make max number of plots configurable

Author: pfitzseb

lib/plots/pane.js

@@ -116,11 +116,11 @@ export default class PlotPane extends PaneItem {
     }
   }
 
-  show (view) {
+  show (view, {maxSize: maxSize} = {maxSize: MAX_SIZE}) {
     if (view) {
       this.ids.push(this.counter += 1)
       this.items.push(view)
-      this.prune()
+      this.prune(maxSize)
       this.activateItem(this.items.length - 1)
     }
     etch.update(this, false)
@@ -139,11 +139,11 @@ export default class PlotPane extends PaneItem {
     }
   }
 
-  prune () {
+  prune (maxSize) {
     const numItems = this.items.length
-    if (numItems <= MAX_SIZE) return
+    if (numItems <= maxSize) return
 
-    const startInd = numItems - MAX_SIZE
+    const startInd = numItems - maxSize
     this.items.forEach((item, ind) => {
       if (ind < startInd && item.teardown) {
         item.teardown()