third_party/WebKit/Source/modules/accessibility/AXTableCell.cpp - chromium/src.git - Git at Google

 /*
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  *     its contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "modules/accessibility/AXTableCell.h"

 #include "core/dom/AccessibleNode.h"
 #include "core/layout/LayoutTableCell.h"
 #include "modules/accessibility/AXObjectCacheImpl.h"
 #include "modules/accessibility/AXTableRow.h"

 namespace blink {

 using namespace HTMLNames;

 AXTableCell::AXTableCell(LayoutObject* layout_object,
                          AXObjectCacheImpl& ax_object_cache)
     : AXLayoutObject(layout_object, ax_object_cache) {}

 AXTableCell::~AXTableCell() = default;

 AXTableCell* AXTableCell::Create(LayoutObject* layout_object,
                                  AXObjectCacheImpl& ax_object_cache) {
   return new AXTableCell(layout_object, ax_object_cache);
 }

 bool AXTableCell::IsTableHeaderCell() const {
   return GetNode() && GetNode()->HasTagName(thTag);
 }

 bool AXTableCell::IsRowHeaderCell() const {
   const AtomicString& scope = GetAttribute(scopeAttr);
   return EqualIgnoringASCIICase(scope, "row") ||
          EqualIgnoringASCIICase(scope, "rowgroup");
 }

 bool AXTableCell::IsColumnHeaderCell() const {
   const AtomicString& scope = GetAttribute(scopeAttr);
   return EqualIgnoringASCIICase(scope, "col") ||
          EqualIgnoringASCIICase(scope, "colgroup");
 }

 bool AXTableCell::ComputeAccessibilityIsIgnored(
     IgnoredReasons* ignored_reasons) const {
   AXObjectInclusion decision = DefaultObjectInclusion(ignored_reasons);
   if (decision == kIncludeObject)
     return false;
   if (decision == kIgnoreObject)
     return true;

   if (!IsTableCell())
     return AXLayoutObject::ComputeAccessibilityIsIgnored(ignored_reasons);

   return false;
 }

 AXObject* AXTableCell::ParentTable() const {
   if (!layout_object_ || !layout_object_->IsTableCell())
     return nullptr;

   // If the document no longer exists, we might not have an axObjectCache.
   if (IsDetached())
     return nullptr;

   // Do not use getOrCreate. parentTable() can be called while the layout tree
   // is being modified by javascript, and creating a table element may try to
   // access the layout tree while in a bad state.  By using only get() implies
   // that the AXTable must be created before AXTableCells. This should always be
   // the case when AT clients access a table.
   // https://bugs.webkit.org/show_bug.cgi?id=42652
   return AXObjectCache().Get(ToLayoutTableCell(layout_object_)->Table());
 }

 AXObject* AXTableCell::ParentRow() const {
   if (!layout_object_ || !layout_object_->IsTableCell())
     return nullptr;

   // If the document no longer exists, we might not have an axObjectCache.
   if (IsDetached())
     return nullptr;

   return AXObjectCache().Get(ToLayoutTableCell(layout_object_)->Row());
 }

 bool AXTableCell::IsTableCell() const {
   AXObject* row = ParentRow();
   return row && row->IsTableRow();
 }

 unsigned AXTableCell::AriaColumnIndex() const {
   uint32_t col_index;
   if (HasAOMPropertyOrARIAAttribute(AOMUIntProperty::kColIndex, col_index) &&
       col_index >= 1) {
     return col_index;
   }

   AXObject* parent = ParentRow();
   return parent ? aria_col_index_from_row_ : 0;
 }

 unsigned AXTableCell::AriaRowIndex() const {
   uint32_t row_index;
   if (HasAOMPropertyOrARIAAttribute(AOMUIntProperty::kRowIndex, row_index) &&
       row_index >= 1) {
     return row_index;
   }

   AXObject* parent = ParentRow();
   return parent ? ToAXTableRow(parent)->AriaRowIndex() : 0;
 }

 static AccessibilityRole DecideRoleFromSibling(LayoutTableCell* sibling_cell) {
   if (!sibling_cell)
     return kCellRole;

   if (Node* sibling_node = sibling_cell->GetNode()) {
     if (sibling_node->HasTagName(thTag))
       return kColumnHeaderRole;
     if (sibling_node->HasTagName(tdTag))
       return kRowHeaderRole;
   }

   return kCellRole;
 }

 AccessibilityRole AXTableCell::ScanToDecideHeaderRole() {
   if (!IsTableHeaderCell())
     return kCellRole;

