Table column headers not exposed appropriately in Mac accessibility

- On existing column headers, we should expose nothing for
AXColumnHeaderUIElements.
- For cells, we should expose only the column headers that are used for that cell,
not all of them as we currently do.
- The children of a column should be exposed (this is what actually fixes the VoiceOver issue in the bug).
- The children and visibleChildren should be the same.

Bug: 775167
Change-Id: Ief4d1ee80cd759250041e78e95e643030c14b361
Reviewed-on: https://chromium-review.googlesource.com/721420
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512707}

content/browser/accessibility/browser_accessibility_cocoa.h

@@ -83,6 +83,9 @@ struct AXTextEdit {
 - (NSString*)valueForRange:(NSRange)range;
 - (NSAttributedString*)attributedValueForRange:(NSRange)range;
 
+- (BOOL)isRowHeaderForCurrentCell:(content::BrowserAccessibility*)header;
+- (BOOL)isColumnHeaderForCurrentCell:(content::BrowserAccessibility*)header;
+
 // Internally-used property.
 @property(nonatomic, readonly) NSPoint origin;
 

content/browser/accessibility/browser_accessibility_cocoa.mm

@@ -805,13 +805,55 @@ NSString* const NSAccessibilityRequiredAttributeChrome = @"AXRequired";
   }
 }
 
+- (BOOL)isColumnHeaderForCurrentCell:(BrowserAccessibility*)header {
+  int cell_first_col = -1;
+  int cell_colspan = -1;
+  browserAccessibility_->GetIntAttribute(ui::AX_ATTR_ARIA_CELL_COLUMN_INDEX,
+                                         &cell_first_col);
+  if (cell_first_col < 0) {
+    browserAccessibility_->GetIntAttribute(ui::AX_ATTR_TABLE_CELL_COLUMN_INDEX,
+                                           &cell_first_col);
+  }
+  if (cell_first_col < 0)
+    return false;
+  browserAccessibility_->GetIntAttribute(ui::AX_ATTR_TABLE_CELL_COLUMN_SPAN,
+                                         &cell_colspan);
+  if (cell_colspan <= 0)
+    cell_colspan = 1;
+  int cell_last_col = cell_first_col + cell_colspan - 1;
+
+  int header_first_col = -1;
+  int header_colspan = -1;
+  header->GetIntAttribute(ui::AX_ATTR_ARIA_CELL_COLUMN_INDEX,
+                          &header_first_col);
+  if (header_first_col < 0) {
+    header->GetIntAttribute(ui::AX_ATTR_TABLE_CELL_COLUMN_INDEX,
+                            &header_first_col);
+  }
+  if (header_first_col < 0)
+    return false;
+
+  header->GetIntAttribute(ui::AX_ATTR_TABLE_CELL_COLUMN_SPAN, &header_colspan);
+  if (header_colspan <= 0)
+    header_colspan = 1;
+  int header_last_col = header_first_col + header_colspan - 1;
+
+  int topmost_col_of_either = std::max(cell_first_col, header_first_col);
+  int bottommost_col_of_either = std::min(cell_last_col, header_last_col);
+  bool has_col_intersection = topmost_col_of_either <= bottommost_col_of_either;
+
+  return has_col_intersection;
+}
+
 - (NSArray*)columnHeaders {
   if (![self instanceActive])
     return nil;
-  if (!ui::IsTableLikeRole(browserAccessibility_->GetRole()) &&
-      !ui::IsCellOrTableHeaderRole(browserAccessibility_->GetRole())) {
+
+  bool is_cell_or_table_header =
+      ui::IsCellOrTableHeaderRole(browserAccessibility_->GetRole());
+  bool is_table_like = ui::IsTableLikeRole(browserAccessibility_->GetRole());
+  if (!is_table_like && !is_cell_or_table_header)
     return nil;
-  }
   BrowserAccessibility* table = [self containingTable];
   if (!table)
     return nil;
@@ -823,10 +865,14 @@ NSString* const NSAccessibilityRequiredAttributeChrome = @"AXRequired";
     int id = uniqueCellIds[i];
     BrowserAccessibility* cell =
         browserAccessibility_->manager()->GetFromID(id);
-    if (cell && cell->GetRole() == ui::AX_ROLE_COLUMN_HEADER)
-      [ret addObject:ToBrowserAccessibilityCocoa(cell)];
+    if (cell && cell->GetRole() == ui::AX_ROLE_COLUMN_HEADER) {
+      // Expose all column headers on table object.
+      // Expose only relevant column headers on cell object.
+      if (is_table_like || [self isColumnHeaderForCurrentCell:cell])
+        [ret addObject:ToBrowserAccessibilityCocoa(cell)];
+    }
   }
-  return ret;
+  return [ret count] ? ret : nil;
 }
 
