Skip connection check during download if files are already local

This applies to "downloads" that actually just toggle the caching status
from "permanently cached" to just "cached" (and back). In these cases
the connection check is skipped which would prevent the tasks from being
run and trigger a warning.

Fixes daneren2005#922

Author: flyingOwl

app/src/main/java/github/daneren2005/dsub/service/DownloadService.java

@@ -536,10 +536,6 @@ public synchronized void downloadBackground(List<MusicDirectory.Entry> songs, bo
 		}
 		revision++;
 
-		if(!Util.isOffline(this) && !Util.isNetworkConnected(this)) {
-			Util.toast(this, R.string.select_album_no_network);
-		}
-
 		checkDownloads();
 		lifecycleSupport.serializeDownloadQueue();
 	}
@@ -2269,7 +2265,17 @@ public synchronized void checkDownloads() {
 			checkArtistRadio();
 		}
 
-		if (!Util.isAllowedToDownload(this)) {
+		// If all files are local (like when permanently caching an already cached file) do not check if device is offline
+		boolean skipNetworkCheck = true;
+		for (DownloadFile d: downloadList) {
+			skipNetworkCheck &= d.isCompleteFileAvailable();
+		}
+		for (DownloadFile d: backgroundDownloadList) {
+			skipNetworkCheck &= d.isCompleteFileAvailable();
+		}
+
+		if (!skipNetworkCheck && !Util.isAllowedToDownload(this)) {
+			Util.toast(this, R.string.select_album_no_network);
 			return;
 		}