I created a subclass of UITextView and now I want to extend the default UIMenuController by adding some buttons. Performing the extension is no problem at all, I just need to add some UIMenuItem so the menuItems array of the shared instance of the UIMenuController.
My question is now: Where do I perform this manipulation? The MenuController is a singleton implementation, so every change I make will affect all the other views that support the menu. So where am I going to add the extra menu items and where do I later remove them again? I am searching for some kind of equivalent to the UIViewController's viewWillAppear method.
Or am I worrying way too much and it is perfectly good practice to implement it in the view controller of the view containing my UITextView subclass?
However, this means that every view controller containing my class as subview would have to implement the same code. Is there a better way?
Edit: Another option is of course to keep the selectors for my class unique and have all other custom views return NO for the selector in -respondsToSelector:. This seems to be the best solution so far to me.
What is the best practice?
It turns out that it works fine to add the items in the app delegate. You need to make sure of course, that other Views supporting the MenuController return NO for your particular selector in -respondsToSelector:.
Good question. Not sure about best practice.
You probably want to use the viewDidAppear and viewWillDisappear to modify that.
Related
What is the best implementation of a tableview in Model View Controller?
I'm developing my app without storyboard, all programmatically .
Is it possible to implement a TableView in a UIView? I tried it, but If I implement the TableView in a view, when the controller recives a button action, I can't modify or access to the tableView of the View...
After that, I tried to implement the tableView in a ViewController and it works perfectly, but I don't know if this is a good implementation because I found the same problem when I wanted to implement a TextView/TextField with a Piker, for example.
My goal was to had a clean code of viewController with a views and controllers (of buttons etc) and now I find myself with a uiviewController with the view and multiples components when I wanted the components were in the corresponding views.
Thank you very much!
It is all possible, and the problems you are running into are not because of it being something that you should not do, but that it is something that inherently works slightly differently than before. To answer your question directly, I would implement the tableView as the modal view controller directly, either as a UITableViewController or a UIViewController that inherits the table views delegate and datasource (this method being chosen if you don't want the table view to use up the entirety of the modal view controller's space).
TableViews are simple to use, but understanding every detail of how they work will make you far stronger and able to use them in any of these scenarios. I am not going to write you a guide on their use, butcontinue studying them before you declare that anything "can not be done".
Knowing what classes to implement the delegate methods becomes very important during these different scenarios. It is often easiest to use textfields delegate's implementation in UITableViewCell's subclass rather than in the UIViewController they are in. This allows for a more modular creation.
I find that working with the storyboard allows for a much quicker learning curve, and also a time saver. The one excuse I will give you for working without a storyboard is if you have an extremely slow computer.
I have a number of objects linking to each other in a circle. Each object holds a reference to it's neighbors, square and triangle are different class types:
The tow classes, triangle and square, are made visible with a ViewController, and they link to each other with segues.
So far, no problem. However, while I'm browsing around in my structure, I keep adding ViewControllers on top of each other. Not only does this seem a bad practice memory-wise, but it also presents the problem that when I want to quit this structure, I have to back-track by closing all ViewControllers that I opened.
So what I'm looking for, is a way to not add the next ViewController on top of the current on in the stack, but to replace the current ViewController with the next one.
I've been looking for a while for a solution, but have little success. So I feel that doing what I want is either impossible, or I'm just not getting an obvious point and don't know what to look for. Do I need a RootViewController for something like this? Or should I create a custom segue that dismisses the old ViewController before adding the new one? I'm really at a loss here.
Add all subView once , in viewDidLoad and give tags to all you SubView after that where you you want to show that view in viewController don't add it just bring it to front by calling the function [[self.view viewWithTag:1]bringToFront]
Since you are probably using a navigationcontroller, you should have a look at the UINavigationController reference. There are methods to modify the navigation stack. You cannot do this only with a storyboard. You will need some custom code.
You should have a look at the UINavigationController method setViewControllers:animated:.
Sounds like you want to do one of a couple things
Replace your rootViewController
Have a rootViewController which acts as a container for a single UIViewController and change that out as needed. In iOS 5 you can do this with a custom UIViewController, but or you could use one which Apple provided.UINavigationController` can do it, but unless you are also using it to navigate a tree like structure of view controllers it's probably not the best option.
Your best answer sort of relies on your need.
If your controllers don't have much state or don't get swapped in and out a lot you could use option 1.
If you expect users to swap between controllers often and quickly and/or your controllers require significant setup or have a lot of state then you might want to a NSArray and just use presentViewController:animated:completion: to show different controllers when needed. Storing your controllers in a NSArray has the added bonus of easily being able to identify their neighbors.
The UINavigation controler's method setViewControllers is an option.
Another would be to pop the most rencent view controller using popViewControllerAnimated:
In some cases popToRootViewControllerAnimated: would be best or even popToViewController:animated:. Hoever, I personally was not successful using popToViewController:animated: but that may have been my fault at that time.
Yes, I think you need a root view controller. I myself tried to exchange the root view controller the other day but failed doing so. In the end it was probably not the most elegant solution but easier for me to implement some dummy root view controller which does nothting but display my app logo in the background (Same as the default image but moved into negative coordinates in order to match the default image on startup. It is laying 'behind' the navigation bar and status bar.). It could show some empty black background or so. In the end it is will most probably never be visible.
