I have a text field that is manually set to be the first responder. There are times when this works fine, and others when it fails.
My application is a game with two methods of play: flashcard and regular. The UITextField that is the source of trouble is hidden and not used in flashcard mode. Once flashcard has loaded once, the keyboard ceases to appear. If the player never switches to flashcard mode, the keyboard never fails. The following is the code to make the keyboard show:
nameBar.hidden = FALSE;
self.animalName.hidden = FALSE;
self.animalName.enabled = YES;
[self.animalName becomeFirstResponder];
This is the code that switches modes:
playViewController = nil;
[playViewController release];
playViewController = [[PlayViewController alloc] initWithNibName:#"PlayView" bundle:nil];
playViewController.delegate = self;
[(vsl_mmp_crittersAppDelegate*)[[UIApplication sharedApplication] delegate] playButtonPlaySound];
playViewController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
playViewController.flashcardMode = TRUE;
[self presentModalViewController:playViewController animated:YES];
[(vsl_mmp_crittersAppDelegate*)[[UIApplication sharedApplication] delegate] playPlayMusic];
I'm really confused about why the UITextField ceases to work after I switch modes, especially since I completely release and re-allocate the play controller to do so.
Thanks for reading.
Where are you calling becomeFirstResponder from?
Calling it from viewDidLoad will give you the behavior you describe, and calling it from viewDidAppear: should show the keyboard each time the view appears.
Related
I have a UIImagePickerController (source type camera) that I use to take pictures. I have it put properly in my .h (added the #property) and .m (#synthesize). Here's what I use to show it:
if (thePicker == nil) {
thePicker = [[UIImagePickerController alloc] init];
thePicker.delegate = self;
thePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
thePicker.allowsEditing = NO;
}
[self presentModalViewController:thePicker animated:YES];
I'm having an odd problem. Every now and again, after closing/opening it a few times, the camera button OR the used button won't work (but the retake and cancel buttons work). I'm not getting any memory warnings and I have a dealloc and didReceiveMemoryWarnings void statement, but they don't get called.
ANyone else having this problem?
I have seen some apps cover it up with their overlay, but you can't remove it. AVCaptureSession really does sound more appropriate for your purposes. I see one example here:
http://www.musicalgeometry.com/?p=1273
Try this it may help u i guess Thanks!!
Ok here is the code that I wrote to display the UIImagePickerController in the camera source. I just declared the myPhotopicker in the header for the property and retain it. Synthesized it in the main code file. Then calling the picker I wrote the code below:
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
if (myPhotopicker==nil) {
myPhotopicker = [[UIImagePickerController alloc] init];
myPhotopicker.delegate = self;
}// create once!
myPhotopicker.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentModalViewController:myPhotopicker animated:NO];
}
Upon calling it, there are a few things that is weird happening to the app.
Sometimes, when there are many apps running in the background (iPhone4), the app would fail to load the camera and crash the app. Though it will load CameraRoll/PhotoAlbums without problem.
If the camera view is able to load (when there are less apps running in the background), tapping the Cancel button on the camera view results in the app rebooting itself (where the Default.png image is shown quickly, and back to the main page - like when we started the app).
I have been trying to figure out this problem, but not sure what to do... pls help.. Thanks.
here is the complete code of image pickercontrol try too find solu. here.
http://www.icodeblog.com/2009/07/28/getting-images-from-the-iphone-photo-library-or-camera-using-uiimagepickercontroller/
Regards,
Shyam Parmar
Rather than your 'create once' logic try creating and releasing each time.
if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
myPhotopicker = [[UIImagePickerController alloc] init];
myPhotopicker.delegate = self;
myPhotopicker.sourceType = UIImagePickerControllerSourceTypeCamera;
[self presentModalViewController:myPhotopicker animated:NO];
[myPhotopicker release];
}
You should also implement the delegate to remove the modal view controller from view when it is dismissed (if you haven't already).
You should also check that the current class conforms to the UINavigationConrollerDelegate protocol.
In my iPhone app, I want to add activity indicator on top of a searchbar.
When it is searching it should display activity indicator.
I have added the activity indicator in XIB and created its outlet.
