UIWindow's makeKeyAndVisible and background task - ios

I've add the background task feature to my application. Here is my app delegate
// AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[self setWindow:[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]];
[self.window setBackgroundColor:[UIColor blackColor]];
if (application.applicationState != UIApplicationStateBackground) {
// Application is launch in because user tap the app icon or from springboard
if ([application respondsToSelector:#selector(setMinimumBackgroundFetchInterval:)]) {
[application setMinimumBackgroundFetchInterval:UIApplicationBackgroundFetchIntervalMinimum];
}
} else {
// Application is launch in background mode
}
RootViewController *rootViewController = [[RootViewController alloc] initByDevice];
[self.window setRootViewController:rootViewController];
[self.window makeKeyAndVisible];
return YES;
}
- (void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
[[DataManager instance] updateDataWithMaxAttempt:5 block:^(BOOL success, NSArray *newData) {
if (success) {
if ([newData count] > 0) {
completionHandler(UIBackgroundFetchResultNewData);
} else {
completionHandler(UIBackgroundFetchResultNoData);
}
} else {
completionHandler(UIBackgroundFetchResultNoData);
}
}];
}
And this is my root view controller
// RootViewController.m
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
NSLog(#"Did appear");
// Do something that I want it to happen only when the application is visible to user
}
When the user tap the app icon, application works like what I expected. I see "Did appear" in console and stuff is happening after that like I expected.
But when the application awake to perform background task (which not visible to user) the RootViewController's viewDidAppear still getting call because of this line
[self.window makeKeyAndVisible];
By calling makeKeyAndVisible, it makes RootViewController visible even though it's only awake for background task. To fix this, I have to move this line to applicationDidBecomeActive
- (void)applicationDidBecomeActive:(UIApplication *)application {
[self.window makeKeyAndVisible];
}
As a result, the RootViewController's viewDidAppear now being call only when the application is in foreground (visible to user). But, my concern is, when application is in device memory (either active or inactive) applicationDidBecomeActive will be call several times.
user launch app
application become active again from springboard
device unlock
finish call
Is there any issue if I call UIWindow's makeKeyAndVisible several times during the application life cycle?

You can easily ensure that makeKeyAndVisible only happens once: wrap it.
if (!self.window.keyWindow) {
[self.window makeKeyAndVisible;
} else if (self.window.hidden) {
self.window.hidden = NO;
}

Related

"Unable to monitor event loop" crash

I add breakpoint and find that it block in the method that
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{
// init local data
[[PDKeychainBindings sharedKeychainBindings] setObject:#"0" forKey:kNEED_GESTURE_LOGIN];
// register notification to notice switching RootVC
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(switchRootControllerWithType:)
name:kNoti_SwitchRootView
object:nil];
// init the third part SDK
[self setupShareSDK];
[self setupBugly];
[self setupUMeng];
[self setupIQKeyBoard];
[self setupZhugeIOWithOptions:launchOptions];
[self setupTrusfort];
// register push service
[self setupJPushWithOptions:launchOptions];
[self dealWithRemoteNotification:launchOptions];
// set local flag
[KXUserIntroManager setupFlag];
if (self.remoteNotification) {
if ([AccountStateManager isLogin])
[self.loginNavigationController showGesturePDViewController];
self.window.rootViewController = self.loginNavigationController;
} else {
self.window.rootViewController = self.launchController;
}
return YES;
}
i also try the way in stackOverFlow ,Add the following code to the above method
NSArray *args = [NSProcessInfo processInfo].arguments;
for(NSString *arg in args){
if ([arg isEqualToString:#"NoAnimations"]) {
[UIView setAnimationsEnabled:false];
}
}
Image link
it is the detail of didFinishLaunching method. it just init some data and create a notification
While this is not a direct answer to your question, it may well be that your issue is symptomatic of the very evident fact that you are doing much too much work, on the main thread, in didFinishLaunchingWithOptions. Your main job in this method is to get out of the way and let the runtime launch the app. You are doing the exact opposite of that.

