[Feature] CSS grid-gap support

src/.stories/Storybook.scss

@@ -112,31 +112,31 @@ $focusedOutlineColor: #4c9ffe;
 
 // Grid
 .grid {
-  display: block;
-  width: 130 * 4px;
-  height: 350px;
+  display: grid;
+  height: 130 * 3px + 20px;
+  grid-gap: 10px;
+  grid-template-columns: auto auto auto auto;
+  width: auto;
   white-space: nowrap;
   border: 0;
   background-color: transparent;
 }
 
 .gridItem {
-  float: left;
   width: 130px;
-  padding: 8px;
-  background: transparent;
-  border: 0;
+  height: 130px;
+  padding: 0;
+  border: none;
+  background-color: transparent;
 
   .wrapper {
     display: flex;
     align-items: center;
     justify-content: center;
-
     width: 100%;
     height: 100%;
-    background: #fff;
-    border: 1px solid #efefef;
-
+    background-color: #fff;
+    transform: scale(1);
     font-size: 28px;
 
     span {
@@ -145,6 +145,31 @@ $focusedOutlineColor: #4c9ffe;
   }
 }
 
+.gridVariableSized {
+  .gridItem {
+    &[data-index='0'] {
+      width: auto !important;
+      height: auto !important;
+      grid-column-end: span 2;
+      grid-row-end: span 2;
+    }
+  }
+
+  &.isSorting {
+    .gridItem {
+      transition: transform 150ms ease;
+    }
+  }
+}
+
+.gridItemVariableSized {
+  &[data-index='0'] {
+    .wrapper {
+      font-size: 56px;
+    }
+  }
+}
+
 // Nested
 .category {
   height: auto;
@@ -183,29 +208,24 @@ $focusedOutlineColor: #4c9ffe;
 }
 
 .stylizedHelper {
-  border: 1px solid #efefef;
-  box-shadow: 0 5px 5px -5px rgba(0, 0, 0, 0.2);
-  background-color: rgba(255, 255, 255, 0.9);
-  border-radius: 3px;
-
-  &.horizontalItem {
-    cursor: col-resize;
-  }
+  &:not(.gridItem),
+  &.gridItem .wrapper {
+    border: 1px solid #efefef;
+    box-shadow: 0 5px 5px -5px rgba(0, 0, 0, 0.2);
+    background-color: rgba(255, 255, 255, 0.9);
+    border-radius: 3px;
 
-  &.gridItem {
-    background-color: transparent;
-    white-space: nowrap;
-    box-shadow: none;
-    border: none;
+    &.horizontalItem {
+      cursor: col-resize;
+    }
 
-    .wrapper {
-      background-color: rgba(255, 255, 255, 0.9);
-      box-shadow: 0 0 7px rgba(0, 0, 0, 0.15);
+    &:focus {
+      box-shadow: 0 0px 5px 1px $focusedOutlineColor;
     }
   }
 
-  &:focus {
-    box-shadow: 0 0px 5px 1px $focusedOutlineColor;
+  &.gridItem .wrapper {
+    transition: transform 150ms ease-in-out;
   }
 }
 

src/.stories/index.js

@@ -22,7 +22,7 @@ function getItems(count, height) {
   return range(count).map((value) => {
     return {
       value,
-      height: height || heights[random(0, heights.length - 1)],
+      height: height == null ? heights[random(0, heights.length - 1)] : height,
     };
   });
 }
@@ -47,7 +47,7 @@ const Item = SortableElement(
     style: propStyle,
     shouldUseDragHandle,
     value,
-    type,
+    itemIndex,
     isSorting,
   }) => {
     const bodyTabIndex = tabbable && !shouldUseDragHandle ? 0 : -1;
@@ -66,6 +66,7 @@ const Item = SortableElement(
           ...propStyle,
         }}
         tabIndex={bodyTabIndex}
+        data-index={itemIndex}
       >
         {shouldUseDragHandle && <Handle tabIndex={handleTabIndex} />}
         <div className={style.wrapper}>
@@ -99,6 +100,7 @@ const SortableList = SortableContainer(
               isDisabled={disabled}
               className={itemClass}
               index={index}
+              itemIndex={index}
               value={value}
               height={height}
               shouldUseDragHandle={shouldUseDragHandle}
@@ -178,14 +180,14 @@ class ListWrapper extends Component {
     height: 600,
   };
 
-  onSortStart = () => {
+  onSortStart = (...args) => {
     const {onSortStart} = this.props;
     this.setState({isSorting: true});
 
     document.body.style.cursor = 'grabbing';
 
     if (onSortStart) {
-      onSortStart(this.refs.component);
+      onSortStart(this.refs.component, ...args);
     }
   };
 
@@ -230,7 +232,7 @@ const SortableReactWindow = (Component) =>
         return (
           <Component
             ref="VirtualList"
-            className={className}
+            className={classNames(className, style.isSorting)}
             itemSize={
               itemHeight == null ? (index) => items[index].height : itemHeight
             }
@@ -510,20 +512,93 @@ storiesOf('General | Layout / Horizontal list', module).add(
   },
 );
 