I am making it hide when the searching finishes, but Activity Indicator does not display.
Problem
I figured out that search function(say A)(where I animate the activity indicator) in turn calls another function(say B) so the main thread is being used in executing the function B. But for activity indicator to animate we require the main thread.
So I tried calling function B using performSelectorInBackGround:withObject method. Now when I click search the activity indicator is shown but the functionality of function B does not execute.
What can be a work-around for this?
There is not quite enough in your question to go on, but to start debugging, I would do the following.
Verify that the activity variably is really wired to the UIActivityIndicator you are creating in IB. (I would set a breakpoint on the setHidden: lines and make sure the variable is not null. Or throw an NSAssert(activity,#"Whoops! actity is null"); in there.)
If the variable is indeed set, I would start checking that it is in the right place in the view hierarchy. (I'd try doing a [self.view addSubview:activity] and see that it appears. You might have to replace it somewhere else.)
You might also want to try having it on by default in IB, until you have everything figured out.
Good Luck. Hope this helps.
Save yourself the hassle of creating a custom activity indicator and use the standard one that's available for you already - in the top bar. Also, IMO users tend to expect that one to spin when something is happening.
UIApplication* app = [UIApplication sharedApplication];
app.networkActivityIndicatorVisible = YES;
Obviously, set it to NO when your activity is over.
First of all, make sure you have #synthesize activity at the top of your .m file. Then in the viewDidLoad method, type activity.hidesWhenStopped = TRUE;. Next, in the method that is called when the search starts, type [activity startAnimating]; and [activity stopAnimating]; in the method when the searching stops.
try this:
set hidesWhenStopped = NO, so that is displayed all the time and then hide and show it manually. But the View should be set in IB to hidden first.
- (void)startActivityView {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc]init];
activity_view.hidden = NO;
[pool drain];
}
- (void)stopActivityView {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc]init];
activity_view.hidden = YES;
[pool drain];
}
- (void)doSomething {
[self performSelectorInBackground:#selector(startActivityView) withObject:nil];
// do some time consuming work
[self performSelectorInBackground:#selector(stopActivityView) withObject:nil];
}
Perhaps you have a view in front of your activity indicator? What if you always bring it to the front....
loadView = [[UIActivityIndicatorView alloc]
initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
loadView.frame = CGRectMake(0.0, 0.0, 40.0, 40.0);
loadView.center = window.center;
loadView.opaque = NO;
[window addSubview: loadView];
[window bringSubviewToFront:loadView];
[loadView startAnimating];
I suggest that you use DSActivityView for showing your activity indicator. The source code can be found at Dejal blog.
Showing, and hiding, the activity view is a simple line of code.
[DSActivityView activityViewForView:self.view];
start animating the activity indicator and with a delay of 0.1 or 0.2 just call the other method u want.... i tried and it is working for me....
I have got the solution and it is as follows.
I just wrote the below line in Search button click event.
[NSThread detachNewThreadSelector:#selector(threadStartAnimating:) toTarget:self withObject:nil];
And defined the function threadStartAnimating: as follows:
-(void)threadStartAnimating:(id)data
{
[activityIndicator setHidden:NO];
[activityIndicator startAnimating];
}
For a cutom camera overlay I need to find out, when the iris is opened, because my overlay will allways shown while the iris is close (and then animating to open).
Any ideas ?
You can listen for the PLCameraViewIrisAnimationDidEndNotification notification. Since this is not officially documented, you might be in violation of the Apple TOS, but I think so long as you write your code so that it's defensive against the possibility that the name or contract of this notification might change (so in the future you might not get the event) you'll probably be ok. In other words, use a timer or other technique to ensure that the thing you want done when the iris is open will definitely happen eventually even if you never get the notification...
Trivial example without the defensive programming. (Of course, you can register an interest only for this specific notification as well, see the docs for the notification center.)
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(notificationCallback:)
name:nil
object:nil
];
- (void) notificationCallback:(NSNotification *) notification {
if ([[notification name] isEqualToString:#"PLCameraViewIrisAnimationDidEndNotification"]) {
NSLog(#"Iris open");
// we don't need to listen any more
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
}
It seems that PLCameraViewIrisAnimationDidEndNotification no longer gets notified in iOS5.