Basically i wanted to implement a popup UIView so i followed what was posted here
POP-UP UIView "IMDB App" style
This works very well. However i have one query. My main view is a tableView. so when a view is popped up i disable scrolling in the table. Now when the popup subView is removed, i need to re-enable scrolling. How do i achieve that? i can't use willRemoveFromSuperview because the popup view is loading a different NIB altogether.
Should i use Notifications?
hope i was clear with explaining the scenario.
Thanks in advance!
Feloneous Cat has the correct answer. This is the perfect use a #protocol in your popup view along with a registered delegate. Something is triggering that popup view to close. Whatever that trigger is, call the protocol and the delegate can handle the situation as needed.
Furthermore, when protocols are used correctly, your code becomes very reusable within a project as well as in other projects.
What you could do is subclass UIView and override removeFromSuperview to send a notification. I don't think there's ever a case where a view gets removed without using the removeFromSuperview method.
Being new to Xcode and Objective-C I find it hard to get my head around the Interface builder and Objective-C when doing things that are following the basic pattern. I have created a subclass of UIViewController that I want to instantiate several times to make a grid with each row being controlled by an instance of this class. So there will be one root view controller (with navigation etc) that should include/genereate all the instances of the custom sub-viewcontroller.
Now what would be the best way to do this? All examples I can find are about navigation, where one view should replace another, but I want to have all the viewcontrollers visible on the same "page". Do I need to create a nib file for the custom controller at all? I have also been thinking about using the UITableView somehow but inserting my custom viewcontroller in every row.
Any help greatly appreciated!
Apple's documentation recommends using one view controller per screen. It is possible to decompose your interface and use multiple view controllers on one screen if you have a good reason to do it, but Apple hasn't really designed their frameworks to support this, so you'll run into pitfalls if you don't know what you're doing.
In this case, I question whether each row of your grid really needs its own view controller. I find it hard to imagine a case where this would be the best choice, although it's hard to say for sure without knowing more about your app. Some things to consider:
What is your custom controller doing? Is it mostly changing the visual appearance of its corresponding grid row? If so, perhaps it would be more appropriate to subclass the UIView itself.
If this object is really behaving as a controller and not a view, consider implementing it as a subclass of NSObject rather than subclassing UIViewController. The UIViewController for your screen can capture events and delegate them to the appropriate custom controller object, or your custom views can capture their own events and notify their associated controllers of those events directly using a delegate pattern.
If you're sure you have a valid reason to implement these objects as UIViewController subclasses, check out my answer to this question.
I'm learning how to develop my own iPhone apps but I'm having a tough time understanding certain concepts.
First, am i right to say that for every view, there must be a view controller for it? And for every view controller, must there be a delegate for it?
Also, what is the role of mainWindow.nib? Most of the tutorials that i've read don't seem to touch that nib at all. What always happens is the setting up of a NavigationController as the root controller, which pushes another ViewController onto the stack and this ViewController will have another nib associated with it.
So can i assume that i can safely ignore the main window nib?
It's all about MVC (Model View Controller), innit?
The Model, well that's up to you - what does your app do? Think of it as the backend, the engine of your app, free of the cruft of font size decisions and touch events.
The View, Apple pretty much wrote that for you. You use their Textfields and tables and imageViews. You assemble them together using Interface Builder into your GUI (packaged as a .nib). You rarely, if ever need to subclass the standard view elements (in a game you want a custom View to draw to, as all your drawing is probably custom). You can break different parts of your GUI into different .nib files if this helps you manage them. It's entirely up to you.
The Controller, so you have probably got some work todo to enable your GUI to represent your model. You need Some Controllers. How many? However many is manageable by you. If you had a view containing 2 subviews would they each need a view controller? Nah, probably not. How complicated is your code to hook up the view to the model?
Some GUI patterns are so common that Apple even wrote the Controller code for you. EG the controller for a UINavigationBar, UINavigationController. So, if your app has hierarchical views that you need to navigate around and you need to display a navigation bar you can use an instance of UINavigationController instead of writing your own class. Yay!
Surely tho, the UINavigationController code (or any other viewController) can't magically know how to integrate with our model, with our view, can it? NO, it can't. In general in Cocoa if there is some class of object that mostly works off the shelf but also has optionally configurable behavoir - allowing us to tailor it to our needs - it is done by Delegation. ie Instead of subclassing UINavigationController we tell the specific instance of it where to find (for want of a better term) it's custom behavoir.
Why? Let's say you have a navigationController, a tableView and a textfield. UINavigationController mostly take care of your navigation needs but you have to have a crazy QUACK sound play each time the user moves to a new view. UITableView is mostly exactly everything you need from a table, EXCEPT you really want the third row in the table on the front page be twice the height of the other rows. And the standard, off -the-shelf UITextField pretty much takes care of your textfield needs EXCEPT you need your textfield to only be editable when the user is facing North. One way to handle this would be to create 3 new classes, a custom UINavigationController, a custom tableView and a custom textfield, and to use these instead. With delegation we could use the classes as they are and have one object be the delegate of all 3 instances - much cleaner.
Delegation is mostly optional, the docs will tell you when, and it's down to you and whether you need that custom behavoir.