 - (NSValue*)columnIndexRange {
@@ -1617,13 +1663,56 @@ NSString* const NSAccessibilityRequiredAttributeChrome = @"AXRequired";
   return NSAccessibilityRoleDescription(role, nil);
 }
 
+- (BOOL)isRowHeaderForCurrentCell:(BrowserAccessibility*)header {
+  int cell_first_row = -1;
+  int cell_rowspan = -1;
+  browserAccessibility_->GetIntAttribute(ui::AX_ATTR_ARIA_CELL_ROW_INDEX,
+                                         &cell_first_row);
+  if (cell_first_row < 0) {
+    browserAccessibility_->GetIntAttribute(ui::AX_ATTR_TABLE_CELL_ROW_INDEX,
+                                           &cell_first_row);
+  }
+  if (cell_first_row < 0)
+    return false;
+
+  browserAccessibility_->GetIntAttribute(ui::AX_ATTR_TABLE_CELL_ROW_SPAN,
+                                         &cell_rowspan);
+  if (cell_rowspan <= 0)
+    cell_rowspan = 1;
+
+  int cell_last_row = cell_first_row + cell_rowspan - 1;
+
+  int header_first_row = -1;
+  int header_rowspan = -1;
+  header->GetIntAttribute(ui::AX_ATTR_ARIA_CELL_ROW_INDEX, &header_first_row);
+  if (header_first_row < 0) {
+    header->GetIntAttribute(ui::AX_ATTR_TABLE_CELL_ROW_INDEX,
+                            &header_first_row);
+  }
+  if (header_first_row < 0)
+    return false;
+
+  header->GetIntAttribute(ui::AX_ATTR_TABLE_CELL_ROW_SPAN, &header_rowspan);
+  if (header_rowspan <= 0)
+    header_rowspan = 1;
+
+  int header_last_row = header_first_row + header_rowspan - 1;
+
+  int topmost_row_of_either = std::max(cell_first_row, header_first_row);
+  int bottommost_row_of_either = std::min(cell_last_row, header_last_row);
+  bool has_row_intersection = topmost_row_of_either <= bottommost_row_of_either;
+
+  return has_row_intersection;
+}
+
 - (NSArray*)rowHeaders {
   if (![self instanceActive])
     return nil;
-  if (!ui::IsTableLikeRole(browserAccessibility_->GetRole()) &&
-      !ui::IsCellOrTableHeaderRole(browserAccessibility_->GetRole())) {
+  bool is_cell_or_table_header =
+      ui::IsCellOrTableHeaderRole(browserAccessibility_->GetRole());
+  bool is_table_like = ui::IsTableLikeRole(browserAccessibility_->GetRole());
+  if (!is_table_like && !is_cell_or_table_header)
     return nil;
-  }
   BrowserAccessibility* table = [self containingTable];
   if (!table)
     return nil;
@@ -1635,10 +1724,12 @@ NSString* const NSAccessibilityRequiredAttributeChrome = @"AXRequired";
     int id = uniqueCellIds[i];
     BrowserAccessibility* cell =
         browserAccessibility_->manager()->GetFromID(id);
-    if (cell && cell->GetRole() == ui::AX_ROLE_ROW_HEADER)
-      [ret addObject:ToBrowserAccessibilityCocoa(cell)];
+    if (cell && cell->GetRole() == ui::AX_ROLE_ROW_HEADER) {
+      if (is_table_like || [self isRowHeaderForCurrentCell:cell])
+        [ret addObject:ToBrowserAccessibilityCocoa(cell)];
+    }
   }
-  return ret;
+  return [ret count] ? ret : nil;
 }
 