I can't figure out what is a suitable solution when the iris has finished opening, there must another option rather than using a 3 second timer.
Check here: https://devforums.apple.com/message/561008#561008
I have a ViewController (ALImagePickerController) which holds, initializes and presents the UIImagePickerController as a child view controller (I have another child view controller for presenting the taken image which is not shown here) and I present (as a modal) the ALImagePickerController when I want to use the camera. So during this the viewDidAppear of the ViewContoller I add an animation to bring in the camera overlay gracefully as the shutter animation disappears.
#interface ALImagePickerController ()
#property (nonatomic) UIImagePickerController *cameraController;
#property (nonatomic) CameraOverlayView *overlayView;
....
#end
#implementation ALImagePickerController
....
- (void)viewDidLoad {
[super viewDidLoad];
[UIApplication sharedApplication].statusBarHidden = YES;
self.cameraController = [UIImagePickerController new];
self.cameraController.sourceType = UIImagePickerControllerSourceTypeCamera;
self.cameraController.delegate = self;
self.cameraController.allowsEditing = NO;
self.cameraController.showsCameraControls = NO;
....
self.overlayView = [CameraOverlayView new];
....
self.overlayView.alpha = 0;
self.cameraController.cameraOverlayView = self.overlayView;
....
// add as child view controller
[self addChildViewController:self.cameraController];
[self.view addSubview:self.cameraController.view];
[self.cameraController didMoveToParentViewController:self];
}
- (void)viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
[UIApplication sharedApplication].statusBarHidden = NO;
}
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
// smoothly bring in the overlay as the native camera shutter animation opens.
[UIView animateWithDuration:0.2 delay:0.3 options:UIViewAnimationCurveEaseOut animations:^{
self.overlayView.alpha = 1.f;
} completion:nil];
}
....
#end
The way I solved this problem is I initialize all the elements with the hidden property set to YES, then call a 3-second delayed selector after I call the camera, where I set all the elements to hidden = NO. It's not an ideal solution but it seems to work, and any lag after the iris is opened is negligible.
You should already know when the camera is ready to take a picture. At least the way I use a custom camera overlay, I init the view with something like self.sourceType = UIImagePickerControllerSourceTypeCamera; and the other usual setup, and the camera is ready (or "iris is open") at that point.
In summary, if one is using a custom camera overlay the way I am used to using it, one will know when the iris is open because it is under your control.
I am totally stumped, here's the situation:
My app uses the Core Location framework to get the current location of the user and then pings my server at TrailBehind for interesting places nearby and displays them as a list. No problems.
To conserve batteries, I turn off the GPS service after I get my data from the server. If the user moves around while using the app and wants a new list he clicks "Refresh" on the navigation controller and the CLLocation service is again activated, a new batch of data is retrieved from the server and the table is redrawn.
While the app is grabbing data from my server I load a loading screen with a spinning globe that says "Loading, please wait" and I hide the navigation bar so they don't hit "back".
So, the initial data grab from the server goes flawlessly.
The FIRST time I hit refresh all the code executes to get a new location, ping the server again for a new list of data and updates the cells. However, instead of loading the table view as it should it restores the navigation controller bar for the table view but still shows my loading view in the main window. This is only true on the device, everything works totally fine in the simulator.
The SECOND time I hit refresh the function works normally.
The THIRD time I hit refresh it fails as above.
The FOURTH time I hit refresh it works normally.
The FIFTH time I hit refresh it fails as above.
etc etc, even refreshes succeed and odd refreshes fail. I stepped over all my code line by line and everything seems to be executing normally. I actually continued stepping over the core instructions and after a huge amount of clicking "step over" I found that the table view DOES actually display on the screen at some point in CFRunLoopRunSpecific, but I then clicked "continue" and my loading view took over the screen.
I am absolutely baffled. Please help!! Many thanks in advance for your insight.
