Learning from Open Source Hit testing with UIWindow

Issue #132

From https://github.com/Flipboard/FLEX/blob/master/Classes/ExplorerInterface/FLEXWindow.m

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        self.backgroundColor = [UIColor clearColor];
        // Some apps have windows at UIWindowLevelStatusBar + n.
        // If we make the window level too high, we block out UIAlertViews.
        // There's a balance between staying above the app's windows and staying below alerts.
        // UIWindowLevelStatusBar + 100 seems to hit that balance.
        self.windowLevel = UIWindowLevelStatusBar + 100.0;
    }
    return self;
}

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
{
    BOOL pointInside = NO;
    if ([self.eventDelegate shouldHandleTouchAtPoint:point]) {
        pointInside = [super pointInside:point withEvent:event];
    }
    return pointInside;
}

From https://github.com/Flipboard/FLEX/blob/master/Classes/ExplorerInterface/FLEXExplorerViewController.m

- (BOOL)shouldReceiveTouchAtWindowPoint:(CGPoint)pointInWindowCoordinates
{
    BOOL shouldReceiveTouch = NO;
    
    CGPoint pointInLocalCoordinates = [self.view convertPoint:pointInWindowCoordinates fromView:nil];
    
    // Always if it's on the toolbar
    if (CGRectContainsPoint(self.explorerToolbar.frame, pointInLocalCoordinates)) {
        shouldReceiveTouch = YES;
    }
    
    // Always if we're in selection mode
    if (!shouldReceiveTouch && self.currentMode == FLEXExplorerModeSelect) {
        shouldReceiveTouch = YES;
    }
    
    // Always in move mode too
    if (!shouldReceiveTouch && self.currentMode == FLEXExplorerModeMove) {
        shouldReceiveTouch = YES;
    }
    
    // Always if we have a modal presented
    if (!shouldReceiveTouch && self.presentedViewController) {
        shouldReceiveTouch = YES;
    }
    
    return shouldReceiveTouch;
}