I'm trying to employ QuickDialog for an iOS 5 iPad app which uses storyboards, but I guess the question would broadly apply to UITableViewController as well.
My understanding is that when I'm initialising the QRootElement, the tableview that QDC creates will replace the view of my class, thus rendering ineffective anything I customise in the IB storyboard. I would like to be able to design the UI in IB, and have the QD table show up as a frame instead of taking over the whole screen.
I think the solution is to have the QuickDialog tableview set up as a subview of my UIView-based class. Is this correct? What would be the best way to achieve this? Would I have to rewrite the root initialiser in my custom view controller that inherits from QDC, or is there a different way, perhaps something like the approach used here?
Thanks!
I would recommend you inherit from the QuickDialogViewController as your main controller. The QDViewController inherits directly from UIViewController (instead of UITableViewController), so it's quite easy to just move the table view around and add controls around it.
If you really want to create everything from Interface Builder, your tableview will have to inherit from QuickdialogTableView, and you'll have to provide the delegate and data source yourself. Look at the QDViewController for that, as you'll have to write pretty much the same code.
Related
Is there some "best-practice" way to add subviews to a UIScrollView?
For Example:
I have a UIViewController which loads images with corresponding description from a server.
Those images+descriptions should be added in a horizontal scrollView.
When the data is loaded, should I create a method in my UIView to handle this stuff,
or is it more convenient to do this in my UIViewController?
Your view controller would be an most appropriate place to handle this, as controllers should connect your view (the scroll view) to the data (the images).
If the scroll view's layout is simple, it could be done entirely with the controller. But, if the layout is complex, you may want to consider subclassing UIScrollView and handling some of the layout there (similar to how UITableView works).
For more info on standard application architecture, read Concepts in Objective-C Programming on Apple's developer site.
By my way of looking at it, the separation of concerns would break down like this:
the UIViewController is responsible for getting the images and handing them to the UIView
UIView is responsible for displaying them.
So the -addSubview: is a view implementation detail, should go in the view, and be opaque to the controller.
There is plenty of opinion that both UIViewController and UIView are confused and intertwined in such a way to make them both part of the conceptual "view" (in a MVC sense), but I think it's still cleaner this way.
As you can see, opinions differ. :) Personally, I despair of MVC, and think Model-View-ViewModel to be a much clearer, cleaner, and more sensible way of approaching all this.
UICollectionView is same as that of UITableView except it is meant to display Images and its description.
Here is what you can do.
Create a UICollectionView, it is the subclass of UIScrollView. SO there is no need of UIScrollview.
Since you need image and description both for each item, I will recommend delete the UICollectionViewItem from UICollectionView.
Create a seperate custom UICollectinViewItem class, define UICollectionItem in .xib file (UIImageVIew and UILabel).
When you define the datasource method "– collectionView:cellForItemAtIndexPath:" define the UICollectionVIewItem class here. Exactly we defines custom UITableVIewCell.
I am gonna design a component in IOS, in which we will have Table view and Grid View; means user can see his data in table or grid. So what i am doing is i added a UIViewController and added two child view controller one for table and another one for collection view. I am handling everything using UIViewController only. Its means when user wants to use my component he has to add as a child view controller only. My question is that "Is it the best practice to use UIViewController like i am doing or Should I convert everything to UIView because UIView is light weight." I am gonna write only presentation logic in my component. We will get data from outside using delegate. And if i should use UIView then when should i use UIViewController?
Thanks
Your current approach is correct.
UIViews should do one and only one thing: paint a view when asked to.
UIViewControllers are more complex. They are are responsible for setting up views with any data they need to do their job, compositing multiple views (or view controllers) together if needed, responding to events from view components or from the device in general, and communicating with the rest of the code/system.
Because your code wants to show two different kinds of information, it fits the UIViewController much better than the plain UIView style.
As you've pointed out, Apple themselves have many examples of UIView subclasses that have delegates and do complex things. However, if you're writing a new component and it is complex (as yours is), I seriously recommend going for the UIViewController approach.
