How to get bitmap from URL using Coil?

Question

I want to load a bitmap from URL and then use palette API to get some colors from that.

On the documentation page, I cannot find the code for getting bitmap directly!

Can anyone help me out?

Demetricedemetris

Answer 1

You can use target method and cast the drawable to bitmap as

    val loader = ImageLoader(this)
    val req = ImageRequest.Builder(this)
        .data("https://images.dog.ceo/breeds/saluki/n02091831_3400.jpg") // demo link
        .target { result ->
            val bitmap = (result as BitmapDrawable).bitmap
        }
        .build()

    val disposable = loader.enqueue(req)

If you using coroutines then use GetRequest (with overloaded execute method with suspend) in your CoroutineScope as:

  coroutineScope.launch{
    val loader = ImageLoader(this)
    val request = ImageRequest.Builder(this)
        .data("https://images.dog.ceo/breeds/saluki/n02091831_3400.jpg")
        .allowHardware(false) // Disable hardware bitmaps.
        .build()

    val result = (loader.execute(request) as SuccessResult).drawable
    val bitmap = (result as BitmapDrawable).bitmap
}

Chromous

What does this line do val disposable = loader.execute(req) – Detect

@IdrisStack that executes the build request and returns a request disposable that can be used to dispose of queued requests, free up resources, or can invoke await for immediate execution. – Chromous

Why do you disable hardware? – Swore

@AchrafAmil I guess it's was probably because of some stability or compatibility issues at that time. – Chromous

@AchrafAmil because many other native libraries do not support it e.g. Pallette, Firebase ML Kit, ... and you cannot pass it to them it will throw an error – Eun

You should avoid creation of ImageLoader every time image load is required because of this issue issuetracker.google.com/issues/231499040#comment3 – Larson

if image was previously loaded and available in cache (memory/disk) then it will return it instantly? basically I have the list of times with image and user can click share button on each item to share text and image content of specific item – Washtub

@Washtub Coil uses in-memory cache so you can try running a test to load large images and see if it always download the images or how efficient it is to use cache. – Chromous

Answer 2

according to Coil's own document, you can download a bitmap in the background in the following way:

val request = ImageRequest.Builder(context)
.data(url)
.build()
val drawable = context.imageLoader.execute(request).drawable

Hanhana