Text Inset NSShadow

// The only contents of an NSTextFieldCell subclass

- (void)drawInteriorWithFrame:(NSRect)cellFrame
                       inView:(NSView *)controlView
{
    // Works but looks really bad
    NSBezierPath *stringPath = [self bezierPathWithString:self.stringValue
                                                   inFont:self.font];
    NSAffineTransform *aTransform = [NSAffineTransform transform];
    [aTransform translateXBy:4
                         yBy:5];
    [stringPath transformUsingAffineTransform:aTransform];

    if (!_innerShadow) {
        _innerShadow = [[NSShadow alloc] init];
        _innerShadow.shadowColor = [[NSColor blackColor] colorWithAlphaComponent:0.9];
        _innerShadow.shadowBlurRadius = 4.0;
        _innerShadow.shadowOffset = NSMakeSize(0, -1.0);
    }

    [NSGraphicsContext saveGraphicsState];

    NSShadow *raisedShaow = [[NSShadow alloc] init];
    raisedShaow.shadowColor = [[NSColor whiteColor] colorWithAlphaComponent:1.0];
    raisedShaow.shadowBlurRadius = 0.0;
    raisedShaow.shadowOffset = NSMakeSize(0, -1.0);
    [raisedShaow set];

    CGContextSetBlendMode([[NSGraphicsContext currentContext] graphicsPort], kCGBlendModeScreen);

    self.textColor = [NSColor blackColor];
    [super drawInteriorWithFrame:cellFrame
                          inView:controlView];

    [NSGraphicsContext restoreGraphicsState];
    [NSGraphicsContext saveGraphicsState];

    NSBezierPath *framePath = [NSBezierPath bezierPathWithRect:cellFrame];
    [framePath setWindingRule:NSEvenOddWindingRule];
    [framePath appendBezierPath:stringPath];
    [stringPath setClip];

    [_innerShadow set];
    [framePath fill];

    [NSGraphicsContext restoreGraphicsState];

    // Doesn't really work, and I've no idea why
    /*CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceGray();
    CGContextRef maskContext = CGBitmapContextCreate(
                          NULL,
                          cellFrame.size.width,
                          cellFrame.size.height,
                          8,
                          cellFrame.size.width,
                          colorspace,
                          0);
    CGColorSpaceRelease(colorspace);

    // Switch to the context for drawing
    [NSGraphicsContext saveGraphicsState];
    [NSGraphicsContext setCurrentContext:[NSGraphicsContext graphicsContextWithGraphicsPort:maskContext
                                                                                    flipped:YES]];

    // Draw a black background to exclude
    [[NSColor blackColor] set];
    CGContextFillRect(maskContext, cellFrame);

    // Draw the string in white to include
    [self.stringValue drawInRect:cellFrame
                  withAttributes:@{
            NSFontAttributeName : self.font,
 NSForegroundColorAttributeName : [NSColor whiteColor]
     }];

    CGImageRef alphaMask = CGBitmapContextCreateImage(maskContext);
    [NSGraphicsContext restoreGraphicsState];

    // Draw a white background in the window
    CGContextRef windowContext = [[NSGraphicsContext currentContext] graphicsPort];

    // Draw the image, clipped by the mask
    CGContextSaveGState(windowContext);
    CGContextClipToMask(windowContext, NSRectToCGRect(cellFrame), alphaMask);

    [_innerShadow set];

    NSRectFill(cellFrame);

    CGContextRestoreGState(windowContext);
    CGImageRelease(alphaMask);*/
}

- (NSBezierPath *)bezierPathWithString:(NSString *)text
                                inFont:(NSFont *)font
{
    // This has some weird alphabet shifting problem
    // Don't use in production until fixed

    NSBezierPath *aPath = [NSBezierPath bezierPath];
    [aPath moveToPoint:NSZeroPoint];

    NSAttributedString *attributedString = [[NSAttributedString alloc] initWithString:text
                                                                           attributes:@{
                                                                 NSFontAttributeName : self.font
                                            }];
    CTLineRef line = CTLineCreateWithAttributedString((CFAttributedStringRef)CFBridgingRetain(attributedString));

    CFArrayRef glyphRuns = CTLineGetGlyphRuns(line);
    CFIndex count = CFArrayGetCount(glyphRuns);

    for (CFIndex index = 0; index < count; index++) {
        CTRunRef currentRun = CFArrayGetValueAtIndex(glyphRuns, index);

        CFIndex glyphCount = CTRunGetGlyphCount(currentRun);

        CGGlyph glyphs[glyphCount];
        CTRunGetGlyphs(currentRun, CTRunGetStringRange(currentRun), glyphs);

        NSGlyph bezierPathGlyphs[glyphCount];
        for (CFIndex glyphIndex = 0; glyphIndex < glyphCount; glyphIndex++) {
            bezierPathGlyphs[glyphIndex] = glyphs[glyphIndex];
        }

        [aPath appendBezierPathWithGlyphs:bezierPathGlyphs
                                    count:glyphCount
                                   inFont:font];
    }

    CFRelease(line);

    [aPath transformUsingAffineTransform:[self verticallyFlippedAffineTransformForRect:aPath.bounds]];

    return aPath;
}

- (NSAffineTransform *)verticallyFlippedAffineTransformForRect:(NSRect)rect
{
    NSAffineTransform *affineTransform = [NSAffineTransform transform];

    NSAffineTransformStruct transformStruct;
    transformStruct.m11 = 1.0;
    transformStruct.m12 = 0.0;
    transformStruct.tX  = 0;
    transformStruct.m21 = 0.0;
    transformStruct.m22 = -1.0;
    transformStruct.tY  = rect.size.height;
    [affineTransform setTransformStruct:transformStruct];

    return affineTransform;
}