MKMapView not calling delegate methods - iphone

In a UIViewController I add a MKMapView to the view controlled by the controller.
- (void)viewDidLoad {
[super viewDidLoad];
CGRect rect = CGRectMake(0, 0, 460, 320);
map = [[MKMapView alloc] initWithFrame:rect];
map.delegate = self;
[self.view addSubview:map];
}
Later in the controller I have
- (void)mapViewDidFinishLoadingMap:(MKMapView *)mapView
{
NSLog(#"done.");
}
Done never gets printed. None of the other delegate methods get called either like mapView:viewForAnnotation: I use a MKMapView in an another app, but this seems to happen on any new application I make. Has anyone else seen this behavior?
EDIT:
The problem seems to be when UIViewController is made the delegate of the MKMapView, a direct subclass of NSObject seems to work okay. I can work around like this, still seems very odd since I've done it before.

I had the exact same problem: I had assigned < MKMapViewDeledate> to my controller, and linked the delegate to "File owner" in Interface Builder, but still my implemented delegate methods were not called.
The reason is that since iOS 4, maps are cached, and whenever an app display a cached map then methods such as "mapViewDidFinishLoadingMap" are not called. Resetting "contents and settings" in the simulator clears the cached maps and therefore solves the issue.

A bit old, but since iOS 7 there is a new method that might work. solved my problem
- (void)mapViewDidFinishRenderingMap:(MKMapView *)mapView fullyRendered:(BOOL)fullyRendered

Perhaps you need to go to the IB and control-drag from the MKMapView to the view conroller, then select delegate to make it a delegate???

maybe quite obvious, but just checking:
Have you made sure your viewcontroller declaration is correctly done.
Something like:
#interface YourViewController : UIViewController <MKMapViewDelegate>

I had a similar problem with the methods of MKMapViewDelegate not being called.
My issue was setting the MKCoordinateRegionMakeWithDistance and regionThatFits in the controller's -viewDidLoad() I wanted to only show the region around my house and not start with the world view. So after adding annotations in the controller's viewDidLoad, I started a timer. When it expires in one second, I zoom in on the region I want with the above APIs and the delegate methods fire. It just makes me a little dizzy and inclined to vomit on my iPad.
Now I only have to deal with the darn low memory warnings.

I had a similar issue in XCode 6.1 building for iOS 8.1 where none of the MKMapViewDelegate methods were being called. In a 2nd application the identical code resulted in the MKMapViewDelegate methods being called as expected.
In ViewController.m the mapView delegate was set as follows:
- (void)viewDidLoad {
...
self.mapView.delegate = self;
In ViewController.h:
#interface myMapViewController : UIViewController <MKMapViewDelegate>
#property (strong, nonatomic) IBOutlet MKMapView *mapView;
#end
I had manually added the IBOutlet line above to the header file, but only in the app where the delegate methods were not being received.
The solution was to delete the IBOutlet line I had added manually to the header, and then go to the storyboard and CTRL-drag from the MKMapView to the #interface block in my ViewController.h. The identical IBOutlet was recreated in the header file with the result that all the delegate methods were called correctly.

I just ran into this again on iOS 7 and figured out something that works consistently. The issue we're typically fighting is calling setRegion before the region has context (view rendered). iOS 7 adds new delegate methods representing all tiles being rendered but pre-iOS 7 the cached tiles prevents the delegate method mapViewDidFinishLoadingMap from being called. Instead I use a "pendingRegion" variable to check if I have "queued" a region change for when the map is rendered and then simply use the viewDidAppear method as a signal the map has been rendered to the screen and hence a region will have context.
Add a variable to your header:
MKCoordinateRegion pendingRegion;
Add this method to your code:
-(void)initPendingRegion {
pendingRegion.center = CLLocationCoordinate2DMake(0.0, 0.0);
}
Add this to your viewDidAppear:
if(pendingRegion.center.latitude != 0.0) {
MKCoordinateRegion useRegion = pendingRegion;
[self initPendingRegion];
[self.mapView setRegion:useRegion animated:YES];
}

My problem is that I forget to set location in the simulator. Go to Simulator -> Debug -> Location -> Custom location... and the MKMapViewDelegate methods will start calling

For me, it worked after adding NSLocationWhenInUseUsageDescription string in Info.plist

