MacViews/a11y: Allow accessibility clients to set new selections in Textfields.

ui/accessibility/platform/ax_platform_node_mac.mm

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ui/accessibility/platform/ax_platform_node_mac.h"
 
 #import <Cocoa/Cocoa.h>
 #include <stddef.h>
 
 #include "base/macros.h"
@@ skipping 352 matching lines @@
       [axAttributes addObjectsFromArray:kValueAttributes];
       break;
     // TODO(tapted): Add additional attributes based on role.
     default:
       break;
   }
   return axAttributes.autorelease();
 }
 
 - (BOOL)accessibilityIsAttributeSettable:(NSString*)attributeName {
+  if (node_->GetData().HasStateFlag(ui::AX_STATE_DISABLED))
+    return NO;
+
   // Allow certain attributes to be written via an accessibility client. A
   // writable attribute will only appear as such if the accessibility element
   // has a value set for that attribute.
   if ([attributeName
           isEqualToString:NSAccessibilitySelectedChildrenAttribute] ||
       [attributeName
-          isEqualToString:NSAccessibilitySelectedTextRangeAttribute] ||
-      [attributeName
           isEqualToString:NSAccessibilityVisibleCharacterRangeAttribute]) {
     return NO;
   }
 
+  if ([attributeName
+          isEqualToString:NSAccessibilitySelectedTextRangeAttribute]) {
+    return YES;
+  }
+
   // Since tabs use the Radio Button role on Mac, the standard way to set them
   // is via the value attribute rather than the selected attribute.
   if ([attributeName isEqualToString:NSAccessibilityValueAttribute] &&
       node_->GetData().role == ui::AX_ROLE_TAB) {
     return !node_->GetData().HasStateFlag(ui::AX_STATE_SELECTED);
   }
 
   if ([attributeName isEqualToString:NSAccessibilityValueAttribute] ||
       [attributeName isEqualToString:NSAccessibilitySelectedTextAttribute]) {
     return !ui::AXNodeData::IsFlagSet(node_->GetData().state,
@@ skipping 14 matching lines @@
   ui::AXActionData data;
 
   // Check for attributes first. Only the |data.action| should be set here - any
   // type-specific information, if needed, should be set below.
   if ([attribute isEqualToString:NSAccessibilityValueAttribute]) {
     data.action = node_->GetData().role == ui::AX_ROLE_TAB
                       ? ui::AX_ACTION_SET_SELECTION
                       : ui::AX_ACTION_SET_VALUE;
   } else if ([attribute isEqualToString:NSAccessibilitySelectedTextAttribute]) {
     data.action = ui::AX_ACTION_REPLACE_SELECTED_TEXT;
+  } else if ([attribute
+                 isEqualToString:NSAccessibilitySelectedTextRangeAttribute]) {
+    data.action = ui::AX_ACTION_SET_SELECTION;
   } else if ([attribute isEqualToString:NSAccessibilityFocusedAttribute]) {
     if ([value isKindOfClass:[NSNumber class]]) {
       data.action =
           [value boolValue] ? ui::AX_ACTION_FOCUS : ui::AX_ACTION_BLUR;
     }
   }
 
   // Set type-specific information as necessary for actions set above.
-  if ([value isKindOfClass:[NSString class]])
+  if ([value isKindOfClass:[NSString class]]) {
     data.value = base::SysNSStringToUTF16(value);
+  } else if (data.action == ui::AX_ACTION_SET_SELECTION &&
+             [value isKindOfClass:[NSValue class]]) {
+    NSRange range = [value rangeValue];
+    data.anchor_offset = range.location;
+    data.focus_offset = NSMaxRange(range);
+  }
 
   if (data.action != ui::AX_ACTION_NONE)
     node_->GetDelegate()->AccessibilityPerformAction(data);
 
   // TODO(patricialor): Plumb through all the other writable attributes as
   // specified in accessibilityIsAttributeSettable.
 }
 
 - (id)accessibilityAttributeValue:(NSString*)attribute {
   SEL selector = NSSelectorFromString(attribute);
@@ skipping 42 matching lines @@
   return [self getStringAttribute:ui::AX_ATTR_DESCRIPTION];
 }
 
 - (id)AXValue {
   if (node_->GetData().role == ui::AX_ROLE_TAB)
     return [self AXSelected];
   return [self getStringAttribute:ui::AX_ATTR_VALUE];
 }
 
