Change NSTimer interval for repeating timer.

Question

Hi,

I am running a mainLoop in Cocoa using an NSTimer set up like this:

        mainLoopTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/fps target:self selector:@selector(mainloop) userInfo:nil repeats:YES];
    [[NSRunLoop currentRunLoop] addTimer:mainLoopTimer forMode:NSEventTrackingRunLoopMode];

At Program startup I set the timeInterval to 0.0 so that the mainloop runs as fast as possible. Anyways, I would like to provide a function to set the framerate(and thus the time interval of the timer) to a specific value at runtime. Unfortunately as far as I know that means that I have to reinitialize the timer since Cocoa does not provide a function like "setTimerInterval" This is what I tried:

    - (void)setFrameRate:(float)aFps
{
    NSLog(@"setFrameRate");
    [mainLoopTimer invalidate];
    mainLoopTimer = nil;

    mainLoopTimer = [NSTimer scheduledTimerWithTimeInterval:1.0/aFps target:self selector:@selector(mainloop) userInfo:nil repeats:YES];
    [[NSRunLoop currentRunLoop] addTimer:mainLoopTimer forMode:NSEventTrackingRunLoopMode];
}

but this throws the following error and stops the mainloop:

2010-06-09 11:14:15.868 myTarget[7313:a0f] setFrameRate 2010-06-09 11:14:15.868 myTarget[7313:a0f] * __NSAutoreleaseNoPool(): Object 0x40cd80 of class __NSCFDate autoreleased with no pool in place - just leaking 2010-06-09 11:14:15.869 myTarget[7313:a0f] * __NSAutoreleaseNoPool(): Object 0x40e700 of class NSCFTimer autoreleased with no pool in place - just leaking 0.614628

I also tried to recreate the timer using the "retain" keyword, but that didn't change anything. Any ideas about how to dynamically change the interval of an NSTimer at runtime?

Thanks!

Answer 1

You can try un-register previous timer and start new one with different frequency. you can un-register by

[yourOldTimer invalidate];
yourOldTimer = nil;

This might solve the purpose.