I also met same issue as yours. I found that: with the iPhone SDK 3.2 - when I create a new UIViewController with an associated xib file (the checkbox option in UIViewController creating dialog), delegate methods of MKMapViewDelegate are never called.
However, when I follow below steps, it runs well.
Create a new UIViewController class (never check the option: create xib file associated with the controller)
Create a new xib file. Add the map using Interface Builder + setting the Owner class with the class on step 1 + setting delegate object of the map point to the owner class.
Implement delegate methods for the UIViewController class in step 1.
When I want to use my ViewController (with the added map), I load it with the nib name as below example:
MapPreviewController* mapPreviewController = [[MapPreviewController alloc]
initWithNibName:#"MapPreviewController" bundle:[NSBundle mainBundle]];
[self.centerPanelView addSubview:mapPreviewController.view];
The code runs ok. I don't know what Apple changes or did with the xib file when I create my UIViewController using the wizard, but it may the root cause of my problem. It takes me 1 day to find this stupid solution.
If you found another one, please share to me.
Thanks

Related

My objects in storyboard don't link correctly with the code

I am trying to use storyboards in my application. I began well, I have added two view controllers with a button to go from the first to the second.
The problem is in this second view controller: the objects I add on it and link with the code do not work. When I set a breakpoint in the view controller code, the 'self.property' is set to nil, whereas it should be instantiated by the storyboard.
I have been looking for an answer for hours, and I really don't understand the problem, since all the rest seems to be good.
I have tried to write the property in the code (strong/nonatomic, nonatomic/retain and even weak/nonatomic), to link the object directly to the code so that it creates the property automatically, but I never get anything else than "nil" with breakpoints.
viewController.h:
#interface NMLoadingViewController : UIViewController
{
__weak IBOutlet UIProgressView *imageProcessingProgressView;
}
#property (weak, nonatomic) IBOutlet UIProgressView *imageProcessingProgressView;
#end
.m:
#synthesize imageProcessingProgressView;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
// Custom initialization
NSLog(#"INIT.");
}
(amont other lines of irrelevant code)
If I set the breakpoint to the "INIT." line, my imageProcessingProgressView is nil. I can't see a reason for that, I guess I have missed a very little detail...
(Note that I have tried this with other objects, like a UILabel, but it did not work either. Stranger, when I had two objects, one of them had an adress which was not nil, but still it was corrupted and did not show the right object.)
Edit: It was a lot of trouble for nothing... The problem is about the Variable View in XCode, which show my variable to "nil", whereas a log shows me a correct object...
Remove this...
{
__weak IBOutlet UIProgressView *imageProcessingProgressView;
}
...and make the property strong.
Change your log message to...
NSLog(#"INIT: %#", self.imageProcessingProgressView);
...and see if you still have a problem. If you do, then take another look at your storyboard connections.
Make sure NMLoadingViewController is the class on your viewController
First try out the answer by #Eric because I do believe that is the real issue.
Also, make sure that you are actually using the interface builder to hook the controls back to the view controller. This is done by dragging a line from the control back to the property of the view controller.

Why a separate instance of ViewController Class is affecting previous instance?

