How can i observe the download percentage on (fun retrieveFromHttp)

[hishampro5]

I am trying to show progress bar to enhancement UX on my app while the book is downloading i am using suspend fun retrieveFromHttp for download the books so is there any way to achieve this or i need do some customization. i think this callBack is available on IOS ? so i am asking is this possible also on android.

for IOS :

private func fulfillIfNeeded(_ url: FileURL, progress: @escaping (Double) -> Void) async throws -> FileURL {
    guard lcp.canFulfill(url) else {
      return url
    }

    do {
      let pub = try await lcp.fulfill(url, progress: progress)
      return pub.localURL

    } catch {
      throw LibraryError.downloadFailed(error)
    }
  }

FYI : readium_version = '3.0.3'

[mickael-menu]

The retrieveFromHttp() function you mentioned is part of the Test App, so you can modify it as needed to add progress callbacks. However, it is not intended for LCP downloads but for regular HTTP downloads. The iOS API you shared is used to acquire an LCP-protected publication. The equivalent in Kotlin is LcpService.acquirePublication(), which accepts an onProgress callback.

kotlin-toolkit/readium/lcp/src/main/java/org/readium/r2/lcp/LcpService.kt

Lines 61 to 64 in dc25e7b

	public suspend fun acquirePublication(
	lcpl: File,
	onProgress: (Double) -> Unit = {},
	): Try<AcquiredPublication, LcpError>

Regarding regular HTTP downloads, you can compute the progress by checking the expected length returned by HttpClient.stream:

kotlin-toolkit/readium/shared/src/main/java/org/readium/r2/shared/util/http/HttpClient.kt

Lines 46 to 49 in dc25e7b

	public class HttpStreamResponse(
	public val response: HttpResponse,
	public val body: InputStream,
	)

Using val expectedLength = response.response.contentLength?.toDouble()?.takeUnless { it <= 0 }.

Then, when writing the content of the response.body on the file system, compute the progress with writtenBytes / expectedLength.

[hishampro5]

Thx sir @mickael-menu but what about Streaming if i need show some progress indicator while book downloading & opening

as i now streaming will download as buffering not all book on one time so is there any way to show some progress indicator while book oping first buffer !

val customHttpClientCallback = object : DefaultHttpClient.Callback {
			override suspend fun onStartRequest(request: HttpRequest): HttpTry<HttpRequest> {
				Timber.d("Readium HTTP Request: ${request.method.name} ${request.url}, original headers: ${request.headers}")

				val modifiedRequest = request.buildUpon()
					.addHeader("Authorization", "Bearer $authToken")
					//	.addHeader("Accept", "audio/mpeg, */*")
					.build()

				Timber.d("Readium HTTP Request (modified): ${modifiedRequest.method.name} ${modifiedRequest.url}, new headers: ${modifiedRequest.headers}")
				return Try.success(modifiedRequest)
			}

			override suspend fun onResponseReceived(request: HttpRequest, response: HttpResponse) {
				Timber.d("Readium HTTP Response for ${request.url}: Status ${response.statusCode}, Content-Type: ${response.mediaType}")
			}

			override suspend fun onRequestFailed(request: HttpRequest, error: HttpError) {
				Timber.e("Readium HTTP Request Failed for ${request.url}: ${error.toDebugDescription()}")
			}
		}
		val httpClient = DefaultHttpClient(callback = customHttpClientCallback)
		val assetRetriever = AssetRetriever(
			contentResolver = activity.contentResolver,
			httpClient = httpClient
		)

		val lcpService = LcpService(
			context = activity.baseContext,
			assetRetriever = assetRetriever
		) ?: error("liblcp is missing on the classpath")

		val authentication = LcpDialogAuthentication()

		val publicationOpener = PublicationOpener(
			publicationParser = DefaultPublicationParser(
				activity.baseContext,
				httpClient = httpClient,
				assetRetriever = assetRetriever,
				null
			),
			contentProtections = listOf(
				lcpService.contentProtection(authentication)
			)
		)


                          // Book URL 
                        val url_ = "${APIClientNew.defaultBasePath}Book/stream-audio/$bookId.mp3"
			val url = AbsoluteUrl(url_)!!

 		         val asset = assetRetriever.retrieve(url).getOrElse {
				return Try.failure(
					OpeningError.PublicationError(
						com.samawy.readerapp.readium.testapp.domain.PublicationError(it)
					)
				)
			}
			
			....
			....
			
			
			val readerInitData = when {
			publication.conformsTo(Publication.Profile.AUDIOBOOK) ->
				openAudio(bookId, publication, initialLocator)

			publication.conformsTo(Publication.Profile.EPUB) || publication.readingOrder.allAreHtml ->
				openEpub(bookId, publication, initialLocator)

			publication.conformsTo(Publication.Profile.PDF) ->
				openPdf(bookId, publication, initialLocator)

			publication.conformsTo(Publication.Profile.DIVINA) ->
				openImage(bookId, publication, initialLocator)

			else ->
				Try.failure(
					OpeningError.CannotRender(
						DebugError("No navigator supports this publication.")
					)
				)
		}
			  

[mickael-menu]

Streaming is designed to start quickly, so we don't have an API to notify progress during streaming. This approach makes sense because we don't download the entire file; instead, multiple HTTP requests occur at different times.

[hishampro5]

@mickael-menu i send you on slack book that i tested on TestApp you can test and see the delay

[qnga]

For the record, I gave a try to Hisham's server and it takes 13 seconds to respond to a HEAD request. At least from France.