De-duplicating code to render subexp and charset containers

src/js/parser/javascript/charset.js

@@ -5,18 +5,7 @@ export default _.extend({}, Base, {
   type: 'charset',
 
   render() {
-    this.label = this.container.text()
-      .addClass('charset-label')
-      .attr({
-        text: this.invert() ? 'None of:' : 'One of:'
-      });
-
-    this.box = this.container.rect()
-      .addClass('charset-box')
-      .attr({
-        rx: 3,
-        ry: 3
-      });
+    this.renderLabeledBox(this.invert() ? 'None of:' : 'One of:');
 
     this.partContainer = this.container.group();
 
@@ -27,30 +16,14 @@ export default _.extend({}, Base, {
   },
 
   position() {
-    var box;
-
     _.invoke(this.parts.elements, 'position');
 
     this.spaceVertically(this.parts.elements, {
       padding: 5
     });
 
-    box = this.label.getBBox();
-
-    this.label.transform(Snap.matrix()
-      .translate(0, box.height));
-
-    this.partContainer.transform(Snap.matrix()
-      .translate(5, 5 + box.height));
-
-    this.box.transform(Snap.matrix()
-      .translate(0, box.height));
-
-    box = this.partContainer.getBBox();
-
-    this.box.attr({
-      width: box.width + 10,
-      height: box.height + 10
+    this.positionLabeledBox(this.partContainer, {
+      padding: 5
     });
   },