UPDATE - Cause found!... please read below & suggest the solution:
While creating a video to show this issue, I have found why does that happen...
Any Control/Element that is defined between #imports & #implementation DetailViewController in .m file is lost by the original detVC when a new instance is created of VC.
Example:
I am including a video that re-creates this issue. As shown, all controls work except a UISegmentedControl & a UILabel.. both of which are defined in DetailViewController.m as:
#import "DetailViewController.h"
UISegmentedControl *sortcontrol;
UILabel *incrementLabel;
#implementation DetailViewController
Video Link - http://www.youtube.com/watch?v=2ABdK0LkGiA
I think we are pretty close.. Waiting for the answer!!
P.S.: I think this info is enough can lead us to the solution, but if needed I can share the code too.
EARLIER:
There's a detailViewController (detVC) in our app which is normally 'pushed' from a UITableViewController.
Now we are also implementing Push Notifications which would 'modally' present the same detVC whenever the notification arrives, which in turn can happen over any view controller.
It works all fine until the detVC through notification is presented while another instance of detVC was already the active view controller (pushed earlier through TableView).
The problem happens when the presented detVC is dismissed - the pushed detVC 'looses' control of about everything - It is not pointing to the same data as earlier & even the UISegmentedControl on Navigation Toolbar points to -1 index on pressing any index!
Why does such thing happen when we are creating a separate instance of detVC? Why does it affect the earlier detVC? How can it be resolved / What about Objective C needs to be learned here? (FYI, we are using ARC in the project)
Thanks
EDIT - Some code:
When Pushed:
ProductDetailViewController *detailViewController = [[ProductDetailViewController alloc] init];
detailViewController.hidesBottomBarWhenPushed = YES;
[self.navigationController pushViewController:detailViewController animated:YES];
detailViewController.serverOffset=serverOffset;
detailViewController.prdctIndex = indexPath.row;
When presented through Notification:
- (void)displaySingleProduct:(NSDictionary*)userInfo{
ProductDetailViewController *onePrdVC = [[ProductDetailViewController alloc] init];
UINavigationController *addNav = [[UINavigationController alloc] initWithRootViewController:onePrdVC];
onePrdVC.justOne=YES;
onePrdVC.onePrdIDtoLoad=[[[userInfo valueForKey:#"prd"] valueForKey:#"id"] intValue];
[self.navigationController presentModalViewController:addNav animated:YES];
}
There is a Product class in detVC which gets the data from the values stored at the prdctIndex row in the SQLite table.
After dismissing the presented detVC through notification, the Product class of the pushed detVC starts pointing to the row which was used for Product class in presented detVC. And there is no such code in viewDidAppear which would alter Product class.
So, this, UISegmentedControl issue mentioned above & some other problems are causing the pain! Basically, the whole detVC acts weird - which re-works if we just pop & re-push it!
EDIT 2
I have more info on it which could lead to the cause.
If I run viewDidLoad on viewDidAppear like this:
if (!justOne) {
aProduct = [allProducts getProduct:(prdctIndex+1) one:NO];
[self viewDidLoad];
[self populateDetails];
}
the pushed detVC regains the control & every element/control starts re-working as expected (but not in the ideal way). So, it is quite clear that the separate instance of presented detVC does messes up the earlier pushed detVC & a re-setting up of all the controls / pointers is required through viewDidLoad.
Can any helpful conclusion can be derived from this info?
When in your code you write:
#import "DetailViewController.h"
UISegmentedControl *sortcontrol;
UILabel *incrementLabel;
#implementation DetailViewController
You are not defining these variables as instance variables (ivars), so they are not individual for each instance. There are three ways to define ivars.
1) The traditional way, in your .h file.
#interface DetailViewController{
UISegmentedControl *sortcontrol;
UILabel *incrementLabel;
}
2) Some additions to objective-C have added support for the next two ways. Like declaring them in your .m file.
#implementation DetailViewController{
UISegmentedControl *sortcontrol;
UILabel *incrementLabel;
}
3) If these ivars use properties to expose them, then you can simply leave out the explicit definition of them. So in .h:
#interface DetailViewController
#property (strong, nonatomic) IBOutlet UISegmentedControl *sortcontrol;
#property (strong, nonatomic) IBOutlet UILabel *incrementLabel;
and then in the .m file:
#implementation DetailViewController
#synthesize sortcontrol;
#synthesize incrementLabel;
Are you loading the view controller from a NIB? If so, it may be that the same instance of the view controller is used each time. You can log the address of your view controller in viewDidLoad and see if this is the case.
It actually depends on how your apps architecture has been created. If you are using TabBarController based application, here is the proper way to do so.
If two instances of the same class are interfering with each other, that strongly suggests that you are not storing all your state in instance variables. I would suspect that something in ProductDetailViewController stores its state in global or class data, and that your problem lives in there.
It's possible that you have done something silly like making ProductDetailViewController a forced singleton (overriding +alloc, which you should almost never do), but generally people remember when they've done that.
Never call viewDidLoad directly. That's only for the system to call. (I know you were just testing, but don't leave that in.)
But are you calling [super viewDidAppear:animated] in your viewDidAppear:? You have to call your superclass in that method.

