In EGOTableViewPullRefresh Demo I see he refer to property self.view and self.tableView in
EGORefreshTableHeaderView *view = [[EGORefreshTableHeaderView alloc] initWithFrame:CGRectMake(0.0f, 0.0f - self.tableView.bounds.size.height, self.view.frame.size.width, self.tableView.bounds.size.height)];
From my understanding view and tableView is the same object, but tableView is a type cast of view, but when I want to see implementation file I can't find it.
I can see .h file with Option+click, but I can't find its implementation. How can I find .m file ?
You cannot see the TableViewController.m file because that implementation is private and Apple doesn't want you to be able to depend on an implementation--only the interface--for two reasons:
If you depend on a specific implementation, they'll never be able to change/improve it because they'll need to continue to provide backward compatibility for some time to come.
Apple doesn't want competitors (e.g., Android, etc.) to be able to easily copy their work.
You need to stick to the public documentation that Apple provides for the UITableView and friends. In there, I think you'll see that the view is an inherited property from the UIView class, whereas tableView is a property that connects the UITableViewController with the proper view for the table it is controlling.
Related
I'm fairly new to Mac development and am slightly confused by the new "storyboard" feature in Xcode 6. What I'm trying to do is segue from one view controller to another in the same window. As of right now, all the different NSViewControllerSegues present the view controller in a new window, be it a modal or just another window. What I'd like to do is just segue within the same window, much in the same way one would on iOS (though an animated transition is not crucial). How would this be achieved?
If you provide a custom segue (subclass of NSStoryboardSegue) you can get the result you are after. There are a few gotchas with this approach though:
the custom segue will use presentViewController:animator so you will need to provide an animator object
because the presented view is not backed by a separate Window object, you may need to provide it with a custom NSView just to catch out mouse events that you don't want to propagate to the underlying NSViewController's view
there's also a Swift-only glitch regarding the custom segue's identifier property you need to watch out for.
As there doesn't seem to be much documentation about this I have made a small demo project with custom segue examples in Swift and Objective-C.
I also have provided some more detail in answer to this question.
(Reviving this as it comes up as first relevant result on Google and I had the same problem but decided against a custom segue)
While custom segues work (at least, the code given in foundry's answer worked under Swift 3; it needs updating for Swift 4), the sheer amount of work involved in writing a custom animator suggests to me that their main use case is custom animations.
The simple solution to changing the content of a window is to create an NSWindowController for your window, and to set its contentViewController to the desired viewController. This is particularly useful if you are following the typical pattern of storyboards and instantiate a new ViewController instance every time you switch.
However.
The NSStoryboard documentation says, quite clearly in macOS, containment (rather than transition) is the more common notion for storyboards which led me to look again at the available tools.
You could use a container view for this task, which adds a NWViewController layer instead of the NSWindowController outlined above. The solution I've gone with is to use an NSTabViewController. In the attributes inspector, set the style to 'unspecified', then select the TabView and set its style to 'tabless'.
To change tabs programatically, you set the selectedTabViewItemIndexof your TabViewController.
This solution reuses the same instance of the ViewControllers for the tab content, so that any data entered in text fields is preserved when the user switches to the other 'tab'.
Simple way with no segues involved to replace the current view controller in the same window:
if let myViewController = self.storyboard?.instantiateController(withIdentifier: "MyViewController") as? MyViewController {
self.view.window?.contentViewController = myViewController
}
I'm working on my first iPad application and using Storyboards for the first time.
I've got UITableViewController in my Storyboard that uses "Dynamic Prototypes" for custom cells.
What I want to do is programatically instantiate my UITableViewController subclasses but loading the super view controller from the Storyboard.
This is because I have a single UI but multiple subclasses for specific functionality that I need for each different instance.
This was very easy to do with .xib files, I would write the following code:
MyViewControllerSubClassA *viewControllerA = [[MyViewControllerSubClassA alloc] initWithNibName:#"generalViewControllerNib" bundle:nil];
MyViewControllerSubClassB *viewControllerB = [[MyViewControllerSubClassB alloc] initWithNibName:#"generalViewControllerNib" bundle:nil];
I know I can assign a subclass in the Storyboard editor when clicking on the View Controller but I want to set the subclass programmatically when instantiating.
This seems impossible to do with Storyboards as they are instantiated automatically.
This makes the entire concept of Storyboards seem flawed and not very OO.
If I move the View Controller out of the Storyboard and into a .xib file I lose the ability to use Dynamic & Static Prototypes cells as these are supported only when using Storyboards. Also Apple's documentation basically says use Storybaords from now on.
