Draw line between two moveable circles in objective-c (iPad) - ios

Question

I'm new to objective-c and am trying to draw a line between moveable circles in Objective-c. I already have code that generates circles. Here is an image that I'd like to create in my app.
http://images.sciencedaily.com/2004/04/040407083832.jpg
Here's my code.
CircleViewController.m
- (void)viewDidLoad
{
[super viewDidLoad];
for (int i=0; i<5; i++) {
CGRect circleFrame = CGRectMake(arc4random() % 500, arc4random() % 500, (arc4random() % 200)+50 , (arc4random() % 200)+50);
CircleView *cirleView = [[CircleView alloc] initWithFrame: circleFrame];
cirleView.backgroundColor = [UIColor clearColor];
CGFloat hue = ( arc4random() % 256 / 256.0 ); // 0.0 to 1.0
CGFloat saturation = ( arc4random() % 128 / 256.0 ) + 0.5; // 0.5 to 1.0, away from white
CGFloat brightness = ( arc4random() % 128 / 256.0 ) + 0.5; // 0.5 to 1.0, away from black
UIColor *color = [UIColor colorWithHue:hue saturation:saturation brightness:brightness alpha:1];
cirleView.circleColor = color;
[self.view addSubview:cirleView];
}
}
CircleView.m
-(void) drawCircle:(CGPoint)p withRadius:(CGFloat)radius inContext:(CGContextRef)contex
{
UIGraphicsPushContext(contex);
CGContextBeginPath(contex);
CGContextAddArc(contex, p.x, p.y, radius, 0, 2*M_PI, YES);
CGContextSetLineWidth(contex, 2.0);
CGContextAddLineToPoint(contex, p.x, p.y);
CGContextDrawPath(contex, kCGPathFillStroke);
UIGraphicsPopContext();
}
- (void)drawRect:(CGRect)rect
{
CGFloat size = self.bounds.size.width/2;
if(self.bounds.size.height < self.bounds.size.width) size = self.bounds.size.height / 2;
size *= 0.90;
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 5.0);
[_circleColor setStroke];
[_circleColor setFill];
CGPoint point1;
point1.x = self.bounds.origin.x + self.bounds.size.width/2;
point1.y = self.bounds.origin.y + self.bounds.size.height/2;
[self drawCircle:point1 withRadius:size inContext:context];
UITapGestureRecognizer *singleFingerTap =
[[UITapGestureRecognizer alloc] initWithTarget:self
action:#selector(handleSingleTap:)];
[self addGestureRecognizer:singleFingerTap];
}
Thank you for your help.

Answer 1

Drawing a line:
-(void) drawLine (CGRect circleViewRect1, CGRect circleViewRect2)
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetStrokeColorWithColor(context, [UIColor blackColor].CGColor);
//line width
CGContextSetLineWidth(context, 1.0);
CGContextMoveToPoint(context, circleViewRect1.center.x + circleViewRect1.bounds.width/2,circleViewRect1.center.y + circleViewRect1.bounds.height/2); //start from first circle radius
CGContextAddLineToPoint(context, circleViewRect2.center.x + circleViewRect2.bounds.width/2,circleViewRect2.center.y + circleViewRect2.bounds.height/2); //draw to this point
// and now draw the Path!
CGContextStrokePath(context);
}
Note:This is only useful if two circle's centers fall in horizontal line. Also, assume that circleViewRect1 is at the left of circleViewRect2. You must figure out the values for other use cases ie if they are at positioned at different angles etc.