Having to 're-focus' on a UIView with VoiceOver - ios

Question

I am trying to make a simple app accessible with VoiceOver.
The app loads a view controller with an opaque view, and tracks the location of one finger on this view. However I cannot understand why I have to re-focus (by tapping) on my view, even after its '(void) accessibilityElementDidBecomeFocused' method is called. I am confused because my view's '(void) accessibilityElementDidLoseFocus' is never called either.
I believe I am correctly following the instructions for View Controller containment from SO and the Apple docs:
1 - http://developer.apple.com/library/ios/#documentation/uikit/reference/UIViewController_Class/Reference/Reference.html#//apple_ref/doc/uid/TP40006926-CH3-SW81
2 - How does View Controller Containment work in iOS 5?
The code to show the new view controller is as follows:
CGRect frame = self.view.bounds;
customViewController = [[FocusIssueCustomViewController alloc] init];
[customViewController loadWithFrame:frame forViewController:self withAlpha:0.5];
// setting properties of the custom view:
[customViewController.view setAccessibilityLabel:#"Touch area"];
[customViewController.view setMultipleTouchEnabled:YES];
[customViewController.view setIsAccessibilityElement:YES];
[customViewController.view setAccessibilityTraits:UIAccessibilityTraitAllowsDirectInteraction];
// inform user the screen has changed:
UIAccessibilityPostNotification(UIAccessibilityLayoutChangedNotification, customViewController.view);
and the loadWithFrame method is as follows:
- (void) loadWithFrame: (CGRect) frame forViewController: (UIViewController*) viewController withAlpha: (float) alphaValue
{
// keep a reference to the view controller that requested the Custom View
[self setOriginatingViewController:viewController];
// load the custom view
[self setCustomView:[[FocusIssueCustomView alloc] initWithFrame:frame]];
[self customView].alpha = alphaValue;
// make this the ViewController for this view
self.view = [self customView];
// add the view controller following guidelines from the
// viewController containment in the UIViewController class reference from the Apple docs
[self.originatingViewController addChildViewController:self];
[self.originatingViewController.view addSubview:self.view];
[self didMoveToParentViewController:self.originatingViewController];
}
This custom view then tracks one touch: the implementation file is given below.
#import "FocusIssueCustomView.h"
#define CIRCLE_DIAMETER 110
#interface FocusIssueCustomView ()
{
// coordinate of this one touch
float xCood, yCood;
}
#end
#implementation FocusIssueCustomView
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
// make the custom view opaque
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGFloat black[] = {0, 0, 0, 1.0};
CGContextSetFillColor(ctx, black);
CGContextAddRect(ctx, rect);
CGContextFillPath(ctx);
[self setAlpha:0.5];
// clear current context
CGContextRef CurrentContext = UIGraphicsGetCurrentContext();
CGContextClearRect(CurrentContext, rect);
// draw a blue circle, no fill for the touch
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 4.0);
CGContextSetRGBStrokeColor(context, 0, 0, 255, 1);
CGRect rectangle = CGRectMake(xCood - CIRCLE_DIAMETER/2, yCood - CIRCLE_DIAMETER/2, CIRCLE_DIAMETER, CIRCLE_DIAMETER);
CGContextAddEllipseInRect(context, rectangle);
CGContextStrokePath(context);
}
- (void) accessibilityElementDidBecomeFocused
{
NSLog(#"Inside the custom view's \"accessibilityElementDidBecomeFocused\" method");
}
- (void) accessibilityElementDidLoseFocus
{
NSLog(#"Inside the custom view's \"accessibilityElementDidLoseFocus\" method");
}
#pragma mark - touch method
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
// if 1 touch on screen, track this touch
if ([[event allTouches] count] == 1)
{
CGPoint point = [[touches anyObject] locationInView:self];
xCood = point.x;
yCood = point.y;
NSLog(#"Touch at (%f, %f)", xCood, yCood);
}
// redraw
[self setNeedsDisplay];
}
#end
I genuinely will need a view controller to control this transparent CustomView (hence the view controller containment approach). That is why I am not simply taking an 'addSubview' approach. Any help is greatly appreciated..
Thanks -
VP