I am planning to write a custom view that will render some stuff using Quartz.
After looking into some sample code in apple site, I decided to subclassing UIView to create my own view:
#interface myView : UIView {
}
#end
Now my question is, what would be the best way t bind my view with the viewController?
While loading from NIB file, we directly assign the view controller file as fileowner type.
In case of custom UIView, how can we do this?
When not working with nib files, you use the loadView method in a UIViewController to create your view. This comment even appears above loadView in the template for a new UIViewController:
// Implement loadView to create a view hierarchy programmatically, without using a nib.
Edit: I may have been too terse here. Basically, then inside your loadView method, you instantiate your myView (using alloc/init, or whatever), and assign it to self.view. Let me know if you need example code.
A little confused by your wording. I assume you want to place your custom view in your UIViewController.
You can easily do this both in Interface builder and within your code.
Code:
myView *view = [[myView alloc] initWithRect:CGRectMake([x],[y],[width], [height]];
[self.view addSubView:view];
[view release];
In Interface Builder:
Select "View" in the Library Objects.
Drag View unto your UIViewController's view.
In the inspector click the i in a circle icon ("View Identity")
Using the class dropdown select the class of your view (myView)
Here's more info: http://developer.apple.com/iphone/library/documentation/DeveloperTools/Conceptual/IB_UserGuide/CustomizingInterfaceBuilder/CustomizingInterfaceBuilder.html#//apple_ref/doc/uid/TP40005344-CH16-SW12
If your viewController already has an Interface Builder .nib file (as when built with the Xcode templates), open it. There's usually a view already in it. You can bring up the inspector for that view, and in the Identity tab of the inspector, change the class of the view controller's view from UIView to your custom view class. Save, rebuild, and your custom class is now bound and will load with that view controller.
If you write and compile your custom view controller (it can be an empty template), it should appear in the inspector to just select as the class for the view controller's view.
Related
I'm having some problems because I don't know how it can be done. Someone help me please.
Problem:
I have a project with a UIViewController class with created all time when I create a new project in Xcode. In this viewController, I have a xib file for designing in Xcode.
What I need is to create some views and design them in Interface Builder like this:
But I need these views to be UIViewControllers, not UIViews.
The project should look like:
So I don't know how I can do this in IB but I can do it from source code in ViewController.m
tab = [[TabBarController alloc] initWithNibName:#"mytestview" bundle:nil];
[tab.view setFrame:CGRectMake(100, 100, 400, 600)];
[self.view addSubview:tab.view];
But it's not my views it's a different object, and if I want to change position or size I must do it from code. How I can do same things in Interface Builder?
Let's consider following example based on Master-Detailed Application for iPhone only.
So, add new view controller in newly created project in Xcode:
I called it NewInsideViewController. Create it without xib:
Open DetailViewController.xib. Drag View Controller and View(*) objects from library to Objects area like this (I changed view's color to LightGray):
Choose this View Controller and change its Class from UIViewController to NewInsideController at the Identity Inspector:
Assign our View(*) to NewInsideController as a view:
Now all main actions in IB finished. We need to create instance of NewInsideController in our DetailViewController. You can do it by hand, but Xcode has a nice feature - drag-n-drop ;)
I called this property as myNewInsideController and DetailViewController.h looks like this:
#import <UIKit/UIKit.h>
#import "NewInsideController.h"
#interface DetailViewController : UIViewController
#property (strong, nonatomic) id detailItem;
#property (strong, nonatomic) IBOutlet NewInsideController *myNewInsideController;
#property (strong, nonatomic) IBOutlet UILabel *detailDescriptionLabel;
#end
Well, now our NewInsideController ready to work and manage its view. Let's add button and action to that view in order to verify this:
Write some code in IBAction in NewInsideController.
- (IBAction)insideButtonClick:(id)sender {
float rPart = arc4random()%100/100.0f;
float gPart = arc4random()%100/100.0f;
self.view.backgroundColor = [UIColor colorWithRed:rPart green:gPart blue:0.5f alpha:1.0f];
}
Run program.
If I understand the question clearly:
You have a parent view and controller, coming from a XIB.
You have placed subviews into the parent view.
You're wanting each subview placed into the parent view to have it's own (custom) controller, but you don't know how to add view controller's to your hierarchy (XCode will not let you drag view controllers into a view's canvas).
So, to answer the question succinctly: Let's assume you have a handful of custom UIViewController's in your project (each view controller consisting of a .h and a .m). Remember that you if you are laying these out in the context of the parent, they shouldn't have their own XIBs (you cannot nest XIBs in IB). What is important to note here is that you should only "layout" the interface in one location. If you want to have a XIB for each subview, this is not the correct approach. What you can (not should) do, however, is have several custom viewControllers, each connected to it's own view sitting within your parentView, and you can have the outlets of your sub view controller's set to objects in this parentView. Phew, kinda messy. The other thing you'd need to be aware of is that your parent view controller would need a reference to each of it's sub view controllers in order for you to be able to access those sub-controllers and their outlets programmatically, so for each sub view controller you add, you would also need to add an IBOutlet in your parent view controller pointing to each subviewController:
ParentViewController.h
#property (nonatomic, weak) IBOutlet CustomUIViewController *firstCustomController;
And then for example to set the background color on the view of your first custom subview/controller:
ParentViewController.m
[[[self firstCustomController] view] setBackgroundColor:[UIColor whiteColor]];
Open up your parent view controller in IB. If you look in your drawer of available objects, you'll find a generic UIViewController object. Drag this into your parent view controller (NOT onto it's views canvas, rather into the parent UIViewController object itself as seen in the left-column of IB builder). Select the generic view controller you've added and set it's class to your desired UIViewController subclass. Now, when your XIB loads, it will instantiate an instance of your custom view controller along with whatever you've added to it's canvas.
