[Lens] Drag dimension to replace (#75895)

* [Lens] Drag to replace

* Add jest tests for drag and drop

* Fix bug in dragging to empty

* Hide dragged dimension when drag starts

* Make table metrics required

* Update class names

* Implement styles on non-droppable items

* Replace drag and drop image in docs

* Remove extra specificity

Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

Author: Wylie Conlon

docs/visualize/images/lens_drag_drop.gif

@@ -205,10 +205,10 @@ describe('Datatable Visualization', () => {
           },
           frame,
         }).groups
-      ).toHaveLength(1);
+      ).toHaveLength(2);
     });
 
-    it('allows all kinds of operations', () => {
+    it('allows only bucket operations one category', () => {
       const datasource = createMockDatasource('test');
       const frame = mockFrame();
       frame.datasourceLayers = { first: datasource.publicAPIMock };
@@ -232,6 +232,40 @@ describe('Datatable Visualization', () => {
       expect(filterOperations({ ...baseOperation, dataType: 'boolean' })).toEqual(true);
       expect(filterOperations({ ...baseOperation, dataType: 'other' as DataType })).toEqual(true);
       expect(filterOperations({ ...baseOperation, dataType: 'date', isBucketed: false })).toEqual(
+        false
+      );
+      expect(filterOperations({ ...baseOperation, dataType: 'number', isBucketed: false })).toEqual(
+        false
+      );
+    });
+
+    it('allows only metric operations in one category', () => {
+      const datasource = createMockDatasource('test');
+      const frame = mockFrame();
+      frame.datasourceLayers = { first: datasource.publicAPIMock };
+
+      const filterOperations = datatableVisualization.getConfiguration({
+        layerId: 'first',
+        state: {
+          layers: [{ layerId: 'first', columns: [] }],
+        },
+        frame,
+      }).groups[1].filterOperations;
+
+      const baseOperation: Operation = {
+        dataType: 'string',
+        isBucketed: true,
+        label: '',
+      };
+      expect(filterOperations({ ...baseOperation })).toEqual(false);
+      expect(filterOperations({ ...baseOperation, dataType: 'number' })).toEqual(false);
+      expect(filterOperations({ ...baseOperation, dataType: 'date' })).toEqual(false);
+      expect(filterOperations({ ...baseOperation, dataType: 'boolean' })).toEqual(false);
+      expect(filterOperations({ ...baseOperation, dataType: 'other' as DataType })).toEqual(false);
+      expect(filterOperations({ ...baseOperation, dataType: 'date', isBucketed: false })).toEqual(
+        true
+      );
+      expect(filterOperations({ ...baseOperation, dataType: 'number', isBucketed: false })).toEqual(
         true
       );
     });
@@ -248,7 +282,7 @@ describe('Datatable Visualization', () => {
           layerId: 'a',
           state: { layers: [layer] },
           frame,
-        }).groups[0].accessors
+        }).groups[1].accessors
       ).toEqual(['c', 'b']);
     });
   });

x-pack/plugins/lens/public/datatable_visualization/visualization.test.tsx

@@ -143,15 +143,29 @@ export const datatableVisualization: Visualization<DatatableVisualizationState>
       groups: [
         {
           groupId: 'columns',
-          groupLabel: i18n.translate('xpack.lens.datatable.columns', {
-            defaultMessage: 'Columns',
+          groupLabel: i18n.translate('xpack.lens.datatable.breakdown', {
+            defaultMessage: 'Break down by',
           }),
           layerId: state.layers[0].layerId,
-          accessors: sortedColumns,
+          accessors: sortedColumns.filter((c) => datasource.getOperationForColumnId(c)?.isBucketed),
           supportsMoreColumns: true,
-          filterOperations: () => true,
+          filterOperations: (op) => op.isBucketed,
           dataTestSubj: 'lnsDatatable_column',
         },
+        {
+          groupId: 'metrics',
+          groupLabel: i18n.translate('xpack.lens.datatable.metrics', {
+            defaultMessage: 'Metrics',
+          }),
+          layerId: state.layers[0].layerId,
+          accessors: sortedColumns.filter(
+            (c) => !datasource.getOperationForColumnId(c)?.isBucketed
+          ),
+          supportsMoreColumns: true,
+          filterOperations: (op) => !op.isBucketed,
+          required: true,
+          dataTestSubj: 'lnsDatatable_metrics',
+        },
       ],
     };
   },

x-pack/plugins/lens/public/datatable_visualization/visualization.tsx

@@ -1,3 +1,7 @@
+.lnsDragDrop-isNotDroppable {
+  opacity: .5;
+}
+
 // Fix specificity by chaining classes
 
 .lnsDragDrop.lnsDragDrop-isDropTarget {

x-pack/plugins/lens/public/drag_drop/__snapshots__/drag_drop.test.tsx.snap

@@ -49,7 +49,7 @@ describe('DragDrop', () => {
     const value = {};
 
     const component = mount(
-      <ChildDragDropProvider dragging={undefined} setDragging={setDragging}>
+      <ChildDragDropProvider dragging={value} setDragging={setDragging}>
         <DragDrop value={value} draggable={true} label="drag label">
           Hello!
         </DragDrop>
@@ -127,4 +127,63 @@ describe('DragDrop', () => {
 
