fix(fields): Implement getClass method

Author: cpcallen

plugins/field-bitmap/src/field-bitmap.ts

@@ -609,6 +609,18 @@ export class FieldBitmap extends Blockly.Field<number[][]> {
       );
     }
   }
+
+  /**
+   * Returns this field's class.
+   *
+   * Used by keyboard navigation to look up the rules for navigating from this
+   * field.
+   *
+   * @returns This field's class.
+   */
+  getClass() {
+    return FieldBitmap;
+  }
 }
 
 interface Buttons {

plugins/field-colour/src/field_colour.ts

@@ -729,6 +729,18 @@ export class FieldColour extends Blockly.Field<string> {
     // the static fromJson method.
     return new this(options.colour, undefined, options);
   }
+
+  /**
+   * Returns this field's class.
+   *
+   * Used by keyboard navigation to look up the rules for navigating from this
+   * field.
+   *
+   * @returns This field's class.
+   */
+  getClass() {
+    return FieldColour;
+  }
 }
 
 /** The default value for this field. */