[CARBON-865] CustomDragLayer component for enabling Drag & Drop ghost row

CHANGELOG.md

@@ -4,12 +4,56 @@
 
 * `ConfigurableItems` now accepts an `onReset` prop to be passed in.
 
-### npm
+## npm
 
 * Carbon now require `npm` version 5 for installing dependencies.
 * To upgrade your version of npm, run `npm install npm@latest`.
 * Then, before running `npm install` in your project folder, run `npm verify cache` to update your cache.
 
+## Draggable ghost row
+
+The `DraggableContext` component now includes a `CustomDragLayer` to enable a ghost row when dragging.
+
+In order to enable this you need to define the `draggableNode` prop on the `<WithDrag>` component. For example:
+
+```
+class DraggableItems extends React.Component {
+  render() {
+    return (
+      <DraggableContext onDrag={ onItemMoved }>
+        <ol>
+          {
+            items.map((item, index) => {
+              return (
+                <WithDrop key={ index } index={ index }>
+                  <DraggableItem />
+                </WithDrop>
+              );
+            });
+          }
+        </ol>
+      </DraggableContext>
+    );
+  }
+}
+
+...
+
+class DraggableItem extends React.Component {
+  render() {
+    return (
+      <li ref={ (node) => { this._listItem = node; } } >
+        <WithDrag draggableNode={ () => { return this._listItem; } }>
+          <span>{ item.content }</span>
+        </WithDrag>
+      </li>
+    );
+  }
+}
+```
+
+Note that the `draggableNode` is passed as a function because the ref `_listItem` is undefined until the component is mounted.
+
 # 1.4.4
 
 * `Date`: Fixes missing background color on validation errors.

src/components/configurable-items/configurable-item-row/__spec__.js

@@ -1,9 +1,10 @@
 import React from 'react';
-import { shallow } from 'enzyme';
+import { shallow, mount } from 'enzyme';
 import ConfigurableItemRow from './configurable-item-row';
 import Checkbox from './../../checkbox';
 import Icon from './../../icon';
 import { WithDrag, WithDrop } from './../../drag-and-drop';
+import DraggableContext from './../../drag-and-drop/draggable-context';
 import { rootTagTest } from './../../../utils/helpers/tags/tags-specs';
 
 describe('ConfigurableItemRow', () => {
@@ -140,13 +141,20 @@ describe('ConfigurableItemRow', () => {
 
   describe('icon', () => {
     beforeEach(() => {
-      wrapper = shallow(
-        <ConfigurableItemRow name='Foo' />
+      wrapper = mount(
+        <DraggableContext onDrag={() => {}}>
+          <ConfigurableItemRow name='Foo' />
+        </DraggableContext>
       );
     });
 
-    it('renders a drag vertical icon', () => {
-      expect(wrapper.find(Icon).props().type).toEqual('drag_vertical')
+    it('renders a drag vertical icon wrapped in WithDrag', () => {
+      wrapper.update(); // this is required because the _draggableNode ref is initially undefined.
+      const withDrag = wrapper.find(WithDrag);
+      const row = wrapper.find(ConfigurableItemRow);
+      expect(withDrag.length).toEqual(1);
+      expect(withDrag.find(Icon).props().type).toEqual('drag_vertical');
+      expect(withDrag.props().draggableNode()).toEqual(row.node._listItem)
     });
   });
 
@@ -157,8 +165,10 @@ describe('ConfigurableItemRow', () => {
       );
     });
 
-    it('renders an <li>', () => {
-      expect(wrapper.find('li').length).toEqual(1)
+    it('renders an <li> wrapped in WithDrop', () => {
+      const withDrop = wrapper.find(WithDrop);
+      expect(withDrop.length).toEqual(1);
+      expect(withDrop.find('li').length).toEqual(1);
     });
-  })
+  });
 });

src/components/configurable-items/configurable-item-row/configurable-item-row.js

@@ -73,15 +73,21 @@ class ConfigurableItemRow extends React.Component {
     );
   }
 
+  iconHTML() {
+    return (
+      <div>
+        <Icon
+          className='configurable-item-row__icon'
+          type='drag_vertical'
+        />
+      </div>
+    );
+  }
+
   icon() {
     return (
-      <WithDrag>
-        <div>
-          <Icon
-            className='configurable-item-row__icon'
-            type='drag_vertical'
-          />
-        </div>
+      <WithDrag draggableNode={ () => { return this._listItem; } } >
+        {this.iconHTML()}
       </WithDrag>
     );
   }
@@ -119,16 +125,25 @@ class ConfigurableItemRow extends React.Component {
     return typeof (dragAndDropActiveIndex) === 'number';
   }
 
-  render() {
+  listItemHTML = () => {
     const { rowIndex, enabled, locked, name, onChange } = this.props;
     return (
-      <WithDrop index={ rowIndex } { ...tagComponent('configurable-item-row', this.props) }>
-        <li className={ this.classes(this.context.dragAndDropActiveIndex, rowIndex) }>
-          <div className='configurable-item-row__content-wrapper'>
-            { this.icon() }
-            { this.checkbox(enabled, locked, name, onChange) }
-          </div>
-        </li>
+      <li
+        className={ this.classes(this.context.dragAndDropActiveIndex, rowIndex) }
+        ref={ (node) => { this._listItem = node; } }
+      >
+        <div className='configurable-item-row__content-wrapper'>
+          { this.icon() }
+          { this.checkbox(enabled, locked, name, onChange) }
+        </div>
+      </li>
+    );
+  }
+
+  render() {
+    return (
+      <WithDrop index={ this.props.rowIndex } { ...tagComponent('configurable-item-row', this.props) }>
+        { this.listItemHTML() }
       </WithDrop>
     );
   }

src/components/configurable-items/configurable-item-row/configurable-item-row.scss

@@ -13,6 +13,12 @@
   cursor: -webkit-grabbing;
 }
 
+.configurable-item-row--dragged {
+  .configurable-item-row__content-wrapper {
+    visibility: hidden;
+  }
+}
+
 .configurable-item-row__content-wrapper {
   align-items: center;
   display: flex;
@@ -22,3 +28,23 @@
 .configurable-item-row__icon {
   cursor: move;
 }
+
+.custom-drag-layer {
+  .configurable-item-row {
+    background-color: $grey-light;
+    border: none;
+    cursor: grabbing;
+    cursor: -moz-grabbing;
+    cursor: -webkit-grabbing;
+
+    .configurable-item-row__icon {
+      cursor: grabbing;
+      cursor: -moz-grabbing;
+      cursor: -webkit-grabbing;
+    }
+
+    .configurable-item-row__content-wrapper {
+      visibility: visible;
+    }
+  }
+}

src/components/drag-and-drop/custom-drag-layer/__definition__.js

@@ -0,0 +1,14 @@
+import CustomDragLayer from './';
+import Definition from './../../../../demo/utils/definition';
+
+const definition = new Definition('custom-drag-layer', CustomDragLayer, {
+  props: ['className'],
+  propTypes: {
+    className: 'String'
+  },
+  propDescriptions: {
+    className: 'Custom classes to apply to the component'
+  }
+});
+
+export default definition;