I would try something like this:
MyViewControllerSubclassA *controllerA = (MyViewControllerSubclassA *)[self.storyboard instantiateViewControllerWithIdentifier:#"myGenericVC"];
I have a similar question to Cocoa - View-Based NSTableView, using one cell in multiple tables, amplified by
Apple's own docs for makeViewWithIdentifier:owner:
"Typically identifier is associated with an external NIB in Interface Builder and the table view will automatically instantiate the NIB with the provided owner."
This seems to imply that you should be able to store the NSTableCellView in a separate nib from the nib containing the NSTableView. However, in my experimenting, I have only ever been able to obtain cells which are contained within the tableview I'm calling this on. I.e., if I cut and paste my cell into a new .xib file, the tableview can no longer find it. What am I doing wrong, or is this actually impossible and I am somehow misreading Apple's docs?
Use - (void)registerNib:(NSNib *)nib forIdentifier:(NSString *)identifier to register a nib to be used with a cell identifier.
If it doesn't work you're probably registering the nib after the tableView data has been loaded. Use [tableView reloadData] afterwords to be sure it's not a timing issue.
I just ran into this problem and I think you cannot use makeViewWithIdentifier:owner: when you're using a dedicated Nib to populate View-Based Tables.
The problem has to do with file owners (ie. view controllers). makeViewWithIdentifier:owner: seems intended to be used with "self" as the owner for simple custom views.
Generally if you have a separate nib for the custom view with outlets, you're going to want a separate view controller too. Otherwise, if your custom view has an outlet and the table displays many custom views, which outlet are you referring to from the "self" table view owner?
So in my test, I've got the AppDelegate as the delegate/datasource of the Table View. I have a CellView.xib, and CellViewController.h/.m with outlets to the interface. Then in my tableView:viewForTableColumn:row: delegate method I have this code:
SSCellViewController *vc = [[SSCellViewController alloc] initWithNibName:#"CellView" bundle:nil];
return vc.view;
What you lose is the cell re-use that happens automatically with makeViewWithIdentifier:owner:. To implement that yourself, you'll also likely have to deal with managing the many view controllers you've created.
I might still be missing something, as I'm coming to OS X development after years of only doing iOS work.
Well, "not getting it" is too harsh; I've got it working in for what for me is a logical setup, but it does not seem to be what iOS deems logical. So I'm not getting something.
Suppose I've got an app that shows two pieces of information; a date and a table. According to the MVC approach I've got three MVC at work here, one for the date, one for the table and one that takes both these MCVs and makes it into a screen, wiring them up.
The master MVC knows how/where it wants to layout the two sub MVC's. Each detail MVC only takes care of its own childeren within the bounds that were specified by the master MVC. Something like:
- (void)loadView {
MVC* mvc1 = [[MVC1 alloc] initwithFrame:...]
[self.view addSubview:mvc1.view];
MVC* mvc2 = [[MVC2 alloc] initwithFrame:...]
[self.view addSubview:mvc2.view];
}
If the above is logical (which is it for me) then I would expect any MVC class to have a constructor "initWithFrame". But an MVC does not, only view have this.
Why?
How would one correctly layout nested MVCs? (Naturally I do not have just these two, but the detail MVCs have sub MVCs again.)
Thanks all for replying. I will study the links that were provided.
Let me try to explain my issue one more time, hopefully to making it more clear. Do note that I already figured out that my view does not match iOS's, since I do not like where my code is going.
Yes, I'm calling a UIViewController an "MVC", since it for me at the moment implements all aspects of a MVC; it has controller code and an embedded view, plus the controller usually also holds and provides the data (all TableView examples implement it like this).
MVC can be present on many levels; basically a UITextField could (should?) be a MVC; there is a view, but also controller logic involved that you do not want to mix with other code. Encapsulation. For example: Java's Swing JTextField has a MVC. So does a JTable, JList, ... Multiple MVC patterns nested in other MVC's to build a whole screen.
This what I expect when some platform says it uses the MVC pattern. So When I coded the table, I created a MVC and only send the loadData message with a date as the parameter to it. It needs to take care of the rest itself. I have a Detail MVC that can slide in; I then tell it the object it needs to show and it needs to take care of the rest itself. Encapsulation.
So I have a lot of UIViewControllers with embedded UIViews. And that is not the way to do it...
One more potential link is the great talk from WWDC 2010 on MVC.
http://developer.apple.com/videos/wwdc/2010/
It is Session 116 - Model-View-Controllr for iPhone OS
The session is chock full of practical advice on how MVC really works, what makes it tick, why it's good. But it also has a lot of intro stuff to help folks new to the concept to wrap their heads around it.
If I understand your sentence on Java's Swing classes above are you talking about the anonymous classes that respond to events? If so those are not "MVC's", they are what is termed 'Observers', when they observe an event from the view they take some action (usually send a message to a controller). Cocoa Touch uses the Target/Action paradigm (and delegation) to achieve this.