Finally, drag a generic UIView onto your canvas, placing it inside your existing controller's view (your screenshot already shows this as done). Right-click your custom view controller, and connect it's 'view' outlet to the view you added.
Now when you run, your custom view controller has a view that is on the screen that is the view of your custom controller subclass, and you didn't do any of it in code.
So now that you've done it, consider whether or not it is the best choice: Nested view controllers are messy to build (as you've seen) and aren't necessarily a good design decision: http://blog.carbonfive.com/2011/03/09/abusing-uiviewcontrollers/
Although iOS5 does support nested view controllers, personally I'd avoid using them. I value a best practice dictating one screen = one view controller.
You never, EVER, want to take views which are already under the control of a certain view controller, and make them subviews of another view controller's view.
View Controllers are the C part in the MVC design pattern - They are in charge of controlling a view (and its subviews). You can't take a view which is being managed by a controller, and stick it as a subview of a different controller's view - If you do that, it becomes ambigous who is responsible to manage this view.
Even though this "sticking" might be possible technically, it creates code which is hard to understand, hard to maintain, and most importantly - will cause bugs due to the unclarity of who is responsible to manage the view, and due to the fact that Apple's View/Controller framework doesn't support this.
For example: If the device is low on memory, Apple makes sure to unload views which are not currently displayed. Apple relies on the view controllers hierarchy to know when it can unload views. If you stick the view controller's view in another view controller's view, it's very likely that the view will never be unloaded even if it isn't visible.
Instead of breaking the view controller hierarchy, do one of the following:
Just add subviews to your view normally, either in interface builder, or in -viewDidLoad: to add them programatically, or (rarer) override -loadView.
Use view controller containment, either with Apple's ready-made ones (UINavigationController,UISplitViewController etc.) or with your own container view controllers (iOS>5).
Display view controllers modally.
The bad idea of breaking a view controller hierarchy is indeed very common and often seen in 3rd parties, probably because it's so easy and seemingly straightforward. Unfortunately this causes the aforementioned bugs :-(
I really recommend to everyone participating in this thread and comments to read Apple's View Controller Programming Guide, and watch WWDC 2011 "View Controller Containment" video.
I'm a little bit lost. I have created a small app that is starting with a tab bar and in one of its view there's a button that should open a Navigation view that contains a table view.
In my NIB file I have put a Navigation Controller that contains a TableView Controller. I have created a sub-class called MyTableViewController which inherits from the UITableViewController. In the NIB I have configured the Custom Class of the TableViewController with my subclass MyTableViewController.
When the button of my App is tapped, I'm loading the NIB file with the initWithNibName but it returns me a UINavigationController.
How does it work to request the creation of MyTableViewController and get a pointer on it when I'm loading my NIB?
Thanks,
Sébastien.
This one has caught me out a few times.
When you do initWithNibName it will take the class from the custom class of the File's Owner, not the custom view of any objects .
I dont actually bother subclassing from UITableviewController any more. Just create a view controller and drag in a table view as a subview. Just make sure you hook up the data source and the delegate.
Link your TableViewController to an IBOutlet so you don't have to mess with initWithNibName.
I created a window based application, and I created a separate UITableViewController file called "HomeViewController" which right now only has a basic table.
In the MainWindow.xib file, I put a UIView in the bottom half of the screen, and I wish to put the HomeViewController tableview within this newly added UIView called "conferences".
Any suggestions as to how to push this file?
First off, usually your primary first view originates from a view controller that is loaded by the UIApplication object. The MainWindow nib's owner is UIApplication so you probably don't want to be mucking with the MainWindow nib. Rather, you want to muck with the view of the view controller loaded by MainWindow nib. If you look at the view displayed in IB for MainWindow.nib, it should say which view controller's view it is loading.
So, in IB for the view of view controller being loaded by MainWindow nib, this is where you want to place your UITableView. For purposes of this explanation, I will call this view controller, MucksViewController and associated nib, MucksView.nib.
I think what I would do, then, is drag and drop a UITableView into the view for MucksView.nib. Position it in the bottom half of the screen, as you described. Attach this UITableView to an IBOutlet property in MucksViewController header file. Next, drag and drop a UIViewController object into the main window for MucksView.nib. Make this UIViewController object's owner your HomeViewController class and also attach it to an IBOutlet property of type HomeViewController in MucksViewController's header file.
Now, in MucksViewController's class file, probably in viewDidLoad method, programmatically make the HomeViewController object the data source and delegate of the UITableView object.
