CGContextSelectFont equivalent

Question

In iOS7 CGContextSelectFont is deprecated. Deprecation message says that I have to use Core Text, but I don't know which is the exact equivalent of this piece of code:

CGContextSelectFont(context, "Helvetica", kBarLabelSize, kCGEncodingMacRoman);
CGContextSetTextDrawingMode(context, kCGTextFill);
CGContextSetRGBFillColor(context, 0, 0, 0, 1.0);
CGContextSetTextMatrix (context, CGAffineTransformMake(1.0, 0.0, 0.0, -1.0, 0.0, 0.0));
CGContextShowTextAtPoint(context, barX, barY, [@"Some text" cStringUsingEncoding:NSUTF8StringEncoding], [barValue length]);

I've been able to create the font with this code:

CFMutableAttributedStringRef attrStr = CFAttributedStringCreateMutable(kCFAllocatorDefault, 0);
CTFontRef font = CTFontCreateWithName(CFSTR("Helvetica"), kBarLabelSize, NULL);
CFAttributedStringSetAttribute(attrStr, CFRangeMake(0, CFAttributedStringGetLength(attrStr)), kCTFontAttributeName, font);

But now haw can I "draw" a text with this font into the context?

Answer 1

As best I can understand from your code, the exact equivalent is:

CGContextSetTextDrawingMode(context, kCGTextFill); // This is the default
[[UIColor blackColor] setFill]; // This is the default
[@"Some text" drawAtPoint:CGPointMake(barX, barY)
           withAttributes:@{NSFontAttributeName:[UIFont fontWithName:@"Helvetica"
                                                                size:kBarLabelSize]
                            }];

Note that your calls to CGContextSetTextDrawingMode and CGContextSetRGBFillColor are setting the values to the defaults. Your call to CGContextSetTextMatrix is not needed when using UIKit drawing like this.

I have no idea what [barValue length] is here, however. I'm assuming that you simply incorrectly used this for the length of @"Some text". (length is not the number of bytes which is what you need. What you probably meant was [barValue lengthOfBytesUsingEncoding:NSUTF8StringEncoding]).

Note that UIKit string drawing (seen here) wraps Core Text.