Added getAllFiles method

Author: HSorensen

runtime/Java/src/org/antlr/v4/runtime/IncludeStrategy.java

@@ -1,5 +1,7 @@
 package org.antlr.v4.runtime;
 
+import java.util.List;
+
 import org.antlr.v4.runtime.misc.Pair;
 
 public interface IncludeStrategy {
@@ -28,6 +30,11 @@ public Pair<CharStream, Integer> fileName2StreamPair(String fileName,
     */
    public String getQualifiedFileName(String lexerIncludeRequest);
 
+   /**
+    * Return the list of qualified file names that have been used for the scanning.
+    * @return List<String>
+    */
+   public List<String>  getAllFiles();
 
 
 }

runtime/Java/src/org/antlr/v4/runtime/IncludeStrategyImpl.java

@@ -6,10 +6,9 @@
 import java.io.InputStream;
 import java.io.Serializable;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Iterator;
-
+import java.util.List;
 import org.antlr.v4.runtime.misc.Pair;
 
 public class IncludeStrategyImpl implements IncludeStrategy, Serializable
@@ -153,6 +152,12 @@ public String getQualifiedFileName(String lexerIncludeName)
 			return getIncludePrefix()+lexerIncludeName+getIncludeSuffix();
 		}
 
-		
+		/**
+		 * Returns all qualified files names
+		 */
+		public List<String>  getAllFiles()
+		{
+			return new ArrayList<String>(this.filenameIndexMap.keySet());
+		}
 
 	}