How to programmatically replace UIToolBar items bu

Question

I have a toolbar with various image buttons, created in Interface Builder.

I'd like to be able to programmatically replace one of the buttons with an activity indicator when pressed, and then put back the original button but change its color from white to yellow when the activity completes.

Is this possible with an IB built toolbar or must I look at building the whole toolbar programmatically and custom views?

Answer 1

Swift has a much easier way. In my case, I am switching the play button with the pause button every touch.

@IBAction func playandPause(sender: UIBarButtonItem) { // Here we are creating an outlet. Hook this up to the bar button item.
    for (index, button) in toolbarItems!.enumerate() { // Enumerating through all the buttons
        if button === sender { // === operator is used to check if the two objects are the exact same instance in memory.
            var barButtonItem: UIBarButtonItem!
            if mediaplayer.playing {
                mediaplayer.pause()
                barButtonItem = UIBarButtonItem.init(barButtonSystemItem: .Play, target: self, action: #selector(playandPause(_:)))
            }else {
                mediaplayer.play()
                barButtonItem = UIBarButtonItem.init(barButtonSystemItem: .Pause, target: self, action: #selector(playandPause(_:)))
            }
            toolbarItems![index] = barButtonItem // Replace the old item with the new item.
            break // Break once we have found the button as it is unnecessary to complete the rest of the loop
        }
    }
}

Answer 2

I think it should be possible. You might either try creating an IBOutlet for that specific button in your ViewController class, and connect the button from IB to that outlet, or you can use the items property of that UIToolbar instance (you do have a reference to that, don't you?) and find the appropriate item in there, create a new NSArray with modified items, and set it back on that toolbar.items property.

HTH

Answer 3

Here is the approach I used It seemed to be much simpler to manage the toolbar entirely programatically so ....

In your view controller declare 1 or more sets of UIBarButtonItem items as property items also declare and hookup the toolbar as a UIToolbar property. Also declare 1 or more arrays to hold the items.

In the implementation In viewDidLoad alloc and set your UIBarButtonItems for example

       playButton = [[UIBarButtonItem alloc]
         initWithBarButtonSystemItem:UIBarButtonSystemItemPlay 
    target:self 
action:@selector(handlePlayClick)];

Flexible buttons (for alignment etc) are declared like this

   flexButton1 =[[UIBarButtonItem alloc]
 initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace 
target:nil action:nil];

There are several initMethods to handle the different types of buttons toolbars support. All follow a syntax similar to the above. Worth noting is the target and action settings. Target: would normally be self, action is the name of the function that button should trigger.

After alloc'ng your UIBarButtons add them to an array using initWithObjects.

Then to assign the buttons to the toolbar you would call

[toolbar setItems:<array name>];

Dont forget to dealloc your UIBarButtons and arrays at the end of your code.

Hope this helps. If you need more code let me know.

Rich D.

Answer 4

Try:

- (void)setTitle:(NSString *)title forItem:(int)item ofToolbar:(UIToolbar *)tb {
    NSMutableArray *newItems = [tb.items mutableCopy];
    UIBarButtonItem *old = [newItems objectAtIndex:1],
    *titled = [[UIBarButtonItem alloc] initWithTitle:title style:old.style target:old.target action:old.action];

    [newItems  replaceObjectAtIndex:1 withObject:titled];
    tb.items = newItems;

    [titled release];
}

Answer 5

Swift

Much has changed since these answers have been posted. Here is a Swift 2.0 solution.

It matters not how the original UIBarButtonItem you are replacing has been created programmatically. All you need is the UIToolbar outlet. To replace, say, the 2nd item from the left, do this:

var toolbarItems = self.toolbar.items
let newItem = UIBarButtonItem(barButtonSystemItem: .Play, target: self, action: "play")
toolbarItems![1] = newItem
self.toolbar.setItems(toolbarItems, animated: true)

Answer 6

A note on this - the toolbar will strip out any color in your icons, so you still won't be able to make it yellow. You'll need to change the image shape to indicate "on" instead.

Alternatively you'll need to load your BarButtonItems with UIButtons (use the initWithCustomView) and set the image of the button appropriately.

HTH