I have a UISegmentedController to allow a user to choose which order they want slides in my app to show up. Im wondering if anyone knows of a method to set it other than value did change. I have other methods that keep getting triggered in viewDidLoad while its being set to their previously selected index. I don't want the other methods triggered until a user changes it. Any suggestions?
Thanks in advance
The simplest way would be adding boolean to your class, e.g. canTrigger. And you can set it to YES, once user changes.
Related
I have a TabBar Application with 2 tabs saving/fetching data to and from CoreData. The problem that I am having is that when the form has been filled and the user has touched the save button the view is not re-loaded or re-initialised. All I want is for the view to be ready for the user to repeat the process with the next set of information. I am probably not thinking about this in the correct way so a pointer in the right direction would be very much appreciated...
Do I need to manually set everything including the managedObjectContext etc. to nil? Or is there something that I can do with methods like viewWillDisappear that will elegantly help me to "re-initialise" that specific tab?
I ave read up the Apple docs on view hierarchies, and life cycles but I just seem to have confused myself...
Thanks in advance for any suggestions, referrals to code or even recommendations on relevant reading material.
It sounds like what you want to do is reload any data to their default states when the user taps a button. Unfortunately, you'll have to do this manually, setting each IBOutlet's value to a meaningful default (probably the empty string).
There are two ways I can think of that would help make this more elegant:
Use an IBOutletCollection and fast enumeration to loop over all the IBOutlets and not have a bunch of code to do each one individually.
If you're switching tabs in between these events, you can something neat and use your app delegate as your UITabBarControllerDelegate for the tabBarController:didSelectViewController: to call the clearing-out method for you instead of relying on viewDidAppear.
I wan't to creata a "CatchNames" class which I can import into a view Controller that shows a text which asks for text input. I would like to be able to add an instance of CatchNames to my view, have it ask the user for three names in a row and return them in an array.
[self.view addSubview:[catchNames view]];
NSArray *myNamesArray = [catchNames namesArray];
The best way would be to have the application freeze kind of the way it does when you are prompted to enter a password in iOS and continue when the user entered 3 names so I can immediately catch the array in the next line.
While this might not be the best description I still hope you understand my problem.
How can I approach this?
Thank you in advance
I guess you appear to be looking to implement a simple form which gets the user input, retrieves and stores it in an array? Hopefully I haven't misunderstood the question, but this seems to be a simple task you can accomplish with one or more UITextField's and a UIButton as a 'Add' or 'Done' call to action.
Are you looking for some general UI coding level help regarding implementing such a view? If so, I would encourage taking a look at the XCode documentations of UITextField (for capturing text), UIButton (for handling actions) and UIView (for view hierarchy and animation implementation).
Some quick notes;
Looks like 3 names are compulsory, so, you may verify whether a UITextField is empty at the button's click action.
Have the array declared in the view controller, not the view
The 'freezing' you require should take care of itself as long as the view offers no other way out for the user other than clicking the button.
Do excuse me if I am oversimplifying the problem. Let me know if you need me to drill down into anything further.
Cheers!
I have an option menu where a user can change the application's settings. I need to track the changes. There is a DONE button, I want to make changes to the data model only when the button is pressed.
My question is, I am not sure the best way to track the changes. I don't want to introduce a giant if blocks in the doneButtonPressed button. Any general advice?
Well, the generic answer is: add callback to your controls in your options screen.
For example if you are using UISlider, then you have to customize it slightly. Probably create a subclass, that would receive touch events and then you redirect them to the delegate. OR you can use this one: RCSwitch
If you are using UIButton's then it's even easier: just add action to it.
After that you can create method like:
-(void) controlDidChange:(UIView*) control {
//mark changed items here
}
Alright, so here is what I am trying to do. I have a UITextField. When I single tap it, I want to call one of my methods. When I double tap (tap it twice with 1 finger) it, I want to edit the text field (as though I had single tapped it on a normal UITextField.)
I am not sure how to go about this. I was thinking of sub-classing UITextField and trying to intercept the touch event as it is sent, but I can't figure out which methods to override to do this. Which methods should I override and how?
Or, if there is a better way to do this, let me know! I'm all ears, and not sure how to proceed.
This would involve several steps:
1.) Add a NSBoolean property that keeps track of whether the user has already tapped the field once recently (you get to decide what recently means here).
2.) Implement the textFieldShouldBeginEditing: method of the delegate assigned to your UITextField. If the user has tapped twice in quick succession (detectable by checking whether or not the boolean property is true), then return YES. If not, call your method, and then return NO.
I have an application with several UITableViewControllers.
Now, the user is allowed to change "Data source". In that case I need to invalidate (reset) data in the relevant UITableViews.
I figured out, that I can use NSNotificationCenter and add these controllers as observers to events which will be generated when the data source changes.
The question is, how do I reset the underlying tables? I can, of course, set some boolean flag, and call UITableView:reloadData in viewWillAppear or viewDidAppear, but I was wondering, if there's a cleaner way of doing it.
Or perhaps I'm completely missing the point, and I don't need NSNotificationCenter altogether.
Thank you very much in advance.
The question is, how do I reset the
underlying tables? I can, of course, set some boolean flag
I'm not sure why you need to use a flag here. When your view controller gets the notification, have it reload the table in the notification handler.
Updating your table will work a bit differently if your UITableView is attached to an NSFetchedResultsController. Is it?