   // Check scope attribute first.
   if (IsRowHeaderCell())
     return kRowHeaderRole;

   if (IsColumnHeaderCell())
     return kColumnHeaderRole;

   // This occurs in an edge case that mixes non-table CSS into a
   // table, and <th role="gridcell">, see bug 798410.
   // The odd CSS causes the <th> to not be a LayoutTableCell,
   // and the ARIA role causes it to fall through to here, because
   // it is not an ARIA/HTML column/row header.
   if (!layout_object_ || !layout_object_->IsTableCell())
     return kCellRole;  // <th role="gridcell">.

   // Check the previous cell and the next cell on the same row.
   LayoutTableCell* layout_cell = ToLayoutTableCell(layout_object_);
   AccessibilityRole header_role = kCellRole;

   // if header is preceded by header cells on the same row, then it is a
   // column header. If it is preceded by other cells then it's a row header.
   if ((header_role = DecideRoleFromSibling(layout_cell->PreviousCell())) !=
       kCellRole)
     return header_role;

   // if header is followed by header cells on the same row, then it is a
   // column header. If it is followed by other cells then it's a row header.
   if ((header_role = DecideRoleFromSibling(layout_cell->NextCell())) !=
       kCellRole)
     return header_role;

   // If there are no other cells on that row, then it is a column header.
   return kColumnHeaderRole;
 }

 AccessibilityRole AXTableCell::DetermineAccessibilityRole() {
   if (!IsTableCell())
     return AXLayoutObject::DetermineAccessibilityRole();

   if (!ParentTable()->IsDataTable())
     return kLayoutTableCellRole;

   aria_role_ = DetermineAriaRoleAttribute();
   return ScanToDecideHeaderRole();
 }

 bool AXTableCell::RowIndexRange(
     std::pair<unsigned, unsigned>& row_range) const {
   if (!layout_object_ || !layout_object_->IsTableCell())
     return false;

   LayoutTableCell* layout_cell = ToLayoutTableCell(layout_object_);
   row_range.first = layout_cell->RowIndex();
   row_range.second = layout_cell->ResolvedRowSpan();

   // Since our table might have multiple sections, we have to offset our row
   // appropriately.
   LayoutTableSection* section = layout_cell->Section();
   LayoutTable* table = layout_cell->Table();
   if (!table || !section)
     return false;

   LayoutTableSection* table_section = table->TopSection();
   unsigned row_offset = 0;
   while (table_section) {
     if (table_section == section)
       break;
     row_offset += table_section->NumRows();
     table_section = table->SectionBelow(table_section, kSkipEmptySections);
   }

   row_range.first += row_offset;
   return true;
 }

 bool AXTableCell::ColumnIndexRange(
     std::pair<unsigned, unsigned>& column_range) const {
   if (!layout_object_ || !layout_object_->IsTableCell())
     return false;

   LayoutTableCell* cell = ToLayoutTableCell(layout_object_);
   column_range.first = cell->Table()->AbsoluteColumnToEffectiveColumn(
       cell->AbsoluteColumnIndex());

   column_range.second = cell->Table()->AbsoluteColumnToEffectiveColumn(
                             cell->AbsoluteColumnIndex() + cell->ColSpan()) -
                         column_range.first;

   return true;
 }

 SortDirection AXTableCell::GetSortDirection() const {
   if (RoleValue() != kRowHeaderRole && RoleValue() != kColumnHeaderRole)
     return kSortDirectionUndefined;

   const AtomicString& aria_sort =
       GetAOMPropertyOrARIAAttribute(AOMStringProperty::kSort);
   if (aria_sort.IsEmpty())
     return kSortDirectionUndefined;
   if (EqualIgnoringASCIICase(aria_sort, "none"))
     return kSortDirectionNone;
   if (EqualIgnoringASCIICase(aria_sort, "ascending"))
     return kSortDirectionAscending;
   if (EqualIgnoringASCIICase(aria_sort, "descending"))
     return kSortDirectionDescending;
   // Technically, illegal values should be exposed as is, but this does
   // not seem to be worth the implementation effort at this time.
   return kSortDirectionOther;
 }