I'd also strongly suggest you take Matthew and Stephen's advice and write a bunch of code. If you don't build that base of intuition, asking the right question (which is most of what is needed to get a good answer) is very difficult.
I really think the WWDC 2010 talk will help.
Good Luck!
If I understand your question -- and I may not, see my comments on it -- I think you're applying the MVC design pattern far too granularly. Most commonly in the setup you describe you'll have a single Model, a single Controller, and multiple Views that are grouped/combined, as in a .xib file.
In Cocoa Touch terms you'd have one UIView that contains a UILabel with the date and a UITableView for your table. These are your Views.
You'll certainly have a Model for the table data, likely an array of data. Your date data might be from its own model if it's a date retrieved from something or calculated or whatever, something entirely separate from the array of data. If it's instead associated with the array data -- they're both pulling from a database, or the date is calculated from the array data, or what have you -- then you have a single Model.
If the data is all coming from a single Model then a single Controller is likely fine. Even if the data is coming from more than one source/Model you likely only need/want one controller in this setup. The UITableView will have a UITableViewController, and that same controller can take care of providing your date as well.
To sum, the Model View Controller design pattern doesn't call for having a bunch of nested sets of models, views, and controllers. They could be, and sufficiently complex projects may call for it. Broadly, though, you'll have a controller that's associated with a model and one or more views, and that set of objects works together to provide a piece of functionality.
Tbee,
I'll post a tiny code example here, since it seems you're not really getting it.
#interface MyView : UIView
#property (retain) IBOutlet UIButton *button1;
#property (retain) IBOutlet UIButton *button2;
#property (assign) bool myData;
-(IBAction) doButton1:(id)sender;
-(IBAction) doButton2:(id)sender;
#end;
#implementation MyView
#synthesize button1 = _button1;
#synthesize button2 = _button2;
#synthesize myData = _myData;
// I'm leaving out the initWithNib, viewDidLoad, etc.
- (IBAction) doButton1:(id)sender
{
// do something as a result of clicking button1
_myData = YES;
}
- (IBAction) doButton2:(id)sender
{
// do something as a result of clicking button2
_myData = NO;
}
#end
Connect those up in InterfaceBuilder, and you've got a working "MVC." You don't need a completely new UIViewController for each button. The one for the View takes care of it.
UITableView and it's associated Views are more complex, and may require an additional UIViewController to help encapsulate. I really don't suggest starting out by using them, but this is a good tutorial here. It's got a lot of images which will show you how to connect things up in IB and the like. It's old, so your XCode may not look like the images, but it helps.
Thanks for the links, I'll look into them.
So far I've rewritten most of my application to using views instead of viewcontrollers (except the toplevel one) and it starts to match up with the API calls that are available like layoutSubviews. What I find disturbing that I need to do this now:
[tableDataSource loadData:date];
[tableView reloadData];
Where in my previous setup all I did was:
[tableViewController loadData:date];
But apparently that is the way to do it. One thing is unclear to me ATM. Since I construct and layout the view in loadView in my AppViewController, how do they get relayouted if the orientation changes. The VC does not have a layoutSubviews, so I should use the didRotateFromInterfaceOrientation and reposition the subviews from there?
BTW, I'm not mixing registering anonymous inner classes as listeners (observers). I'm very experienced with writing Swing components and JavaFX controls. And that probably is the culprit, in Java(FX) every component has a view and a controller (not always a model).
When I create a new UIViewController in xcode, it offers to make me an associated nib for the interface. However, when I create a UIView, it does not. If my understanding of MVC is correct, views should really be the parts that contain the interface elements (i.e. the nib) while view controllers are the parts that hook the functionality to the views they control.
I'm sure I'll be able to get it working together either way, so this is more of an exploratory question.
This seems like a case where I'm missing some fundamental understanding of how these two parts should be used. What am I missing?
Because UIView is usually not used in such way.
However How do I associate a nib (.xib) file with a UIView?
The answer I eventually got that satisfied my interest was roughly this:
The job of a view controller is to manage a view hierarchy. Interface Builder is an excellent tool for creating view hierarchies. Xcode offers to create a .xib when you create a new view controller because chances are high that you'll want to load the controllers' views from a .xib.
.xib files aren't necessarily meant to hold every UIView (or subclass) that goes into the view, just a general outline of views that don't change during the life of the view. The other UIViews are much easier to create programmatically since they change often.
I had a similar confusion. Basically (according to the MVC) the View is contained inside the Controller. In the iPhone this means that UIViewController has a property called 'view' which is a UIView instance.
A XIB file (and this is not mentioned often) is a serialised UIView instance. It is roughly an XML sub format which represents a UIView with all its subsequent views. So when you create a UIViewController, a UIView is created in the form of a XIB and bounded to that controller.
A new UIView therefore does not have a XIB because they are essentially the same thing...