 - (NSValue*)rowIndexRange {
@@ -2054,17 +2145,7 @@ NSString* const NSAccessibilityRequiredAttributeChrome = @"AXRequired";
 - (NSArray*)visibleChildren {
   if (![self instanceActive])
     return nil;
-  NSMutableArray* ret = [[[NSMutableArray alloc] init] autorelease];
-  uint32_t childCount = browserAccessibility_->PlatformChildCount();
-  for (uint32_t index = 0; index < childCount; ++index) {
-    BrowserAccessibilityCocoa* child = ToBrowserAccessibilityCocoa(
-        browserAccessibility_->PlatformGetChild(index));
-    if ([child isIgnored])
-      [ret addObjectsFromArray:[child visibleChildren]];
-    else
-      [ret addObject:child];
-  }
-  return ret;
+  return [self children];
 }
 
 - (NSArray*)visibleColumns {
@@ -2753,12 +2834,20 @@ NSString* const NSAccessibilityRequiredAttributeChrome = @"AXRequired";
     [ret addObjectsFromArray:@[
       NSAccessibilityColumnIndexRangeAttribute,
       NSAccessibilityRowIndexRangeAttribute,
-      NSAccessibilityColumnHeaderUIElementsAttribute,
-      NSAccessibilityRowHeaderUIElementsAttribute,
       NSAccessibilityARIAColumnIndexAttribute,
       NSAccessibilityARIARowIndexAttribute,
       @"AXSortDirection",
     ]];
+    if ([self internalRole] != ui::AX_ROLE_COLUMN_HEADER) {
+      [ret addObjectsFromArray:@[
+        NSAccessibilityColumnHeaderUIElementsAttribute,
+      ]];
+    }
+    if ([self internalRole] != ui::AX_ROLE_ROW_HEADER) {
+      [ret addObjectsFromArray:@[
+        NSAccessibilityRowHeaderUIElementsAttribute,
+      ]];
+    }
   } else if ([role isEqualToString:@"AXWebArea"]) {
     [ret addObjectsFromArray:@[
       @"AXLoaded", NSAccessibilityLoadingProgressAttribute

content/renderer/accessibility/blink_ax_tree_source.cc

@@ -905,15 +905,15 @@ void BlinkAXTreeSource::SerializeNode(WebAXObject src,
   // parent is the row, the row adds it as a child, and the column adds it
   // as an indirect child.
   int child_count = src.ChildCount();
+  std::vector<int32_t> indirect_child_ids;
   for (int i = 0; i < child_count; ++i) {
     WebAXObject child = src.ChildAt(i);
-    std::vector<int32_t> indirect_child_ids;
     if (!is_iframe && !child.IsDetached() && !IsParentUnignoredOf(src, child))
       indirect_child_ids.push_back(child.AxID());
-    if (indirect_child_ids.size() > 0) {
-      dst->AddIntListAttribute(
-          ui::AX_ATTR_INDIRECT_CHILD_IDS, indirect_child_ids);
-    }
+  }
+  if (indirect_child_ids.size() > 0) {
+    dst->AddIntListAttribute(ui::AX_ATTR_INDIRECT_CHILD_IDS,
+                             indirect_child_ids);
   }
 
