cocoa - Copies of NSRects not displaying -

i trying make simple cocoa program. have little black box (a subclass of nsview drawing nsrect on screen) following mouse around. part have working. need is: when click mouse want leave "copy" of black box behind.

i have been trying work on 5 hours , have tried under sun. sure solution simple, guess missing grasping of fundamental concepts.

here have (a "stay" supposed copy stays behind):

@property nsmutablearray *stays;  ...  - (void) makestay {     if (!_stays)         _stays = [[nsmutablearray alloc]init];      nsvalue *newstay = [nsvalue valuewithrect:self.frame];     [_stays addobject:newstay]; }  ...   -(void)drawrect:(nsrect)rect {     [[nscolor blackcolor] set];     nsrectfill([self bounds]);      (int x = 0; x < _stays.count; x++) {         nsrectfill([_stays[x] rectvalue]);     } } 

any on how understand fundamentals of nsview work appreciated!

from code i'm guessing problem bounds.

it looks have nsview moving around screen - it's frame location in superview , saving in makestay.

in drawrect fill view's bounds - in view coordinates. try fill "stays", these in superview coordinates treated view coordinates , undoubtedly outside of bounds of view , clipped.

try instead having "board" view filling window, , box view subview of that. board view should keep , draw list of "stays", "box" view when clicked should add current frame board views list. stays in bounds of board.

hth.