Write Text on an NSImage in Swift-OSX - swift

Question

I have the following objective C Code to write text onto an Image. I'm new to Swift. How can I do this in Swift?
float width = 10.0;
float height = 10.0;
NSImage *finalImage = [[NSImage alloc] initWithSize:NSMakeSize(width, height)];
// obtain images - your sources may vary
NSImage *overlay = [[NSImage alloc] initWithData:[NSData dataWithContentsOfFile:#"/path/to/overlay_image.jpg"]];
NSImage *mainImage = [[NSImage alloc] initWithData:[NSData dataWithContentsOfFile:#"/path/to/main_image.jpg"]];
[finalImage lockFocus];
// draw the base image
[mainImage drawInRect:NSMakeRect(0, 0, width, height)
fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1.0];
// draw the overlay image at some offset point
[overlay drawInRect:NSMakeRect(10, 10, [overlay size].width, [overlay size].height)
fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1.0];
[finalImage unlockFocus];
NSData *finalData = [finalImage TIFFRepresentation];
[[[NSBitmapImageRep imageRepWithData:finalData] representationUsingType:NSJPEGFileType properties:nil] writeToFile:[NSString stringWithFormat:#"/path/to/folder/new_image.jpg"] atomically:YES];
UPDATE:
I have the following method to draw a string onto an Image..But it when I use this method I get cropped out image portions..Seems something is wrong with it..Please advice.
func drawText(image :NSImage) ->NSImage
{
let text = "Sample Text"
let font = NSFont.boldSystemFont(ofSize: 18)
let imageRect = CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height)
let textRect = CGRect(x: 5, y: 5, width: image.size.width - 5, height: image.size.height - 5)
let textStyle = NSMutableParagraphStyle.default().mutableCopy() as! NSMutableParagraphStyle
let textFontAttributes = [
NSFontAttributeName: font,
NSForegroundColorAttributeName: NSColor.white,
NSParagraphStyleAttributeName: textStyle
]
let im:NSImage = NSImage(size: image.size)
let rep:NSBitmapImageRep = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: Int(image.size.width), pixelsHigh: Int(image.size.height), bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false, colorSpaceName: NSCalibratedRGBColorSpace, bytesPerRow: 0, bitsPerPixel: 0)!
im.addRepresentation(rep)
im.lockFocus()
image.draw(in: imageRect)
text.draw(in: textRect, withAttributes: textFontAttributes)
im.unlockFocus()
return im
}

Answer 1

Here's this code in Swift 3
let width: CGFloat = 10.0
let height: CGFloat = 10.0
let finalImage = NSImage(size: NSMakeSize(width, height))
// obtain images - your sources may vary
var overlay: NSImage?
var mainImage: NSImage?
if let url = URL(string: "/path/to/overlay_image.jpg") {
do {
let data = try Data(contentsOf: url)
overlay = NSImage(data: data)
} catch {
print("Unable to get data")
}
}
if let url = URL(string: "/path/to/main_image.jpg") {
do {
let data = try Data(contentsOf: url)
mainImage = NSImage(data: data)
} catch {
print("Unable to get data")
}
}
finalImage.lockFocus()
// draw the base image
mainImage?.draw(in: NSMakeRect(0, 0, width, height), from: NSZeroRect, operation: NSCompositingOperation.sourceOver, fraction: 1.0)
// draw the overlay image at some offset point
if overlay != nil {
overlay?.draw(in: NSMakeRect(10, 10, overlay!.size.width, overlay!.size.height), from: NSZeroRect, operation: NSCompositingOperation.sourceOver, fraction: 1.0)
}
finalImage.unlockFocus()
if let finalData = finalImage.tiffRepresentation, let url = URL(string: "/path/to/folder/new_image.jpg") {
do {
try NSBitmapImageRep(data: finalData)?.representation(using: NSJPEGFileType, properties: [:])?.write(to: url)
} catch {
print("Failed to write")
}
}