NSRect frame = [(NSButton *)sender frame];
NSPoint menuOrigin = [[(NSButton *)sender superview] convertPoint:NSMakePoint(frame.origin.x, frame.origin.y+frame.size.height+40)
toView:nil];
NSEvent *event = [NSEvent mouseEventWithType:NSLeftMouseDown
location:menuOrigin
modifierFlags:NSLeftMouseDownMask // 0x100
timestamp:nil
windowNumber:[[(NSButton *)sender window] windowNumber]
context:[[(NSButton *)sender window] graphicsContext]
eventNumber:0
clickCount:1
pressure:1];
NSMenu *menu = [[NSMenu alloc] init];
[menu insertItemWithTitle:@"add"
action:@selector(add:)
keyEquivalent:@""
atIndex:0];
[NSMenu popUpContextMenu:menu withEvent:event forView:(NSButton *)sender];
