CODEWITHSUNDEEP
iphoneobjective-ccocoa-touchcore-animation
Coocoo4Cocoa
Coocoo4Cocoa

Reputation: 50836

Is it possible to use Core Animation to fade out a UIBarButtonItem?

I'm curious, is it possible to somehow intertwine Core Animation to give a "fade out" of a UIBarButtonItem? I have a tableView which I represent with two different data sources. Once a particular data source gets triggered, I'd like to fade out the current UIToolBar options and fade in new ones.

Thanks for pointing me in the right direction.

Upvotes: 5

Views: 3312

Answers (2)

phatblat
phatblat

Reputation: 4070

If you really are using a UIToolbar (note the lower-case "b") and not a UINavigationBar, there is a very easy way to change the buttons and have the transition automatically fade without dropping to Core Animation.

If you're using Interface Builder, you'll need a reference to the toolbar in your code. Create an IBOutlet property and link the toolbar to it in IB:

@property (nonatomic, retain) IBOutlet UIToolbar *toolbar;

This will allow you to reference the UIToolbar as self.toolbar. Then, create your new buttons and add them to an NSArray and pass this to the -[UIToolbar setItems:animated:] method as follows:

UIBarButtonItem *newItem = [[[UIBarButtonItem alloc] 
                                initWithBarButtonSystemItem:UIBarButtonSystemItemDone 
                                target:self 
                                action:@selector(handleTap:)] autorelease];
NSArray *newButtons = [NSArray arrayWithObjects:newItem, nil];
[self.toolbar setItems:newButtons animated:YES];

Upvotes: 7

Ben Gottlieb
Ben Gottlieb

Reputation: 85532

I don't believe there's a way to control the alpha on a UIBarButtonItem, but the UIToolbar class already has a method to support what you're trying to do: -setItems:animated:.

Upvotes: 2

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