I just solved a really weird problem I had where I needed this class to behave sort of like a singleton but not really. Here's a code snippet
#implementation HMFPicturePreviewModalPanel
__weak static UIViewController *presentingInventoryViewController = nil;
static HMFPicturePreviewModalPanel *sharedPicturePreviewModalPanel = nil;
+(void)showPopupWithImage:(UIImage *)image withStartPoint:(CGPoint)startPoint withStartView:(UIView *)startView {
//this checks if there is already a panel visible.
if (![presentingInventoryViewController.view viewWithTag:kHMFPicturePreviewModalPanelTag]) {
sharedPicturePreviewModalPanel = [[HMFPicturePreviewModalPanel alloc] initWithFrame:presentingInventoryViewController.view.bounds withimage:image];
[presentingInventoryViewController.view addSubview:sharedPicturePreviewModalPanel];
[sharedPicturePreviewModalPanel showFromPoint:[startView convertPoint:startPoint toView:presentingInventoryViewController.view]];
}
}
+(void)changePresentingInventoryViewController:(UIViewController *)newInventoryViewController {
[sharedPicturePreviewModalPanel removeFromSuperView];
presentingInventoryViewController = newInventoryViewController;
}
+(void)removePresentingInventoryViewController {
[sharedPicturePreviewModalPanel removeFromSuperView];
presentingInventoryViewController = nil;
}
Is this called a semi-singleton? There's only ever going to be one of these on the screen at a time. I had to recreate this each time for it to work, hence why I couldn't do it as just a singleton.
What are the cons to this solution?
Also is it okay to have a __weak static variable?
Related
I am very new to objective c and OpenEars so please forgive me if I have some messy code and if I am lost in very simple problem.
Anyhow, I have two controllers in this application. The first being the default ViewController and the second one being a new one that I made called ReplyManagerController.
The code in the ViewController basically uses the one in the tutorial with some (maybe more some) changes.
EDIT:
The app is supposed to be a basic app where a user says something and the app replies.
But the original problem was that I could not get the string to display or TTS to work when my ViewController got it's string from another class/controller.
The answer in my below mentions that it was probably because my other class was calling my ViewController without the self.fliteController initialized.
How would I initialize the ViewController with self.fliteController initialized?
ViewController.m
- (void) pocketsphinxDidReceiveHypothesis:(NSString *)hypothesis recognitionScore:(NSString *)recognitionScore utteranceID:(NSString *)utteranceID {
NSString *strResult = hypothesis; //speech to text to string
ReplyManager* replyObject = [[ReplyManager alloc] init];
[replyObject speechResult:(NSString*)strResult viewController:self];
}
- (void) getReply:(NSString*)replyStr{
[self.fliteController say:replyStr withVoice:self.slt];
[self updateText:replyStr];
}
- (IBAction)updateText:(NSString*)replyStr{
labelOne.text = replyStr;
labelOne.adjustsFontSizeToFitWidth = YES;
labelOne.minimumFontSize = 0;
}
Any help will be great! Thanks!
ReplyManager.m
- (void) speechResult:(NSString*)strResult {
NSString *replystr;
NSString *greetings = #"Hi!";
NSString *sorry = #"Sorry I didn't catch that?";
ViewController* getReply = [[ViewController alloc] init];
if ([strResult isEqualToString:#"HELLO"])
{
replystr = greetings;
[getReply getReply:(NSString*)replystr];
}
else
{
replystr = sorry;
[getReply getReply:(NSString*)replystr];
}
}
EDIT 2:
viewDidLoad Method
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
self.fliteController = [[OEFliteController alloc] init];
self.slt = [[Slt alloc] init];
self.openEarsEventsObserver = [[OEEventsObserver alloc] init];
[self.openEarsEventsObserver setDelegate:self];
}
ViewController* getReply = [[ViewController alloc] init];
Here you init a new ViewController which does not have self.fliteController defined most likely. You need to reuse previos controller, for example like this:
[replyObject speechResult:(NSString*)strResult viewController:self];
So you can use already initialized viewController later. Overall it is better to initialize objects like viewController or replyController beforehand, not inside callback methods.
It sounds like a timing issue where you're trying to use fliteController before it's been initialized.
In your ViewController class, where do you assign a value to the fliteController property? In an initializer? -(void)viewDidLoad?
In ReplyManagerController add:
ViewController* getReply = [[ViewController alloc] init];
// Add these lines
NSLog(getReply.fliteController); // Is this nil?
[getReply.view layoutIfNeeded];
NSLog(getReply.fliteController); // Is it still nil?