Video of the strange behavior:
Relevant Code:
RootViewControllerMethods (This is the base view for this TableView project)
- (void)viewDidLoad {
//Start the Current Location controller as soon as the program starts. The Controller calls delegate methods
//that will update the list and refresh
[MyCLController sharedInstance].delegate = self;
[[MyCLController sharedInstance].locationManager startUpdatingLocation];
lv = [[LoadingViewController alloc] initWithNibName:#"Loading" bundle:nil];
[self.navigationController pushViewController:lv animated:YES];
[super viewDidLoad];
}
- (void)updateClicked {
//When the location is successfully updated the UpdateCells method will stop the CL manager from updating, so when we want to update the location
//all we have to do is start it up again. I hope.
[[MyCLController sharedInstance].locationManager startUpdatingLocation];
[self.navigationController pushViewController:lv animated:YES];
//LV is a class object which is of type UIViewController and contains my spinning globe/loading view.
}
-(void)updateCells {
//When the Core Location controller has updated its location it calls this metod. The method sends a request for a JSON dictionary
//to trailbehind and stores the response in the class variable jsonArray. reloadData is then called which causes the table to
//re-initialize the table with the new data in jsonArray and display it on the screen.
[[MyCLController sharedInstance].locationManager stopUpdatingLocation];
if(self.navigationController.visibleViewController != self) {
self.urlString = [NSString stringWithFormat:#"http://www.trailbehind.com/iphone/nodes/%#/%#/2/10",self.lat,self.lon];
NSURL *jsonURL = [NSURL URLWithString:self.urlString];
NSString *jsonData = [[NSString alloc] initWithContentsOfURL:jsonURL];
NSLog(#"JsonData = %# \n", jsonURL);
self.jsonArray = [jsonData JSONValue];
[self.tableView reloadData];
[self.navigationController popToRootViewControllerAnimated:YES];
[jsonData release];
}
}
CLController Methods: Basically just sends all the data straight back to the RootViewController
// Called when the location is updated
- (void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
NSLog(#"New Location: %# \n", newLocation);
NSLog(#"Old Location: %# \n", oldLocation);
#synchronized(self) {
NSNumber *lat = [[[NSNumber alloc] init] autorelease];
NSNumber *lon = [[[NSNumber alloc] init] autorelease];
lat = [NSNumber numberWithFloat:newLocation.coordinate.latitude];
lon = [NSNumber numberWithFloat:newLocation.coordinate.longitude];
[self.delegate noteLat:lat];
[self.delegate noteLon:lon];
[self.delegate noteNewLocation:newLocation];
[self.delegate updateCells];
}
}
The first thought is that you may not want to send startUpdatingLocation to the CLLocationManager until after you've pushed your loading view. Often the first -locationManager:didUpdateToLocation:fromLocation: message will appear instantly with cached GPS data. This only matters if you're acting on every message and not filtering the GPS data as shown in your sample code here. However, this would not cause the situation you've described - it would cause the loading screen to get stuck.
I've experienced similarly weird behavior like this in a different situation where I was trying to pop to the root view controller when switching to a different tab and the call wasn't being made in the correct place. I believe the popToRootViewController was being called twice for me. My suspicion is that your loading view is either being pushed twice or popped twice.
I recommend implementing -viewWillAppear:, -viewDidAppear:, -viewWillDisappear: and -viewDidDisappear: with minimal logging in your LoadingViewController.
- (void)viewWillAppear:(BOOL)animated {
NSLog(#"[%# viewWillAppear:%d]", [self class], animated);
[super viewWillAppear:animated];
}
- (void)viewDidAppear:(BOOL)animated {
NSLog(#"[%# viewDidAppear:%d]", [self class], animated);
[super viewDidAppear:animated];
}
- (void)viewWillDisappear:(BOOL)animated {
NSLog(#"[%# viewWillDisappear:%d]", [self class], animated);
[super viewWillDisappear:animated];
}
- (void)viewDidDisappear:(BOOL)animated {
NSLog(#"[%# viewDidDisappear:%d]", [self class], animated);
[super viewDidDisappear:animated];
}
Then, run a test on your device to see if they are always being sent to your view controller and how often. You might add some logging to -updateClicked to reveal double-taps.
