gistfile1.m

        [NSAnimationContext beginGrouping];
        [[NSAnimationContext currentContext] setDuration:0.25];
        [[NSAnimationContext currentContext] setTimingFunction:kCAMediaTimingFunctionEaseOut]; 
        
        [[[popoverWindow contentView] animator] setAlphaValue:1.0];
        [[popoverWindow animator] setAlphaValue:1.0];
        [[popoverWindow animator] setFrame:newFrame display:YES];
        
        [NSAnimationContext endGrouping];