     expect(component).toMatchSnapshot();
   });
+
+  test('items that have droppable=false get special styling when another item is dragged', () => {
+    const component = mount(
+      <ChildDragDropProvider dragging={'ignored'} setDragging={() => {}}>
+        <DragDrop value="ignored" draggable={true} label="a">
+          Ignored
+        </DragDrop>
+        <DragDrop onDrop={(x: unknown) => {}} droppable={false}>
+          Hello!
+        </DragDrop>
+      </ChildDragDropProvider>
+    );
+
+    expect(component.find('[data-test-subj="lnsDragDrop"]').at(1)).toMatchSnapshot();
+  });
+
+  test('additional styles are reflected in the className until drop', () => {
+    let dragging: string | undefined;
+    const getAdditionalClasses = jest.fn().mockReturnValue('additional');
+    const component = mount(
+      <ChildDragDropProvider
+        dragging={dragging}
+        setDragging={() => {
+          dragging = 'hello';
+        }}
+      >
+        <DragDrop value="ignored" draggable={true} label="a">
+          Ignored
+        </DragDrop>
+        <DragDrop
+          onDrop={(x: unknown) => {}}
+          droppable
+          getAdditionalClassesOnEnter={getAdditionalClasses}
+        >
+          Hello!
+        </DragDrop>
+      </ChildDragDropProvider>
+    );
+
+    const dataTransfer = {
+      setData: jest.fn(),
+      getData: jest.fn(),
+    };
+    component
+      .find('[data-test-subj="lnsDragDrop"]')
+      .first()
+      .simulate('dragstart', { dataTransfer });
+    jest.runAllTimers();
+
+    component.find('[data-test-subj="lnsDragDrop"]').at(1).simulate('dragover');
+    expect(component.find('.additional')).toHaveLength(1);
+
+    component.find('[data-test-subj="lnsDragDrop"]').at(1).simulate('dragleave');
+    expect(component.find('.additional')).toHaveLength(0);
+
+    component.find('[data-test-subj="lnsDragDrop"]').at(1).simulate('dragover');
+    component.find('[data-test-subj="lnsDragDrop"]').at(1).simulate('drop');
+    expect(component.find('.additional')).toHaveLength(0);
+  });
 });

x-pack/plugins/lens/public/drag_drop/_drag_drop.scss

@@ -49,6 +49,11 @@ interface BaseProps {
    */
   droppable?: boolean;
 
+  /**
+   * Additional class names to apply when another element is over the drop target
+   */
+  getAdditionalClassesOnEnter?: () => string;
+
   /**
    * The optional test subject associated with this DOM element.
    */
@@ -97,6 +102,12 @@ export const DragDrop = (props: Props) => {
       {...props}
       dragging={droppable ? dragging : undefined}
       isDragging={!!(draggable && value === dragging)}
+      isNotDroppable={
+        // If the configuration has provided a droppable flag, but this particular item is not
+        // droppable, then it should be less prominent. Ignores items that are both
+        // draggable and drop targets
+        droppable === false && Boolean(dragging) && value !== dragging
+      }
       setDragging={setDragging}
     />
   );
@@ -107,9 +118,13 @@ const DragDropInner = React.memo(function DragDropInner(
     dragging: unknown;
     setDragging: (dragging: unknown) => void;
     isDragging: boolean;
+    isNotDroppable: boolean;
   }
 ) {
-  const [state, setState] = useState({ isActive: false });
+  const [state, setState] = useState({
+    isActive: false,
+    dragEnterClassNames: '',
+  });
   const {
     className,
     onDrop,
@@ -120,13 +135,20 @@ const DragDropInner = React.memo(function DragDropInner(
     dragging,
     setDragging,
     isDragging,
+    isNotDroppable,
   } = props;
 
-  const classes = classNames('lnsDragDrop', className, {
-    'lnsDragDrop-isDropTarget': droppable,
-    'lnsDragDrop-isActiveDropTarget': droppable && state.isActive,
-    'lnsDragDrop-isDragging': isDragging,
-  });
+  const classes = classNames(
+    'lnsDragDrop',
+    className,
+    {
+      'lnsDragDrop-isDropTarget': droppable,
+      'lnsDragDrop-isActiveDropTarget': droppable && state.isActive,
+      'lnsDragDrop-isDragging': isDragging,
+      'lnsDragDrop-isNotDroppable': isNotDroppable,
+    },
+    state.dragEnterClassNames
+  );
 
   const dragStart = (e: DroppableEvent) => {
     // Setting stopPropgagation causes Chrome failures, so
@@ -159,19 +181,25 @@ const DragDropInner = React.memo(function DragDropInner(
 
     // An optimization to prevent a bunch of React churn.
     if (!state.isActive) {
-      setState({ ...state, isActive: true });
+      setState({
+        ...state,
+        isActive: true,
+        dragEnterClassNames: props.getAdditionalClassesOnEnter
+          ? props.getAdditionalClassesOnEnter()
+          : '',
+      });
     }
   };
 
   const dragLeave = () => {
-    setState({ ...state, isActive: false });
+    setState({ ...state, isActive: false, dragEnterClassNames: '' });
   };
 
   const drop = (e: DroppableEvent) => {
     e.preventDefault();
     e.stopPropagation();
 
-    setState({ ...state, isActive: false });
+    setState({ ...state, isActive: false, dragEnterClassNames: '' });
     setDragging(undefined);
 
     if (onDrop && droppable) {

x-pack/plugins/lens/public/drag_drop/drag_drop.test.tsx

@@ -27,6 +27,14 @@
   overflow: hidden;
 }
 
+.lnsLayerPanel__dimension-isHidden {
+  opacity: 0;
+}
+
+.lnsLayerPanel__dimension-isReplacing {
+  text-decoration: line-through;
+}
+
 .lnsLayerPanel__triggerLink {
   padding: $euiSizeS;
   width: 100%;