There sure are a lot of UIButton questions here, and I was hoping to find the answer to this, but nothing quite like this particular issue.
I have a few buttons, and I can call button.highlighted = YES; for any button when the program runs and it shows up highlighted.
I thought I could then use this same technique to set a button's highlight state to YES after it pressed, and then set it to NO after another button is pressed. This way, the current selection remains highlighted.
For example:
-(IBAction) buttonPressed:(UIButton *)button
{
if (button.tag==1)
{
self.button1.highlighted=YES;
self.button2.highlighted=NO;
// do other program stuff here
}
if (button.tag==2)
{
self.button2.highlighted=YES;
self.button1.highlighted=NO;
// do other program stuff here
}
}
Even though the highlights work fine if I place the highlighted = YES; code inside viewDidLoad. But the above code does not work. The highlight doesn't stick. The buttons works, and does the other stuff it needs to do, but the highlights fail to stick.
I would think this should be pretty basic. Is iOS somehow automatically setting all button highlights to NO on its own after any button operation?
May be you should use other means to present the highlight status, because of the statement from UIControl's documentation:
By default, a control is not
highlighted. UIControl automatically
sets and clears this state
automatically when a touch enters and
exits during tracking and when there
is a touch up.
You might try using the 'selected' property instead of the 'highlighted' property.
Related
When my application launches, the first NSTextField is being selected like this:
I can edit the NSTextField fine, but when I press enter to end the editing, the text becomes selected again, and the editing does not end.
I followed the Apple tutorial here, and I had the same problem with the text field being perpetually highlighted.
How do I stop this? I would like it so the text field is not the first responder of the app so it's not edited right away, and when it is being edited, clicking outside of the text field will end it. I'm not sure where to put the [[textField window]makeFirstResponder:nil] to stop the editing in the latter case.
I'm running Yosemite 10.10.2.
Your text field is selecting the text, due to the default implementation of becomeFirstResponder in NSTextField.
To prevent selection, subclass NSTextField, and override becomeFirstResponder to deselect any text:
- (BOOL) becomeFirstResponder
{
BOOL responderStatus = [super becomeFirstResponder];
NSRange selectionRange = [[self currentEditor] selectedRange];
[[self currentEditor] setSelectedRange:NSMakeRange(selectionRange.length,0)];
return responderStatus;
}
The resulting behavior is that the field does not select the text when it gets the focus.
To make nothing the first responder, call makeFirstResponder:nil after your application finishes launching. I like to subclass NSObject to define doInitWithContentView:(NSView *)contentView, and call it from my NSApplicationDelegate. In the code below, _window is an IBOutlet:
- (void) applicationDidFinishLaunching:(NSNotification *)aNotification {
// Insert code here to initialize your application
[_menuController doInitWithContentView:_window.contentView];
}
The reason your field is getting focus when the application starts is because the window automatically gives focus to the first control. It determines what is considered first, by scanning left to right, top down (it scans left to right first, since a text field placed at the top right will still get focused). One caveat is that if the window is restorable, and you terminate the application from within Xcode, then whatever field was last focused will retain the focus state from the last execution.
I am using IB, there's a property on NSTextField called Refuses First Responder. Ticking that will prevent the highlighting of the text field immediately after the window is presented. There's some more detailed info about Refuses First Responder in this question.
No need to subclass. Simply set refusesFirstResponder = YES;
NSTextField *textField = [NSTextField new];
textField.refusesFirstResponder = YES;
That's it! Do that and it won't highlight the text in the field.
I have an NSComboBox. I've set an action selector. When the box gets hidden the selector fires, even if the user never touched it. Yes, I need to hide it.
IBOutlet NSComboBox *comboBox;
[comboBox setAction:#selector(onComboBoxSelection:)];
- (void)onComboBoxSelection:(id)sender
{
NSLog(#"Why does this fire twice");
//My code doesn't actually set hidden here, it's just for proof while debugging the issue.
[comboBox setHidden:YES];
}
Why would hiding an NSControl fire it's selector? What's the best way to fix it?
Update:
I've fixed it by wrapping the method. But I'd still like to understand why, or other ways to fix it.
- (void)onComboBoxSelection:(id)sender
{
if(![sender isHidden]{
NSLog(#"Now only fires once");
//My code doesn't actually set hidden here, it's just for proof while debugging the issue.
[comboBox setHidden:YES];
}
}
Set a breakpoint in onComboBoxSelection: and look at the backtrace when it's called the second time (type bt in the debugger to see the backtrace). That will explain what's going.
A combo box is both a text field and a popup, and it will fire actions for both. The text field action is fired when editing ends, either by hitting the Return key or when it resigns first responder (e.g., tabbing out to another field).
