Feature/uiimage support

[evnaz]

Hi,

I'm trying to implement an extension to create UIImage from SVG file.
I used NodeRenderer.renderToImage() for that. For some reason the image is always empty.
Can anybody advise me what is wrong here? Are there any plans to have such functionality?

Thanks

[ystrot]

Hi Eugene,

You don't need to write your extension, you can use something like this:

func svgToImge(resourceName: String, size: CGSize) -> UIImage {
    let rootNode = SVGParser.parse(path: resourceName)
    let macawView = MacawView(node: rootNode, frame:CGRect(origin: CGPoint.zero, size: size))
    UIGraphicsBeginImageContext(size)
    macawView.layer.render(in: UIGraphicsGetCurrentContext()!)
    let img =  UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return img!
}

[evnaz]

Hi @ystrot,

The benefits of an UIImage extension are

• avoiding redundant image drawing (since the SVG's already drawn inside the MacawView)
• having easy to use interface for image creating

Wouldn't it be great to have such feature as a part of the lib and not a workaround?

[Quanhua-Guan]

when use MacawView, it has to be in main thread. however, we need to get the image in background thread. @ystrot

[BrettAtMangoHealth]

Hi @ystrot,
Similarly to @Quanhua-Guan, our team is trying to retrieve the image in a background thread and cannot use a MacawView + the code snippet you provided to get the job done as it results in a blank (and black) image.

[lubiluk]

I've noticed that turning an SVG into UIImage works only when MacawView used for that conversion is actually added to view hierarchy. I guess that doesn't satisfy many use cases.

[amarunko]

Hello, @lubiluk, why do you think so? For me this extension working for a case, when MacawView not in view hierarchy right now. Can you explain your problem if it exists in little details?

[lubiluk]

Now when I tested it again it renders an image just fine. Sorry!

[ystrot]

Hi Eugene,

Thanks you for your proposal. Now this feature available through Node.toNativeImage(size:layout:) method.

Sorry we didn't take your original PR. Final implementation was quite different from the solution you provided, in particular:

• Node extension is more natural for Macaw API than UIImage extension.
• It's better to convert node rather than SVG file to an image, because you can create a scene without using SVG.
• Such a method should also handle content layout properly, etc.

Anyway, let us know if you'll find something else to improve in Macaw and we'll be happy to approve your work next time.