Custom Views(Chapter 17 of Cocoa Programming for Mac OS X)

#import "StretchView.h"


@implementation StretchView

- (id)initWithFrame:(NSRect)rect
{
    if (![super initWithFrame:rect]) 
    {
        return nil;
    }
    
    srandom(time(NULL));
    
    path = [[NSBezierPath alloc] init];
    [path setLineWidth:3.0];
    NSPoint p = [self randomPoint];
    [path moveToPoint:p];
    int i;
    for(i=0;i<15;i++)
    {
        p = [self randomPoint];
        [path lineToPoint:p];
    }
    [path closePath];
    return self;
}

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

- (NSPoint)randomPoint
{
    NSPoint result;
    NSRect r = [self bounds];
    result.x = r.origin.x + random() % (int)r.size.width;
    result.y = r.origin.y + random() % (int)r.size.height;
    return result;
}

- (void)drawRect:(NSRect)dirtyRect
{
    NSRect bounds = [self bounds];
    [[NSColor greenColor] set];
    [NSBezierPath fillRect:bounds];
    
    [[NSColor whiteColor] set];
    [path stroke];
}

@end