Bug 1522383 - Assign gridcell role to cells inside a table with grid role, r=Jamie

Differential Revision: https://phabricator.services.mozilla.com/D43858

--HG--
extra : moz-landing-system : lando

accessible/generic/Accessible.cpp

@@ -1508,6 +1508,18 @@ role Accessible::ARIATransformRole(role aRole) const {
                                            nsGkAtoms::_true, eCaseMatters)) {
       return roles::PARENT_MENUITEM;
     }
+
+  } else if (aRole == roles::CELL) {
+    // A cell inside an ancestor table element that has a grid role needs a
+    // gridcell role
+    // (https://www.w3.org/TR/html-aam-1.0/#html-element-role-mappings).
+    const TableCellAccessible* cell = AsTableCell();
+    if (cell) {
+      TableAccessible* table = cell->Table();
+      if (table && table->AsAccessible()->IsARIARole(nsGkAtoms::grid)) {
+        return roles::GRID_CELL;
+      }
+    }
   }
 
   return aRole;

accessible/tests/mochitest/role/test_aria.html

@@ -141,6 +141,7 @@
       // ////////////////////////////////////////////////////////////////////////
       // roles transformed by ARIA state attributes
       testRole("togglebutton", ROLE_TOGGLE_BUTTON);
+      testRole("implicit_gridcell", ROLE_GRID_CELL);
 
       // ////////////////////////////////////////////////////////////////////////
       // ignore unknown roles, take first known
@@ -344,6 +345,13 @@
   <div role="section" id="section">section</div>
   <div role="sectionhead" id="sectionhead">sectionhead</div>
 
+  <!-- roles transformed by ARIA roles of ancestors -->
+  <table role="grid">
+    <tr>
+      <td id="implicit_gridcell">foo</td>
+    </tr>
+  </table>
+
   <!-- roles transformed by ARIA state attributes -->
   <button aria-pressed="true" id="togglebutton">
 

accessible/tests/mochitest/tree/test_aria_grid.html

@@ -73,8 +73,8 @@
             role: ROLE_ROW,
             tagName: "TR",
             children: [
-              { // td generic cell accessible
-                role: ROLE_CELL,
+              { // td implicit role="gridcell"
+                role: ROLE_GRID_CELL,
                 children: [
                   { // td text leaf
                     role: ROLE_TEXT_LEAF,
@@ -231,7 +231,7 @@
   <div id="crazy_grid2" role="grid">
     <table role="presentation">
       <tr role="row">
-        <td id="ct_cell1">cell1</td>
+        <td id="implicit_gridcell">cell1</td>
         <td role="gridcell">cell2</td>
       </tr>
     </table>