Keeping a UIButton selected after a touch

Question

After my user clicks a button, I'd like that button to stay pushed during the time that I perform a network operation. When the network operation is complete, I want the button to return to its default state.

I've tried calling -[UIButton setSelected:YES] right after the button push (with a corresponding call to -[UIButton setSelected:NO] after my network op finishes) but it doesn't seem to do anything. Same thing if I call setHighlighted:.

I suppose I could try swapping out the background image to denote a selected state for the duration of the network op, but that seems like a hack. Any better suggestions?

Here's what my code looks like:

- (IBAction)checkInButtonPushed
{
    self.checkInButton.enabled = NO;
    self.checkInButton.selected = YES;
    self.checkInButton.highlighted = YES;
    [self.checkInActivityIndicatorView startAnimating];
    [CheckInOperation startWithPlace:self.place delegate:self];
}

- (void)checkInCompletedWithNewFeedItem:(FeedItem*)newFeedItem wasNewPlace:(BOOL)newPlace possibleError:(NSError*)error;
{
    [self.checkInActivityIndicatorView stopAnimating];
    self.checkInButton.enabled = YES;
    self.checkInButton.selected = NO;
    self.checkInButton.highlighted = NO;
}

score 74 · Accepted Answer · edited Oct 13 '14 at 17:17

74

How are you setting the images for the different UIControlStates on the button? Are you setting a background image for UIControlStateHighlighted as well as UIControlStateSelected?

UIImage *someImage = [UIImage imageNamed:@"SomeResource.png"];
[button setBackgroundImage:someImage forState:UIControlStateHighlighted];
[button setBackgroundImage:someImage forState:UIControlStateSelected];

If you're setting the selected state on the button touch down event rather than touch up inside, your button will actually be in a highlighted+selected state, so you'll want to set that too.

[button setBackgroundImage:someImage forState:(UIControlStateHighlighted|UIControlStateSelected)];

Edit:

To sum up my remarks in the comments and to address the code you posted...you need to set your background images for the full UIControl state that you're in. According to your code snippet, this control state would be disabled + selected + highlighted for the duration of the network operation. This means that you would need to do this:

[button setBackgroundImage:someImage forState:(UIControlStateDisabled|UIControlStateHighlighted|UIControlStateSelected)];

If you remove the highlighted = YES, then you would need this:

[button setBackgroundImage:someImage forState:(UIControlStateDisabled|UIControlStateSelected)];

Get the picture?

edited Oct 13 '14 at 17:17

ffizzik

45
7

answered Nov 23 '09 at 18:30

Bryan Henry

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In effect, I believe I'm doing what you suggest; I'm just doing it through Interface Builder. I added the code I'm using to my question above...perhaps that would shed some light on the problem? The behavior I want is that I want the button to stay selected through the duration of my network operation. What I'm seeing is that the button highlights when touched, then the highlight goes away when the touch is done. The button -never- gets selected. Why this wouldn't work makes no sense to me, so I feel like I'm doing something stupid. I've checked all my IB connections and they're good... – Greg Maletic Nov 23 '09 at 19:02
I don't believe you can set a background image for the highlighted+selected state in Interface Builder, only the highlighted and selected states separately. If your button was in a state such that highlighted and selected were both set, I believe it would default to your normal image, not either of the highlighted or selected images. From your code, you're setting the state of the button such that both selected and highlighted are YES. Is checkInButtonPushed connected to "Touch Up Inside" or something else? – Bryan Henry Nov 23 '09 at 19:10
Yes, it is connected to "Touch Up Inside". And if I remove the code related to the 'highlighted' state, it still doesn't work. The 'selected' state never gets shown. – Greg Maletic Nov 23 '09 at 19:26
Also, why are you disabling the button? That would actually mean that the button state is disabled+highlighted+selected. If you removed the line setting highlighted to YES, then you have disabled+selected, so you need to set an image for the (UIControlStateDisabled|UIControlStateSelected) state. – Bryan Henry Nov 23 '09 at 19:36
Okay, that was the problem. When I took out the disable functionality, it worked as expected. Thanks! (To answer your question, I'm disabling the button because I don't want anyone pushing it again while the network operation is going on.) – Greg Maletic Nov 23 '09 at 19:48
You can certainly keep disabling the button, and you can even keep setting highlighted to YES as well - you just need to make sure that you set a background image for the proper control state of the button if you want to do so. – Bryan Henry Nov 23 '09 at 20:04

Hlung · Answer 2 · 2012-03-05T09:16:11.357

I have an easier way. Just use "performSelector" with 0 delay to perform [button setHighlighted:YES] . This will perform re-highlighting after the current runloop ends.

- (IBAction)buttonSelected:(UIButton*)sender {
    NSLog(@"selected %@",sender.titleLabel.text);
    [self performSelector:@selector(doHighlight:) withObject:sender afterDelay:0];
}

- (void)doHighlight:(UIButton*)b {
    [b setHighlighted:YES];
}

score 28 · Answer 3 · answered Oct 20 '11 at 17:20

"Everything gets better when you turn power on"

    button.selected = !button.selected;

works perfectly... after I connected the outlet to the button in the Interface Builder.

