Purpose

GameTimer is a light-weight timer that you can use for iOS games. It can be enhanced easily for more complex projects. One use is to update a progressbar whilst the main timer is running.

GameTimer incorporates 2 timers that work in unison - referred to as longTimer and shortTimer. The shortTimer acts as a 'finer' resolution timer that can be used to update a progressbar or continually poll a network connection (for example). It's interval is usually set to a fraction of the longTimer.

GameTimer automatically pauses when the app enters the BACKGROUND and 'unpauses' when the app is ACTIVE again.

Supported OS & SDK Versions

• Supported build target - iOS 7.0
• Earliest supported deployment target - iOS 6.0

ARC Compatibility

GameTimer requires ARC.

If you wish to convert your whole project to ARC, then run the Edit > Refactor > Convert to Objective-C ARC... tool in Xcode and make sure all files that you wish to use ARC for are checked.

Thread Safety

The stopTimer method must be called from the same thread that called the startTimer method.

Installation

To install GameTimer into your app, drag the GameTimer.h and GameTimer.m files into your project.

Add:

#import "GameTimer.h"

to the top of any class (*.h or *.m) that will use GameTimer.

Make sure the class conforms to the GameTimerDelegate protocol:

Modify .h file:

@interface ViewController : UIViewController <GameTimerDelegate>

Implement Protocol methods such as:

-(void)longTimerExpired: (GameTimer *)gameTimer
{
    //Time is up
}

Declare a instance variable/property:

@property (strong, nonatomic) GameTimer *gameTimer;

Initialise the timer in a method such as viewDidLoad:

self.gameTimer = [[GameTimer alloc] initWithLongInterval:2*60 andShortInterval:5 andDelegate:self]; //2 minute timer with short intervals of 5 seconds

Start the timer when you want to start:

[self.gameTimer startTimer];

Stop the timer prematurely if required:

[self.gameTimer stopTimer];

Properties

The 'finer' resolution timer duration. This must be less than longInterval. The behaviour of GameTimer is unpredictable otherwise. The units are in seconds. It can be as small as 0.1 milliseconds.

@property float shortInterval;

The overall timer duration. When this timer expires, then GameTimer deactivates by itself. It automatically cleans it's memory after deactivating the shortTimer and longTimer. The units are in seconds. It can be as small as 0.1 milliseconds.

@property float longInterval;

The amount of time in seconds since GameTimer was started, excluding when the app enters the BACKGROUND state.

@property (nonatomic, readonly) float time;

The delegate must respond to longTimerExpired: method. This is mandatory. It is called when the longTimer expires.

@property(nonatomic, weak) IBOutlet id <GameTimerDelegate> delegate;

Methods

This method is used to initialise GameTimer. GameTimer MUST NOT be initialised using init: Initialising GameTimer does not automatically begin the timer.

An example:

self.gameTimer = [[GameTimer alloc] initWithLongInterval:2*60 andShortInterval:0.5 andDelegate:self];

The above example will create a GameTimer with a longInterval of 120 seconds. It will fire the shortTimerExpired: method every 0.5 seconds.

Always allocate GameTimer to the instance variable ONCE (such as in viewDidLoad method). If you need to change the settings, stop the timer and then do so using the properties i.e.

[self.gameTimer stop];
self.gameTimer.longInterval = 3*60; //change settings
[self.gameTimer start]; //then start the timer

If you need to deallocate GameTimer, then stop GameTimer first. i.e.

[self.gameTimer stop];
self.gameTimer = nil;

Class Initializer.

- (id)initWithLongInterval:(float)longInterval andShortInterval: (float)shortInterval 
andDelegate:(id <GameTimerDelegate>) delegate;

Stops the timer. This MUST be called from the same thread that called the startTimer method.

- (void) stopTimer;

Restarts the timer.

- (void) startTimer;

Pauses the timer

-(void)pauseTime;

Unpauses the timer

-(void)unPauseTime;

Delegate methods

This method is fired when the longTimer expires. GameTimer will stop at this point. You will need to call the startTimer method to restart the timer. It is mandatory for the delegate to implement this.

-(void)longTimerExpired: (GameTimer *)gameTimer;

This method is fired when the shortTimer expires. It will continue to fire until the longTimer expires, at which point GameTimer will stop. It is optional for the delegate to implement this. In order to update a progressbar, this method should be implemented and used in conjunction with the time value and the longInterval value. The method is not expected to fire at precise moments. It is only for tasks such as updating, polling etc.

-(void)shortTimerExpired: (GameTimer *)gameTimer time: (float)time longInterval: (float)longInterval;

Example Projects

The example project will demonstrate how to use the basic features of the class. It will update a progressbar. Obviously it can be extended to your game engine for example. Imagination is the key.

Known Issues

WARNING: If the reference to the newly created gameTimer is changed to point to a brand new [GameTimer alloc], then you must call the stopTimer method before reallocating. This is because NSRunLoop keeps a strong reference.

An example (CORRECT WAY - EVEN THOUGH I RECOMMEND NEVER REALLOCATING):

  self.gameTimer = [[GameTimer alloc] initWithLongInterval:2*60 andShortInterval:0.5 andDelegate:self]; //First allocation
  [self.gameTimer stop];
  self.gameTimer = [[GameTimer alloc] initWithLongInterval:5 andShortInterval:2 andDelegate:self]; //Second NEW allocation

Any Questions

Feel Free to suggest improvements, fork, report bugs or ask any questions.

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