Window ordering and XIB - objective-c

Question

I am setting my first steps in OSX development and I've run into some problems. I have quite some experience with iOS development but the window system for OSX programs is something else.
I am making a client for a social network like twitter and need 2 seperate window controller for first starting the app, one if you are logged in to show your timeline and one for logging in, if you are not yet logged in. In the info.plist you need to give it a main.xib. For this I made an empty xib which I hide, the second the app starts. This is not really a good solutions IMO, what is a better solution for this? I want to keep the windows seperate from the appdelegate because that way I can keep my code seperated.
This gives me a problem, when I open my 'second' window to login it shows up but isn't active. I have tried all the things like, orderFront:, activateIgnoringOtherApps:, makeKeyAndOrderFront: & more. But this all doesn't work..
So: First off, is there a better way to handle the main.xib that is needed in the info.plist and if not, is there a way around the focus problem?
I'm working om osx 10.7

Answer 1

For more than one-offs, you really ought to separate your app delegate from your window controllers. Go ahead and create a new Cocoa application from the template. In MainMenu.xib, delete the window. In AppDelegate.h delete the IBOutlet to the NSWindow. Create a couple new subclasses of NSWindowController complete with XIBs--perhaps LoginWindowController and TimelineWindowController.
For "final" NSWindowController subclasses (i.e. those which won't be subclassed), the best practice for designated initializers is
//for our example class LoginWindowController
- (id)init
{
self = [super initWithWindowNibName:#"LoginWindowController"];
if (self) {
//....
}
return self;
}
Now in your app delegate, you should have #properties for the two different window controller instances:
//Within AppDelegate.m
#import "AppDelegate.h"
#import "LoginWindowController.h"
#import "TimelineWindowController.h"
#interface AppDelegate ()
#property (nonatomic) LoginWindowController *loginWindowController;
#property (nonatomic) TimelineWindowController *timelineWindowController;
//For the sake of this demo, add a property for the loggedIn state:
#property (nonatomic) BOOL loggedIn;
#end
You ought to have some sort of method in your app delegate that presents the correct window controller. Let's call it -updateWindowVisibility:
- (void)updateWindowVisibility
{
BOOL isLoggedIn = self.loggedIn;
BOOL loginWindowVisible = self.loginWindowController.window.isVisible;
BOOL showLoginWindow = !isLoggedIn;
BOOL timelineWindowVisible = self.timelineWindowController.window.isVisible;
BOOL showTimelineWindow = isLoggedIn;
if (!loginWindowVisible && showLoginWindow) {
if (!self.loginWindowController) self.loginWindowController = [[LoginWindowController alloc] init];
[self.loginWindowController showWindow:nil];
} else if (loginWindowVisible && !showLoginWindow) {
[self.loginWindowController close];
self.loginWindowController = nil;
}
if (!timelineWindowVisible && showTimelineWindow) {
if (!self.timelineWindowController) self.timelineWindowController = [[TimelineWindowController alloc] init];
[self.timelineWindowController showWindow:nil];
} else if (timelineWindowVisible && !showTimelineWindow) {
[self.timelineWindowController close];
self.timelineWindowController = nil;
}
}
This method as implemented above does a tiny bit more work than is necessary given the present setup, but should be easier to modify when you need to show/hide other windows. All that's left to do at this point is to call -updateWindowVisibility from -applicationDidFinishLaunching:.
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
self.isLoggedIn = NO;
[self updateWindowVisibility];
}
I've posted an example app to github which demonstrates this approach.

Answer 2

In terms of structure (your first question), I would recommend this:
Create a XIB with one blank window and a big NSView (called, say, megaView) covering it. Create an IBOutlet in AppDelegate for your big NSView. Set the app to use this XIB on load.
Create two separate NSView XIBs: one for the state of being logged in, one for the state of being logged out. Put your layout in these.
Create two NSViewController subclasses: one controlling the logic of each NSView you just created. Let's call them LoggedOutViewController and LoggedInViewController.
Jump back to the two NSViews you created. Set the File Owner of your logged in NSView to LoggedInViewController and the File Owner of your logged out NSView to LoggedOutViewController. Hook up each File Owner's view (right-click on File Owner to find it) to the respective NSView.
In your app delegate, determine the user's authentication status in whatever way you need.
If logged in, do this:
NSViewController *loggedInController = [[NSViewController alloc] initWithNibName:#"NibNameGoesHere" bundle:nil];
[[self megaView] addSubview:[loggedInController view]];
Otherwise do the above process with your loggedOutController:
NSViewController *loggedOutController = [[NSViewController alloc] initWithNibName:#"OtherNibNameGoesHere" bundle:nil];
[[self megaView] addSubview:[loggedOutController view]];
That should get you what you want and will likely clear up your second question in the process. The difference between my answer and Nate's is that mine uses the same window. Instantiating view controllers conditionally and loading their views into superviews is probably the most important aspect of Cocoa I learned.