Keep leftBarButtonItems on new UIViewcontroller when pushed - cocoa

I have a UIViewController embedded in a UINavigationController. The rootViewController now contains already some buttons as leftBarButtonItems.
Now when I push a new UIViewController on top of the UINavigationController I want the new UIViewController to keep the existing leftBarButtonItems extended with the Back-Button.
Right now the situations is as follows: When I push the new UIViewController then the existing leftBarButtonItems disappear and only the Back-Button is visible.

Each UIViewController has it's own "navigationItem" property, which acts as the navigation bar representation for that viewcontroller. When you add buttons to the navigationItem of a particular UIViewController they are limited in scope to the viewcontroller to which they were added, and they don't persist into other viewcontrollers.
Basically, you'll have to add the buttons to the navigationItem of each viewcontroller as it loads. You can make this simpler by writing adding a method to do this work to a class other than your UIViewControllers. What happens when you touch each button might be viewcontroller specific though, so you'll have to think through how touch actions will be fed back to the relevant viewcontroller. Perhaps introduce some kind of NavigationBarDelegate protocol or something?

I found what seems like a hacky way to get around this when pushing multiple instances of the same view controller on to a detail view controller which I assume would work similarly. Before pushing the new view controller I used this: (browser is my new view controller)
self.browser.navigationItem setLeftBarButtonItem:self.detailViewController.navigationItem.leftBarButtonItem animated:YES]; // Sets popover view controller button.
[self.detailViewController.navigationController pushViewController:self.browser animated:YES];
This probably isn't a good way to do it but it seems to work in my situation.

Related

NSToolbar in Xcode 7 using Storyboards (NSWindowController -> NSSplitViewController)

