How to handle first responder status for NSTextField subclass? - objective-c

I'm working on a project which needs a special text field to edit byte values. My current solution is a dedicated readonly textfield and a "..." button to open a popover as shown in the image below:
Now I try to make my solution more user friendly. My goals are these:
If the text field gets the first responder status, the popover automatically opens.
The complete text is selected.
If the user leaves the text field with tab or selecting any field outside of the popover, the popover should automatically close.
If the user types any valid number and suffix the byte value is updated (e.g. "10 GB")
Currently I'm a little bit clueless. My questions are these:
Where is the best location to detect in in the subclass when the text field got first responder?
How can I detect when the field resigns being first responder?
Are there other, simpler solutions?

I could implement everything using - (BOOL)becomeFirstResponder as a hook to display the popover and observing the first responder to automatically hide the popover:
- (void)viewDidMoveToWindow
{
[super viewDidMoveToWindow];
[self.window addObserver:self forKeyPath:NSStringFromSelector(#selector(firstResponder)) options:0 context:NULL];
}
As a start point, I published a working project with the classes on GitHub (MIT License):
Project on GitHub

Related

UITextField - Action on resignFirstResponder -- possible?

I have created a form that has a number of text fields that save to NSStrings that are then used deeper in the app.
Currently, if you hit the return key (done) on the GUI keyboard, the keyboard is dismissed, and the data in the text field is saved to its NSString. Likewise, if the background is touched the same occurs.
However, if I touch another text field, without doing one of the above first, the variable is not saved. Is there a way to do this? Perhaps a way to perform an action when a specific text field release firstresponder?
The best solution for your issue is just to use the
-(void)textFieldDidEndEditing:(UITextField *)textField
And then you can just access the textField and store the textFields text in the appropriate string every time focus is lost.

UIPicker with UITextField

I made a research and all posts here are very blury regarding this issue.
I would like to use a UIPicker when pressing on a UITextField.
I would realy appriciate a step by step guide.
I tryd all posts here but every post gives me only a portion of what I need and I can't seem to connect it all together.
This is the last part of my application and i'm going crazy to finish it..
Thank you in advanced!
Gal
There is an inputAccessoryView property that contains a view that will appear instead of a keyboard on the bottom of the screen. Create a UIPicker, adjust its frame, provide values and assign it to the inputAccessoryView property.
UIPicker will appear when user taps on your UITextField.
If you don't need editing, you may use a UILabel instead of the UITextField. Solution is the same. I have a ready-made class if you need.
Here's a way:
http://www.youtube.com/watch?v=t_F1ex5opgA&t=14m10s
-(BOOL)textfieldShouldBeginEditing:(UITextField *)textField
where textField is the name of your text field.
Call your UIPickerView and return NO so that your picker is loaded rather than the keyboard.
The idea is to call an action that opens the UIPicker when the user taps the UITextField. Because the UITextField does not responde to the usual touchUpInside events that UIButtons respond to, I would just overlay a transparent UIButton on top of the UITextField and just in case, make the text field's userInteractionEnabled property NO. Hook the UIButton to responde to touchUpInside and call a method that opens the UIPicker. Another option would be an immediate response to the text field's touch by implementing "textFieldShouldBeginEditing" and immediately resigning the text field.
The next step would be to present the UIPicker - if we are talking about iPad, this would best be done by using a UIPopoverController. On iPhone, maybe consider bringing it up modally. When you create the view controller that holds this UIPicker, be sure to add a delegate property to it so that whatever value that was selected on the picker can be transfered back to the main view controller and on to the UITextField.
Hope this helps with getting you started.

Getting UIPicker to appear when user selects a UITextField

I have a simple UITextField called month where I get users to simply enter the month they want via the keyboard that comes up. I would now like it for them to be able to use a UIPickerDate (or UIPicker) to make this selection instead. So when they press on the text field, a mini UIPicker appears and they make there selection, press anywhere on the screen and the picker disappears.
Does anyone know how to do this or has any suggestions? I am pretty new to programming and have looked at other answers but everyone seems to be referring to this being done in a table.
Thanks in advance!
You can set the inputView property on the UITextField to be an instance of UIDatePicker. When the instance of UITextField becomes the first responder, the picker view will be displayed with the standard keyboard animation.
// Assume that self.monthTextField and self.datePicker
// are properties of the view controller class
self.monthTextField.inputView = self.datePicker;
As for dismissing, that depends on the context. If there are more text fields to populate, consider adding a UIToolbar as the inputAccessoryView of self.monthTextField. Then you can add something like a UIBarButtonItem to make the next text field the first responder, similar to how the standard keyboard provides a Next button.

NSTextField with built in validation

I have in my app an NSTextField for creating a new file. I would like to have this textfield smart enough to show a small icon which show if the currently entered filename is valid (not yet exists) or not.
This icon should also change when the textfield contents change.
What is the way to achieve that?
Thanks!
This is the method you are looking for:
- (void)controlTextDidChange:(NSNotification *)aNotification
This is called by the textfield's delegate when the text changes. Perform your validation in the method and update your UI accordingly.

IPad dismiss Keyboard without knowing which Textfield opened it

Is there a way to do a general resignFirstResponder to hide the keyboard regardless of what textfield/view/etc calls it?
Reason is I have a lot of textfields on my view and don't want to have to resignFirstResponder for all textfields to hide the keyboard. Just want a general
[self resignFirstResponder].
Any ideas?
Thanks in advance
I know that this has already been marked as answered, but for those that run into this like I did you can just use the following method on the view that contains the textfields.
- (BOOL)endEditing:(BOOL)force
This method looks at the current view and its subview hierarchy for the text field that is currently the first responder. If it finds one, it asks that text field to resign as first responder. If the force parameter is set to YES, the text field is never even asked; it is forced to resign. UIView Documentation
[self.view endEditing:YES];
it will hide keyboard when we click on view.
You can dismiss the keyboard without any reference to UITextfield / UITextView with help of below code:
[[[UIApplication sharedApplication] keyWindow] endEditing:YES];
this will dismiss the keyboard globally without the reference.
hope this will help you.
The easiest way to do this is to have a method for whenever you want to dismiss the keyboard that looks like this:
-(void)dismissKeyboard {
[firstField becomeFirstResponder];
[firstField resignFirstResponder];
}
You can check these questions:
Is it possible to make the iPhone keyboard invisible / remove it without resigning first responder?
Hide Input Keyboard on iPhone Without Knowing First Responder?
In summary:
You can call becomeFirstResponder on some other thing that you choose. It could be a UIViewController or a UIView. I had a similar problem before, I needed to make my keyboard go away when I was pushing my view controller back to its caller, without knowing which textfield was the first responder. Then, on viewWillAppear of my view controller which I was returning back, I called [self becomeFirstResponder] and the keyboard of the pushed view was gone. Because this made whichever text field was it loose being the first responder
In my own app when I had more than one text field and would like to make the keyboard go away regardless which of the fields called it, I would just wrote a method and let each and every of them resignFirstResponder.
I assume that as a programmer, you should have the clear knowledge how many text fields are on your view controller and how you can access them, otherwise it'll get messed up and you app won't look good... :-P