Reference the class that a subview was added from

I'm adding a subview to my primary iPad UIViewController, and within that subview I need to reference said view controller in order to play a video using that controller.
Can anyone help me out with the way that should be done, and possibly a code example?
Thank you in advance.
Regards,
Ed
EDIT (A LITTLE BIT MORE INFO):
This subview is a view from a uiviewcontroller class that is designed for the iPhone. It's a table that loads a video when a row is pressed. The movieplayer loads the video within the referenced viewcontroller (which is why I want to reference the iPad view controller from within the subview). The view is basically used within an iPad app in it's same form.
This sounds like an architecture problem. It's not up to your view to tell something to play a sound. That's a controller's job. It's up to your view to tell "someone" that it was touched, or slid, or whatever the user has done. "Someone" (who is watching) will then perform the correct response to that.
To do this, your view should generally take a target, and possibly and action. Look at how UIControl (for example, UIButton) informs other objects that it has been activated. The observer (controller) then reacts accordingly.
EDIT
The view should not load a video. A view controller should load the video and install it into the correct view. The only job the view has is to tell its view controller that it has been pressed. UITableView handles this automatically with the UITableViewDelegate method tableView:didSelectRowAtIndexPath:. If you're not using a UITableView, you should still follow this pattern. The view accepts has a delegate and tells the delegate (controller) that something was selected. Then the controller updates the views with the new data.
You probably already have the main view living in a property of your application delegate (it is commonly assigned via the application's .xib file, look in the app delegate's applicationDidFinishLaunching: method, where it adds the main view as a subview to the window, something like:
[window addSubview:primaryController.view];
[window makeKeyAndVisible];
).
So anywhere in your app where you need to access the main view, you can do:
[(MyAppDelegateType*)([UIApplication sharedApplication].delegate).primaryController somePrimaryControllerMethod];
Edit: while this will work, I agree with Rob Napier that this isn't the best way to do it, architecture-wise.
You could just use [yourSubview superview] to get the superview.
Can't you just add a property to the view like this:
#property (nonatomic, assign) UIViewController *parentViewController;
And on initialization of the view (from within the UIViewController), set the property:
UIView *customView = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 460.0f)];
customView.parentViewController = self;
And from then on you should be able to call the parentViewController from within the view.
Edit: Rob Napier has a good point, it's probably a better idea to set a target and selector from within the view instead of a view controller. This way you should be able to hook up methods directly with the view. The properties would look like this:
#property (nonatomic assign) id target;
#property (nonatmic, assign) SEL selector;
And perhaps add a designated initializer to your view:
- (id)initWithFrame:(CGRect)aFrame target:(id)aTarget selector:(SEL)aSelector
{
self = [super initWithFrame:aFrame];
if (self)
{
self.target = aTarget;
self.selector = aSelector;
}
return self;
}

UITableViewController loading inside a UIViewController inside a UIViewController issue

I don't really know if what I'm doing is the right way to do it. Right now it seems to be working until it hits a certain point with a EXC_BAD_ACCESS message.
I'll describe what I'm doing as best and with the most relevant details I can tell:
I have a CalendarViewController that inherits UIViewController which is loading from a .xib file (CalendarViewController.xib). The class contains a UIView called contentView which I created and which I initialize with another nib file based on a class which is also inherited from UIViewController:
- (void)viewDidLoad {
[super viewDidLoad];
calendarView = [[CalendarView alloc] initWithNibName:#"CalendarView" bundle:nil];
[contentView addSubview:calendarView.view];
}
(calendarView is the class inheriting UIViewController and viewDidLoad is from CalendarViewController.
CalendarView.xib has a UITableViewController with it's respective UITableView. This Table View Controller is linked to a CalendarTableController to which I also generated a .xib file for it.
Everything is being created just right (apparently) but it is crashing somewhere very unexpected. CalendarTableController also implements a DateLoaderDelegate which loads information from an xml on an external url.
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
// When the data has all finished loading, we set a copy of the
// loaded data for us to access. This will allow us to not worry about
// whether a load is already in progress when accessing the data.
self.lastLoadedMatchXMLData = [self.matchXMLData copy];
// Make sure the _delegate object actually has the xmlDidFinishLoading
// method, and if it does, call it to notify the delegate that the
// data has finished loading.
if ([_delegate respondsToSelector:#selector(xmlDidFinishLoading)])
{
[_delegate xmlDidFinishLoading];
}
}
The application is getting to this point without any problem. _delegate is containing the correct object (a CalendarTableController which implements the DateLoaderDelegate). But when it arrives to the line:
if ([_delegate respondsToSelector:#selector(xmlDidFinishLoading)])
it crashes with the EXC_BAD_ACCESS, I don't really know the reason, if I look at the debugger, the crash is not occurring in any of my classes as any of them are appearing in the execution stack. URLConnectionClient seems to be generating it, but I don't really know why. The loading of the xml had worked earlier before I rearranged the ViewControllers to work as I have described now.
Any ideas?
It's weird. I fixed the problem but I had to dedicate the whole UIViewController to contain the UITableView. What I did was this:
Create an IBOutlet with the custom UITableViewController (CalendarTableViewController) in the custom UIViewController.
In the loaded .xib file I linked the IBOutlet to a created UITableViewController declared as a CalendarTableViewController.
This way I solved the problem of the UITableViewController being deallocated without reason. But now the image views I had placed in the intermediate UIViewController wouldn't appear. I had to set that UIViewController to contain solely the CalendarTableView and place the image views in the initial UIViewController. Weird, isn't it? I don't like much the hierarchy I created... but for now that will do =S
Check that you have defined properties for all of your subviews and that you are retaining everything that you need to be. Bad Access May mean that you're attempting to call respondsToSelector on an object that has been released.
Have you tried calling loadView before adding the nested controller's view to the parent's view?
Maybe viewDidLoad is not executing before you add the view and some variables were never initialized.

