Bug 1783561 - Allow a custom View for 3rd party downloads

This will allow clients easily implement their own UI

Backport of https://github.com/mozilla-mobile/firefox-android/commit/c53dd65718579006e174803acf683ffd44075049

components/feature/downloads/src/main/java/mozilla/components/feature/downloads/DownloadsFeature.kt

@@ -56,13 +56,25 @@ value class Filename(val value: String)
 value class ContentSize(val value: Long)
 
 /**
- * Action for when the positive button of a download dialog was tapped.
+ * The list of all applications that can perform a download, including this application.
+ */
+@JvmInline
+value class ThirdPartyDownloaderApps(val value: List<DownloaderApp>)
+
+/**
+ * Callback for when the user picked a certain application with which to download the current file.
+ */
+@JvmInline
+value class ThirdPartyDownloaderAppChosenCallback(val value: (DownloaderApp) -> Unit)
+
+/**
+ * Callback for when the positive button of a download dialog was tapped.
  */
 @JvmInline
 value class PositiveActionCallback(val value: () -> Unit)
 
 /**
- * Action for when the negative button of a download dialog was tapped.
+ * Callback for when the negative button of a download dialog was tapped.
  */
 @JvmInline
 value class NegativeActionCallback(val value: () -> Unit)
@@ -86,7 +98,10 @@ value class NegativeActionCallback(val value: () -> Unit)
  * @property promptsStyling styling properties for the dialog.
  * @property shouldForwardToThirdParties Indicates if downloads should be forward to third party apps,
  * if there are multiple apps a chooser dialog will shown.
- * @property customDownloadDialog An optional delegate for showing a download dialog.
+ * @property customFirstPartyDownloadDialog An optional delegate for showing a dialog for a download
+ * that will be processed by the current application.
+ * @property customThirdPartyDownloadDialog An optional delegate for showing a dialog for a download
+ * that can be processed by multiple installed applications including the current one.
  */
 @Suppress("LongParameterList", "LargeClass")
 class DownloadsFeature(
@@ -101,7 +116,10 @@ class DownloadsFeature(
     private val fragmentManager: FragmentManager? = null,
     private val promptsStyling: PromptsStyling? = null,
     private val shouldForwardToThirdParties: () -> Boolean = { false },
-    private val customDownloadDialog: ((Filename, ContentSize, PositiveActionCallback, NegativeActionCallback) -> Unit)? = null,
+    private val customFirstPartyDownloadDialog:
+    ((Filename, ContentSize, PositiveActionCallback, NegativeActionCallback) -> Unit)? = null,
+    private val customThirdPartyDownloadDialog:
+    ((ThirdPartyDownloaderApps, ThirdPartyDownloaderAppChosenCallback, NegativeActionCallback) -> Unit)? = null,
 ) : LifecycleAwareFeature, PermissionsFeature {
 
     var onDownloadStopped: onDownloadStopped
@@ -187,13 +205,25 @@ class DownloadsFeature(
         val shouldShowAppDownloaderDialog = shouldForwardToThirdParties() && apps.size > 1
 
         return if (shouldShowAppDownloaderDialog) {
-            showAppDownloaderDialog(tab, download, apps)
+            when (customThirdPartyDownloadDialog) {
+                null -> showAppDownloaderDialog(tab, download, apps)
+                else -> customThirdPartyDownloadDialog.invoke(
+                    ThirdPartyDownloaderApps(apps),
+                    ThirdPartyDownloaderAppChosenCallback {
+                        onDownloaderAppSelected(it, tab, download)
+                    },
+                    NegativeActionCallback {
+                        useCases.cancelDownloadRequest.invoke(tab.id, download.id)
+                    },
+                )
+            }
+
             false
         } else {
             if (applicationContext.isPermissionGranted(downloadManager.permissions.asIterable())) {
                 when {
-                    customDownloadDialog != null && !download.skipConfirmation -> {
-                        customDownloadDialog.invoke(
+                    customFirstPartyDownloadDialog != null && !download.skipConfirmation -> {
+                        customFirstPartyDownloadDialog.invoke(
                             Filename(download.realFilenameOrGuessed),
                             ContentSize(download.contentLength ?: 0),
                             PositiveActionCallback {
@@ -309,6 +339,20 @@ class DownloadsFeature(
     ) {
         appChooserDialog.setApps(apps)
         appChooserDialog.onAppSelected = { app ->
+            onDownloaderAppSelected(app, tab, download)
+        }
+
+        appChooserDialog.onDismiss = {
+            useCases.cancelDownloadRequest.invoke(tab.id, download.id)
+        }
+
+        if (!isAlreadyAppDownloaderDialog() && fragmentManager != null && !fragmentManager.isDestroyed) {
+            appChooserDialog.showNow(fragmentManager, DownloadAppChooserDialog.FRAGMENT_TAG)
+        }
+    }
+
+    @VisibleForTesting
+    internal fun onDownloaderAppSelected(app: DownloaderApp, tab: SessionState, download: DownloadState) {
         if (app.packageName == applicationContext.packageName) {
             if (applicationContext.isPermissionGranted(downloadManager.permissions.asIterable())) {
                 startDownload(download)
@@ -322,7 +366,7 @@ class DownloadsFeature(
             } catch (error: ActivityNotFoundException) {
                 val errorMessage = applicationContext.getString(
                     R.string.mozac_feature_downloads_unable_to_open_third_party_app,
-                        app.name
+                    app.name,
                 )
                 Toast.makeText(applicationContext, errorMessage, Toast.LENGTH_SHORT).show()
             }
@@ -330,15 +374,6 @@ class DownloadsFeature(
         }
     }
 
-        appChooserDialog.onDismiss = {
-            useCases.cancelDownloadRequest.invoke(tab.id, download.id)
-        }
-
-        if (!isAlreadyAppDownloaderDialog() && fragmentManager != null && !fragmentManager.isDestroyed) {
-            appChooserDialog.showNow(fragmentManager, DownloadAppChooserDialog.FRAGMENT_TAG)
-        }
-    }
-
     private fun getAppDownloaderDialog() = findPreviousAppDownloaderDialogFragment()
         ?: DownloadAppChooserDialog.newInstance(
             promptsStyling?.gravity,

components/feature/downloads/src/main/java/mozilla/components/feature/downloads/ui/DownloaderAppAdapter.kt

@@ -16,10 +16,10 @@ import mozilla.components.feature.downloads.R
 /**
  * An adapter for displaying the applications that can perform downloads.
  */
-internal class DownloaderAppAdapter(
+class DownloaderAppAdapter(
     context: Context,
     private val apps: List<DownloaderApp>,
-    val onAppSelected: ((DownloaderApp) -> Unit)
+    val onAppSelected: ((DownloaderApp) -> Unit),
 ) : RecyclerView.Adapter<DownloaderAppViewHolder>() {
 
     private val inflater = LayoutInflater.from(context)
@@ -49,11 +49,14 @@ internal class DownloaderAppAdapter(
 /**
  * View holder for a [DownloaderApp] item.
  */
-internal class DownloaderAppViewHolder(
+class DownloaderAppViewHolder(
     itemView: View,
     val nameLabel: TextView,
-    val iconImage: ImageView
+    val iconImage: ImageView,
 ) : RecyclerView.ViewHolder(itemView) {
+    /**
+     * Show a certain downloader application in the current View.
+     */
     fun bind(app: DownloaderApp, onAppSelected: ((DownloaderApp) -> Unit)) {
         itemView.app = app
         itemView.setOnClickListener {