But, I'm wondering, do you really need HomeViewController? It would be cleaner just to make MucksViewController the data source and delegate.
I hope this helps and is not too confusing.
Instead of a UITableViewController, use a UIViewController which implements the tableview delegate and datasource. in your MainWindow.xib, add a standard uitableview as a subview to the view where it should be. then also drag a HomeViewController to the xib (which should now be a uiviewcontroller sub class). click on the tableview, open the inspecor, go to connections, and drag the delegate and datasource to the HomeViewController in the xib.
I'm working on an app that has three table view controllers in a navigation stack. The root view controller and the second VC have toolbars, but I want to add a subview to the second view controller like this. (The color is just there for visualization.)
I want to add the view programmatically, since I haven't been able to do it with IB without major headaches. Right now, I've been able to kind of get what I want by drawing a UIView in the second view controller like this:
- (void)viewDidLoad {
[super viewDidLoad]
UIView *detailView = [[UIView alloc] initWithFrame:CGRectMake(0, 392, 320, 44)];
detailView = [UIColor redColor];
[self.navigationController.view addSubview:detailView];
[detailView release];
}
The problem with this approach is that once the UIView is loaded in the second view controller, it stays loaded and is drawn in the third and root view controllers. I've tried a variety of methods of removing the UIView, including setting the detailView to nil in viewDidUnload, calling removeFromSuperview in didSelectRowAtIndexPath (which removed the view from the whole stack).
I've also tried adding the subview to self.view, but that pushes it below the visible area of the table view, so I have to scroll up to see it, and it snaps back down when I let go.
Clearly, adding this subview to the navigation controller is not the best way to do what I want, but I'm at a loss as to where to go from here.
As you've already discovered, you definitely should not be reaching up into the navigation controller's view.
You want your SecondViewController to be an UIViewController that implements the UITableViewDelegate and UITableViewDataSource and whose view lays out the UITableView and the UIView you wish to use for your stationary 'footer' in it's own main UIView.
It helps to keep in mind that UITableViewController is ultimately is just a convenience for creating a view controller whose view consists entirely of a UITableView.
Anyway, rather than attempt to put a pile of that code inline in this answer, you can browse it (or svn co) from this read-only svn repo.
EDITED (now that it's not midnight, putting some code/explanation directly in answer):
For the controller to be pushed onto the nav stack that needs the footer create a new UIViewController-based class (do NOT check the 'UITableViewController subclass' box in the template selection dialog).
Add instance variables for the UITableView and the UIView that is to be the extra bottom view.
#interface SecondViewController : UIViewController <UITableViewDelegate, UITableViewDataSource> {
UITableView* tableView;
UIView* customFooterView;
}
#property (nonatomic,retain) IBOutlet UITableView* tableView;
#property (nonatomic,retain) IBOutlet UIView* customFooterView;
#end
In IB add a UITableView and UIView to the existing root view for the controller and lay them out as desired (probably worth altering the auto-resize parameters too if your app can be used in both landscape and portrait). Hook up the two views to the outlets defined for them in the "File's Owner" and also ensure you hook up the UITableView's delegate and dataSource properties to point at the "File's Owner."
Then just implement the UITableViewDelegate and UITableViewDataSource protocols as appropriate for your application.
If you want to lay out the entire 'footer' view in IB then go right ahead. Otherwise you can easily add items programmatically in viewDidLoad (and remember to tear it down in viewDidUnload).
I don't like the approach. You should put your table view inside another view, and put your detail view together in that view.
Despite of that, I think you can remove your view in viewWillDisappear method of your view controller. I also notice that you did not keep your detailView as a private variable, which you should do because you need to reference it when removing it later (I still wonder how you have done it.)
Note that viewDidUnload is called in case of view unloading (i.e. releasing from its controller), so it is not related to navigation.
Not sure which behavior you're looking for but try one of these:
Assign the detailView to the tableFooterView property of the tableview on the second VC.
Reduce the height of the table view and add the detailView to self.view.
I've managed to get my myself confused... I've got a fairly complex View Controller much of which is developed programatically. I'd like to pop up a "dialog" on top of the view controller at some point and I'd like to "design" that view in Interface Builder because it's fairly straightforward (background UIImageView, some UILabels and a UIButton).
I've created the .xib and am now subclassing UIView with the IBOutlets,etc. I'm now trying to wire it up and realizing I probably need to add an initWithNibName: method so this will instantiate correctly...then I realize that I'm really just making another UIViewController and I don't think we're supposed to have UIViewController views w/in other UIViewController views?!?
So now I'm re-thinking how to go about this "correctly." How best to use IB to design a simple 1/4 screen view that will pop up over a main view?
Call +[NSBundle loadNibNamed:owner:] to load the NIB file that contains your view. If you specify your view controller (i.e., self) as the owner, any connections you make to File's Owner in the NIB file will then be made to the view controller. So you could declare an outlet to your custom view in the view controller and after the call
[NSBundle loadNibNamed:#"MyView" owner:self];
the outlet variable will point to the view object. Alternatively, you can use -[NSBundle loadNibNamed:owner:options:], which returns an array of the top-level objects in the NIB.