Setting up a power meter in cocos2d

I am a straight noob. Everyone else says it, but I'm dead serious.

My question is, what is the best way to make a power meter to move a o开发者_如何转开发bject? Meaning, how to set it up so that the longer the player holds the more power they get. Also how, would I incorporate physics?

What I'd like to accomplish is to have a player holding onto something so that when he taps on the screen and hold he powers up, and when he lets go he throws the object a certain distance.

just checking if the there is any thouch sequence or not is rather an easy thing, you just have to overload two functions for your scene class, one to inform you whenever a touch sequence begins and one to tell you touch is ended. the source code example is describe in this link. after than i think you need a gauge to show how much power is gathered so far, the easiest way is to use a texture with full power shown in it and the set it as texture and then show it little by little as the power goes up just as the code below:

// to create the gauge with zero power
CCSprite *s=[CCSprite spriteWithTexture:[CCTextureCache addImage:@"gauge.png"] rect:CGRectMake(0,0,0,10)];
// and then whenever the power changes you call this method
[s setTextureRect:CGRectmake(0,0,power,10)]

note that in my code i am using a 100x10 texture (power is somthing between 0..100 and texture height is 10 as the last parameter in both CGRectMake functions)