 - (NSNumber*)AXEnabled {
-  return [NSNumber
-      numberWithBool:!ui::AXNodeData::IsFlagSet(node_->GetData().state,
-                                                ui::AX_STATE_DISABLED)];
+  return @(!ui::AXNodeData::IsFlagSet(node_->GetData().state,
+                                      ui::AX_STATE_DISABLED));
 }
 
 - (NSNumber*)AXFocused {
   if (ui::AXNodeData::IsFlagSet(node_->GetData().state,
                                 ui::AX_STATE_FOCUSABLE))
-    return [NSNumber numberWithBool:(node_->GetDelegate()->GetFocus() ==
-                                     node_->GetNativeViewAccessible())];
-  return [NSNumber numberWithBool:NO];
+    return
+        @(node_->GetDelegate()->GetFocus() == node_->GetNativeViewAccessible());
+  return @NO;
 }
 
 - (id)AXParent {
   if (!node_)
     return nil;
   return NSAccessibilityUnignoredAncestor(node_->GetParent());
 }
 
 - (NSArray*)AXChildren {
   if (!node_)
@@ skipping 21 matching lines @@
   return [NSValue valueWithSize:self.boundsInScreen.size];
 }
 
 - (NSString*)AXTitle {
   return [self getStringAttribute:ui::AX_ATTR_NAME];
 }
 
 // Misc attributes.
 
 - (NSNumber*)AXSelected {
-  return [NSNumber
-      numberWithBool:node_->GetData().HasStateFlag(ui::AX_STATE_SELECTED)];
+  return @(node_->GetData().HasStateFlag(ui::AX_STATE_SELECTED));
 }
 
 - (NSString*)AXPlaceholderValue {
   return [self getStringAttribute:ui::AX_ATTR_PLACEHOLDER];
 }
 
 // Text-specific attributes.
 
 - (NSString*)AXSelectedText {
   NSRange selectedTextRange;
   [[self AXSelectedTextRange] getValue:&selectedTextRange];
   return [[self AXValue] substringWithRange:selectedTextRange];
 }
 
 - (NSValue*)AXSelectedTextRange {
   int textDir, start, end;
   node_->GetIntAttribute(ui::AX_ATTR_TEXT_DIRECTION, &textDir);
   node_->GetIntAttribute(ui::AX_ATTR_TEXT_SEL_START, &start);
   node_->GetIntAttribute(ui::AX_ATTR_TEXT_SEL_END, &end);
   // NSRange cannot represent the direction the text was selected in, so make
   // sure the correct selection index is used when creating a new range, taking
   // into account the textfield text direction as well.
   bool isReversed = (textDir == ui::AX_TEXT_DIRECTION_RTL) ||
                     (textDir == ui::AX_TEXT_DIRECTION_BTT);
   int beginSelectionIndex = (end > start && !isReversed) ? start : end;
-  return [NSValue
-      valueWithRange:NSMakeRange(beginSelectionIndex, abs(end - start))];
+  return [NSValue valueWithRange:{beginSelectionIndex, abs(end - start)}];
 }
 
 - (NSNumber*)AXNumberOfCharacters {
-  return [NSNumber numberWithInteger:[[self AXValue] length]];
+  return @([[self AXValue] length]);
 }
 
 - (NSValue*)AXVisibleCharacterRange {
-  return [NSValue
-      valueWithRange:NSMakeRange(0, [[self AXNumberOfCharacters] intValue])];
+  return [NSValue valueWithRange:{0, [[self AXNumberOfCharacters] intValue]}];
 }
 
 - (NSNumber*)AXInsertionPointLineNumber {
   // Multiline is not supported on views.
-  return [NSNumber numberWithInteger:0];
+  return @0;
 }
 
 @end
 
 namespace ui {
 
 // static
 AXPlatformNode* AXPlatformNode::Create(AXPlatformNodeDelegate* delegate) {
   AXPlatformNodeBase* node = new AXPlatformNodeMac();
   node->Init(delegate);
@@ skipping 35 matching lines @@
   }
   NotifyMacEvent(native_node_, event_type);
 }
 
 int AXPlatformNodeMac::GetIndexInParent() {
   // TODO(dmazzoni): implement this.  http://crbug.com/396137
   return -1;
 }
 
 }  // namespace ui