Support for data:// URIs

[chimbori]

I looked through the issues, trying to see if there’s a plan to support Data URIs, but didn’t find anything concrete.

https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URIs

[chimbori]

Here’s a custom Fetcher for Data URIs:

internal class Base64ImageFetcher(private val context: Context) : Fetcher<Uri> {
  override fun handles(data: Uri) = data.scheme == "data"

  override suspend fun fetch(pool: BitmapPool, data: Uri, size: Size, options: Options) = DrawableResult(
      drawable = BitmapDrawable(context.resources, base64Decode(data.toString())),
      isSampled = false,
      dataSource = DataSource.MEMORY
  )

  override fun key(data: Uri) = data.toString()

  companion object {
    private fun base64Decode(dataURI: String): Bitmap? {
      val decodedBytes = Base64.decode(dataURI.substringAfter(','), DEFAULT)
      return BitmapFactory.decodeByteArray(decodedBytes, 0, decodedBytes.size)
    }
  }
}

Use it as:

ImageLoader.Builder(context)
    .componentRegistry {
      add(Base64ImageFetcher(context))
    }
    .build()

[nachtien]

Here's a custom Fetcher for Data URIs that works on version 2.2.2

class Base64ImageFetcher(
    private val context: Context,
    private val data: Uri,
) : Fetcher {

    override suspend fun fetch() = DrawableResult(
        drawable = BitmapDrawable(
            context.resources,
            base64Decode(data.toString())
        ),
        isSampled = false,
        dataSource = DataSource.MEMORY
    )

    companion object {
        private fun base64Decode(dataURI: String): Bitmap? {
            val decodedBytes = Base64.decode(dataURI.substringAfter(','), Base64.DEFAULT)
            return BitmapFactory.decodeByteArray(decodedBytes, 0, decodedBytes.size)
        }
    }

    class Factory : Fetcher.Factory<Uri> {

        override fun create(data: Uri, options: Options, imageLoader: ImageLoader): Fetcher {
            return Base64ImageFetcher(options.context, data)
        }
    }
}

[brianguertin]

When my company went to implement this, we observed data: URIs are supported natively by web browsers (obviously), but also by the popular sd_webimage loader on iOS.

Coil was the only one that didn't already work. Makes sense to include the above^ in the repo (but, it could be better. instead of returning bitmap, it should pass the bytes to the decoders)

Anyway, thanks for the sample code :)