Overlay an image when app is inactive

I'm using these code to
1) overlay an image when the app is inactive (double tap the home button twice).
2) Remove the image when the app is active (reopen the app)
In appdelegate.h file:
#property (nonatomic, strong) UIImageView *splashScreenImageView;
In appdelegate.m file:
- (void)applicationWillResignActive:(UIApplication *)application
{
UIImage *splashScreenImage = [UIImage imageNamed:#"BackgroundScreenCaching"];
_splashScreenImageView = [[UIImageView alloc] initWithImage:splashScreenImage];
[self.window addSubview:_splashScreenImageView];
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
if(_splashScreenImageView != nil) {
[_splashScreenImageView removeFromSuperview];
_splashScreenImageView = nil;
}
}
Problem:
However, SOMETIME when pressing the home button twice, the iOS still caches the app screen with sensitive information instead of the overlay image in iOS 11. Tested no issue in iOS10.
Updated
Issue still persist after changing to this:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
BOOL result = [super application:application didFinishLaunchingWithOptions:launchOptions];
...
UIImage *splashScreenImage = [UIImage imageNamed:#"BackgroundScreenCaching"];
_splashScreenImageView = [[UIImageView alloc] initWithImage:splashScreenImage];
[_splashScreenImageView setFrame:self.window.bounds];
return result;
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
if(_splashScreenImageView != nil) {
[_splashScreenImageView removeFromSuperview];
}
}
- (void)applicationWillResignActive:(UIApplication *)application
{
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
[self.window addSubview:_splashScreenImageView];
}
I found a tricky way and it works with iOS 11 or iOS 10.
In Appdelegate.m file:
#implementation AppDelegate {
UIImageView *splashScreenImageView;
UIViewController *viewController;
}
Add this code in didFinishLaunchingWithOptions to set image and update frame
splashScreenImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height)];
splashScreenImageView.image = [UIImage imageNamed:#"BackgroundScreenCaching"];
Implement this method for getting topmost view controller
- (UIViewController *)topViewController{
return [self topViewController:[UIApplicationsharedApplication].keyWindow.rootViewController];
}
- (UIViewController *)topViewController:(UIViewController *)rootViewController
{
if (rootViewController.presentedViewController == nil) {
return rootViewController;
}
if ([rootViewController.presentedViewController isKindOfClass:[UINavigationController class]]) {
UINavigationController *navigationController = (UINavigationController *)rootViewController.presentedViewController;
UIViewController *lastViewController = [[navigationController viewControllers] lastObject];
return [self topViewController:lastViewController];
}
UIViewController *presentedViewController = (UIViewController *)rootViewController.presentedViewController;
return [self topViewController:presentedViewController];
}
Now in applicationWillResignActive method first get the top viewController and set splashScreenImageView on that view as subview
- (void)applicationWillResignActive:(UIApplication *)application {
viewController = [self topViewController];
[viewController.view addSubview:splashScreenImageView];
}
Finally in applicationDidBecomeActive when app open first remove the overlay image and open app
- (void)applicationDidBecomeActive:(UIApplication *)application {
[splashScreenImageView removeFromSuperview];
}
This tricks will work.
Your code should work fine ,
May be your app didn't get time to alloc your imageView on time when applicationWillResignActive called
and you are re-creating object every time . with [UIImageView alloc] initWithImage
So my suggestion is put this code in didFinishLaunching
UIImage *splashScreenImage = [UIImage imageNamed:#"BackgroundScreenCaching"];
_splashScreenImageView = [[UIImageView alloc] initWithImage:splashScreenImage];
and just add subview on UIWindow and remove it when applicationDidBecomeActive
Also bring _splashScreenImageView to front !!
Hope it may solve your problem
Good Luck
UPDATE
to add in main queue
dispatch_async(dispatch_get_main_queue(), ^{
[self.window addSubview:_splashScreenImageView];
[self.window bringSubviewToFront:_splashScreenImageView];
});
to remove in main queue
dispatch_async(dispatch_get_main_queue(), ^{
[_splashScreenImageView removeFromSuperview];
});
UPDATE 2
according to https://developer.apple.com/library/content/qa/qa1838/_index.html
and
https://developer.apple.com/library/content/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/StrategiesforHandlingAppStateTransitions/StrategiesforHandlingAppStateTransitions.html
Prepare for the App Snapshot
Shortly after an app delegate’s applicationDidEnterBackground: method returns, the system takes a snapshot of the app’s windows. Similarly, when an app is woken up to perform background tasks, the system may take a new snapshot to reflect any relevant changes. For example, when an app is woken to process downloaded items, the system takes a new snapshot so that can reflect any changes caused by the incorporation of the items. The system uses these snapshot images in the multitasking UI to show the state of your app.
If you make changes to your views upon entering the background, you can call the snapshotViewAfterScreenUpdates: method of your main view to force those changes to be rendered. Calling the setNeedsDisplay method on a view is ineffective for snapshots because the snapshot is taken before the next drawing cycle, thus preventing any changes from being rendered. Calling the snapshotViewAfterScreenUpdates: method with a value of YES forces an immediate update to the underlying buffers that the snapshot machinery uses.
Try to present temp view controller applicationDidEnterBackground as done in demo of Apple
I fix your bug like this:
#import "AppDelegate.h"
#interface AppDelegate () {
UIImageView *test ;
}
#end
#implementation AppDelegate
- (void)applicationDidEnterBackground:(UIApplication *)application {
UIImage *splashScreenImage = [UIImage imageNamed:#"ic_target_black"];
test = [[UIImageView alloc] initWithImage:splashScreenImage];
[self.window addSubview:test];
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
if (test) {
[test removeFromSuperview];
}
}
#end
Do this two simple steps to set your black image when double click the app and it is in recent apps list. And remove the black image when the application becomes active.
#interface AppDelegate (){
UIImageView *test ;
}
- (void)applicationWillResignActive:(UIApplication *)application {
UIImage *splashScreenImage = [UIImage imageNamed:#"ss.png"];
test = [[UIImageView alloc] initWithImage:splashScreenImage];
[self.window addSubview:test];
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
if (test) {
[test removeFromSuperview];
}
}

