I am currently working on an iPhone 2.1 application. I am new to Objective C, coming from a Java background.
My application has as a base the Utility Application template available in Xcode with the iPhone SDK. Currently I have some controls, such as an UISlider and text box, in the FlipsideView. The UISlider already has a method which is being called when the value changes, using targets and selectors. However, I would also like to be able to read, from the MainView, the current (or last) value of the UISlider and textbox.
Keep in mind I am new to development on a Mac, and would appreciate any guidance as to where I should look up such information, be it through the use of delegates or perhaps I am missing something obvious in the structure of the template.
UPDATE: I am taking a look at the structure and have some more details: The UISlider is being created in FlipsideView.m. I noticed that the Done button is created from RootViewController.m and probably I should move the UISlider code over there. I may incorrectly be using the View to keep code that would be more appropiate in a Controller.
Ultimately you should be updating some underlying object with the values from the controller. In general, the slider belongs in the view layer – it’s a display element. The action that adjusting the slider produces, however, is a component of the controller and it should fire back into your model to update a value. I highly recommend drawing boxes on a sheet of paper and trying to produce a clean a separation as possible for your application’s layers – doing so in this case would produce two views for each ‘side’ of the utility which would, via a controller, relate to a model. Then, the act of moving the slider would ‘instantly’ update the model on the back. The Cocoa Fundamental video on the iPhone developer site demonstrates this to great effect.