   if (src.IsScrollableContainer()) {

content/test/data/accessibility/aria/aria-columnheader-expected-mac.txt

 AXWebArea
-++AXTable AXColumnHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXHeader='AXGroup' AXRowHeaderUIElements=[]
+++AXTable AXColumnHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXHeader='AXGroup'
 ++++AXRow AXIndex='0'
-++++++AXCell AXTitle='Browser' AXColumnHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXColumnIndexRange={"len":1,"loc":0} AXRowHeaderUIElements=[] AXRowIndexRange={"len":1,"loc":0}
+++++++AXCell AXTitle='Browser' AXColumnIndexRange={"len":1,"loc":0} AXRowIndexRange={"len":1,"loc":0}
 ++++++++AXStaticText AXValue='Browser'
-++++++AXCell AXTitle='Rendering Engine' AXColumnHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=[] AXRowIndexRange={"len":1,"loc":0}
+++++++AXCell AXTitle='Rendering Engine' AXColumnIndexRange={"len":1,"loc":1} AXRowIndexRange={"len":1,"loc":0}
 ++++++++AXStaticText AXValue='Rendering Engine'
 ++++AXRow AXIndex='1'
-++++++AXCell AXTitle='Chrome' AXColumnHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXColumnIndexRange={"len":1,"loc":0} AXRowHeaderUIElements=[] AXRowIndexRange={"len":1,"loc":1}
+++++++AXCell AXTitle='Chrome' AXColumnHeaderUIElements=["AXCell Browser"] AXColumnIndexRange={"len":1,"loc":0} AXRowIndexRange={"len":1,"loc":1}
 ++++++++AXStaticText AXValue='Chrome'
-++++++AXCell AXTitle='Blink' AXColumnHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=[] AXRowIndexRange={"len":1,"loc":1}
+++++++AXCell AXTitle='Blink' AXColumnHeaderUIElements=["AXCell Rendering Engine"] AXColumnIndexRange={"len":1,"loc":1} AXRowIndexRange={"len":1,"loc":1}
 ++++++++AXStaticText AXValue='Blink'
 ++++AXRow AXIndex='2'
-++++++AXCell AXTitle='Safari' AXColumnHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXColumnIndexRange={"len":1,"loc":0} AXRowHeaderUIElements=[] AXRowIndexRange={"len":1,"loc":2}
+++++++AXCell AXTitle='Safari' AXColumnHeaderUIElements=["AXCell Browser"] AXColumnIndexRange={"len":1,"loc":0} AXRowIndexRange={"len":1,"loc":2}
 ++++++++AXStaticText AXValue='Safari'
-++++++AXCell AXTitle='WebKit' AXColumnHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=[] AXRowIndexRange={"len":1,"loc":2}
+++++++AXCell AXTitle='WebKit' AXColumnHeaderUIElements=["AXCell Rendering Engine"] AXColumnIndexRange={"len":1,"loc":1} AXRowIndexRange={"len":1,"loc":2}
 ++++++++AXStaticText AXValue='WebKit'
 ++++AXColumn AXHeader='AXCell Browser' AXIndex='0'
 ++++AXColumn AXHeader='AXCell Rendering Engine' AXIndex='1'
-++++AXGroup
+++++AXGroup
\ No newline at end of file

