UIPickerView inside UIScrollView hitTest to disable Scrollview? - objective-c

Question

I am currently building an application which has a resized UIPickerView on a scrollview the problem I am facing is that when you try to scroll the picker the scrollview is moving instead.
For the past few hours I have tried to fix this by disabling the scrollview when the picker is selected by creating a UIScrollView sub class which performs the following hitTest:
- (UIView*)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView* result = [super hitTest:point withEvent:event];
if ([result.superview isKindOfClass:[UIPickerView class]])
{
NSLog(#"Cancel touch");
self.canCancelContentTouches = NO;
self.delaysContentTouches = NO;
self.scrollEnabled = NO;
}
else
{
self.canCancelContentTouches = YES;
self.delaysContentTouches = YES;
self.scrollEnabled = YES;
}
return result;
}
With this above code I find that when I click and hold certain sections of the UIPickerView it cancels the touch and disables the UIScrollview OK and I can move the UIPicker to select a new value, however when I certain areas on the PickerView and do an NSLog on the reported class like below
NSLog(#"%#", [result.superview class]);
It outputs UIPickerTableViewWrapperCell to the console and the isKindOfClass[UIPickerView class] never gets entered.
I have also tried isMemberOfClass which also does not work.
Any help would be appreciated.
Thanks Aaron

Answer 1

I think I have figured this out, by searching the class description to see if it contains #"UIPicker*"
- (UIView*)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView* result = [super hitTest:point withEvent:event];
NSString *viewDescription = [result.superview class].description;
NSRange range = [viewDescription rangeOfString : #"UIPicker"];
if (range.location != NSNotFound)
{
NSLog(#"Cancel touch on ScrollView");
self.canCancelContentTouches = NO;
self.delaysContentTouches = NO;
self.scrollEnabled = NO;
}
else
{
self.canCancelContentTouches = YES;
self.delaysContentTouches = YES;
self.scrollEnabled = YES;
}
return result;
}
Now when I drag the UIPicker it works perfectly and the scrollview does not move at all, unless I am clicking on that and dragging it.
Aaron