || mRole == roles::OUTLINEITEM) {
1.143 + Accessible* grandParent = parent->Parent();
1.144 + if (grandParent && grandParent->Role() == mRole)
1.145 + mParent = grandParent;
1.146 + }
1.147 +}
1.148 +
1.149 +Accessible*
1.150 +AccGroupInfo::FirstItemOf(Accessible* aContainer)
1.151 +{
1.152 + // ARIA tree can be arranged by ARIA groups case #1 (previous sibling of a
1.153 + // group is a parent) or by aria-level.
1.154 + a11y::role containerRole = aContainer->Role();
1.155 + Accessible* item = aContainer->NextSibling();
1.156 + if (item) {
1.157 + if (containerRole == roles::OUTLINEITEM && item->Role() == roles::GROUPING)
1.158 + item = item->FirstChild();
1.159 +
1.160 + if (item) {
1.161 + AccGroupInfo* itemGroupInfo = item->GetGroupInfo();
1.162 + if (itemGroupInfo && itemGroupInfo->ConceptualParent() == aContainer)
1.163 + return item;
1.164 + }
1.165 + }
1.166 +
1.167 + // ARIA list and tree can be arranged by ARIA groups case #2 (group is
1.168 + // a child of an item).
1.169 + item = aContainer->LastChild();
1.170 + if (!item)
1.171 + return nullptr;
1.172 +
1.173 + if (item->Role() == roles::GROUPING &&
1.174 + (containerRole == roles::LISTITEM || containerRole == roles::OUTLINEITEM)) {
1.175 + item = item->FirstChild();
1.176 + if (item) {
1.177 + AccGroupInfo* itemGroupInfo = item->GetGroupInfo();
1.178 + if (itemGroupInfo && itemGroupInfo->ConceptualParent() == aContainer)
1.179 + return item;
1.180 + }
1.181 + }
1.182 +
1.183 + // Otherwise, it can be a direct child if the container is a list or tree.
1.184 + item = aContainer->FirstChild();
1.185 + if (ShouldReportRelations(item->Role(), containerRole))
1.186 + return item;
1.187 +
1.188 + return nullptr;
1.189 +}
1.190 +
1.191 +Accessible*
1.192 +AccGroupInfo::NextItemTo(Accessible* aItem)
1.193 +{
1.194 + AccGroupInfo* groupInfo = aItem->GetGroupInfo();
1.195 + if (!groupInfo)
1.196 + return nullptr;
1.197 +
1.198 + // If the item in middle of the group then search next item in siblings.
1.199 + if (groupInfo->PosInSet() >= groupInfo->SetSize())
1.200 + return nullptr;
1.201 +
1.202 + Accessible* parent = aItem->Parent();
1.203 + uint32_t childCount = parent->ChildCount();
1.204 + for (int32_t idx = aItem->IndexInParent() + 1; idx < childCount; idx++) {
1.205 + Accessible* nextItem = parent->GetChildAt(idx);
1.206 + AccGroupInfo* nextGroupInfo = nextItem->GetGroupInfo();
1.207 + if (nextGroupInfo &&
1.208 + nextGroupInfo->ConceptualParent() == groupInfo->ConceptualParent()) {
1.209 + return nextItem;
1.210 + }
1.211 + }
1.212 +
1.213 + NS_NOTREACHED("Item in the middle of the group but there's no next item!");
1.214 + return nullptr;
1.215 +}
1.216 +
1.217 +bool
1.218 +AccGroupInfo::ShouldReportRelations(role aRole, role aParentRole)
1.219 +{
1.220 + // We only want to report hierarchy-based node relations for items in tree or
1.221 + // list form. ARIA level/owns relations are always reported.
1.222 + if (aParentRole == roles::OUTLINE && aRole == roles::OUTLINEITEM)
1.223 + return true;
1.224 + if (aParentRole == roles::TREE_TABLE && aRole == roles::ROW)
1.225 + return true;
1.226 + if (aParentRole == roles::LIST && aRole == roles::LISTITEM)
1.227 + return true;
1.228 +
1.229 + return false;
1.230 +}