Another thought, while your #synchronized block is a good idea, it will only hold off other threads from executing those statements until the first thread exits the block. I suggest moving the -stopUpdatingLocation message to be the first statement inside that #synchronized block. That way, once you decide to act on some new GPS data you immediately tell CLLocationManager to stop sending new data.
Can you try and debug your application to see where the control goes when calling updateCells? Doesn't seem to be anything apparently wrong with the app.
Make sure that there are no memory warnings while you are in the LoadingViewController class. If there is a memory warning and your RootViewController's view is being released, then the viewDidLoad will be called again when you do a pop to RootViewController.
Keep breakpoints in viewDidLoad and updateCells. Are you sure you are not calling LoadingViewController anywhere else?
So, I never did get this to work. I observe this behavior on the device only every time I call popViewController programatically instead of allowing the default back button on the navigation controller to do the popping.
My workaround was to build a custom loading view, and flip the screen to that view every time there would be a delay due to accessing the internet. My method takes a boolean variable of yes or no - yes switches to the loading screen and no switches back to the normal view. Here's the code:
- (void)switchViewsToLoading:(BOOL)loading {
// Start the Animation Block
CGContextRef context = UIGraphicsGetCurrentContext();
[UIView beginAnimations:nil context:context];
[UIView setAnimationTransition: UIViewAnimationTransitionFlipFromLeft forView:self.tableView cache:YES];
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
[UIView setAnimationDuration:.75];
// Animations
if(loading) {
if (lv == nil) { lv = [[LoadingViewController alloc] initWithNibName:#"Loading" bundle:nil]; }
[self.view addSubview:lv.view];
[self.view sendSubviewToBack:self.tableView];
self.title = #"TrailBehind";
}
else {
[lv.view removeFromSuperview];
}
// Commit Animation Block
[UIView commitAnimations];
//It looks kind of dumb to animate the nav bar buttons, so set those here
if(loading) {
self.navigationItem.rightBarButtonItem = nil;
self.navigationItem.leftBarButtonItem = nil;
self.title = #"TrailBehind";
}
else {
UIBarButtonItem *feedback = [[UIBarButtonItem alloc] initWithTitle:#"Feedback" style:UIBarButtonItemStylePlain target:self action:#selector(feedbackClicked)];
self.navigationItem.rightBarButtonItem = feedback;
UIBarButtonItem *update = [[UIBarButtonItem alloc] initWithTitle:#"Move Me" style:UIBarButtonItemStylePlain target:self action:#selector(updateClicked)];
self.navigationItem.leftBarButtonItem = update;
[feedback release];
[update release];
}
}
Looking at your original code, I suspect this block very much:
- (void)viewDidLoad {
...
lv = [[LoadingViewController alloc] initWithNibName:#"Loading" bundle:nil];
[self.navigationController pushViewController:lv animated:YES];
[super viewDidLoad];
}
viewDidLoad is called every time the NIB is loaded, which can happen multiple times, especially if you run low on memory (something that seems likely given your remark that it only happens on device). I recommend that you implement -didReciveMemoryWarning, and after calling super, at the very least print a log so you can see whether it's happening to you.
The thing that bothers me about the code above is that you're almost certainly leaking lv, meaning that there may be an increasing number of LoadingViewControllers running around. You say it's a class variable. Do you really mean it's an instance variable? ivars should always use accessors (self.lv or [self lv] rather than lv). Do not directly assign to them; you will almost always do it wrong (as you are likely dong here).
I came across this while searching for the exact same issue, so while I'm sure you've already solved your problem by now, I figured I'd post my solution in case someone else runs across it...
This error seems to be caused when you assign two IBActions to the same UIButton in interface builder. It turned out that the button I used to push the view controller onto the stack was assigned to two IBActions, and each one was pushing a different controller onto the navigationController's stack (although you'll only end up seeing one of them - perhaps the last one to be called). So anyway, pressing the back button on the topmost view doesn't really dismiss it (or maybe it's dismissing the 2nd, unseen controller), and you have to press twice to get back.
Anyway, check your buttons and be sure they're only assigned to a single IBAction. That fixed it for me.