diff --git a/lib/scatter.js b/lib/scatter.js
index 7066dcb..021f4df 100644
--- a/lib/scatter.js
+++ b/lib/scatter.js
@@ -34,6 +34,11 @@ export class BaseEvent {
 const START = 'onStart'
 const UPDATE = 'onUpdate'
 const END = 'onEnd'
+const DRAG_UPDATE = 'onDragUpdate'
+const DRAG_COMPLETE = 'onDragComplete'
+const MOVED = 'onMoved'
+const RESIZED = 'onResized'
+const ZOOMED = 'onZoomed'
 
 /**
  * A scatter event that describes how the scatter has changed.
@@ -892,7 +897,7 @@ export class AbstractScatter extends Throwable {
                 translate: delta,
                 scale: this.scale,
                 about: this.currentAbout,
-                type: null
+                type: DRAG_UPDATE
             })
             this.onTransform.forEach(function(f) {
                 f(event)
@@ -906,7 +911,7 @@ export class AbstractScatter extends Throwable {
                 scale: this.scale,
                 about: this.currentAbout,
                 fast: false,
-                type: null
+                type: DRAG_COMPLETE
             })
             this.onTransform.forEach(function(f) {
                 f(event)
@@ -920,7 +925,7 @@ export class AbstractScatter extends Throwable {
                 translate: { x: dx, y: dy },
                 about: about,
                 fast: true,
-                type: null
+                type: MOVED
             })
             this.onTransform.forEach(function(f) {
                 f(event)
@@ -933,7 +938,7 @@ export class AbstractScatter extends Throwable {
             let event = new ScatterEvent(this, {
                 scale: this.scale,
                 fast: false,
-                type: null
+                type: RESIZED
             })
             this.onTransform.forEach(function(f) {
                 f(event)
@@ -949,7 +954,7 @@ export class AbstractScatter extends Throwable {
                 scale: this.scale,
                 about: about,
                 fast: false,
-                type: null
+                type: ZOOMED
             })
             this.onTransform.forEach(function(f) {
                 f(event)