Refactor: Convert from-base64 impl. to Scala

Author: TheBizzle

src/main/BitmapExtension.java

@@ -116,35 +116,6 @@ public void perform(Argument args[], Context context)
     }
   }
 
-  public static class FromBase64 implements Reporter {
-
-    public Syntax getSyntax() {
-      return SyntaxJ.reporterSyntax(new int[] { Syntax.StringType() }, Syntax.WildcardType());
-    }
-
-    public String getAgentClassString() {
-      return "OTPL";
-    }
-
-    public Object report(Argument args[], Context context)
-        throws ExtensionException, LogoException {
-      String[] splits = args[0].getString().split(",");
-      if (splits.length != 2) {
-        throw new ExtensionException("Base 64 string must start with a preamble like 'data:image/png;base64,...'");
-      }
-      String base64   = splits[1];
-      byte[] bytes    = Base64.getDecoder().decode(base64);
-      try {
-        BufferedImage image = ImageIO.read(new ByteArrayInputStream(bytes));
-        return new LogoBitmap(image);
-      }
-      catch (final IOException ex) {
-        throw new ExtensionException(ex);
-      }
-    }
-
-  }
-
   public static class ToBase64 implements Reporter {
 
     public Syntax getSyntax() {

src/main/BitmapExtension.scala

@@ -0,0 +1,38 @@
+package org.nlogo.extensions.bitmap
+
+import java.io.{ ByteArrayInputStream, IOException }
+import java.util.Base64
+
+import javax.imageio.ImageIO
+
+import org.nlogo.api.{ Argument, Context, ExtensionException, Reporter }
+import org.nlogo.core.Syntax
+
+class FromBase64 extends Reporter {
+
+  def getSyntax:           Syntax = Syntax.reporterSyntax(ret = Syntax.WildcardType, right = List(Syntax.StringType))
+  def getAgentClassString: String = "OTPL"
+
+  def report(args: Array[Argument], context: Context): AnyRef = {
+
+    val arr = args(0).getString.split(",")
+
+    val base64 =
+      if (arr.length == 2) {
+        arr(1)
+      } else {
+        throw new ExtensionException("This primitive only accepts input that is base64-encoded.")
+      }
+
+    val bytes = Base64.getDecoder().decode(base64)
+
+    try {
+      val image = ImageIO.read(new ByteArrayInputStream(bytes))
+      new LogoBitmap(image)
+    } catch {
+      case ex: IOException => throw new ExtensionException(ex)
+    }
+
+  }
+
+}