Question

When you tap on a UIBarButtonItem in a UIToolbar, there is a white glow effect.

Is there a possibility to fire an event to show this effect?

I don’t want to press the button. Only the effect should be displayed. I want to visualize to the user, that there is new content behind this button.

Thanks for your help!

Answer 1

The following method assumes you are using the toolbarItems property of a navigation controller and that the button you want to highlight is the last item in that array. You can apply it to any toolbar, of course, and pick a different array index if necessary.

Right now this is not exactly perfect, because the animation moves the new button from the lower left of the screen. However, I think that can be turned off with a little effort.

Note that I used PeakJi’s image.

I hope this works for you.

Enjoy,

Damien

- (void)highlightButton {
    NSArray *originalFooterItems = self.toolbarItems;
    NSMutableArray *footerItems = [originalFooterItems mutableCopy];
    [footerItems removeLastObject];

    NSString* pathToImageFile = [[NSBundle mainBundle] pathForResource:@"white_glow" ofType:@"png"];
    UIImage* anImage = [UIImage imageWithContentsOfFile:pathToImageFile];
    UIImageView *imageView = [[UIImageView alloc] initWithImage:anImage];
    imageView.frame = CGRectMake(0, 0, 40, 40);

    UIBarButtonItem *flashImage = [[UIBarButtonItem alloc] initWithCustomView:imageView];
    [footerItems addObject:flashImage];

    [UIView animateWithDuration:0.3
                          delay: 0.0
                        options: UIViewAnimationOptionCurveEaseOut
                     animations:^{
                         self.toolbarItems = footerItems;                     }
                     completion:^(BOOL finished){
                         [UIView animateWithDuration:.3
                                               delay: 0.0
                                             options:UIViewAnimationOptionCurveEaseIn
                                          animations:^{
                                              self.toolbarItems = originalFooterItems;
                                          }
                                          completion:nil];
                     }];
}