My code needs to check on a sensor value until it becomes 1 or the code reach the time out. Hence I am thinking of such an infinite loop.
The sensor is a singleton object that has access to sensor value at real-time. The default value is 0 and I want to monitor for the value change to 1.
for (;;) {
int sensorVal = [sensor getVal];
if (sensorVal == 1) break;
if (timeout) break;
}
But the problem is that I don't want to have an infinite loop in my code. I am wondering if there is a better way to write this in Objective-C?
You can achieve this with using the KVO (key Value observation).
Observe for changes that you want:
[sensor addObserver:self forKeyPath:@"val" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil];//observing the key in this class
Then use this delegate method:
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if([keyPath isEqualToString:@"val"]) {
/* Do the work here */
}
}
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