Android Components > Feature > Downloads

Feature implementation for apps that want to use Android downloads manager.

Usage

Setting up the dependency

Use Gradle to download the library from maven.mozilla.org (Setup repository):

implementation "org.mozilla.components:feature-downloads:{latest-version}"

The AbstractFetchDownloadService also requires extra permissions needed to post notifications and to start downloads

• android.permission.POST_NOTIFICATIONS
• android.permission.FOREGROUND_SERVICE
• android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK

The implementing service in the client app also needs to declare dataSync as foregroundServiceType in the manifest for Android 14 compatibility. Adding the FOREGROUND_SERVICE_DATA_SYNC permission in the app manifest is not needed since it is declared in feature-downloads module.

DownloadsFeature

Feature implementation for proving download functionality for the selected session.

//This will be called before starting each download in case you don't have the right permissions
// or if the user removed your permissions.
val onNeedToRequestPermissions = {
        session: Session, download: Download ->
    //request permission e.g (WRITE_EXTERNAL_STORAGE)

    // After you get granted the permissions, remember to call downloadsFeature.onPermissionsGranted()
    // to start downloading the pending download.
}

//This will be called after every download is completed.
val onDownloadCompleted = {
        download: Download, downloadId: Long ->
    //Show some UI to let user know the download was completed.
}

val downloadsFeature =
    DownloadsFeature(context,
    onNeedToRequestPermissions /*Optional*/,
    onDownloadCompleted /*Optional*/,
    fragmentManager /*Optional, if it is provided, before every download a dialog will be shown*/,
    dialog /*Optional, if it is not provided a simple dialog will be shown before every download, with a positive button and negative button.*/,
    sessionManager = sessionManager)

//Starts observing the selected session for new downloads and forward it to
// the download manager
downloadsFeature.start()

//Stop observing the selected session
downloadsFeature.stop()

DownloadDialogFragment

This is general representation of a dialog meant to be used in collaboration with DownloadsFeature to show a dialog before a download is triggered. If SimpleDownloadDialogFragment is not flexible enough for your use case you should inherit for this class.

class FocusDialogDownloadFragment : DownloadDialogFragment() {

    /*Creating a customized the dialog*/
    override fun onCreateDialog(bundle: Bundle?): AlertDialog {
        //DownloadsFeature will add these metadata before calling show() on the dialog.
        val fileName = arguments?.getString(KEY_FILE_NAME)
        //Not used, just for the sake you can use this metadata
        val url = arguments?.getString(KEY_URL)
        val contentLength = arguments?.getString(KEY_CONTENT_LENGTH)

        val builder = AlertDialog.Builder(requireContext())
        builder.setCancelable(true)
        builder.setTitle(getString(R.string.download_dialog_title))

        val inflater = activity!!.layoutInflater
        val dialogView = inflater.inflate(R.layout.download_dialog, null)
        builder.setView(dialogView)

        dialogView.download_dialog_icon.setImageResource(R.drawable.ic_download)
        dialogView.download_dialog_file_name.text = fileName
        dialogView.download_dialog_cancel.text = getString(R.string.download_dialog_action_cancel)
        dialogView.download_dialog_download.text =
            getString(R.string.download_dialog_action_download)

        dialogView.download_dialog_warning.text = getString(R.string.download_dialog_warning)

        setCancelButton(dialogView.download_dialog_cancel)
        setDownloadButton(dialogView.download_dialog_download)

        return builder.create()
    }

    private fun setDownloadButton(button: Button) {
        button.setOnClickListener {
            //Letting know DownloadFeature that can proceed with the download
            onStartDownload()
            TelemetryWrapper.downloadDialogDownloadEvent(true)
            dismiss()
        }
    }

    private fun setCancelButton(button: Button) {
        button.setOnClickListener {
           TelemetryWrapper.downloadDialogDownloadEvent(false)
            dismiss()
        }
    }
}

//Adding our dialog to DownloadsFeature
val downloadsFeature = DownloadsFeature(
            context(),
            sessionManager = sessionManager,
            fragmentManager = fragmentManager,
            dialog = FocusDialogDownloadFragment()
        )

downloadsFeature.start()

SimpleDownloadDialogFragment

A confirmation dialog to be called before a download is triggered.

SimpleDownloadDialogFragment is the default dialog if you don't provide a value to DownloadsFeature. It is composed by a title, a negative and a positive bottoms. When the positive button is clicked the download is triggered.

//To use the default behavior, just provide a fragmentManager/childFragmentManager.
        downloadsFeature = DownloadsFeature(
            requireContext(),
            sessionManager = components.sessionManager,
            fragmentManager = fragmentManager /*If you're inside a Fragment use childFragmentManager '*/
        )

        downloadsFeature.start()

Customizing SimpleDownloadDialogFragment.

        val dialog = SimpleDownloadDialogFragment.newInstance(
                dialogTitleText = R.string.dialog_title,
                positiveButtonText = R.string.download,
                negativeButtonText = R.string.cancel,
                cancelable = true,
                themeResId = R.style.your_theme
            )

        downloadsFeature = DownloadsFeature(
            requireContext(),
            sessionManager = components.sessionManager,
            fragmentManager = fragmentManager,
            dialog = dialog
        )

        downloadsFeature.start()

Facts

This component emits the following Facts:

Action	Item	Description
RESUME	notification	The user resumes a download.
PAUSE	notification	The user pauses a download.
CANCEL	notification	The user cancels a download.
TRY_AGAIN	notification	The user taps on try again when a download fails.
OPEN	notification	The user opens a downloaded file.
DISPLAY	prompt	A download prompt was shown.
CANCEL	prompt	A download prompt was canceled.

License

This Source Code Form is subject to the terms of the Mozilla Public
License, v. 2.0. If a copy of the MPL was not distributed with this
file, You can obtain one at http://mozilla.org/MPL/2.0/