drastically improved viewport

src/state/middleware/auto-scroll.js

@@ -30,16 +30,14 @@ export default (getMarshal: () => DimensionMarshal) =>
       scrollWindow,
     });
 
-    return (action: Action): mixed => {
+    const shouldCancel = (action: Action) =>
       // Need to cancel any pending auto scrolling when drag is ending
-      if (isDragEnding(action)) {
-        scroller.cancel();
-        next(action);
-        return;
-      }
-
+      isDragEnding(action) ||
       // A new bulk collection is starting - cancel any pending auto scrolls
-      if (action.type === 'BULK_COLLECTION_STARTING') {
+      action.type === 'BULK_COLLECTION_STARTING';
+
+    return (action: Action): mixed => {
+      if (shouldCancel(action)) {
         scroller.cancel();
         next(action);
         return;

src/state/move-to-next-index/in-home-list.js

@@ -134,8 +134,6 @@ export default ({
   const distance: Position = subtract(newPageBorderBoxCenter, previousPageBorderBoxCenter);
   const distanceWithScroll: Position = withDroppableDisplacement(droppable, distance);
 
-  console.log('request jump scroll', distanceWithScroll);
-
   return {
     pageBorderBoxCenter: previousPageBorderBoxCenter,
     impact: newImpact,

src/state/scroll-viewport.js

@@ -2,7 +2,6 @@
 import { getRect, type Rect } from 'css-box-model';
 import type { Position } from 'css-box-model';
 import { subtract, negate } from './position';
-import { offsetByPosition } from './spacing';
 import type { Viewport } from '../types';
 
 export default (viewport: Viewport, newScroll: Position): Viewport => {
@@ -11,10 +10,12 @@ export default (viewport: Viewport, newScroll: Position): Viewport => {
 
   // We need to update the frame so that it is always a live value
   // The top / left of the frame should always match the newScroll position
-  const change: Position = subtract(diff, viewport.scroll.current);
-  const frame: Rect = getRect(
-    offsetByPosition(viewport.frame, change)
-  );
+  const frame: Rect = getRect({
+    top: newScroll.y,
+    bottom: newScroll.y + viewport.frame.height,
+    left: newScroll.x,
+    right: newScroll.x + viewport.frame.width,
+  });
 
   const updated: Viewport = {
     frame,

src/view/window/get-viewport.js

@@ -49,5 +49,7 @@ export default (): Viewport => {
     },
   };
 
+  console.log('viewport', viewport);
+
   return viewport;
 };