Make DownloadManager the sole entry point for DownloadService (#9140)

* Rename functions for DownloadService internal use

* Call DownloadService.start via DownloadManager

* Inline DownloadService.stop into pauseDownloads

* Inline DownloadService.stop into clearQueue

NotificationReceiver will now also stop the DownloadService when
receiving ACTION_CLEAR_DOWNLOADS.

* Provide DownloadService.isRunning via DownloadManager

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadManager.kt

@@ -48,22 +48,18 @@ class DownloadManager(
     val queue: DownloadQueue
         get() = downloader.queue
 
-    /**
-     * Tells the downloader to begin downloads.
-     *
-     * @return true if it's started, false otherwise (empty queue).
-     */
-    fun startDownloads(): Boolean {
-        return downloader.start()
-    }
+    // For use by DownloadService only
+    fun downloaderStart() = downloader.start()
+    fun downloaderStop(reason: String? = null) = downloader.stop(reason)
+
+    val isDownloaderRunning
+        get() = DownloadService.isRunning
 
     /**
-     * Tells the downloader to stop downloads.
-     *
-     * @param reason an optional reason for being stopped, used to notify the user.
+     * Tells the downloader to begin downloads.
      */
-    fun stopDownloads(reason: String? = null) {
-        downloader.stop(reason)
+    fun startDownloads() {
+        DownloadService.start(context)
     }
 
     /**
@@ -71,6 +67,7 @@ class DownloadManager(
      */
     fun pauseDownloads() {
         downloader.pause()
+        DownloadService.stop(context)
     }
 
     /**
@@ -78,6 +75,7 @@ class DownloadManager(
      */
     fun clearQueue() {
         downloader.clearQueue()
+        DownloadService.stop(context)
     }
 
     /**

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadService.kt

@@ -95,7 +95,7 @@ class DownloadService : Service() {
     override fun onDestroy() {
         scope.cancel()
         _isRunning.value = false
-        downloadManager.stopDownloads()
+        downloadManager.downloaderStop()
         if (wakeLock.isHeld) {
             wakeLock.release()
         }
@@ -111,8 +111,8 @@ class DownloadService : Service() {
         return null
     }
 
-    private fun stopDownloads(@StringRes string: Int) {
-        downloadManager.stopDownloads(getString(string))
+    private fun downloaderStop(@StringRes string: Int) {
+        downloadManager.downloaderStop(getString(string))
     }
 
     private fun listenNetworkChanges() {
@@ -122,13 +122,13 @@ class DownloadService : Service() {
                 withUIContext {
                     if (isOnline()) {
                         if (downloadPreferences.downloadOnlyOverWifi().get() && !isConnectedToWifi()) {
-                            stopDownloads(R.string.download_notifier_text_only_wifi)
+                            downloaderStop(R.string.download_notifier_text_only_wifi)
                         } else {
-                            val started = downloadManager.startDownloads()
+                            val started = downloadManager.downloaderStart()
                             if (!started) stopSelf()
                         }
                     } else {
-                        stopDownloads(R.string.download_notifier_no_network)
+                        downloaderStop(R.string.download_notifier_no_network)
                     }
                 }
             }