I am building a custom control that looks like the one in the image below.
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
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.
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.
Related
I want to make the horizontal swipeable page like YouTube. Is there an object in XCode for this? How do I have to do it? I did not find a tutorial about it. Sorry for my English.
Like this
There are tons of components already made for this in the internet, you can try looking at the cocoacontrols site.
If you still want to write your own code for this, one way is writing a custom UIView subclass. The YouTube feature looks very simple and as far as I can guess, they can use two separate UIView subclasses: one for the menu and one for the pages, just as a container.
For the menu you can use UIStackViews or a single UIViews with UIButtons for the page's titles and another view for the selection effect that moves with the UIButton's touch event. This view should provide a delegate or any notification system that fits better to you in order to notify the container that needs to load the right UIViewController's view inside the container.
The container can be a UIView that loads the view property from the UIViewController subclass on demand. Make sure to add the loaded view controller as a child of the parent view controller, otherwise you will loose some important features.
I hope it can help you to start.
I do understand how to go about making the UIKeyboard push up the UIView if the active UITextView is blocked by the UIKeyboard as per this question: How to make a UITextField move up when keyboard is present?.
What I'm wondering is, from a design perspective, how do you go about implementing the keyboardDidShow and keyboardDidHide methods so that all of the views in your app, whether they be a UIView, UITableView, or UIScrollView all have this functionality and so you need to implement these methods only once?
The only way I could think of would be to have the view property of the UIViewController always set to a UIView, and if you have a UIViewController that needs a UIScrollView or UITableView, just attach it as a subview to this. Then if the UITextView is being blocked, just move the parent UIView up so it will move all of the views that are attached to it.
Does this sound like a good plan, or is it even worth it? Anyone else have any other ideas?
This is a little old, but it's a great article about using firstResponder methods to tell views to slide up. I, personally, like to put my UITextField in a parent container and move it all up. However, I do NOT suggest putting everything in there and moving it all up, because the UITextField "feels" better just above the keyboard. But I do like the background or certain items to move up with the UITextField.
See below: http://cocoawithlove.com/2008/10/sliding-uitextfields-around-to-avoid.html
This is a nice implementation that moves the field up based on the section of the screen it's in (upper, middle, lower). Works very well. May need to be updated for newest SDK, but should be pretty easy.
In experimenting with this, I noticed that if you want to make a BaseViewController that implements this functionality to work for everything that inherits from it, you have to attach another view on top of the UIViewController's view property in order to get it to work. Reason is, if you push the UIViewController's view property up when the keyboard appears, then it resets itself if the app comes back from being active and it's messy.
The problem with this however, is now in all of your child classes you have to attach your subviews to this new view property instead of the regular view property. Also, you probably have to make a custom UITableViewController which will inherit from your BaseViewController class so it can inherit the keyboard notification methods.
Ultimately, I've found it's not the worst idea to have another view on top of the UIViewController's property for a bunch of different scenarios. Making a custom UITableViewController isn't that big of a deal either. So if you have a lot of text fields in your app, this might not be the worst way to go.
Here is the requirement of my application:
There is a calendar type view which will show Date, Day, Total work hours of that day. What I need, when I click anywhere in that particular square block then it redirects my page to a new view.
I am thinking to should add multiple button and UIView on that button.
That can solve my problem but it is little bit problematic. How should I to do this?
Please look at UITapGestureRecognizer for your view. I think this is what you're looking for.
Here is a link to a tutorial on using UITapGestureRecognizer
Create a subclass of UIControl and a XIB with a UIView in it. Set the class type for the UIView to your new UIControl (not the file owner but the UIView). Then in the UIControl in the initWithCoder: method create the display component and add to view. Then set up you properties that you need to populate those controls.
To use this new control place a UIView where you want it on your screen and size it. Change its class type (in the inspector) to your new subclass. Now you can add outlets and actions to this view just like you would a UIButton. The only downfall is can't set the display controls from the inspector, you'll have to do that in the program. But the good side is you get a similar interface to a button and you can make it look anyway you like.
Hope this helps.
I have an app with an image view. When the user clicks on this view I want to run some code which will change the colour of a label and then hide this view
I have everything setup in the interface, i.e. Outlets etc, but I dont see any events available to associate
Can anyone help or point me in the direction of a good tutorial asap please?
Cheers
Paul
You shouldn't use an image view for this, you should use a UIButton. ImageViews are designed primarily to display, not allow for interaction (which is why their userInteractionEnabled flag is OFF by default.)
Take a look at the documentation for UIResponder - all UIViews, including UIImageView, inherit from it. In turn, UIResponder defines a set of methods you can override to handle the kind of event you're looking at. Start by subclassing UIImageView (call it MyImageView), then override the touchesEnded:withEvent: method.
As Ben Gottlieb said, however, this may be kind of an abuse of the UIKit framework - just make sure the user interaction you're creating makes sense and conforms to good UI practices.
The last time I needed to do this I just used a button also. You can always set up the highlighted state so that it doesn't highlight when someone taps on it if that's what you're trying to avoid.
Note that the higher level UI "actions" are implemented in UIControl, so if all you need to do is track actions like "Touch Up Inside" then it's possible to avoid the event layer, create a UIView in Interface Builder, then change the class to UIControl. You should then be able to use the connections inspector and connect any of those control actions to whatever.
If you place views inside the UIControl and the subviews have "User Interaction Enabled" unchecked (that is, user interaction is disabled) then taps and such inside the UIControl just ignore those and fall through to the UIControl. So another way to do this if you needed to for some reason would be to create a UIView, change the class to UIControl, then place one or more UIImageViews, UILabels, or whatever you want in your generic UIControl view. You can then get actions from the generic UIControl as if all that stuff wasn't inside it.
alt text http://www.davidhomes.net/question.gif
I'm farily new to iphone dev (<3 months on my free time) and I'm starting development of my second app.
From the image, I'm adding a number of UIViews as subviews to my main UIViewController.view, the number of Views to add varies based on user selectable data.
Each view contains several controls, a label, a UITextField and a Horizontal UIViewPicker.
For simplicity I put a (VERY ROUGH) mock-up here with only two buttons.
Because I want to improve the GUI, I want to overlay an UIViewImage as the top sub-views of the added UIView, something like in the image.
The question is on passing through the events to the objects below it. I've read somewhere that one way was to use clipping, but the actual shape is more complex than just an oval frame.
Somewhere else I read that one could add four UIImages, one at each border, which would let the events pass through this hole. Seems like a dirty solution to me (Although I'm sure it would work)
Any ideas about the best way to do this? Any links to a tutorial or recipe online?
Your help is appreciated
thanks
david
Have you looked at protocols? You can define protocols for your views or objects, and the users of that object (the subviews underneath for example) can implement the protocol, set itself as the objects delegate and when actions happen they will notified through the protocols. So for example
An AboveView will declare a protocol that declares methods when a certain gesture was senced by that view so something like
-(void)didMakeCircleGesture...
as a property the underneathview will have a delegate, so in your method that actually sence the gesture youll have at the end something like
[delegate didMakeCircleGesture];
in turn the delegate is the view underneath or something, and it will conform to the protocol defined by the AboveView, and as part of it it will have to declare the method didMakeCircleGesture, so as a result when one makes a circle gesture in the AboveView the underneath view that conformed to the protocol will be told of the event and it can take appropriate action