how to set up device's lock time manually for iOS - ios

Question

i know in iOS, if you leave your device idle for 45 seconds, the screen will become dim, if idle for another 15 seconds, the device will be locked automatically.
and we can disable the auto lock by
[UIApplication sharedApplication].idleTimerDisabled = YES
however, i do want this feature, just want to make it longer, is there any method (no jailbreak) that i can manually setup this timer?
thanks

Answer 1

You can achieve this to an extent by monitoring the user's interaction with your app (touch events) and setting [UIApplication sharedApplication].idleTimerDisabled = NO; when a custom idle timer expires.
You can learn more about monitoring events on this blog. However I've outlined the steps below with code updates for ARC.
A bit of background on what is possible after testing this. Apple's internal idle timer runs regardless if idleTimerDisabled = YES; is set. What this means is that if the user has not interacted with the phone past the Auto-Lock setting (i.e. 1 minute) when idleTimerDisabled = NO; is set the device will half dim immediately and turn off completely after 15 seconds. So what we can do is disable idleTimer, and manually create a new timer which waits x minutes before enabling the idleTimer again.
This will effectively allow you to increase the Auto-Lock time. I don't think you can decrease it (i.e. user has Auto-Lock Never, and you want to lock the device after a minute).
With the following code (assuming you have Auto-Lock set to 1 minute) the app will stay awake for 2 minutes, after which we set idleTimerDisabled = NO; dimming the app for 15 seconds before it turns off.
Add the following two files to your project (original source here):
ELCUIApplication.h
//
// ELCUIApplication.h
//
// Created by Brandon Trebitowski on 9/19/11.
// Copyright 2011 ELC Technologies. All rights reserved.
//
#import <Foundation/Foundation.h>
// # of minutes before application times out
#define kApplicationTimeoutInMinutes 2
// Notification that gets sent when the timeout occurs
#define kApplicationDidTimeoutNotification #"ApplicationDidTimeout"
/**
* This is a subclass of UIApplication with the sendEvent: method
* overridden in order to catch all touch events.
*/
#interface ELCUIApplication : UIApplication {
NSTimer *_idleTimer;
}
/**
* Resets the idle timer to its initial state. This method gets called
* every time there is a touch on the screen. It should also be called
* when the user correctly enters their pin to access the application.
*/
- (void)resetIdleTimer;
#end
ELCUIApplication.m
//
// ELCUIApplication.m
//
// Created by Brandon Trebitowski on 9/19/11.
// Copyright 2011 ELC Technologies. All rights reserved.
//
#import "ELCUIApplication.h"
#implementation ELCUIApplication
- (void)sendEvent:(UIEvent *)event {
[super sendEvent:event];
// Fire up the timer upon first event
if(!_idleTimer) {
[self resetIdleTimer];
}
// Check to see if there was a touch event
NSSet *allTouches = [event allTouches];
if ([allTouches count] > 0) {
UITouchPhase phase = ((UITouch *)[allTouches anyObject]).phase;
if (phase == UITouchPhaseBegan) {
[self resetIdleTimer];
}
}
}
- (void)resetIdleTimer {
if (_idleTimer) {
[_idleTimer invalidate];
// [_idleTimer release];
}
// Schedule a timer to fire in kApplicationTimeoutInMinutes * 60
float timeout = kApplicationTimeoutInMinutes * 60;
_idleTimer = [NSTimer scheduledTimerWithTimeInterval:timeout
target:self
selector:#selector(idleTimerExceeded)
userInfo:nil
repeats:NO];
}
- (void)idleTimerExceeded {
/* Post a notification so anyone who subscribes to it can be notified when
* the application times out */
[[NSNotificationCenter defaultCenter]
postNotificationName:kApplicationDidTimeoutNotification object:nil];
}
//- (void) dealloc {
// [_idleTimer release];
// [super dealloc];
//}
#end
In your Supporting Files folder open up main.m, update the following:
#import <UIKit/UIKit.h>
#import "AppDelegate.h"
int main(int argc, char *argv[])
{
#autoreleasepool {
return UIApplicationMain(argc, argv, #"ELCUIApplication", NSStringFromClass([AppDelegate class]));
}
}
In AppDelegate.m edit the didFinishLaunchingWithOptions: method and add the applicationDidTimeout: method.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.
[UIApplication sharedApplication].idleTimerDisabled = YES;
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(applicationDidTimeout:)
name:kApplicationDidTimeoutNotification object:nil];
return YES;
}
- (void) applicationDidTimeout:(NSNotification *) notif {
NSLog(#"applicationDidTimeout");
[UIApplication sharedApplication].idleTimerDisabled = NO;
}