 }  // namespace blink
	/*
	* Copyright (C) 2008 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	*
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
	* its contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "modules/accessibility/AXTableCell.h"

	#include "core/dom/AccessibleNode.h"
	#include "core/layout/LayoutTableCell.h"
	#include "modules/accessibility/AXObjectCacheImpl.h"
	#include "modules/accessibility/AXTableRow.h"

	namespace blink {

	using namespace HTMLNames;

	AXTableCell::AXTableCell(LayoutObject* layout_object,
	AXObjectCacheImpl& ax_object_cache)
	: AXLayoutObject(layout_object, ax_object_cache) {}

	AXTableCell::~AXTableCell() = default;

	AXTableCell* AXTableCell::Create(LayoutObject* layout_object,
	AXObjectCacheImpl& ax_object_cache) {
	return new AXTableCell(layout_object, ax_object_cache);
	}

	bool AXTableCell::IsTableHeaderCell() const {
	return GetNode() && GetNode()->HasTagName(thTag);
	}

	bool AXTableCell::IsRowHeaderCell() const {
	const AtomicString& scope = GetAttribute(scopeAttr);
	return EqualIgnoringASCIICase(scope, "row") \|\|
	EqualIgnoringASCIICase(scope, "rowgroup");
	}

	bool AXTableCell::IsColumnHeaderCell() const {
	const AtomicString& scope = GetAttribute(scopeAttr);
	return EqualIgnoringASCIICase(scope, "col") \|\|
	EqualIgnoringASCIICase(scope, "colgroup");
	}

	bool AXTableCell::ComputeAccessibilityIsIgnored(
	IgnoredReasons* ignored_reasons) const {
	AXObjectInclusion decision = DefaultObjectInclusion(ignored_reasons);
	if (decision == kIncludeObject)
	return false;
	if (decision == kIgnoreObject)
	return true;

	if (!IsTableCell())
	return AXLayoutObject::ComputeAccessibilityIsIgnored(ignored_reasons);

	return false;
	}

	AXObject* AXTableCell::ParentTable() const {
	if (!layout_object_ \|\| !layout_object_->IsTableCell())
	return nullptr;

	// If the document no longer exists, we might not have an axObjectCache.
	if (IsDetached())
	return nullptr;

	// Do not use getOrCreate. parentTable() can be called while the layout tree
	// is being modified by javascript, and creating a table element may try to
	// access the layout tree while in a bad state. By using only get() implies
	// that the AXTable must be created before AXTableCells. This should always be
	// the case when AT clients access a table.
	// https://bugs.webkit.org/show_bug.cgi?id=42652
	return AXObjectCache().Get(ToLayoutTableCell(layout_object_)->Table());
	}

	AXObject* AXTableCell::ParentRow() const {
	if (!layout_object_ \|\| !layout_object_->IsTableCell())
	return nullptr;

	// If the document no longer exists, we might not have an axObjectCache.
	if (IsDetached())
	return nullptr;

	return AXObjectCache().Get(ToLayoutTableCell(layout_object_)->Row());
	}

	bool AXTableCell::IsTableCell() const {
	AXObject* row = ParentRow();
	return row && row->IsTableRow();
	}

	unsigned AXTableCell::AriaColumnIndex() const {
	uint32_t col_index;
	if (HasAOMPropertyOrARIAAttribute(AOMUIntProperty::kColIndex, col_index) &&
	col_index >= 1) {
	return col_index;
	}

	AXObject* parent = ParentRow();
	return parent ? aria_col_index_from_row_ : 0;
	}

	unsigned AXTableCell::AriaRowIndex() const {
	uint32_t row_index;
	if (HasAOMPropertyOrARIAAttribute(AOMUIntProperty::kRowIndex, row_index) &&
	row_index >= 1) {
	return row_index;
	}

	AXObject* parent = ParentRow();
	return parent ? ToAXTableRow(parent)->AriaRowIndex() : 0;
	}

	static AccessibilityRole DecideRoleFromSibling(LayoutTableCell* sibling_cell) {
	if (!sibling_cell)
	return kCellRole;

	if (Node* sibling_node = sibling_cell->GetNode()) {
	if (sibling_node->HasTagName(thTag))
	return kColumnHeaderRole;
	if (sibling_node->HasTagName(tdTag))
	return kRowHeaderRole;
	}

	return kCellRole;
	}

	AccessibilityRole AXTableCell::ScanToDecideHeaderRole() {
	if (!IsTableHeaderCell())
	return kCellRole;