Hi I've seen this question asked a few times already but with no definite answer yet so I created it for xcode 7 and swift2 (which may have changed things a bit anyway).
I created a project using Xcode 7 and Cocoa OSX Story boards + swift2, so my project started with a NSWindowController that Connects to a NSViewController (as expected!). I added a NSToolbar to my window controller and added a NSButton to the toolbar. I changed my NSViewController to be one of the new NSSplitViewController that links to three NSViewControllers and displays their views horizontally - with vertical dividers - (similar to the layout you see in the photo app or pages in Yosemite +). My final goal will be that the button in My toolbar shows and hides the first split.
It is my understanding is, and I would expect that to achieve this I should create an action in the NSSplitViewController that changes the auto layout constrains more or less in the way they are working it out here: How to do collapse and expand view in mac application?.
And then somehow link this action to the NSButton that is in the Toolbar... which happens to be in the NSWindowController (far up and isolated in the hierarchy)...
I have already gone through other questions about NSToolbar and storyboards and failed to accomplish my goal:
The YouTube video: Cocoa Programming L17 - NSToolbar which is the closest I found to solve the problem, but his method does not work for storyboards, only creating your own xib file.
In this question: How to use NSToolBar in Xcode 6 and Storyboard? One person proposes to make the link using the first reponder and expecting everything to hook up at run-time (which looks a bit dodgy and not the way apple would implement it I think...). A second person suggested to create a view controller variable in the NSWindowController and manipulate its properties from there... but again, a bit dodgy too.
One latest comment I saw in that question which seems the best way to tackle the problem (but still not as good as I guess it could be) is to add a NSObjectController to the dock of each scene and when the scene loads, set the values of the objects to the other secene's controller. Is this really the best way to go ahead? If so, how could I achieve this one?
Apple did mention (again) in WWDC15 that they created storyboards for osx and the split-view controller that owns view-controllers so that you can move your logic and work to the specific view-controller, so I would be expecting to do everything from inside my split-view controller as this is the target that needs to change.
Does anyone know how to achieve this from the view controller itself? I really haven't been able to find a way to connect my ToolBarItem to it.
OK, I've created this question quite a few days ago and no answer so far so I've answer with what I recently did to overcome the problem.
After I created my Xcode project I did this:
Created a subclass MySplitViewController for the NSSplitViewController
Added an IBOutlet for each NSSplitViewItem. For example:
#IBOutlet weak var mySplitViewItem: NSSplitViewItem!
Created a subclass WindowController for the NSWindowController
Added an IBAction in the WindowController class that links to the NSToolbarItem (my button)
Added a property that gets the Window Controller's content as MySplitViewController
var mySplitViewController: MySplitViewController {
return self.window?.contentViewController as! MySplitViewController
}
Now I can access the split view controller's property from the Window Controller in the action I created:
mySplitViewController. mySplitViewItem.collapsed = true
I created some sample code that does this (but using a view controller and changing the text for a label here, just in case someone wants to see a working project with this behaviour. And a blog post about it too :)
One person proposes to make the link using the first reponder and expecting everything to hook up at run-time (which looks a bit dodgy and not the way apple would implement it I think...).
I think this first responder method is actually the proper way.
As an example:
Add something similar to the following, in whichever view controller makes sense.
#IBAction func doSomething(_ sender: AnyObject?) {
print("Do something.")
}
This will magically show up in the first responder:
In your storyboard, right-click the orange "first responder" icon above your window controller, and you should see doSomething in the very long list. You just need to connect that up to your toolbar button.
In the following screen capture, you can see my "Toggle Sidebar" button is connected to the toggleSidebar action in my first responder.
I didn't even have to write this method — it's provided by NSSplitViewController:
#IBAction open func toggleSidebar(_ sender: Any?)
So, I was working this same issue and finding no solution as you experienced. I read your post and was trying to figure how I would implement your solution when it occurred to me to use a notification. In about 30 seconds, I had a perfectly fine working solution:
In your windowController add an IBAction to post a notification like so
-(IBAction)toggleMasterViewClicked:(id)sender
{
[[NSNotificationCenter defaultCenter] postNotificationName:#"TestNotification" object:nil];
}
Hook up that action to your NSToolbarItem, then in the viewController add self as an observer for that notification like so
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(toggleMasterView:) name:#"TestNotification" object:nil];
In your case, selector would be updateMyLabelText
I don't really see any downside here. No reference to other objects needed, no dependancies. Works flawlessly for me
While connectiong IBActions works by using either the First Responder or by adding an "Object" to the scene, then changing its class to the window's view controller class, this doesn't help with IBOutlets and delegates that you'd like to point to the view controller.
Here's a work-around for that:
Add the Toolbar to the View Controller, not to its Window. That way, you can make all the IBOutlet connections in the View Controller Scene easily. I've done that for years and found no issues with it, even when using Tabs.
You'll have to assign the window's toolbar in code, then. E.g. like this:
#interface ViewController ()
#property (weak) IBOutlet NSToolbar *toolbar; // connect this in your storyboard to the Toolbar that you moved to the View Controller Scene
#end
- (void)viewWillAppear {
[super viewWillAppear];
self.view.window.toolbar = self.toolbar;
}

