Try to use the new OS 10.10 accessibility APIs to make tab bar cells...

Try to use the new OS 10.10 accessibility APIs to make tab bar cells accessible. For some reason they are not selectable by accessibility.

ThirdParty/PSMTabBarControl/source/PSMTabBarCell.h

@@ -50,6 +50,8 @@
 @property(nonatomic, readonly) float desiredWidthOfCell;
 @property(nonatomic, readonly) id<PSMTabStyle> style;
 @property(nonatomic, assign) NSLineBreakMode truncationStyle;  // How to truncate title.
+@property(nonatomic, readonly) BOOL isSelected;
+@property(nonatomic, readonly) NSAccessibilityElement<NSAccessibilityRadioButton> *element;
 // creation/destruction
 - (id)initWithControlView:(PSMTabBarControl *)controlView;

ThirdParty/PSMTabBarControl/source/PSMTabBarCell.m

@@ -12,6 +12,52 @@
 #import "PSMProgressIndicator.h"
 #import "PSMTabDragAssistant.h"
+@interface PSMTabBarCell()<PSMProgressIndicatorDelegate>
+- (NSView<PSMTabBarControlProtocol> *)psmTabControlView;
+@end
+
+@interface PSMTabBarControlAccessibilityElement : NSAccessibilityElement<NSAccessibilityRadioButton>
+@property(nonatomic, assign) PSMTabBarCell *cell;
+- (instancetype)initWithCell:(PSMTabBarCell *)cell;
+@end
+
+@implementation PSMTabBarControlAccessibilityElement
+
+- (instancetype)initWithCell:(PSMTabBarCell *)cell {
+    self = [super init];
+    if (self) {
+        self.accessibilityRole = NSAccessibilityRadioButtonRole;
+        self.accessibilityLabel = @"Tab";
+        self.accessibilityParent = cell;
+        self.accessibilityEnabled = YES;
+        self.cell = cell;
+    }
+    return self;
+}
+
+- (id)accessibilityValue {
+    return @(self.cell.isSelected);
+}
+
+- (NSString *)accessibilityLabel {
+    return @"Tab";
+}
+
+- (BOOL)accessibilityPerformPress {
+    return NO;
+}
+
+- (NSRect)accessibilityFrame {
+    return self.cell.frame;
+}
+
+- (id)accessibilityParent {
+    return self.cell.psmTabControlView;
+}
+
+@end
+
+
 // A timer that does not keep a strong reference to its target. The target
 // should invoke -invalidate from its -dealloc method and release the timer to
 // avoid getting called posthumously.
@@ -64,9 +110,6 @@
 @end
-@interface PSMTabBarCell()<PSMProgressIndicatorDelegate>
-@end
-
 @implementation PSMTabBarCell  {
     NSSize _stringSize;
     PSMProgressIndicator *_indicator;
@@ -74,6 +117,7 @@
     PSMWeakTimer *_delayedStringValueTimer;  // For bug 3957
     BOOL _hasIcon;
     BOOL _highlighted;
+    PSMTabBarControlAccessibilityElement *_element;
 }
 #pragma mark - Creation/Destruction
@@ -91,6 +135,7 @@
         _hasCloseButton = YES;
         _modifierString = [@"" copy];
         _truncationStyle = NSLineBreakByTruncatingTail;
+        _element = [[PSMTabBarControlAccessibilityElement alloc] initWithCell:self];
     }
     return self;
 }
@@ -125,6 +170,8 @@
         } else {
             [self setCurrentStep:0];
         }
+        _element = [[PSMTabBarControlAccessibilityElement alloc] initWithCell:self];
+        _element.cell = self;
     }
     return self;
 }
@@ -139,6 +186,8 @@
     if (_tabColor) {
         [_tabColor release];
     }
+    _element.cell = nil;
+    [_element release];
     [super dealloc];
 }
@@ -387,6 +436,10 @@
     return self;
 }
+- (BOOL)isSelected {
+    return ([self tabState] == PSMTab_SelectedMask);
+}
+
 #pragma mark - Accessibility
 - (BOOL)accessibilityIsIgnored {
@@ -433,7 +486,7 @@
     } else if ([attribute isEqualToString:NSAccessibilityTitleAttribute]) {
         attributeValue = [self stringValue];
     } else if ([attribute isEqualToString: NSAccessibilityValueAttribute]) {
-        attributeValue = [NSNumber numberWithBool:([self tabState] == 2)];
+        attributeValue = @(self.isSelected);
     } else {
         attributeValue = [super accessibilityAttributeValue:attribute];
     }

ThirdParty/PSMTabBarControl/source/PSMTabBarControl.m

@@ -1739,6 +1739,13 @@ const NSInteger kPSMStartResizeAnimation = 0;
     if ([[self delegate] respondsToSelector:@selector(tabViewDidChangeNumberOfTabViewItems:)]) {
         [[self delegate] tabViewDidChangeNumberOfTabViewItems:aTabView];
     }
+
+    NSMutableArray *elements = [NSMutableArray array];
+    for (PSMTabBarCell *cell in [_cells subarrayWithRange:NSMakeRange(0, self.numberOfVisibleTabs)]) {
+        [elements addObject:cell.element];
+        cell.element.accessibilityFrameInParentSpace = cell.frame;
+    }
+    [self setAccessibilityChildren:elements];
 }
 - (NSDragOperation)tabView:(NSTabView *)tabView draggingEnteredTabBarForSender:(id<NSDraggingInfo>)tagViewItem {
@@ -1992,7 +1999,11 @@ const NSInteger kPSMStartResizeAnimation = 0;
         if (![_addTabButton isHidden]) {
             [children addObject:_addTabButton];
         }
-        attributeValue = NSAccessibilityUnignoredChildren(children);
+        NSMutableArray *elements = [NSMutableArray array];
+        for (PSMTabBarCell *cell in children) {
+            [elements addObject:cell.element];
+        }
+        attributeValue = elements;
     } else if ([attribute isEqualToString: NSAccessibilityTabsAttribute]) {
         attributeValue = NSAccessibilityUnignoredChildren(_cells);
     } else if ([attribute isEqualToString:NSAccessibilityValueAttribute]) {