-storiesOf('General | Layout / Grid', module).add('Basic setup', () => {
-  return (
-    <div className={style.root}>
-      <ListWrapper
-        component={SortableList}
-        axis={'xy'}
-        items={getItems(10, 110)}
-        helperClass={style.stylizedHelper}
-        className={classNames(style.list, style.stylizedList, style.grid)}
-        itemClass={classNames(style.stylizedItem, style.gridItem)}
-      />
-    </div>
-  );
-});
+storiesOf('General | Layout / Grid', module)
+  .add('Basic setup', () => {
+    const transformOrigin = {
+      x: 0,
+      y: 0,
+    };
+
+    return (
+      <div className={style.root}>
+        <ListWrapper
+          component={SortableList}
+          axis={'xy'}
+          items={getItems(10, false)}
+          helperClass={style.stylizedHelper}
+          className={classNames(style.list, style.stylizedList, style.grid)}
+          itemClass={classNames(style.stylizedItem, style.gridItem)}
+        />
+      </div>
+    );
+  })
+  .add('Large first item', () => {
+    const transformOrigin = {
+      x: 0,
+      y: 0,
+    };
+
+    return (
+      <div className={style.root}>
+        <ListWrapper
+          component={SortableList}
+          axis={'xy'}
+          items={getItems(9, false)}
+          helperClass={style.stylizedHelper}
+          className={classNames(
+            style.list,
+            style.stylizedList,
+            style.grid,
+            style.gridVariableSized,
+          )}
+          itemClass={classNames(
+            style.stylizedItem,
+            style.gridItem,
+            style.gridItemVariableSized,
+          )}
+          onSortStart={(_, {node}, event) => {
+            const boundingClientRect = node.getBoundingClientRect();
+
+            transformOrigin.x =
+              ((event.clientX - boundingClientRect.left) /
+                boundingClientRect.width) *
+              100;
+            transformOrigin.y =
+              ((event.clientY - boundingClientRect.top) /
+                boundingClientRect.height) *
+              100;
+          }}
+          onSortOver={({nodes, newIndex, index, helper}) => {
+            const finalNodes = arrayMove(nodes, index, newIndex);
+            const oldNode = nodes[index].node;
+            const newNode = nodes[newIndex].node;
+            const helperScale = newNode.offsetWidth / oldNode.offsetWidth;
+            const helperWrapperNode = helper.childNodes[0];
+
+            helperWrapperNode.style.transform = `scale(${helperScale})`;
+            helperWrapperNode.style.transformOrigin = `${transformOrigin.x}% ${transformOrigin.y}%`;
+
+            finalNodes.forEach(({node}, i) => {
+              const oldNode = nodes[i].node;
+              const scale = oldNode.offsetWidth / node.offsetWidth;
+              const wrapperNode = node.childNodes[0];
+
+              wrapperNode.style.transform = `scale(${scale})`;
+              wrapperNode.style.transformOrigin =
+                newIndex > i ? '0 0' : '100% 0';
+            });
+          }}
+          onSortEnd={() => {
+            [...document.querySelectorAll(`.${style.wrapper}`)].forEach(
+              (node) => {
+                node.style.transform = '';
+              },
+            );
+          }}
+        />
+      </div>
+    );
+  });
 
 storiesOf('General | Configuration / Options', module)
   .add('Drag handle', () => {

src/SortableContainer/index.js

@@ -11,6 +11,7 @@ import {
   closest,
   events,
   getScrollingParent,
+  getContainerGridGap,
   getEdgeOffset,
   getElementMargin,
   getLockPixelOffsets,
@@ -260,16 +261,18 @@ export default function sortableContainer(
         // Need to get the latest value for `index` in case it changes during `updateBeforeSortStart`
         const {index} = node.sortableInfo;
         const margin = getElementMargin(node);
+        const gridGap = getContainerGridGap(this.container);
         const containerBoundingRect = this.scrollContainer.getBoundingClientRect();
-        const dimensions = getHelperDimensions({collection, index, node});
+        const dimensions = getHelperDimensions({index, node, collection});
 
         this.node = node;
         this.margin = margin;
+        this.gridGap = gridGap;
         this.width = dimensions.width;
         this.height = dimensions.height;
         this.marginOffset = {
-          x: this.margin.left + this.margin.right,
-          y: Math.max(this.margin.top, this.margin.bottom),
+          x: this.margin.left + this.margin.right + this.gridGap.x,
+          y: Math.max(this.margin.top, this.margin.bottom, this.gridGap.y),
         };
         this.boundingClientRect = node.getBoundingClientRect();
         this.containerBoundingRect = containerBoundingRect;
@@ -425,7 +428,17 @@ export default function sortableContainer(
         });
 
         if (onSortStart) {
-          onSortStart({node, index, collection, isKeySorting}, event);
+          onSortStart(
+            {
+              node,
+              index,
+              collection,
+              isKeySorting,
+              nodes: this.manager.getOrderedRefs(),
+              helper: this.helper,
+            },
+            event,
+          );
         }
 
         if (isKeySorting) {
@@ -458,7 +471,7 @@ export default function sortableContainer(
         active: {collection},
         isKeySorting,
       } = this.manager;
-      const nodes = this.manager.refs[collection];
+      const nodes = this.manager.getOrderedRefs();
 
       // Remove the event listeners if the node is still in the DOM
       if (this.listenerNode) {
@@ -533,6 +546,7 @@ export default function sortableContainer(
             newIndex: this.newIndex,
             oldIndex: this.index,
             isKeySorting,
+            nodes,
           },
           event,
         );
@@ -818,6 +832,8 @@ export default function sortableContainer(
           newIndex: this.newIndex,
           oldIndex,
           isKeySorting,
+          nodes,
+          helper: this.helper,
         });
       }
     }

src/utils.js

@@ -259,6 +259,19 @@ export function getScrollingParent(el) {
   }
 }
 
+export function getContainerGridGap(element) {
+  const style = window.getComputedStyle(element);
+
+  if (style.display === 'grid') {
+    return {
+      x: getPixelValue(style.gridColumnGap),
+      y: getPixelValue(style.gridRowGap),
+    };
+  }
+
+  return {x: 0, y: 0};
+}
+
 export const KEYCODE = {
   TAB: 9,
   ESC: 27,