A note on history: Apple used to be of the advice that UIViewControllers should only show/composit UIViews and not other UIViewControllers (even though, confusingly, they didn't always follow their own advice!). This would align with their making of some quite complex UIView subclasses. However, they changed this stance a while back, and added support to UIViewControllers for compositing other UIViewControllers' views inside them. If Apple's stance had always been as it is now, you might find that some of their UIView subclasses were implemented as UIViewControllers!
As an experiment, it would probably be quite educational to try and implement your component both ways. I predict that you'd find UIView approach more unwieldy, with you having manually re-plumb some of the 'wiring' that you'd get 'for free' with the UIViewController approach.
Avoid putting logic in UIView subclass.
As I think you can make grid view by using table view just simply add multiple views on each cells
at time of switching grid to list or list to grid simply check your type and reload tableview
Maybe this is a silly question, but I've bumped into it a number of times during iOS Development.
Sometimes I'll develop a view component that I want to use on multiple screens, so I'll decide to subclass UIView and make it something I can use in multiple places.
Then, I start adding functionality to it. Maybe it needs to respond to an NSNotification, or it is supposed to respond to user touches.
At a certain point, I start wondering if I should really be making a UIViewController subclass, and add it to my UI as a child ViewController.
Is there any consensus on where to draw the line between adding some behaviors to a UIView, and when to create a full UIViewController?
I can't tell you about the consensus, but here's my opinion:
Subclass UIView only when...
You want to do custom drawing
You need to customize some behaviour of an already existing UIView subclass
You have special needs for layouting subviews. Most layouting can be done by UIViewController, though.
Maybe for special touch handling that you can't be done with gesture recognizers
Subclass UIViewController in all other cases. You almost always need a controller anyway, for writing glue code that ties together views and models, or for handling user interaction. Consequently, Apple has made it easy in UIKit to let controllers do all the work and to keep views as "stupid" as possible. For instance, it is very simple to nest controllers to create complex view hierarchies, without the need to have a single view subclass.
An indicator that subclassing UIView is not the first thing one should do is the section titled "Alternatives to Subclassing" in the UIView class reference. An indicator that subclassing UIViewController is the preferred thing to do is that there is no such section in the UIViewController class reference :-)
You should use a controller anytime that you need to handle or control data. Views are supposed to be as stupid as possible, not knowing what they are displaying but rather where. You can easily subclass and reuse ViewControllers. A good example, say you need to retrieve a string (or text) from the user throughout your app via a popover controller and a modal. Create a generic subclass of UIViewController that has a view with a textfield and a button. You can then use this view and it's controller in any capacity you need. Reusing it in the popover, modal or anywhere else (and generally passing the data back through delegation). Since you are dealing with data you should not being using a sole subclass of UIView.
From my experience I subclass UIViewControllers more often then UIViews. It is a little difficult for me to understand if you are solely talking about Containers or reuse of views in general application workflow. Either way though it should be the same.
I've used the embedded view controllers to load reusable table views from time to time. I've found that it's useful sometimes but not always. Communication between the two can be cumbersome, like if you want the embedded controller to communicate back up to the container. Delegation makes it easier but still cumbersome. It also limits you to iOS 6, if I remember right iOS 5 and lower don't support embedded controllers.
If it's just adding methods you can use a category to store some extra methods. I do that a lot on NSManagedObjects that I don't want to subclass and if I regenerate the NSManagedObject from the datamodel I don't lose the code in my categories. Gives me added functionality like calculated fields or conversion methods without having to subclass. If you don't need those methods for a particular instance just exclude the reference to the category.
Subclassing never is bad though IMO.
(screenshot below helps explain what I am trying to do)
The idea behind this is that I have a UIView, with various different UI elements inside, for example, let's say I have a UIView, and inside there we have a UILabel.
Now I'm wanting to duplicate the UIView (with the label inside) BUT somehow after that I need to perhaps make a change to the label, e.g. change the text property.
The reason I need something like this is so I can structure the UIView with everything I need in it looking nice, but to actually have different data with different copies of it.