content/test/data/accessibility/aria/aria-rowheader-expected-mac.txt

 AXWebArea
-++AXTable AXColumnHeaderUIElements=[] AXHeader='AXGroup' AXRowHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"]
+++AXTable AXHeader='AXGroup' AXRowHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"]
 ++++AXRow AXIndex='0'
-++++++AXCell AXTitle='Browser' AXColumnHeaderUIElements=[] AXColumnIndexRange={"len":1,"loc":0} AXRowHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXRowIndexRange={"len":1,"loc":0}
+++++++AXCell AXTitle='Browser' AXColumnIndexRange={"len":1,"loc":0} AXRowIndexRange={"len":1,"loc":0}
 ++++++++AXStaticText AXValue='Browser'
-++++++AXCell AXTitle='Chrome' AXColumnHeaderUIElements=[] AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXRowIndexRange={"len":1,"loc":0}
+++++++AXCell AXTitle='Chrome' AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=["AXCell Browser"] AXRowIndexRange={"len":1,"loc":0}
 ++++++++AXStaticText AXValue='Chrome'
-++++++AXCell AXTitle='Safari' AXColumnHeaderUIElements=[] AXColumnIndexRange={"len":1,"loc":2} AXRowHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXRowIndexRange={"len":1,"loc":0}
+++++++AXCell AXTitle='Safari' AXColumnIndexRange={"len":1,"loc":2} AXRowHeaderUIElements=["AXCell Browser"] AXRowIndexRange={"len":1,"loc":0}
 ++++++++AXStaticText AXValue='Safari'
 ++++AXRow AXIndex='1'
-++++++AXCell AXTitle='Rendering Engine' AXColumnHeaderUIElements=[] AXColumnIndexRange={"len":1,"loc":0} AXRowHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXRowIndexRange={"len":1,"loc":1}
+++++++AXCell AXTitle='Rendering Engine' AXColumnIndexRange={"len":1,"loc":0} AXRowIndexRange={"len":1,"loc":1}
 ++++++++AXStaticText AXValue='Rendering Engine'
-++++++AXCell AXTitle='Blink' AXColumnHeaderUIElements=[] AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXRowIndexRange={"len":1,"loc":1}
+++++++AXCell AXTitle='Blink' AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=["AXCell Rendering Engine"] AXRowIndexRange={"len":1,"loc":1}
 ++++++++AXStaticText AXValue='Blink'
-++++++AXCell AXTitle='WebKit' AXColumnHeaderUIElements=[] AXColumnIndexRange={"len":1,"loc":2} AXRowHeaderUIElements=["AXCell Browser","AXCell Rendering Engine"] AXRowIndexRange={"len":1,"loc":1}
+++++++AXCell AXTitle='WebKit' AXColumnIndexRange={"len":1,"loc":2} AXRowHeaderUIElements=["AXCell Rendering Engine"] AXRowIndexRange={"len":1,"loc":1}
 ++++++++AXStaticText AXValue='WebKit'
 ++++AXColumn AXIndex='0'
 ++++AXColumn AXIndex='1'
 ++++AXColumn AXIndex='2'
-++++AXGroup
+++++AXGroup
\ No newline at end of file

