Views a11y: Announce Table Columns for TableView

Implements the ITableProvider and ITableItemProvider for UIA.
Currently just supports TableView's column headers. Row headers
are not supported in TableView's control.

AX-Relnotes: Column Headers in TableView are announceable.
Bug: 1078623
Change-Id: I7c8ba49cd8de9fffe471e91c4d6d4e759c9ddc29
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2348541
Commit-Queue: Mohamed Mansour <mmansour@microsoft.com>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799200}

ui/views/accessibility/ax_virtual_view.cc

@@ -21,6 +21,7 @@
 #include "ui/base/ui_base_types.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/views/accessibility/view_accessibility.h"
+#include "ui/views/accessibility/view_ax_platform_node_delegate.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 
@@ -386,7 +387,10 @@ gfx::NativeViewAccessible AXVirtualView::GetFocus() {
 }
 
 ui::AXPlatformNode* AXVirtualView::GetFromNodeID(int32_t id) {
-  // TODO(nektar): Implement.
+  AXVirtualView* virtual_view = GetFromId(id);
+  if (virtual_view) {
+    return virtual_view->ax_platform_node();
+  }
   return nullptr;
 }
 
@@ -423,6 +427,18 @@ gfx::AcceleratedWidget AXVirtualView::GetTargetForNativeAccessibilityEvent() {
   return gfx::kNullAcceleratedWidget;
 }
 
+base::Optional<bool> AXVirtualView::GetTableHasColumnOrRowHeaderNode() const {
+  return GetDelegate()->GetTableHasColumnOrRowHeaderNode();
+}
+
+std::vector<int32_t> AXVirtualView::GetColHeaderNodeIds() const {
+  return GetDelegate()->GetColHeaderNodeIds();
+}
+
+std::vector<int32_t> AXVirtualView::GetColHeaderNodeIds(int col_index) const {
+  return GetDelegate()->GetColHeaderNodeIds(col_index);
+}
+
 bool AXVirtualView::IsIgnored() const {
   return GetData().IsIgnored();
 }
@@ -473,6 +489,12 @@ View* AXVirtualView::GetOwnerView() const {
   return nullptr;
 }
 
+ViewAXPlatformNodeDelegate* AXVirtualView::GetDelegate() const {
+  DCHECK(GetOwnerView());
+  return static_cast<ViewAXPlatformNodeDelegate*>(
+      &GetOwnerView()->GetViewAccessibility());
+}
+
 AXVirtualViewWrapper* AXVirtualView::GetOrCreateWrapper(
     views::AXAuraObjCache* cache) {
 #if defined(USE_AURA)

ui/views/accessibility/ax_virtual_view.h

@@ -40,6 +40,7 @@ namespace views {
 class AXAuraObjCache;
 class View;
 class ViewAccessibility;
+class ViewAXPlatformNodeDelegate;
 
 // Implements a virtual view that is used only for accessibility.
 //
@@ -99,6 +100,8 @@ class VIEWS_EXPORT AXVirtualView : public ui::AXPlatformNodeDelegateBase {
   }
   AXVirtualView* virtual_parent_view() { return virtual_parent_view_; }
 
+  ui::AXPlatformNode* ax_platform_node() { return ax_platform_node_; }
+
   // Returns true if |view| is contained within the hierarchy of this
   // AXVirtualView, even as an indirect descendant. Will return true if |view|
   // is also this AXVirtualView.
@@ -153,10 +156,16 @@ class VIEWS_EXPORT AXVirtualView : public ui::AXPlatformNodeDelegateBase {
   bool IsOffscreen() const override;
   const ui::AXUniqueId& GetUniqueId() const override;
   gfx::AcceleratedWidget GetTargetForNativeAccessibilityEvent() override;
+  base::Optional<bool> GetTableHasColumnOrRowHeaderNode() const override;
+  std::vector<int32_t> GetColHeaderNodeIds() const override;
+  std::vector<int32_t> GetColHeaderNodeIds(int col_index) const override;
 
   // Gets the real View that owns our shallowest virtual ancestor,, if any.
   View* GetOwnerView() const;
 
+  // Gets the view platform delegate if exists, otherwise nullptr.
+  ViewAXPlatformNodeDelegate* GetDelegate() const;
+
   // Gets or creates a wrapper suitable for use with tree sources.
   AXVirtualViewWrapper* GetOrCreateWrapper(views::AXAuraObjCache* cache);
 

ui/views/accessibility/view_ax_platform_node_delegate.cc

@@ -540,6 +540,46 @@ const ui::AXUniqueId& ViewAXPlatformNodeDelegate::GetUniqueId() const {
   return ViewAccessibility::GetUniqueId();
 }
 
+base::Optional<bool>
+ViewAXPlatformNodeDelegate::GetTableHasColumnOrRowHeaderNode() const {
+  if (!GetAncestorTableView())
+    return false;
+  return !GetAncestorTableView()->visible_columns().empty();
+}
+
+std::vector<int32_t> ViewAXPlatformNodeDelegate::GetColHeaderNodeIds() const {
+  std::vector<int32_t> col_header_ids;
+  if (!virtual_children().empty()) {
+    for (const std::unique_ptr<AXVirtualView>& header_cell :
+         virtual_children().front()->children()) {
+      const ui::AXNodeData& header_data = header_cell->GetData();
+      if (header_data.role == ax::mojom::Role::kColumnHeader) {
+        col_header_ids.push_back(header_data.id);
+      }
+    }
+  }
+  return col_header_ids;
+}
+
+std::vector<int32_t> ViewAXPlatformNodeDelegate::GetColHeaderNodeIds(
+    int col_index) const {
+  std::vector<int32_t> columns = GetColHeaderNodeIds();
+  if (columns.size() <= size_t{col_index}) {
+    return {};
+  }
+  return {columns[col_index]};
+}
+
+TableView* ViewAXPlatformNodeDelegate::GetAncestorTableView() const {
+  ui::AXNodeData data;
+  view()->GetViewAccessibility().GetAccessibleNodeData(&data);
+
+  if (!ui::IsTableLike(data.role))
+    return nullptr;
+
+  return static_cast<TableView*>(view());
+}
+
 bool ViewAXPlatformNodeDelegate::IsOrderedSetItem() const {
   const ui::AXNodeData& data = GetData();
   return (view()->GetGroup() >= 0) ||

ui/views/accessibility/view_ax_platform_node_delegate.h

@@ -17,6 +17,7 @@
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/views/accessibility/view_accessibility.h"
+#include "ui/views/controls/table/table_view.h"
 #include "ui/views/widget/widget_observer.h"
 
 namespace ui {
@@ -83,6 +84,9 @@ class ViewAXPlatformNodeDelegate : public ViewAccessibility,
   bool IsMinimized() const override;
   // Also in |ViewAccessibility|.
   const ui::AXUniqueId& GetUniqueId() const override;
+  base::Optional<bool> GetTableHasColumnOrRowHeaderNode() const override;
+  std::vector<int32_t> GetColHeaderNodeIds() const override;
+  std::vector<int32_t> GetColHeaderNodeIds(int col_index) const override;
 
   // Ordered-set-like and item-like nodes.
   bool IsOrderedSetItem() const override;
@@ -108,6 +112,9 @@ class ViewAXPlatformNodeDelegate : public ViewAccessibility,
 
   ChildWidgetsResult GetChildWidgets() const;
 
+  // Gets the real TableView, otherwise nullptr.
+  TableView* GetAncestorTableView() const;
+
   // We own this, but it is reference-counted on some platforms so we can't use
   // a unique_ptr. It is destroyed in the destructor.
   ui::AXPlatformNode* ax_platform_node_;