I'm not certain this is the best approach, but it's the only one I could come up with. If anyone has any ideas on how to do this, or any ideas on a better approach I'd really appreciate it. A lot!
I personally think the best answer is to create each view separately and configure it as needed. You can make a method that just configures new UIViews to look the same, and pass each view through it.
However, if you really need to copy a UIView, you can archive it, and then unarchive it:
id copyOfView =
[NSKeyedUnarchiver unarchiveObjectWithData:[NSKeyedArchiver archivedDataWithRootObject:originalView]];
UIView *myView = (UIView *)copyOfView;
[self.view addSubview:myView];
If you have a bunch of these, make sure you're using the Instruments time profiler to check your drawing efficiency.
This is a very natural and useful thing to do. What you're looking for is a container view controller. Put your reusable "cell" into its own view controller and its own nib file. Then, in your parent view controller, use addChildViewController: to add as many of these as you'd like and configure each of them. They can each have their own IBOutlets that you can use to modify the contents.
This is very similar to the pattern used by UITableView and UITableViewCell (it doesn't use "child view controllers" specifically, but it does use this pattern).
For full details, see "Creating Custom Container View Controllers" in the View Controller Programming Guide for iOS.
Note that Storyboard includes a "Container View" as an option in the object templates to make this even easier.
If you want lower-level access, you can also do this by hand using UINib to load the nib file and wire its outlets (and this is how we used to do it before iOS 5), but today I would use child view controllers.
If you have only one label inside it the obvious solution is to have a custom UIView subclass with that label added as a subview. Everytime you need a new view you make an instance of your custom subclass and set the label text. If you have multiple things to set, some of which are common to all your custom subclass views you can use the prototype design pattern, it's pretty straight forward to implement.
Often, when I'm making my apps, I'm in this situation : I have a UINavigationController, handling the view stack, some UIViewControllers, controlling their respective views...
But when I want to add several custom UIViews in my mainView, I don't know how to manage my code.
Each UIViewController needs to handle one and only one view (wich normally occupy all the screen size), and a view should not control their content (update it a the extrême limit).
You can't neither do this :
[myViewController1.view addSubview:childViewController.view];
So if I want to achieve something like this, what should I do ?
The orange parts have to be 3 instances of the same UIView(Controller?), but with a content depending of a NSObject (User, obviously).
I think this very important to segment your content, this should be an easy problem, but I found a lot of contradictory answers so, what's the best practice to handle this common issue?
Theses orange views should be instances of UIViewControllers in order for it to handle their UITableViewDatasource? Is addChildViewController relevant in this case?
I already found a lot of things which work, but I don't know what should I do...
Also, I'm using xibs.
Thanks in advance if you can help me (and other people I think).
You can do it either way (view or view controller) depending on how you want to handle things. Certainly, you can have one object be the data source for multiple tables, so in that case, you would just add multiple views. If, however, you want to keep your code more compartmentalized, then add view controllers, and have each control its own view -- to do this, you do need to use addChildViewController, and use the methods that Apple describes for creating custom container controllers. Alternatively, you can use container views in a storyboard which makes the process of creating custom container controllers simpler.
You're on the right path... Create separate instances of your subviews, and add them to your view. If you will have more than 3 (for instance, imagine coverview for your music, and you could scroll indefinitely left and right), I'd take a look at UICollectionViewController ... That will help manage cell re-use.
But, if it's just 3, just create three instances with different frames and add them to your view.
Here's how I'd do it:
each orange box will be a custom view (inherits from UIView)
the view will have the label, image and the tableview.
since you are not sure of the number of instances of these views you'd be using, its better to use some kind of tagging, so that you can have one place for the datasource and delegate methods of the tables in these orange views.
in the datasource and the delegate methods, you can make use of the tableView.tag (same as the orangeView.tag property).
I personally dislike having more than one viewController in a view (except the splitVC), probably because I haven't had a such requirement.
I dont see how a uiviewcontroller for orange box would help, over a uiview.
as #James Boutcher mentioned in his answer, UICollectionViews will simplify this issue further.
Why not creating a UIView class and overriding the drawRect method and then adding subView for this class in your myViewController1.view