Getting notified when a phone call ends when app is in background

I know similar questions are asked but none of them helped.
My Observation
There are two cases: 1) When app is running and in the foreground, visible to the user 2) User presses home button and app moves to the background, not visible to the user. In case 1) when a phone call comes and end I get all the events with no problem. In case 2) I get no events, but when user opens the app, then I get all the events that has happened when app was in the background.
My Question
How can I get my code working even when app is in the background? Or, how can I move my app from background to foreground when those events happen?
What I've tried
I've tried enabling background fetch at Background Modes at Info.plist with an implementation of -(void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler. It had no effect.
Below is my code:
AppDelegate.m:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// some other code above
self.callCenter = [[CTCallCenter alloc] init];
[self.callCenter setCallEventHandler:^(CTCall *call)
{
UINavigationController *nc = (UINavigationController *) [[(AppDelegate *) [[UIApplication sharedApplication] delegate] window] rootViewController];
MainViewController *vc = nc.viewControllers[0];
[vc setCallState:call.callState];
}
}
MainViewController.m
-(void)setCallState:(NSString *)callStateString
{
if ([callStateString isEqualToString:CTCallStateConnected])
{
NSLog(#"call connected!");
} else if ([callStateString isEqualToString:CTCallStateDialing])
{
NSLog(#"call dialing!");
} else if ([callStateString isEqualToString:CTCallStateDisconnected])
{
NSLog(#"call disconnected!");
} else if ([callStateString isEqualToString:CTCallStateIncoming])
{
NSLog(#"call incoming!");
} else
{
NSLog(#"unknown call state %#", callStateString);
}
}

MMDrawerController unrecognized selector

I'm trying to setup a siderbar navigation menu for my app. I'm using the MMDrawerController lib, but I'm running into an issue. I've added a button and use these methods to call the sidebar:
-(void)setupLeftMenuButton{
MMDrawerBarButtonItem * leftDrawerButton = [[MMDrawerBarButtonItem alloc] initWithTarget:self action:#selector(leftDrawerButtonPress:)];
[self.navigationItem setLeftBarButtonItem:leftDrawerButton animated:YES];
}
-(void)leftDrawerButtonPress:(id)sender{
[self.mm_drawerController toggleDrawerSide:MMDrawerSideLeft animated:YES completion:nil];
}
I'm using a Navigation Controller with a View Controller attached in which I'm calling this method. This viewcontroller is called ViewController2.
Whenever I press the button to pull out the sidemenu, it crashes and returns this error:
* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[ViewController2 mm_drawerController]: unrecognized selector sent to instance 0x835b440'
What am I doing wrong?
edit:
AppDelegate.h
#import "AppDelegate.h"
#import "MMDrawerController.h"
#import "ViewController2.h"
#import "MMLeftSideDrawerViewController.h"
#import "MMRightSideDrawerViewController.h"
#import "MMDrawerVisualState.h"
#import "MMDrawerVisualStateManager.h"
#import <QuartzCore/QuartzCore.h>
#interface AppDelegate ()
#property (nonatomic,strong) MMDrawerController * drawerController;
#end
#implementation AppDelegate
-(BOOL)application:(UIApplication *)application willFinishLaunchingWithOptions:(NSDictionary *)launchOptions{
UIViewController * leftSideDrawerViewController = [[MMLeftSideDrawerViewController alloc] init];
UIViewController * centerViewController = [[ViewController2 alloc] init]; // MAYBE SOMETHING WRONG HERE?
UIViewController * rightSideDrawerViewController = [[MMRightSideDrawerViewController alloc] init];
UINavigationController * navigationController = [[UINavigationController alloc] initWithRootViewController:centerViewController];
[navigationController setRestorationIdentifier:#"MMCenterNavigationControllerRestorationKey"];
self.drawerController = [[MMDrawerController alloc]
initWithCenterViewController:navigationController
leftDrawerViewController:leftSideDrawerViewController
rightDrawerViewController:rightSideDrawerViewController];
[self.drawerController setRestorationIdentifier:#"MMDrawer"];
[self.drawerController setMaximumRightDrawerWidth:200.0];
[self.drawerController setOpenDrawerGestureModeMask:MMOpenDrawerGestureModeAll];
[self.drawerController setCloseDrawerGestureModeMask:MMCloseDrawerGestureModeAll];
[self.drawerController
setDrawerVisualStateBlock:^(MMDrawerController *drawerController, MMDrawerSide drawerSide, CGFloat percentVisible) {
MMDrawerControllerDrawerVisualStateBlock block;
block = [[MMDrawerVisualStateManager sharedManager]
drawerVisualStateBlockForDrawerSide:drawerSide];
if(block){
block(drawerController, drawerSide, percentVisible);
}
}];
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[self.window setRootViewController:self.drawerController];
return YES;
}
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];
return YES;
}
- (void)applicationWillResignActive:(UIApplication *)application
{
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
- (void)applicationWillEnterForeground:(UIApplication *)application
{
// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}
- (void)applicationWillTerminate:(UIApplication *)application
{
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}
- (BOOL)application:(UIApplication *)application shouldSaveApplicationState:(NSCoder *)coder{
return YES;
}
- (BOOL)application:(UIApplication *)application shouldRestoreApplicationState:(NSCoder *)coder{
return YES;
}
- (UIViewController *)application:(UIApplication *)application viewControllerWithRestorationIdentifierPath:(NSArray *)identifierComponents coder:(NSCoder *)coder
{
NSString * key = [identifierComponents lastObject];
if([key isEqualToString:#"MMDrawer"]){
return self.window.rootViewController;
}
else if ([key isEqualToString:#"MMCenterNavigationControllerRestorationKey"]) {
return ((MMDrawerController *)self.window.rootViewController).centerViewController;
}
else if ([key isEqualToString:#"MMLeftSideDrawerController"]){
return ((MMDrawerController *)self.window.rootViewController).leftDrawerViewController;
}
else if ([key isEqualToString:#"MMRightSideDrawerController"]){
return ((MMDrawerController *)self.window.rootViewController).rightDrawerViewController;
}
return nil;
}
#end
Take a look at the example have you tried something like in case you are using navigation
(or swapping view in case you are not)
[(UINavigationController*)self.mm_drawerController.centerViewController pushViewController: animated:YES];

