Added -[TUIView ancestorSharedWithView:]

lib/UIKit/TUIView.h

@@ -304,6 +304,12 @@ extern CGRect(^TUIViewCenteredLayout)(TUIView*);
 - (void)willMoveToWindow:(TUINSWindow *)newWindow;
 - (void)didMoveToWindow;
 
+/**
+ * Returns the closest ancestor that is shared by the receiver and another view,
+ * or nil if there is no such view.
+ */
+- (TUIView *)ancestorSharedWithView:(TUIView *)view;
+
 /**
  Note: returns YES ff view == reciever
  */

lib/UIKit/TUIView.m

@@ -723,7 +723,7 @@ else CGContextSetRGBFillColor(context, 1, 0, 0, 0.3); CGContextFillRect(context,
 	} else {\
 		[self.subviews insertObject:view atIndex:index];\
 	}\
- 	[view removeFromSuperview]; /* will call willAdd:nil and didAdd (nil) */ \
+	[view removeFromSuperview]; /* will call willAdd:nil and didAdd (nil) */ \
 	[view willMoveToSuperview:self]; \
 	view.nsView = _nsView;
 
@@ -835,6 +835,20 @@ else CGContextSetRGBFillColor(context, 1, 0, 0, 0.3); CGContextFillRect(context,
 
 #define END_EACH_SUBVIEW }
 
+- (TUIView *)ancestorSharedWithView:(TUIView *)view
+{
+	TUIView *parentView = self;
+
+	do {
+		if ([view isDescendantOfView:parentView])
+			return parentView;
+
+		parentView = parentView.superview;
+	} while (parentView);
+
+	return nil;
+}
+
 - (BOOL)isDescendantOfView:(TUIView *)view
 {
 	TUIView *v = self;