Question

Given that drawRect takes a CGRect ‘rect’, how can I create 4 separate CGFloat variables with the individual values of rect (x,y,width,height)? I need to use the variables on an individual basis to determine certain drawing scales within the drawRect method.

- (void)drawRect:(CGRect)rect {
 CGFLoat x = ***x value of rect***;
 CGFLoat y = ***y value of rect***;
 CGFloat width = ***width value of rect***;
 CGFloat height = ***height value of rect***;
 }

Thanks in advance for your help!

Answer 1

I’d suggest you brush up on some basic C materials as the question is pretty basic C structure stuff (no big deal — we were all there once).

Given:

struct CGPoint {
  CGFloat x;
  CGFloat y;
};
typedef struct CGPoint CGPoint;

/* Sizes. */

struct CGSize {
  CGFloat width;
  CGFloat height;
};
typedef struct CGSize CGSize;

/* Rectangles. */

struct CGRect {
  CGPoint origin;
  CGSize size;
};
typedef struct CGRect CGRect;

You want:
– (void)drawRect:(CGRect)rect {
CGFLoat x = rect.origin.x;
CGFLoat y = rect.origin.y;
CGFloat width = rect.size.width;
CGFloat height = rect.size.height;
}

Or, better yet, because there are functions for such madness:

- (void)drawRect:(CGRect)rect {
     CGFLoat x = CGRectGetMinX(rect);
     CGFLoat y = CGRectGetMinY(rect);
     CGFloat width = CGRectGetWidth(rect);
     CGFloat height = CGRectGetHeight(rect);
 }