You do not need to setBackgroundImage:forState:, the builder allows you to specify the background (gets resized if necessary) or/and foreground (not resizing) images.

score 27 · Answer 4 · edited Apr 07 '12 at 18:17

27

Try using NSOperationQueue to achieve this. Try out code as follows:

[[NSOperationQueue mainQueue] addOperationWithBlock:^{
    theButton.highlighted = YES;
}];

Hope this helps.

edited Apr 07 '12 at 18:17

Parth Bhatt

19,381
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answered Mar 31 '12 at 19:24

roberto.buratti

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1
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This is a great solution, Roberto & Parth. One small detail, though, is that you will occasionally see a "flicker" if the user holds his finger down on the button. Is there any way to prevent the flicker? – Scott Lieberman Jan 08 '13 at 07:50

Bob Spryn · Answer 5 · 2013-03-30T21:50:13.470

8

Use a block so you don't have to build a whole separate method:

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 0), dispatch_get_main_queue(), ^{
    theButton.highlighted = YES;
});

Update

To be clear you still need to set the background (or normal image) for the combination states as well as the regular ones like sbrocket says in the accepted answer. At some point your button will be both selected and highlighted, and you won't have an image for that unless you do something like this:

[button setBackgroundImage:someImage forState (UIControlStateHighlighted|UIControlStateSelected)];

Otherwise your button can fall back to the UIControlStateNormal image for the brief selected+highlighted state and you'll see a flash.

edited Mar 30 '13 at 21:50

answered Apr 05 '12 at 23:49

Bob Spryn

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FYI `dispatch_get_current_queue()` is stated as being "unreliable". – Jacob Relkin Sep 14 '12 at 00:39
1

Where is that stated? What's the alternative? – Bob Spryn Sep 14 '12 at 03:38
Is there significance in using `dispatch_after` as opposed to `dispatch_async`? – Ilya Jul 27 '15 at 22:17
Yep. `dispatch_async` is a better choice. – Bob Spryn Jul 28 '15 at 02:16

score 4 · Answer 6 · answered Jul 16 '16 at 12:19

In swift I'm doing it like the following.

I create a Subclass of UIButton and implemented a custom property state

class ActiveButton: UIButton {

    private var _active = false
    var active:Bool {
        set{
            _active = newValue
            updateState()
        }
        get{
            return _active
        }
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.addTarget(self, action: #selector(ActiveButton.touchUpInside(_:)), forControlEvents: .TouchUpInside)
    }

    func touchUpInside(sender:UIButton) {
        active = !active
    }

    private func updateState() {
        NSOperationQueue.mainQueue().addOperationWithBlock {
            self.highlighted = self.active
        }
    }

}

Works perfectly for me.

score 1 · Answer 7 · answered Aug 11 '11 at 22:52

I had a similar problem where I wanted a button to keep it's highlight after click. The problem is if you try to use setHighlighted:YES inside of you click action it will reset right after you click action, - (IBAction)checkInButtonPushed

I solved this by using a NSTimer like this

NSTimer *timer;
timer = [NSTimer scheduledTimerWithTimeInterval: 0.01
                                         target: self
                                       selector: @selector(selectCurrentIndex)
                                       userInfo: nil
                                        repeats: NO];

and then call setHighlighted:YES from my selectCurrentIndex method. I use regular UIButtonTypeRoundedRect buttons.

score 0 · Answer 8 · answered Nov 24 '13 at 02:36

Here is a C# / MonoTouch (Xamarin.iOS) implementation using approaches presented above. It assumes you have set the Highlighted image state already, and configures the selected and selected|highlighted states to use the same image.

var selected = button.BackgroundImageForState(UIControlState.Highlighted);
button.SetBackgroundImage(selected, UIControlState.Selected);
button.SetBackgroundImage(selected, UIControlState.Selected | UIControlState.Highlighted);
button.TouchUpInside += delegate
{
    NSTimer.CreateScheduledTimer(TimeSpan.FromMilliseconds(0), delegate
    {
        button.Highlighted = true;
        NSTimer.CreateScheduledTimer(TimeSpan.FromMilliseconds(200), delegate
        {
            button.Highlighted = false;
        });
    });
};

score 0 · Answer 9 · answered Mar 30 '12 at 14:39

I have another way ...if you don't want to use images, and you want the effect of a pressed button, You can subclass the Button and here's my code:

in the .h File:

@interface reservasButton : UIButton {

BOOL isPressed;
}
 @end

In the .m File:

#import <QuartzCore/QuartzCore.h>


 @implementation reservasButton

 -(void)setupView {  //This is for Shadow

    self.layer.shadowColor = [UIColor blackColor].CGColor;
    self.layer.shadowOpacity = 0.5; 
    self.layer.shadowRadius = 1;    
    self.layer.shadowOffset = CGSizeMake(2.0f, 2.0f); //comment
    //   self.layer.borderWidth = 1;
    self.contentVerticalAlignment   = UIControlContentVerticalAlignmentCenter;
    self.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;

    // [self setBackgroundColor:[UIColor whiteColor]];

    //  self.opaque = YES;


}

-(id)initWithFrame:(CGRect)frame{
    if((self = [super initWithFrame:frame])){
        [self setupView];
    }

    return self;
}

-(id)initWithCoder:(NSCoder *)aDecoder{
    if((self = [super initWithCoder:aDecoder])){
        [self setupView];
    }

    return self;
}

//Here is the important code

 -(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{


  if (isPressed == FALSE) {

      self.contentEdgeInsets = UIEdgeInsetsMake(1.0,1.0,-1.0,-1.0);
      self.layer.shadowOffset = CGSizeMake(1.0f, 1.0f);
      self.layer.shadowOpacity = 0.8;

      [super touchesBegan:touches withEvent:event];

      isPressed = TRUE;

     }
     else {

         self.contentEdgeInsets = UIEdgeInsetsMake(0.0,0.0,0.0,0.0);
         self.layer.shadowOffset = CGSizeMake(2.0f, 2.0f);
         self.layer.shadowOpacity = 0.5;

         [super touchesEnded:touches withEvent:event];

         isPressed = FALSE;

     }


 } `

Keeping a UIButton selected after a touch

9 Answers9

Edit:

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