Adds handling of external subtitles for anime

src/main/java/net/knarcraft/ffmpegconverter/converter/Converter.java

@@ -452,7 +452,7 @@ public abstract class Converter {
      * @param input <p>The text to print.</p>
      * @throws IOException <p>If a write is not possible.</p>
      */
-    static void print(String input) throws IOException {
+    private static void print(String input) throws IOException {
         if (!input.equals("")) {
             writer.write(input);
             writer.flush();
@@ -479,4 +479,37 @@ public abstract class Converter {
         writer.newLine();
         writer.flush();
     }
+
+    /**
+     * Checks whether there exists an external image subtitle with the same filename as the file
+     * @param directory <p>The directory containing the file.</p>
+     * @param file <p>The file to be converted.</p>
+     * @return <p>The extension of the subtitle or empty if no subtitle was found.</p>
+     */
+    String hasExternalImageSubtitle(String directory, String file) {
+        String path = stripExtension(file);
+        for (String subtitleExtension : new String[] {".idx", ".sub"}) {
+            if (new File(directory + File.separator + path + subtitleExtension).exists()) {
+                return path + subtitleExtension;
+            }
+        }
+        return "";
+    }
+
+    /**
+     * Checks whether there exists an external subtitle with the same filename as the file
+     * @param directory <p>The directory containing the file.</p>
+     * @param file <p>The file to be converted.</p>
+     * @return <p>The extension of the subtitle or empty if no subtitle was found.</p>
+     */
+    String hasExternalSubtitle(String directory, String file) {
+        String path = stripExtension(file);
+        for (String subtitleExtension : new String[] {".srt", ".ass"}) {
+            System.out.println(directory + File.separator + path + subtitleExtension);
+            if (new File(directory + File.separator + path + subtitleExtension).exists()) {
+                return path + subtitleExtension;
+            }
+        }
+        return "";
+    }
 }