CODEWITHSUNDEEP
iphoneios5uicontrol
Cosmin
Cosmin

Reputation: 2908

iOS Custom Control

I am building a custom control that looks like the one in the image below.

enter image description here

It will basically be a menu with a slider. The arrows will allow me to change the three days show on the slider track. Acoording to the day I select with the slider I want to change some views on the main screen (this menu will on the bottom of my page). So basically this is the only thing that I will "listen" in my main controller: if some day has been selected.

I have figured out all the code I will have to write, but I am not sure wether I should subclass UIControl or UIView. And if so, where should I write the code of my controller (changing the days, adding the drag effec, etc ) in the UIControl (UIView)? Or should I subclass UIViewController, and write there all the code there. (but if so, why should I subclass UIControl (UIView) in the first way).

So basically I want to know what extra files I need to create, besides the view interface of my custom control(which I did in the IB), where should I put the code (IBOutlets, IBAction methods) and how do I communicate with the main view controller (I set the main controller as a delegate of my custom control?).

Sorry for the long post.

Thanks

Upvotes: 1

Views: 887

Answers (2)

Jason Harwig
Jason Harwig

Reputation: 45591

The short answer is you should subclass UIControl and put all of the logic to draw the component and interact with the component there. UIControl inherits from UIView and adds target/action behavior. This way you can sendAction:to:forEvents: with UIControlEventValueChanged whenever the date changes.

You could alternatively implement a delegate protocol for when the user changes the selected date.

For example:

@protocol DateSliderDelegate <NSObject>
  - (void)dateSlider:(id)slider dateDidChange:(NSDate *)date fromDate:(NSDate *)oldDate;
@end

You don't want to use a UIViewController since it's job is to manage higher-level views, like the screen that your widget is on. You'll use a view controller later when you are consuming your component and do things like set the date to display initially and listen for change events.

Upvotes: 2

DarkDust
DarkDust

Reputation: 92414

I recommend to subclass UIControl. Users of this control can do [yourControl addTarget:self action:@selector(someMethod:) forControlEvents:UIControlValueChanged]; to react to changed values. In your control, when you have determined that a new day has been selected, you call [self sendActionsForControlsEvents:UIControlValueChanged]; and voila, all interested classes will get informed.

Keep that control as self-contained as possible. This means, only give it as much logic as you need to, and nothing more. Think about how you use Apple provided UI elements: try to make yours as generic (if practical; use common sense here). In short: you should thrive to make this control generic enough that it could be useful to you in other projects or other places of your app.

Upvotes: 4

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