tags:

views:

64

answers:

3
Q: 

Compare the value of a variable at intervals

Hey I have a problem comparing the value of a CGPoint (struct with two ints: x and y) with another at certain time intervals.

One is called location and has the value of where the cursor is. Every half a second or so, I want to see if it changed. How do I do this? The language is Objective-C (so C++/C stuff should work)

A: 

As noted in the CGGeometry docs, Apple provides a function, CGPointEqualToPoint(), for doing just this. You would have a CGPoint variable that stores the old value and compare it to the new value you get.

Chuck  2009-09-02 17:34:30
Yes, but I'm wondering how to temporarily store the value of a CGPoint and compare it later.
 2009-09-02 17:37:54
A: 

Take a look at the NSTimer documentation. It does what you want.

Cinder6  2009-09-02 17:52:59
I'm using that. The problem is storing the value of the touch location and not updating it.
 2009-09-02 17:54:42
+1  A: 

What are you trying to do with this? Would it make more sense to use Key Value Observing to observe when one or both values change?

Martin Gordon  2009-09-02 18:04:31
I'm trying to check when the user keeps his finger at the same spot, and only increment a variable ticks when the finger has moved.
 2009-09-02 18:07:10
The four touches*:withEvent: methods of UIResponder should help you, particularly touchesMoved:withEvent:
Martin Gordon  2009-09-02 18:11:06
Wow...I was even using those functions. Just had to put ticks += 10 in the touchesMoved:withEvent one. I feel stupid...
 2009-09-02 18:23:29

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