decode_interceptor.md

DecodeInterceptor

Translations: 简体中文

The decoding process of Sketch supports changing the input and output before and after decoding through interceptors.

First implement the DecodeInterceptor interface to implement your DecodeInterceptor, and then register it through the addDecodeInterceptor() method, as follows:

class MyDecodeInterceptor : DecodeInterceptor {

    // If the current DecodeInterceptor will modify the returned results and is only used for some requests, then please give a unique key to build the cache key, otherwise give null
    override val key: String = "MyDecodeInterceptor"

    // Used for sorting, the larger the value, the further back in the list. The value range is 0 ~ 100. Usually zero. Only EngineDecodeInterceptor can be 100
    override val sortWeight: Int = 0

    @WorkerThread
    override suspend fun intercept(
        chain: DecodeInterceptor.Chain,
    ): Result<DecodeResult> {
        val newRequest = chain.request.newRequest {
            colorType(Bitmap.Config.RGB_565)
        }
        return chain.proceed(newRequest)
    }
}

// Register for all ImageRequests when customizing Sketch
Sketch.Builder(context).apply {
    components {
        addDecodeInterceptor(MyDecodeInterceptor())
    }
}.build()

// Register for a single ImageRequest when loading an image
ImageRequest(context, "https://example.com/image.jpg") {
    components {
        addDecodeInterceptor(MyDecodeInterceptor())
    }
}

Tip

1. MyDecodeInterceptor demonstrates a case of changing the Bitmap.Config of all requests to RGB_565
2. If you want to modify the return result, just intercept the result returned by the proceed method and return a new DecodeResult
3. If you don’t want to execute the request anymore, just don’t execute the proceed method.