Cocoa NSView: Making circles but they are getting cropped - cocoa

Question

the outer edges of my circle at each point of the compass are getting cropped (presumably by the rect frame). How do I get the circle to display within the frame? (This is getting created from a button click):
In my AppController.m
#import "AppController.h"
#import "MakeCircle.h"
#implementation AppController
- (IBAction)makeCircle:(id)sender {
MakeCircle* newCircle = [[MakeCircle alloc] initWithFrame:NSMakeRect(100.0, 100.0, 30.0, 30.0)];
[[[[NSApplication sharedApplication] mainWindow] contentView] addSubview:newCircle];
[newCircle release];
}
#end
In my MakeCircle.m
- (void)drawRect:(NSRect)rect {
[self setNeedsDisplay:YES];
[[NSColor blackColor] setStroke];
// Create our circle path
NSBezierPath* circlePath = [NSBezierPath bezierPath];
[circlePath appendBezierPathWithOvalInRect: rect];
//give the line some thickness
[circlePath setLineWidth:4];
// Outline and fill the path
[circlePath stroke];
}
Thanks.

Answer 1

I think you see only half of the edge, right? You can calculate the half of the thickness of the edge and subtract that from the rectangle:
#define STROKE_COLOR ([NSColor blackColor])
#define STROKE_WIDTH (4.0)
- (void)drawRect:(NSRect)dirtyRect {
NSBezierPath *path;
NSRect rectangle;
/* Calculate rectangle */
rectangle = [self bounds];
rectangle.origin.x += STROKE_WIDTH / 2.0;
rectangle.origin.y += STROKE_WIDTH / 2.0;
rectangle.size.width -= STROKE_WIDTH / 2.0;
rectangle.size.height -= STROKE_WIDTH / 2.0;
path = [NSBezierPath path];
[path appendBezierPathWithOvalInRect:rectangle];
[path setLineWidth:STROKE_WIDTH];
[STROKE_COLOR setStroke];
[path stroke];
}
I have no Mac at the moment, so I can't test it, but I think it should solve your problem.
Als don't call [self setNeedsDisplay:YES]. The method is used when you want to redraw your whole NSView, and calling it from the drawing method is a little bit recursive. That's why I'm surprised your code actually draws something.
And I have another tip: [[NSApplication sharedApplication] mainWindow] is actually the same as [NSApp mainWindow]. NSApp is a global variable containing the main application.
Hope it helps,
ief2