open a new view inside app delegate

the app delegate.h file is as follows
#import <UIKit/UIKit.h>
#class AFAViewController;
#class OpenInChromeController;
#class AFABarcodeScanner;
#interface AFAAppDelegate : NSObject <UIApplicationDelegate,UIAlertViewDelegate>
{
OpenInChromeController *openInChromeController_;
AFABarcodeScanner *bs;
}
#property (strong, nonatomic) UIWindow *window;
#property (strong, nonatomic)AFAViewController *viewController;
#property(strong,nonatomic)AFABarcodeScanner *bs;
#end
the app delegate.m file is as follows
#import "AFAAppDelegate.h"
#import "AFAViewController.h"
#import "OpenInChromeController.h"
#import "AFABarcodeScanner.h"
#implementation AFAAppDelegate
#synthesize bs;
#synthesize window;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone)
{
self.viewController = [[AFAViewController alloc] initWithNibName:#"AFAViewController_iPhone" bundle:nil];
}
else
{
self.viewController = [[AFAViewController alloc] initWithNibName:#"AFAViewController_iPad" bundle:nil];
}
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
return YES;
}
- (void)applicationWillResignActive:(UIApplication *)application
{
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
- (void)applicationWillEnterForeground:(UIApplication *)application
{
// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}
- (void)applicationWillTerminate:(UIApplication *)application
{
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}
-(void)actionSheet:(UIActionSheet *)actionSheet clickedButtonAtIndex:(NSInteger)buttonIndex
{
if (buttonIndex == 0)
{
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:
#"itms-apps://itunes.apple.com/us/app/chrome/id535886823"]];
}
}
- (BOOL)application:(UIApplication *)application openURL:(NSURL *)url sourceApplication:(NSString *)sourceApplication annotation:(id)annotation
{
UIAlertView *alertView;
alertView = [[UIAlertView alloc] initWithTitle:#"Error" message:#"inside open url" delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alertView show];
AFABarcodeScanner *vc = [[AFABarcodeScanner alloc] initWithNibName:#"AFABarcodeScanner" bundle:nil];
[self.view addSubview:vc.view];
return YES;
}
#end
i would like open the new view inside the custom url function. When the request is obtained from external web page the view inside the application delegate must be opened.
There are couple of ways to achieve it:
First: AppDelegate has a property window. A window is a view, so you can do
[self.window addSubview:newView];
Second: a view controller can reach the window without dealing with the app delegate.
[controller.view addSubview:overlayView];
Get the instance of the AFAViewController(self.viewController) and add the subview to this view or else present AFABarcodeScanner as model if possible

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