How Do I (Re)Use the Same Nib in Multiple View Controllers

Okay I just typed this whole question out and then managed to delete it. Sigh. Anyway, standard disclosure that I have searched everywhere and banged my head on the keyboard and can't figure this out.
I'm building a basic app based on the utility application template (with a MainViewController and FlipsideViewController). Side note: I still don't understand the purpose of MainView and FlipsideView in this scheme so if someone can explain it that wouldn't be too terrible :D
Anyway, at the bottom of both of these views I want to have a toolbar. It was easy enough to add that to a given view with IB, but I want the toolbar to have its own controller and model because I want to keep its state consistent across the two views. Accordingly I'd like to load that view from a nib but it seems I'm doing something wrong. I followed the advice here: NSViewController and multiple subviews from a Nib but obviously borked it up so more insight would be appreciated.
I did the following things:
I created ToolBarViewController which is basically empty but is the file owner of ToolBar.xib. Inside ToolBar.xib I have a view with a frame the size of the toolbar and inside that a toolbar. In MainView.xib I've got a view element of the same size which is wired up to toolBarView found in the code below...
In MainViewController.h:
#import "ToolBarViewController.h"
#interface MainViewController : UIViewController <FlipsideViewControllerDelegate, MKMapViewDelegate> {
...
ToolBarViewController *toolBarViewController;
IBOutlet UIView *toolBarView;
}
...
#property(nonatomic, retain) ToolBarViewController *toolBarViewController;
#property(nonatomic, retain) IBOutlet UIView *toolBarView;
In MainViewController.m:
#synthesize toolBarViewController;
#synthesize toolBarView;
- (void)loadView
{
[super loadView];
toolBarViewController = [[ToolBarViewController alloc] initWithNibName:#"ToolBar" bundle:nil];
[[toolBarViewController view] setFrame:[toolBarView frame]];
[[self view] replaceSubview:toolBarView with:[toolBarViewController view]];
}
When I build and run I get the warning for the last line above that 'UIView' may not respond to 'replaceSubview:with' and on running it the following exception is thrown:
*** -[MainView replaceSubview:with:]: unrecognized selector sent to instance 0x450c540
Can anyone explain what I'm doing wrong? Thanks!å
There is no such method as [UIView replaceSubview:with:]. That's an NSView method. You should have gotten a warning about this when you compiled.
To do the same thing, you'd need to use [[self view] insertSubview:aboveSubview:] and then [toolbarView removeFromSuperview].
That said, I'm not certain if this is how you want to mess with the toolbar. I'd probably try something more like:
self.toolbarItems = [toolbarViewController toolbarItems];
That's because there's no such UIView's replaceSubview:with: (there's a method like that for NSView on the Mac, though).
Remember that Objective-C warnings are usually errors ;) in general I tend to never leave them without treatment, and I even turn them into errors:
http://akosma.com/2009/07/16/objective-c-compiler-warnings/