Click in view of NSCollectionViewItem

I'm new to Cocoa dev, so many concepts of it are not clear to me...
I'm trying to build a simple app which will use Flickr API to retrieve user photosets and show them in a NSCollectionView, by clicking them, will start to download the photos of the photo set.
I'm using Xcode 5.0.1 with latest SDK which is 10.9
After reading some articles about how to use binding to deal with NSCollectionView, I'm now facing another problem regarding handling events in NSCollectionViewItem.
Per I understanding, mouse events can be easily handled by implement
-(void) mouseDown:(NSEvent *)theEvent
In a NSView subclass, say
#interface MyViewController : NSView {
}
And assign the view custom class to the subclass I made (MyViewController) in InterfaceBuilder.
Now, I have no problem to do as above, and the mousedown did handled as expect in most of widgets.
The problem is, I have a NSCollectionViewItem subclass as below:
#interface MyItemController : NSCollectionViewItem {
}
I'm trying to implement mousedown method there, this class was set to as File's Owner in a separated nib file. And the view will be automatically load when the NSCollectionView loaded.
Now, MyItemController cannot be as customer class in the view object in IB which is obviously because of it is not a NSView subclass but a NSCollectionViewItem subclass.
If I write a subclass of NSView and make the custom class of view object, I can get the mousedown.
However, I cannot get the representedObject and index of NSMutableArray in this approach and they are the essential information I need.
So my question is, what is the right way to deal with mouse events view of NSCollectionViewItem?
My code in GitHub here:
https://github.com/jasonlu/flickerBackupTool
Thanks!
UPDATE
I found a approach to solve this problem is by subclassing NSView and implement mousedown and use super, subviews to get and index and the array itself
- (void)mouseDown:(NSEvent *)theEvent {
NSCollectionView *myCollectionView = (NSCollectionView *)[self superview];
NSInteger index = [[myCollectionView subviews] indexOfObject:self];
NSLog(#"collection view super view: %#",myCollectionView);
NSLog(#"collection index: %ld",index);
NSLog(#"array: %#", [[myCollectionView content] objectAtIndex:index]);
}
It seems work, but I'm not sue if this is the best practice, it looks like depends on view too much and took a long way to reach the array.
I wouldn't bet that NSCollectionView always creates all subviews (subviews which are far away from the viewing area might be delayed and/or reused). Therefore, I wouldn't rely upon subview searching.
Overload NSViewController to create an NSView so that the representedObject assigned to the NSViewController is accessible from the NSView. From there you could search the actual content for index determination.
Overloading NSCollectionView and recording the actual index during view creation would probably not work well because a deleted item probably doesNot re-create any views.

What is the pattern of navigating between UIViewControllers in iOS?

I have a bunch of UIViewControllers subclasses (let's call them MainForm, DetailForm, MoreMinorDetails). Basically the idea is that AppDelegate class instantiates MainForm, user presses some type of button on MainForm and DetailForm comes up. Then on a button on the DetailForm launches MoreMinorDetails. And of course, I should be able to go back down to the MainForm.
Note that there aren't any UINavigationController objects anywhere in sight.
What is the accepted pattern to move between UIViewControllers in a manner described above?
Or am I going about it in the wrong way?
I'll be happy with either XCode or MonoTouch based explanation.
You can use a UINavigationController and hide the navigation bar:
self.navigationController.navigationBar.hidden = YES;
Then in your button's action just push the next view controller:
-(void)buttonAction:(id)sender
{
NextViewController *nextViewController = [[NextViewController alloc] init];
[self.navigationController pushViewController:nextViewController animated:YES];
}
To go back, use
-(void)goBack
{
[self.navigationController popViewControllerAnimated:YES];
}
To go to a certain view controller (you have to know exactly when it was pushed onto the navigation controller's stack):
-(void)goToViewController
{
[self.navigationController popToViewController:[self.navigationController.viewControllers objectAtIndex:1] animated:YES];
}
Or to pop to your root view controller
[self.navigationController popToRootViewControllerAnimated:YES];
This way, you will obtain the UINavigationController's functionality and keep all the space in the view.
AngryHacker,
My simple suggestion is to follow zoul one. I think the simplest way to achieve what you want it' to create a UINavigationController and use it as a containment controller for other controllers.
So, the way could be create a UINavigationController in the AppDelegate and set it as the rootViewController for your window. When you create a UINavigationController you can pass to it a root controller (in this case MainForm).
In MT it looks like the following (do not trust the code because I've written it by hand)
private UINavigationController navController;
public override bool FinishedLaunching (UIApplication app, NSDictionary options)
{
navController = new UINavigationController(new MainForm());
window.RootViewController = navController;
window.MakeKeyAndVisible ();
return true;
}
Now, when you launch the app you will see the MainForm's view and will able to allow navigation among different controllers.
For example, within MainForm you can go to DetailForm like:
this.NavigationController.PushViewController(new DetailForm(), true);
The same applies within DetailForm to MoreMinorDetails.
To go one step back, for example from MoreMinorDetails to DetailForm use
this.NavigationController.PopViewControllerAnimated(false);
To go to the the root controller (MainForm) within DetailForm or MoreMinorDetails use
this.NavigationController.PopToRootViewControllerAnimated(false);
About the space, it's not a problem. I guess you have two ways. The first is to move the bar items you have created within the navigation controller bar. In each controller you can decide what buttons make visible or not. The second is to hide completely the navigation bar and use the button you've already created.
In both ways you can attach actions to these buttons and allow the navigation between controllers. Furthermore, if you choose the first you can also hide the back button for your navigation bar.
A simple note to take in mind is the following:
Since the navigation bar is unique for a UINavigationController, the bar will maintains its state for all the controllers you push in the navigation controller. To explain the concept suppose you have two controllers, say A and B. You first push A and in its ViewWillAppear method you hide a button. When you push B, the button still remains not visible. If you want to unhide the button in B, you can play with its ViewWillAppear method (like before) and so on...
If you don't want to play with UINavigationController you should take a look to new view controller containment functionality provided by UIViewController class. This applies only from iOS >= 5. You can obtain the same effect of UINavigationController mechanism but it could be more difficult to achieve.
Hope that helps.