Does the above fix the problem? If so, you're probably initializing fliteController in -(void)viewDidLoad. What's the result of the two NSLog statements?
Hello I am currently having issues bridging a variable in my completion block. I want to set isPreviewPlaying to NO in the completion block but I can't.
static void completionCallback (SystemSoundID mySSID, void *myself) {
AudioServicesRemoveSystemSoundCompletion (mySSID);
AudioServicesDisposeSystemSoundID(mySSID);
CFRelease(myself);
UIButton *previewButton = (__bridge UIButton*)myself;
[previewButton setTitle:#"Preview" forState:UIControlStateNormal];
_isPreviewPlaying = NO // I want to do this, but I can't.
}
- (void)previewButtonPressed:(id)sender {
if (_isPreviewPlaying) {
_isPreviewPlaying = NO;
NSLog(#"STOP");
AudioServicesDisposeSystemSoundID(soundID);
} else {
NSString * selectedPreviewSound = [self.soundFile objectAtIndex: _soundFileIndex];
AudioServicesCreateSystemSoundID((__bridge CFURLRef)[NSURL fileURLWithPath: selectedPreviewSound], &soundID);
AudioServicesPlaySystemSound (soundID);
_isPreviewPlaying = YES;
AudioServicesAddSystemSoundCompletion(soundID, NULL, NULL, completionCallback, (__bridge_retained void *)sender);
[sender setTitle:#"Stop" forState:UIControlStateNormal];
}
}
You will need to pass the class instance to the completion block function, as it's a C function, and that way you can access properties and methods on the instance.
That is the intent of myself parameter I believe, however you are currently releasing it using CFRelease() for some reason I cannot fathom (I am assuming that sender is a button as previewButtonPressed: looks like a button event callback, and releasing it won't do it any favours; read crash).
Therefore I would suggest:
Remove the CFRelease() call.
Cast myself to whatever the class is: MyClass *myclass = (MyClass *)myself;.
Call myclass.previewPlaying = NO; (assuming it's a property). Call [myclass previewNotPlaying] (see below).
Pass self instead of sender to AudioServicesAddSystemSoundCompletion().
EDIT Having said that, I now see you are using the button instance to display information. Instead of calling the property, above, call a method on the instance instead and make that method do the work:
- (void)previewNotPlaying
{
// _previewButton is an IBOutlet to the button
[_previewButton setTitle:#"Preview" forState:UIControlStateNormal];
_isPreviewPlaying = NO;
}
According to the official FAQ from ver.2 to customize your text/content depending on what sharer was selected by the user, you need:
subclass from SHKActionSheet and override
dismissWithClickedButtonIndex
set your new subclass name in
configurator (return it in (Class)SHKActionSheetSubclass;).
It doesn't work for me. But even more: I put
NSLog(#"%#", NSStringFromSelector(_cmd));
in (Class)SHKActionSheetSubclass to see if it's even got called. And it's NOT ;(( So ShareKit doesn't care about this config option...
Has anybody worked with this before?
thank you!
UPD1: I put some code here.
Here's how my subclass ITPShareKitActionSheet looks like. According to the docs I need to override dismissWithClickedButtonIndex:animated:, but to track if my class gets called I also override the actionSheetForItem::
+ (ITPShareKitActionSheet *)actionSheetForItem:(SHKItem *)item
{
NSLog(#"%#", NSStringFromSelector(_cmd));
ITPShareKitActionSheet *as = (ITPShareKitActionSheet *)[super actionSheetForItem:item];
return as;
}
- (void)dismissWithClickedButtonIndex:(NSInteger)buttonIndex animated:(BOOL)animate
{
NSLog(#"%#", NSStringFromSelector(_cmd));
NSString *sharersName = [self buttonTitleAtIndex:buttonIndex];
[self changeItemForService:sharersName];
[super dismissWithClickedButtonIndex:buttonIndex animated:animate];
}
And here's what I do in code to create an action sheet when user presses 'Share' button:
- (IBAction)shareButtonPressed:(id)sender
{
// Create the item to share
SHKItem *item = [SHKItem text:#"test share text"];
// Get the ShareKit action sheet
ITPShareKitActionSheet *actionSheet = [ITPShareKitActionSheet actionSheetForItem:item];
// Display the action sheet
[actionSheet showInView:self.view]; // showFromToolbar:self.navigationController.toolbar];
}
When I run this code, press 'Share' button and select any sharer I expect to get two lines in log:
actionSheetForItem: - custom action sheet got created
dismissWithClickedButtonIndex:animated: - custom mechanics to
process action sheet's pressed button got called.
But for some reason I get only the first line logged.
I was having the same issues but I've suddenly got it to call my Subclass successfully.
