Question

I am trying to loop through and programmatically make a grid of 256 NSButtons (16×16). The code I have so far is below. This is in Objective-C for my Mac app. So I am logging to see which tag I get when I click a button, but it keep returning the same tag every time.

I want it so that every button goes 1-256 from left to right, top to bottom. This code successfully makes them load into my view, but the tags are wrong.

    #define N_ROWS  16
    #define N_COLS  16
    int btnSpaceDifference = 1;
    int btnSpacing = N_ROWS + btnSpaceDifference;

    for (int j = 0; j < N_ROWS; j++) {

        for (int i = 0; i < N_COLS; i++) {
            paintPixel = [[[NSButton alloc] initWithFrame:NSMakeRect(10 + (i * btnSpacing), 10 + (j * btnSpacing), 16, 16)] autorelease];
            [paintPixel setTitle:@""];
            [paintPixel setBezelStyle:NSBorderlessWindowMask];
            [paintPixel setTag:j + i * N_ROWS + 1];
            [paintPixel setAction:@selector(btnPaintAction:)];
            [[[box.tabViewItems objectAtIndex:0]view] addSubview:paintPixel];
        }
    }

-(void)btnPaintAction:(id)sender{
    NSLog(@"%ld", paintPixel.tag);
}

Answer 1

Not sure how its compiling, you might have paintPixel defined elsewhere. But you need to change your btnPaintAction from:

-(void)btnPaintAction:(id)sender {
     NSLog(@"%ld", paintPixel.tag);
}

To something like this:

-(void)btnPaintAction:(id)sender {
     NSButton * myButton = (NSButton *) sender;
     NSLog(@"%ld", myButton.tag);
}