NSWindow with round corners and shadow

Question

I\'m trying to crate a NSWindow without title bar (NSBorderlessWindowMask) with round corners and a shadow, similar to the below \"Welcome

Answer 1

As the Apple Developer Documentation perfectly points out:

When adding shadows to a layer, the shadow is part of the layer’s content but actually extends outside the layer’s bounds rectangle. As a result, if you enable the masksToBounds property for the layer, the shadow effect is clipped around the edges. If your layer contains any transparent content, this can cause an odd effect where the portion of the shadow directly under your layer is still visible but the part extending beyond your layer is not. If you want a shadow but also want to use bounds masking, you use two layers instead of one. Apply the mask to the layer containing your content and then embed that layer inside a second layer of the exact same size that has the shadow effect enabled.

Full Article: https://developer.apple.com/library/mac/documentation/cocoa/conceptual/coreanimation_guide/SettingUpLayerObjects/SettingUpLayerObjects.html#//apple_ref/doc/uid/TP40004514-CH13-SW12

So in fact you have to work with two views/layers:

- (id)initWithContentRect:(NSRect)contentRect styleMask:(NSUInteger)aStyle backing:(NSBackingStoreType)bufferingType defer:(BOOL)flag
{
self = [super initWithContentRect:contentRect styleMask:NSBorderlessWindowMask backing:bufferingType defer:flag];

if ( self )
{
    [self setOpaque:NO];
    [self setBackgroundColor:[NSColor clearColor]];
    [self setMovableByWindowBackground:TRUE];
    [self setStyleMask:NSBorderlessWindowMask];
    [self setHasShadow:YES];
}

return self;
}

- (BOOL)canBecomeKeyWindow {
return YES;
}

-(BOOL)canBecomeMainWindow {
return YES;
}

- (void) setContentView:(NSView *)aView {

NSView *backView = [[NSView alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
backView.wantsLayer             = YES;
backView.layer.masksToBounds    = NO;
backView.layer.shadowColor      = [NSColor shadowColor].CGColor;
backView.layer.shadowOpacity    = 0.5;
backView.layer.shadowOffset     = CGSizeMake(0, -3);
backView.layer.shadowRadius     = 5.0;
backView.layer.shouldRasterize  = YES;


NSView *frontView = [aView initWithFrame:CGRectMake(backView.frame.origin.x + 15, backView.frame.origin.y + 15, backView.frame.size.width - 30, backView.frame.size.height - 30)];
[backView addSubview: frontView];
frontView.layer.cornerRadius    = 8;
frontView.layer.masksToBounds   = YES;
frontView.layer.borderColor     = [[NSColor darkGrayColor] CGColor];
frontView.layer.borderWidth     = 0.5;

[super setContentView:backView];

}

Have a closer look at the "initWithFrame" part of the code. Best greetings from Tyrol, Austria!