Define CGRectmake with CGPoint and/or CGSize

12,950

Solution 1

I think this is what you have in mind:

    - (void) logRects
    {
        CGFloat
            x      = 10.0,
            y      = 20.0,
            width  = 50.0,
            height = 60.0;

        CGPoint point = {x, y};
        CGSize  size  = {width, height};

        CGRect  rect1 = {1, 3, size};
        CGRect  rect2 = {point, size};
        CGRect  rect3 = {point, size.width, size.height};

            //using designated (named) initialisers
        CGRect  rect4 = {.origin.x=3, .origin.y=5, .size = {100,100}};

            //with designated initialisers, order doesn't matter
        CGRect  rect5 = {.size=size, .origin.x=3, .origin.y=5};

        NSLog (@"rect1 %@",NSStringFromCGRect(rect1));
        NSLog (@"rect2 %@",NSStringFromCGRect(rect2));
        NSLog (@"rect3 %@",NSStringFromCGRect(rect3));
        NSLog (@"rect4 %@",NSStringFromCGRect(rect4));
        NSLog (@"rect5 %@",NSStringFromCGRect(rect5));
    }

But note the discussion here:
Why use functions like CGRectMake?

This kind of compound literal syntax seems to me much easier to read and write, although functions have the edge when it comes to futureproofing ( + you get autocomplete).

update
see also this more recent q&a:

CGRect syntax I haven't seen before

Solution 2

CGRectMake(1, 3, size):

    CGRectMake(1, 3, size.width, size.heigh)

CGRectMake(pointB, size):

    CGRectMake(pointB.x, pointB.y, size.width, size.height)

CGRectMake(pointB, size.width, size.height):

    CGRectMake(pointB.x, pointB.y, size.width, size.height)

A CGRect just looks like this:

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

And CGPoint and CGSize just look like this:

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

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

CGRectMake is the following function:

CG_INLINE CGRect
CGRectMake(CGFloat x, CGFloat y, CGFloat width, CGFloat height)
{
  CGRect rect;
  rect.origin.x = x; 
  rect.origin.y = y;
  rect.size.width = width; 
  rect.size.height = height;
  return rect;
}

So instead of:

CGRect r = CGRectMake(pointB.x, pointB.y, size.width, size.height)

You can simply write:

CGRect r;

r.origin = pointB;
r.size = size;

If you feel like creating your own CGRectMake, feel free to do so:

CG_INLINE CGRect
MyPrivateCGRectMake(CGPoint p, CGSize s)
{
  CGRect rect;
  rect.origin = p;
  rect.size = s;
  return rect;
}

But there is no way you can change which arguments an already existing function accepts.

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Updated on June 04, 2022

Comments

  • Plot
    Plot almost 2 years

    This is a very simple question of which i can't seem to find the answer. How to do this :

    CGRectMake(1, 3, size) 
    

    or

    CGRectMake(pointB, size) 
    

    or

     CGRectMake(pointB, size.width, size.height) 
    

    instead of

    CGRectMake(self.someview.frame.origin.x, self.someview.frame.origin.y, self.someotherview.frame.size.width, self.someotherview.frame.size.height) 
    

    ?? Thank you ! :)

    EDIT:

    The method CGRectmake takes CGFloat. I would like it to take CGSize, and/or CGpoint as arguments of the method.