SplitView in Storyboard, can't connect delegate

I have an iPad interface defined in a storyboard, with a SplitViewController. I want to set the delegate of the SplitViewController to point to the detail controller, but IB won't allow that connection to be made.
Putting an "object" object and changing the class to that of my detail controller makes the delegate point to a different instance of the detail controller than the one displayed.
My attempts to connect it manually (in didFinishLaunching) in the app delegate were fruitless, the delegate was still nil.
Changing the delegate to the AppDelegate and implementing the protocol there worked, but passing messages to the detail controller didn't work (even though I verified that I was referencing the same instance).
Nothing works. I can set self.splitViewController.delegate = self when detail view loads, and then it becomes the delegate with no problem. But I miss any delegate calls that happen before that point.
For context, I need to get the splitviewcontroller's delegate calls so that I can show a button in the detailview to show a popover, as is standard practice. Right now, if the app is launched in portrait, it has to be rotated to landscape and then back for the button to show.
I've done this with "normal" xibs with no issue. It seems to be a special case of the more general problem of not being allowed to connect outlets across scenes in a storyboard.
I have no idea why this worked this time and not the first 80 times, but I added this to my AppDelegate:
UISplitViewController *splitViewController = (UISplitViewController *)self.window.rootViewController;
UINavigationController *navigationController = [splitViewController.viewControllers lastObject];
splitViewController.delegate = (id)navigationController.topViewController;

Switching from a UITableview controller to a viewcontroller

I'm just learning and playing with the apple Seismic XML example
http://developer.apple.com/library/ios/#samplecode/SeismicXML/Introduction/Intro.html
I've got most of it figured out, but the one area I can't get past is, if I want to remove the tableview controller and create a view controller populated with a tableview. I can get the tableview to appear fine, but no matter what I try I can never get it to populate.
In the viewdidload area I can setup the tableview, color the background, do whatever I want to do, but I seem to 'lose' control of it somehow.
In short, would someone please be able to give me the steps involved in correctly changing the tableviewcontroller to a viewcontroller with a tableview in the apple example?
Thank you.
Lian, you need to read the documentation on UITableViewController. http://developer.apple.com/library/ios/#documentation/UserExperience/Conceptual/TableView_iPhone/AboutTableViewsiPhone/AboutTableViewsiPhone.html
I'm not sure what you mean by "remove the tableview controller and create a view controller populated with a tableview" or why you would want this configuration. If you're having trouble with populating the tableViewController, you just pass in the data, usually from an NSArray or NSDictionary in the cellForRowAtIndexPath method. You either need to select the UITableViewController template when you create the class file or include the UITableViewDataSource and UITableViewDelegate if you're adding a tableView to a ViewController.
If you mean you want to change the view controller on screen, then you're looking to pop to another view using the navigation controller.

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