Firstly My Configurator is setup as so:
-(Class) SHKActionSheetSubclass{
return NSClassFromString(#"TBRSHKActionSheet");
}
Now My Subclass:
.h File
#import "SHKActionSheet.h"
#interface TBRSHKActionSheet : SHKActionSheet
#end
.m implementation override:
#import "TBRSHKActionSheet.h"
#import "SHKActionSheet.h"
#import "SHKShareMenu.h"
#import "SHK.h"
#import "SHKConfiguration.h"
#import "SHKSharer.h"
#import "SHKShareItemDelegate.h"
#implementation TBRSHKActionSheet
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}
+ (SHKActionSheet *)actionSheetForItem:(SHKItem *)i
{
NSLog(#"%#", NSStringFromSelector(_cmd));
SHKActionSheet *as = [self actionSheetForType:i.shareType];
as.item = i;
return as;
}
- (void)dismissWithClickedButtonIndex:(NSInteger)buttonIndex animated:(BOOL)animated
{
NSInteger numberOfSharers = (NSInteger) [sharers count];
// Sharers
if (buttonIndex >= 0 && buttonIndex < numberOfSharers)
{
bool doShare = YES;
SHKSharer* sharer = [[NSClassFromString([sharers objectAtIndex:buttonIndex]) alloc] init];
[sharer loadItem:item];
if (shareDelegate != nil && [shareDelegate respondsToSelector:#selector(aboutToShareItem:withSharer:)])
{
doShare = [shareDelegate aboutToShareItem:item withSharer:sharer];
}
if(doShare)
[sharer share];
}
// More
else if ([SHKCONFIG(showActionSheetMoreButton) boolValue] && buttonIndex == numberOfSharers)
{
SHKShareMenu *shareMenu = [[SHKCONFIG(SHKShareMenuSubclass) alloc] initWithStyle:UITableViewStyleGrouped];
shareMenu.shareDelegate = shareDelegate;
shareMenu.item = item;
[[SHK currentHelper] showViewController:shareMenu];
}
[super dismissWithClickedButtonIndex:buttonIndex animated:animated];
}
Finally on my implementation file I've not modified the call to SHKActionSheet as Vilem has suggested because of some dependancies that seemed to cause conflicts for me.
So this is my caller (straight from tutorial):
NSURL *url = [NSURL URLWithString:#"http://getsharekit.com"];
SHKItem *item = [SHKItem URL:url title:#"ShareKit is Awesome!" contentType:SHKURLContentTypeWebpage];
// Get the ShareKit action sheet
SHKActionSheet *actionSheet = [SHKActionSheet actionSheetForItem:item];
// ShareKit detects top view controller (the one intended to present ShareKit UI) automatically,
// but sometimes it may not find one. To be safe, set it explicitly
[SHK setRootViewController:self];
// Display the action sheet
[actionSheet showFromToolbar:self.navigationController.toolbar];
This Calls no problems for me.
edit: by far the best way to achieve this is to use SHKShareItemDelegate. More info is in ShareKit's FAQ.
I'm still new to Objective-C so I'm having a hard time with this. In my AppController, When a user clicks on one of the ads in my app, then closes the ad and returns to my app, I would like to destroy and recreate the ad (Long story as to why). For some reason though, my code isn't working. There are no errors or warnings, but it doesn't do what I intended it to do. This is what my code looks like:
#import "MoPubManager.h"
......
- (void)applicationWillEnterForeground:(UIApplication *)application
{
MoPubManager *obj = [[MoPubManager alloc] init];
if( obj.adView ) {
[[MoPubManager sharedManager] destroyBanner];
}
[obj.adView refreshAd];
}
_adView, destroy banner, and refresh ad are both in the MoPubManager file, so as you can see I imported the file and turned MoPubManager into an object. (obj.adView was originally just _adView in MoPubManager.h, but I had to switch it to obj.adView to avoid warnings.) I may just be using the wrong calls, I would post the MoPubManager.mm file where the calls originally are but its a full page or two
In the line:
MoPubManager *obj = [[MoPubManager alloc] init];
You are creating a new instance of the MoPubManager class.
Next you are checking whether the adView property of that newly instantiated class is not nil. Unless adView gets populated in the init method of MoPubManager, this will always be nil, so the destroyBanner method will not be called.