content/test/data/accessibility/html/table-th-colheader-expected-mac.txt

 AXWebArea
-++AXTable AXColumnHeaderUIElements=["AXCell Firstname","AXCell Lastname"] AXHeader='AXGroup' AXRowHeaderUIElements=[]
+++AXTable AXColumnHeaderUIElements=["AXCell Firstname","AXCell Lastname"] AXHeader='AXGroup'
 ++++AXRow AXIndex='0'
-++++++AXCell AXTitle='Firstname' AXColumnHeaderUIElements=["AXCell Firstname","AXCell Lastname"] AXColumnIndexRange={"len":1,"loc":0} AXRowHeaderUIElements=[] AXRowIndexRange={"len":1,"loc":0}
+++++++AXCell AXTitle='Firstname' AXColumnIndexRange={"len":1,"loc":0} AXRowIndexRange={"len":1,"loc":0}
 ++++++++AXStaticText AXValue='Firstname'
-++++++AXCell AXTitle='Lastname' AXColumnHeaderUIElements=["AXCell Firstname","AXCell Lastname"] AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=[] AXRowIndexRange={"len":1,"loc":0}
+++++++AXCell AXTitle='Lastname' AXColumnIndexRange={"len":1,"loc":1} AXRowIndexRange={"len":1,"loc":0}
 ++++++++AXStaticText AXValue='Lastname'
 ++++AXRow AXIndex='1'
-++++++AXCell AXTitle='Jill' AXColumnHeaderUIElements=["AXCell Firstname","AXCell Lastname"] AXColumnIndexRange={"len":1,"loc":0} AXRowHeaderUIElements=[] AXRowIndexRange={"len":1,"loc":1}
+++++++AXCell AXTitle='Jill' AXColumnHeaderUIElements=["AXCell Firstname"] AXColumnIndexRange={"len":1,"loc":0} AXRowIndexRange={"len":1,"loc":1}
 ++++++++AXStaticText AXValue='Jill'
-++++++AXCell AXTitle='Smith' AXColumnHeaderUIElements=["AXCell Firstname","AXCell Lastname"] AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=[] AXRowIndexRange={"len":1,"loc":1}
+++++++AXCell AXTitle='Smith' AXColumnHeaderUIElements=["AXCell Lastname"] AXColumnIndexRange={"len":1,"loc":1} AXRowIndexRange={"len":1,"loc":1}
 ++++++++AXStaticText AXValue='Smith'
 ++++AXColumn AXHeader='AXCell Firstname' AXIndex='0'
 ++++AXColumn AXHeader='AXCell Lastname' AXIndex='1'
-++++AXGroup
+++++AXGroup
\ No newline at end of file

content/test/data/accessibility/html/table-th-rowheader-expected-mac.txt

 AXWebArea AXTitle='Table example - th rowheader'
-++AXTable AXColumnHeaderUIElements=[] AXHeader='AXGroup' AXRowHeaderUIElements=["AXCell Firstname","AXCell Lastname"]
+++AXTable AXHeader='AXGroup' AXRowHeaderUIElements=["AXCell Firstname","AXCell Lastname"]
 ++++AXRow AXIndex='0'
-++++++AXCell AXTitle='Firstname' AXColumnHeaderUIElements=[] AXColumnIndexRange={"len":1,"loc":0} AXRowHeaderUIElements=["AXCell Firstname","AXCell Lastname"] AXRowIndexRange={"len":1,"loc":0}
+++++++AXCell AXTitle='Firstname' AXColumnIndexRange={"len":1,"loc":0} AXRowIndexRange={"len":1,"loc":0}
 ++++++++AXStaticText AXValue='Firstname'
-++++++AXCell AXTitle='Jill' AXColumnHeaderUIElements=[] AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=["AXCell Firstname","AXCell Lastname"] AXRowIndexRange={"len":1,"loc":0}
+++++++AXCell AXTitle='Jill' AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=["AXCell Firstname"] AXRowIndexRange={"len":1,"loc":0}
 ++++++++AXStaticText AXValue='Jill'
 ++++AXRow AXIndex='1'
-++++++AXCell AXTitle='Lastname' AXColumnHeaderUIElements=[] AXColumnIndexRange={"len":1,"loc":0} AXRowHeaderUIElements=["AXCell Firstname","AXCell Lastname"] AXRowIndexRange={"len":1,"loc":1}
+++++++AXCell AXTitle='Lastname' AXColumnIndexRange={"len":1,"loc":0} AXRowIndexRange={"len":1,"loc":1}
 ++++++++AXStaticText AXValue='Lastname'
-++++++AXCell AXTitle='Smith' AXColumnHeaderUIElements=[] AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=["AXCell Firstname","AXCell Lastname"] AXRowIndexRange={"len":1,"loc":1}
+++++++AXCell AXTitle='Smith' AXColumnIndexRange={"len":1,"loc":1} AXRowHeaderUIElements=["AXCell Lastname"] AXRowIndexRange={"len":1,"loc":1}
 ++++++++AXStaticText AXValue='Smith'
 ++++AXColumn AXIndex='0'
 ++++AXColumn AXIndex='1'
-++++AXGroup
+++++AXGroup
\ No newline at end of file