Question

In Cocoa Programming for Mac OS X (Hillegass), there is a class in chapter 19:

@interface BigLetterView : NSView {
NSColor *bgColor;
}
@property (strong) NSColor *bgColor;
@end

The accessor is defined like this:

- (void)setBgColor:(NSColor *)c {
bgColor = c;
[self setNeedsDisplay:YES]; }

This looked correct to me, but it creates an infinite loop: bgColor = c calls setBgColor:c

Is this code correct ?

How to redefine a setter? What do I need to compile this code ?

Answer 1

In modern Xcode/llvm you can clean up your code a bit.

Namely you dont need to declare neither a member variable as backing variable, nor a synthesize statement.

If you dont declase synthesize your self, a property foo will have the backing variable _foo

So this code should work

@interface BigLetterView : NSView 
@property (nonatomic, strong) NSColor *bgColor;
@end

@implementation BigLetterView
@synthesize bgColor = _bgColor;

- (void)setBgColor:(NSColor *)c 
{
    _bgColor = c;
    [self setNeedsDisplay:YES]; 
}
@end