Question

    #import "DotAnimation.h"


@implementation DotAnimation
DoodlePad* dp;

-(void)setupView {
    Ball = CGRectMake(10, 10, 10, 10);
    [NSTimer scheduledTimerWithTimeInterval:(1.0f / 30.0f) target:self selector:@selector(traceBall) userInfo:nil repeats:YES];
}

-(id)initWithCoder:(NSCoder *)aDecoder {
    if (self == [super initWithCoder:aDecoder]){
        [self setupView];
    }
    return self;
}

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [self setupView];
    }
    return self;
}


/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.*/
- (void)drawRect:(CGRect)rect {
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [[UIColor yellowColor] CGColor]);
    CGContextFillEllipseInRect(context, Ball);

}
-(void)traceBall{
    vector<CGPoint>::iterator L = dp.doodlePoints->begin();
    while(L != dp.doodlePoints->end()){
        Ball.origin.x += (*L).x;
        Ball.origin.y += (*L).y;
        ++L;
    }
    [self setNeedsDisplay];
}

- (void)dealloc
{
    [super dealloc];
}

@end

I have this Animation I am trying to use in another file.
So i figure i do something like

trace = [[DotAnimation alloc]initWithCoder];

or

trace = [[DotAnimation alloc]initWithFrame];

I am unsure which one to use or if i am even writing this correctly.

I want to be able to use:

    while(k != dp.doodlePoints->end()){
    Ball.origin.x += (*k).x;
    Ball.origin.y += (*k).y;
    ++k;
}

In another file but I don’t know how to call Ball.origin from DotAnimation

Also it would be great if you could link me to good information on understanding this.

Answer 1

initWithCoder is called by the framework when you embed an object into a XIB. Like a ViewController for example. So you should not call it by yourself.

Calling initWithFrame could be a better solution if you want to set the frame (like that seems to be done here). But you may give a frame, and add a subview created by yourself.

if you don’t want to create the subview by yourself, then it’s initWithNibName:bundle: that you may call/override. Creating the XIB that contains the view. But you will still need to add that view as subview to the main view that is showing that animated view.