	// Check scope attribute first.
	if (IsRowHeaderCell())
	return kRowHeaderRole;

	if (IsColumnHeaderCell())
	return kColumnHeaderRole;

	// This occurs in an edge case that mixes non-table CSS into a
	// table, and <th role="gridcell">, see bug 798410.
	// The odd CSS causes the <th> to not be a LayoutTableCell,
	// and the ARIA role causes it to fall through to here, because
	// it is not an ARIA/HTML column/row header.
	if (!layout_object_ \|\| !layout_object_->IsTableCell())
	return kCellRole; // <th role="gridcell">.

	// Check the previous cell and the next cell on the same row.
	LayoutTableCell* layout_cell = ToLayoutTableCell(layout_object_);
	AccessibilityRole header_role = kCellRole;

	// if header is preceded by header cells on the same row, then it is a
	// column header. If it is preceded by other cells then it's a row header.
	if ((header_role = DecideRoleFromSibling(layout_cell->PreviousCell())) !=
	kCellRole)
	return header_role;

	// if header is followed by header cells on the same row, then it is a
	// column header. If it is followed by other cells then it's a row header.
	if ((header_role = DecideRoleFromSibling(layout_cell->NextCell())) !=
	kCellRole)
	return header_role;

	// If there are no other cells on that row, then it is a column header.
	return kColumnHeaderRole;
	}

	AccessibilityRole AXTableCell::DetermineAccessibilityRole() {
	if (!IsTableCell())
	return AXLayoutObject::DetermineAccessibilityRole();

	if (!ParentTable()->IsDataTable())
	return kLayoutTableCellRole;

	aria_role_ = DetermineAriaRoleAttribute();
	return ScanToDecideHeaderRole();
	}

	bool AXTableCell::RowIndexRange(
	std::pair<unsigned, unsigned>& row_range) const {
	if (!layout_object_ \|\| !layout_object_->IsTableCell())
	return false;

	LayoutTableCell* layout_cell = ToLayoutTableCell(layout_object_);
	row_range.first = layout_cell->RowIndex();
	row_range.second = layout_cell->ResolvedRowSpan();

	// Since our table might have multiple sections, we have to offset our row
	// appropriately.
	LayoutTableSection* section = layout_cell->Section();
	LayoutTable* table = layout_cell->Table();
	if (!table \|\| !section)
	return false;

	LayoutTableSection* table_section = table->TopSection();
	unsigned row_offset = 0;
	while (table_section) {
	if (table_section == section)
	break;
	row_offset += table_section->NumRows();
	table_section = table->SectionBelow(table_section, kSkipEmptySections);
	}

	row_range.first += row_offset;
	return true;
	}

	bool AXTableCell::ColumnIndexRange(
	std::pair<unsigned, unsigned>& column_range) const {
	if (!layout_object_ \|\| !layout_object_->IsTableCell())
	return false;

	LayoutTableCell* cell = ToLayoutTableCell(layout_object_);
	column_range.first = cell->Table()->AbsoluteColumnToEffectiveColumn(
	cell->AbsoluteColumnIndex());

	column_range.second = cell->Table()->AbsoluteColumnToEffectiveColumn(
	cell->AbsoluteColumnIndex() + cell->ColSpan()) -
	column_range.first;

	return true;
	}

	SortDirection AXTableCell::GetSortDirection() const {
	if (RoleValue() != kRowHeaderRole && RoleValue() != kColumnHeaderRole)
	return kSortDirectionUndefined;

	const AtomicString& aria_sort =
	GetAOMPropertyOrARIAAttribute(AOMStringProperty::kSort);
	if (aria_sort.IsEmpty())
	return kSortDirectionUndefined;
	if (EqualIgnoringASCIICase(aria_sort, "none"))
	return kSortDirectionNone;
	if (EqualIgnoringASCIICase(aria_sort, "ascending"))
	return kSortDirectionAscending;
	if (EqualIgnoringASCIICase(aria_sort, "descending"))
	return kSortDirectionDescending;
	// Technically, illegal values should be exposed as is, but this does
	// not seem to be worth the implementation effort at this time.
	return kSortDirectionOther;
	}

	} // namespace blink