MacViews: Fix VoiceOver feedback in editable fields.

ui/accessibility/platform/ax_platform_node_mac.mm

Index: ui/accessibility/platform/ax_platform_node_mac.mm
diff --git a/ui/accessibility/platform/ax_platform_node_mac.mm b/ui/accessibility/platform/ax_platform_node_mac.mm
index 240240e6180bc11f40e56de4fa36fdafd9e65b81..67da9536cc19da3c2cdc6a5b4b8aa103a654a2a6 100644
--- a/ui/accessibility/platform/ax_platform_node_mac.mm
+++ b/ui/accessibility/platform/ax_platform_node_mac.mm
@@ -412,6 +412,32 @@ void NotifyMacEvent(AXPlatformNodeCocoa* target, ui::AXEvent event_type) {
   return axAttributes.autorelease();
 }
 
+- (NSArray*)accessibilityParameterizedAttributeNames {
+  if (!node_)
+    return nil;
+
+  static NSArray* const kEditableTextAttributes = [@[
+    NSAccessibilityLineForIndexParameterizedAttribute,
+    NSAccessibilityRangeForLineParameterizedAttribute,
+    NSAccessibilityStringForRangeParameterizedAttribute,
+    NSAccessibilityRangeForPositionParameterizedAttribute,
+    NSAccessibilityRangeForIndexParameterizedAttribute,
+    NSAccessibilityBoundsForRangeParameterizedAttribute,
+    NSAccessibilityRTFForRangeParameterizedAttribute,
+    NSAccessibilityStyleRangeForIndexParameterizedAttribute,
+    NSAccessibilityAttributedStringForRangeParameterizedAttribute,
+  ] retain];
+
+  switch (node_->GetData().role) {
+    case ui::AX_ROLE_TEXT_FIELD:
+    case ui::AX_ROLE_STATIC_TEXT:
+      return kEditableTextAttributes;

[dmazzoni, 2017/06/26 16:50:05]

If we're exposing these for STATIC_TEXT, maybe a better
name would be kSelectableTextAttributes?

[tapted, 2017/06/27 00:56:24]

Good point! Done.

+    default:
+      break;
+  }
+  return nil;
+}
+
 - (BOOL)accessibilityIsAttributeSettable:(NSString*)attributeName {
   if (node_->GetData().HasState(ui::AX_STATE_DISABLED))
     return NO;
@@ -494,6 +520,14 @@ void NotifyMacEvent(AXPlatformNodeCocoa* target, ui::AXEvent event_type) {
   return nil;
 }
 
+- (id)accessibilityAttributeValue:(NSString*)attribute
+                     forParameter:(id)parameter {
+  SEL selector = NSSelectorFromString([attribute stringByAppendingString:@":"]);
+  if ([self respondsToSelector:selector])
+    return [self performSelector:selector withObject:parameter];
+  return nil;
+}
+
 // NSAccessibility attributes. Order them according to
 // NSAccessibilityConstants.h, or see https://crbug.com/678898.
 
@@ -633,6 +667,69 @@ void NotifyMacEvent(AXPlatformNodeCocoa* target, ui::AXEvent event_type) {
   return @0;
 }
 
+// Parameterized text-specific attributes.
+
+- (id)AXLineForIndex:(id)parameter {
+  DCHECK([parameter isKindOfClass:[NSNumber class]]);
+  // Multiline is not supported on views.
+  return @0;

[tapted, 2017/06/26 09:18:51]

This matches what's currently done for AXInsertionPointLineNumber

for more complex stuff, we probably want to continue with that AXTextMarker
refactoring, and share the same logic.

+}
+
+- (id)AXRangeForLine:(id)parameter {
+  DCHECK([parameter isKindOfClass:[NSNumber class]]);
+  DCHECK_EQ(0, [parameter intValue]);
+  return [NSValue valueWithRange:{0, [[self getAXValueAsString] length]}];
+}
+
+- (id)AXStringForRange:(id)parameter {
+  DCHECK([parameter isKindOfClass:[NSValue class]]);
+  return [[self getAXValueAsString] substringWithRange:[parameter rangeValue]];
+}
+
+- (id)AXRangeForPosition:(id)parameter {
+  DCHECK([parameter isKindOfClass:[NSValue class]]);
+  // TODO(tapted): Hit-test [parameter pointValue] and return an NSRange.
+  NOTIMPLEMENTED();
+  return nil;
+}
+
+- (id)AXRangeForIndex:(id)parameter {
+  DCHECK([parameter isKindOfClass:[NSNumber class]]);
+  NOTIMPLEMENTED();
+  return nil;
+}
+
+- (id)AXBoundsForRange:(id)parameter {
+  DCHECK([parameter isKindOfClass:[NSValue class]]);
+  // TODO(tapted): Provide an accessor on AXPlatformNodeDelegate to obtain this
+  // from ui::TextInputClient::GetCompositionCharacterBounds().
+  NOTIMPLEMENTED();

[tapted, 2017/06/26 09:18:51]

This is the only one I've been able to hit with basic voiceover usage. returning
nil just means it highlights the view bounds instead

+  return nil;
+}
+
+- (id)AXRTFForRange:(id)parameter {
+  DCHECK([parameter isKindOfClass:[NSValue class]]);
+  NOTIMPLEMENTED();
+  return nil;
+}
+
+- (id)AXStyleRangeForIndex:(id)parameter {
+  DCHECK([parameter isKindOfClass:[NSNumber class]]);
+  NOTIMPLEMENTED();
+  return nil;
+}
+
+- (id)AXAttributedStringForRange:(id)parameter {
+  DCHECK([parameter isKindOfClass:[NSValue class]]);
+  base::scoped_nsobject<NSAttributedString> attributedString(
+      [[NSAttributedString alloc]
+          initWithString:[self AXStringForRange:parameter]]);
+  // TODO(tapted): views::WordLookupClient has a way to obtain the actual
+  // decorations, and BridgedContentView has a conversion function that creates
+  // an NSAttributedString. Refactor things so they can be used here.
+  return attributedString.autorelease();
+}
+
 @end
 
 namespace ui {