When you hide the combo box, the text field resigns first responder and fires its action.
What you probably want to do is check if combo box value has actually changed, and only then proceed with hiding the combo box, etc.
Another option is to use data bindings to observe changes to the combo box. Bind the combo box value to a property on your controller. Then implement the property setter in your controller.
try this [comboBox setHidden:1];
here is the low down:
-(IBAction)button1click:(id)sender;
{
label1.hidden=YES;
textfield1.hidden=YES;
label2.hidden=NO;
textfield2.hidden=NO;
-(IBAction)button2click:(id)sender;
{
label1.hidden=NO;
textfield1.hidden=NO;
label2.hidden=YES;
textfield2.hidden=YES;
the is issue is that when i first open my screen all 4 labels are visible. By default button1 radio is checked but label2 and textfield 2 are visible when they shouldnt be. if i press button1 even though it is already selected the items with hide and then all is good. My issue is having them hidden when the screen first opens up.
Thanx all for you help
You can, in your viewDidLoad method:
-(void) viewDidLoad
{
[super viewDidLoad];
[self button1click:nil]; //nil or the instance of button1 if you need it
}
In this way, you will execute the same code when you press button1 without duplicate your code.
You can take one of two approaches to hide the label.
a) in Interface builder you can click the check box for hidden in the attributes inspector. If you do that the default behavior will always be hidden when the app launches then you can make it visible in code like your example shows
b) add your existing code to hide the label to your view controllers - (void)viewDidLoad method.
both methods work equally well.
When you create that objects you can set foo.isHidden = YES
I have a set of UIButtons (defined in a xib) who have labels that need to be updated periodically. In the ViewDidLoad method of the view controller of those buttons' superview, I have an update method that does, for each button:
button.titleLabel.text = #"Relevant Text";
[button setNeedsDisplay];
and when you tap a button, another method runs which pops up a UIAlertView, which in turn calls back a method on the view controller which does much the same thing as the initial text setting method:
button.titleLabel.text = #"New Text";
[button setNeedsDisplay];
however, this code simply isn't working, the button label's text doesn't get updated in either method, it remains a blank white button. In the xib I don't define any text on the buttons - there's no point, the button text doesn't make sense unless it's set at runtime. Anyway, on a lark, I decided to set the text of one of the buttons to "test test test".
Now, when I tap that particular button, it pops up the UIAlertView but in the background changes the text of the button to "test test test test". And this time, the UIAlertView callback does what I expect it to and sets the text for only that button. When I hit it again, the text goes back to "test test test test" until I dismiss the UIAlertView, which again will run the callback method and set the button text to whatever the method should.
I have no idea what's going on here, or why setting the text initially in the xib has any relation to whether or not I can set that text later programatically. Obviously this isn't the behavior I want, I want to know how to for sure set the text on the buttons.
Edit: SVD's advice about setTitle:ForState: solved my problem, thanks. I'm still curious though as to why the title label set in the .xib shows up, but only when I have a UIAlertView pop up.
You may need to use [setTitle: forState:] to set the button title for normal and highlighted (or selected) state.
(And do make sure the button is connected to the outlet, as jtbandes points out).
I have a set of UIButtons (defined in a xib) who have labels that need to be updated periodically. In the ViewDidLoad method of the view controller of those buttons' superview, I have an update method that does, for each button:
button.titleLabel.text = #"Relevant Text";
[button setNeedsDisplay];
and when you tap a button, another method runs which pops up a UIAlertView, which in turn calls back a method on the view controller which does much the same thing as the initial text setting method:
button.titleLabel.text = #"New Text";
[button setNeedsDisplay];
however, this code simply isn't working, the button label's text doesn't get updated in either method, it remains a blank white button. In the xib I don't define any text on the buttons - there's no point, the button text doesn't make sense unless it's set at runtime. Anyway, on a lark, I decided to set the text of one of the buttons to "test test test".
Now, when I tap that particular button, it pops up the UIAlertView but in the background changes the text of the button to "test test test test". And this time, the UIAlertView callback does what I expect it to and sets the text for only that button. When I hit it again, the text goes back to "test test test test" until I dismiss the UIAlertView, which again will run the callback method and set the button text to whatever the method should.
I have no idea what's going on here, or why setting the text initially in the xib has any relation to whether or not I can set that text later programatically. Obviously this isn't the behavior I want, I want to know how to for sure set the text on the buttons.
Edit: SVD's advice about setTitle:ForState: solved my problem, thanks. I'm still curious though as to why the title label set in the .xib shows up, but only when I have a UIAlertView pop up.
You may need to use [setTitle: forState:] to set the button title for normal and highlighted (or selected) state.
(And do make sure the button is connected to the outlet, as jtbandes points out).