How to draw a string on a CALayer in OSX?

0
votes

I'm having trouble drawing a string in a custom CALayer. The drawInContext method is called but nothing is visible on the screen. I can fill the layer with a solid colour but can't seem to draw a string onto it.

Any suggestions? Thanks.

- (void)drawInContext:(CGContextRef)ctx
{
    CGContextSaveGState(ctx);

    NSString *myString = @"Hello World";    
    NSDictionary *attr = [NSDictionary dictionaryWithObjectsAndKeys:
                                    [NSFont systemFontOfSize:14], NSFontAttributeName, nil];

    [myString drawAtPoint:NSMakePoint(0,0) withAttributes:attr];

    CGContextRestoreGState(ctx);
}
2
objective-cmacoscalayer

2 Answers

2
votes

I didn't want to use Quartz to draw a string but I guess I have to. So here is what I ended up doing 

   NSString *string = @"Hello world";
   CGContextSelectFont (ctx,"Helvetica", 24, kCGEncodingMacRoman);
   CGContextSetTextDrawingMode (ctx, kCGTextFillStroke);
   CGContextShowTextAtPoint (ctx, 40, 40, [string UTF8String], (int)[string length]);

Alternative solution

    [NSGraphicsContext saveGraphicsState];

    NSGraphicsContext *currentContext = [NSGraphicsContext graphicsContextWithGraphicsPort:theContext flipped:NO];
    [NSGraphicsContext setCurrentContext:currentContext]; 

    //Draw here

    [NSGraphicsContext restoreGraphicsState];
0
votes

You'd probably want to use a CATextLayer. Get the parent layer, add your text to the TextLayer, then use -addSublayer to add the TextLayer to the parent layer.