Keeping a UIButton selected after a touch - ios

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;
}

Answer 1

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?

Answer 2

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];
}

Answer 3

"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.

Answer 4

Try using NSOperationQueue to achieve this. Try out code as follows:
[[NSOperationQueue mainQueue] addOperationWithBlock:^{
theButton.highlighted = YES;
}];
Hope this helps.

Answer 5

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.

Answer 6

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.

Answer 7

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.

Answer 8

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;
}
} `

Answer 9

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;
});
});
};