Prevent downloading songs that are already loaded. (base: fluddokt/opsu/76778f8)

- All beatmap set IDs are now stored in a set in OsuGroupList.
- OsuParser now checks the directory name for beatmap set IDs if the OsuFile doesn't contain one (for older beatmap formats).

Tweaks:
- Clear completed downloads when hitting "Import All".
- Call Download.updateReadSoFar() upon starting downloads instead of waiting for user to hover over the button (causing an unnecessary delay).

Signed-off-by: Jeffrey Han <itdelatrisu@gmail.com>

src/itdelatrisu/opsu/downloads/DownloadNode.java

@@ -21,6 +21,7 @@ package itdelatrisu.opsu.downloads;
 import itdelatrisu.opsu.ErrorHandler;
 import itdelatrisu.opsu.GameImage;
 import itdelatrisu.opsu.Options;
+import itdelatrisu.opsu.OsuGroupList;
 import itdelatrisu.opsu.Utils;
 import itdelatrisu.opsu.downloads.Download.Status;
 
@@ -296,6 +297,12 @@ public class DownloadNode {
 		g.setColor((focus) ? BG_FOCUS : (hover) ? BG_HOVER : BG_NORMAL);
 		g.fillRect(buttonBaseX, y, buttonWidth, buttonHeight);
 
+		// map is already loaded
+		if (OsuGroupList.get().containsBeatmapSetID(beatmapSetID)) {
+			g.setColor(Utils.COLOR_BLUE_BUTTON);
+			g.fillRect(buttonBaseX, y, buttonWidth, buttonHeight);
+		}
+
 		// download progress
 		if (dl != null) {
 			float progress = dl.getProgress();
@@ -349,7 +356,7 @@ public class DownloadNode {
 		else if (status == Download.Status.WAITING)
 			info = String.format("%s...", status.getName());
 		else {
-			if (hover)
+			if (hover && status == Download.Status.DOWNLOADING)
 				info = String.format("%s: %s left (%s)", status.getName(), download.getTimeRemaining(), download.getDownloadSpeed());
 			else
 				info = String.format("%s: %.1f%% (%s/%s)", status.getName(), progress,