However, the destroyBanner method is being called on a sharedManager... indicating a singleton pattern in use. Therefore you should not be creating a new instance as this goes against the reason for using a singleton. (You only ever have one instance of a class when using a singleton - see this for more info)
Without seeing more code, it seems that you should be calling something like:
if( [MoPubManager sharedManager].adView ) {
[[MoPubManager sharedManager] destroyBanner];
}
[[MoPubManager sharedManager].adView refreshAd];
First, what subclass is MoPubManager... It compiles fine? The problem here seems to be that you are creating a new MoPubManager instance, but you are using a singleton to destroy it, and they don't have the same reference. You should use something diferent like:
MoPubManager *obj = [[MoPubManager alloc] init];
if( [MoPubManager sharedManager].adView ) {
[[MoPubManager sharedManager] destroyBanner];
}
[[MoPubManager sharedManager].adView refreshAd];
You are not using correctly the singleton pattern.
try this , maybe will help you
- (void)applicationWillEnterForeground:(UIApplication *)application
{
MoPubManager *obj = [MoPubManager sharedManager];
if( obj.adView ) {
[obj destroyBanner];
}
[obj.adView refreshAd];
}
So I'm still kind of new to Objective-C, and this was my first app that I'm now updating. The idea is this: The whole app is basically various lists of stuff. It asks the API for 15 posts, shows those with a Load More button. Click Load More, it loads 15 more, etc. The API that it loads these from has a token system with a timeout built in. Too long between requests, and you have to get a new token. So I want to have a singleton to use anywhere in my app so I can just do [APIMachine getToken] and behind the scenes, it checks if the time since the last request was too long (or this is the first request), if so, gets a new token, otherwise returns the one we already have. I'm following the singleton pattern I've found in so many places, but every time the Load More button uses [APIMachine getToken]it gets either nothing or something completely random. I had it print this stuff in the logs, and one time I even got a UITableViewCell as my token. Looks like variables are being overwritten somehow. But I really can't figure it out.
So here it is:
static PoorAPI2 *_instance;
#implementation PoorAPI2
#synthesize apiToken, timeOpened, tokenTTL;
+ (PoorAPI2*)sharedAPI
{
#synchronized(self) {
if (_instance == nil) {
_instance = [[super allocWithZone:NULL] init];
}
}
return _instance;
}
-(NSString *)API_open{
//boring code to get api token redacted
if ([doneness isEqualToString:#"success"]) {
NSDictionary *data = [json objectForKey:#"data"];
apiToken = [data objectForKey:#"api_token"];
tokenTTL = [data objectForKey:#"ttl"];
timeOpened = [NSDate date];
}else{
NSLog(#"FFFFFFFUUUUUUUUUUUU this error should be handled better.");
}
return apiToken;
}
-(BOOL)isConnectionOpen{
return ([timeOpened timeIntervalSinceNow] > tokenTTL);
}
-(NSString *)getToken{
if([self isConnectionOpen]){
return apiToken;
}else{
return [_instance API_open];
}
}
-(id)init{
if(self = [super init]){
apiToken = [[NSString alloc] initWithString:#""];
timeOpened = [[NSDate alloc] initWithTimeIntervalSinceNow:0];
tokenTTL = 0;
}
return self;
}
+ (id)allocWithZone:(NSZone *)zone
{
return [[self sharedAPI]retain];
}
- (id)copyWithZone:(NSZone *)zone
{
return self;
}
- (id)retain
{
return self;
}
- (unsigned)retainCount
{
return NSUIntegerMax; //denotes an object that cannot be released
}
- (void)release
{
//do nothing
}
- (id)autorelease
{
return self;
}
#end
I can only hope I'm doing something seriously foolish and this will be a hilarious point-and-laugh-at-that-guy thread. Then at least my app will work.
In API_open, you store three objects in instance variables, but they're not objects you own, so they'll probably be gone by the time you need them and replaced by something unpredictable. You need to retain them or use proper setters.
You problem is:
static PoorAPI2 *_instance;
C, and by inheritance Objective-C, do not initialize variables. Just change to:
static PoorAPI2 *_instance = nil;
Also I am of the school that adding extra code to try to prevent the singleton from being used as a single is a total waste of time, and only give you more code with more possibilities for bugs.
So if I was you then I would remove every method from +[PoorApi2 allocWithZone:] and down. Objective-C is a dynamic language and if a client wanted to instantiate a second instance of your singleton then it would be able to do so despite all your wasted extra lines of code. At the most I would add a log like this:
-(id)init{
if (_instance) NSLog(#"WARNING: PoorAPI2 already has a shared instance.");
if(self = [super init]){
apiToken = [[NSString alloc] initWithString:#""];
timeOpened = [[NSDate alloc] initWithTimeIntervalSinceNow:0];
tokenTTL = 0;
}
return self;
}
Creating a second instance of a singleton is a programming error and should be caught in development. Not a problem you should add extra lines of code to hide.