[Lens] Consistent Drag and Drop styles

src/plugins/kibana_react/public/field_button/field_button.tsx

@@ -19,7 +19,8 @@
 
 import './field_button.scss';
 import classNames from 'classnames';
-import React, { ReactNode, HTMLAttributes } from 'react';
+import React, { ReactNode, HTMLAttributes, ButtonHTMLAttributes } from 'react';
+import { CommonProps } from '@elastic/eui';
 
 export interface FieldButtonProps extends HTMLAttributes<HTMLDivElement> {
   /**
@@ -56,7 +57,14 @@ export interface FieldButtonProps extends HTMLAttributes<HTMLDivElement> {
    * The component will render a `<button>` when provided an `onClick`
    */
   onClick?: () => void;
+  /**
+   * Applies to the inner `<button>`  or `<div>`
+   */
   dataTestSubj?: string;
+  /**
+   * Pass more button props to the `<button>` element
+   */
+  buttonProps?: ButtonHTMLAttributes<HTMLButtonElement> & CommonProps;
 }
 
 const sizeToClassNameMap = {
@@ -79,6 +87,8 @@ export function FieldButton({
   isDraggable = false,
   onClick,
   dataTestSubj,
+  buttonProps,
+  ...rest
 }: FieldButtonProps) {
   const classes = classNames(
     'kbnFieldButton',
@@ -88,8 +98,18 @@ export function FieldButton({
     className
   );
 
+  const contentClasses = classNames('kbn-resetFocusState', 'kbnFieldButton__button');
+
+  const innerContent = (
+    <>
+      {fieldIcon && <span className="kbnFieldButton__fieldIcon">{fieldIcon}</span>}
+      {fieldName && <span className="kbnFieldButton__name">{fieldName}</span>}
+      {fieldInfoIcon && <div className="kbnFieldButton__infoIcon">{fieldInfoIcon}</div>}
+    </>
+  );
+
   return (
-    <div className={classes}>
+    <div className={classes} {...rest}>
       {onClick ? (
         <button
           onClick={(e) => {
@@ -99,17 +119,14 @@ export function FieldButton({
             onClick();
           }}
           data-test-subj={dataTestSubj}
-          className={'kbn-resetFocusState kbnFieldButton__button'}
+          className={contentClasses}
+          {...buttonProps}
         >
-          {fieldIcon && <span className="kbnFieldButton__fieldIcon">{fieldIcon}</span>}
-          {fieldName && <span className="kbnFieldButton__name">{fieldName}</span>}
-          {fieldInfoIcon && <div className="kbnFieldButton__infoIcon">{fieldInfoIcon}</div>}
+          {innerContent}
         </button>
       ) : (
-        <div className={'kbn-resetFocusState kbnFieldButton__button'} data-test-subj={dataTestSubj}>
-          {fieldIcon && <span className="kbnFieldButton__fieldIcon">{fieldIcon}</span>}
-          {fieldName && <span className="kbnFieldButton__name">{fieldName}</span>}
-          {fieldInfoIcon && <div className="kbnFieldButton__infoIcon">{fieldInfoIcon}</div>}
+        <div className={contentClasses} data-test-subj={dataTestSubj}>
+          {innerContent}
         </div>
       )}
 

x-pack/plugins/lens/public/_mixins.scss

@@ -11,3 +11,39 @@
     transparentize(red, .9) 100%
   );
 }
+
+// Static styles for a draggable item
+@mixin lnsDraggable {
+  @include euiSlightShadow;
+  background: lightOrDarkTheme($euiColorEmptyShade, $euiColorLightestShade);
+  border: $euiBorderWidthThin dashed transparent;
+  cursor: grab;
+}
+
+// Static styles for a drop area
+@mixin lnsDroppable {
+  border: $euiBorderWidthThin dashed $euiBorderColor;
+}
+
+// Hovering state for drag item and drop area
+@mixin lnsDragDropHover {
+  &:hover {
+    border: $euiBorderWidthThin dashed $euiColorMediumShade;
+  }
+}
+
+// Style for drop area when there's an item being dragged
+@mixin lnsDroppableActive {
+  background-color: transparentize($euiColorVis0, .9);
+}
+
+// Style for drop area while hovering with item
+@mixin lnsDroppableActiveHover {
+  background-color: transparentize($euiColorVis0, .75);
+  border: $euiBorderWidthThin dashed $euiColorVis0;
+}
+
+// Style for drop area that is not allowed for current item
+@mixin lnsDroppableNotAllowed {
+  opacity: .5;
+}

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

@@ -1,13 +1,54 @@
-.lnsDragDrop-isNotDroppable {
-  opacity: .5;
+@import '../variables';
+@import '../mixins';
+
+.lnsDragDrop {
+  transition: background-color $euiAnimSpeedFast ease-in-out, border-color $euiAnimSpeedFast ease-in-out;
+}
+
+// Draggable item
+.lnsDragDrop-isDraggable {
+  @include lnsDraggable;
+  @include lnsDragDropHover;
+
+  // Include a possible nested button like when using FieldButton
+  > .kbnFieldButton__button {
+    cursor: grab;
+  }
+
+  &:focus {
+    @include euiFocusRing;
+  }
+}
+
+// Draggable item when it is moving
+.lnsDragDrop-isHidden {
+  opacity: 0;
+}
+
+// Drop area
+.lnsDragDrop-isDroppable {
+  @include lnsDroppable;
 }
 
-// Fix specificity by chaining classes
+// Drop area when there's an item being dragged
+.lnsDragDrop-isDropTarget {
+  @include lnsDroppableActive;
+}
 
-.lnsDragDrop.lnsDragDrop-isDropTarget {
-  background-color: transparentize($euiColorSecondary, .9);
+// Drop area while hovering with item
+.lnsDragDrop-isActiveDropTarget {
+  @include lnsDroppableActiveHover;
+}
+
+// Drop area that is not allowed for current item
+.lnsDragDrop-isNotDroppable {
+  @include lnsDroppableNotAllowed;
 }
 
-.lnsDragDrop.lnsDragDrop-isActiveDropTarget {
-  background-color: transparentize($euiColorSecondary, .75);
+// Drop area will be replacing existing content
+.lnsDragDrop-isReplacing {
+  &,
+  .lnsLayerPanel__triggerLink {
+    text-decoration: line-through;
+  }
 }

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

@@ -15,7 +15,7 @@ describe('DragDrop', () => {
   test('renders if nothing is being dragged', () => {
     const component = render(
       <DragDrop value="hello" draggable label="dragging">
-        Hello!
+        <button>Hello!</button>
       </DragDrop>
     );
 
@@ -24,7 +24,11 @@ describe('DragDrop', () => {
 
   test('dragover calls preventDefault if droppable is true', () => {
     const preventDefault = jest.fn();
-    const component = mount(<DragDrop droppable>Hello!</DragDrop>);
+    const component = mount(
+      <DragDrop droppable>
+        <button>Hello!</button>
+      </DragDrop>
+    );
 
     component.find('[data-test-subj="lnsDragDrop"]').simulate('dragover', { preventDefault });
 
@@ -33,7 +37,11 @@ describe('DragDrop', () => {
 
   test('dragover does not call preventDefault if droppable is false', () => {
     const preventDefault = jest.fn();
-    const component = mount(<DragDrop>Hello!</DragDrop>);
+    const component = mount(
+      <DragDrop>
+        <button>Hello!</button>
+      </DragDrop>
+    );
 
     component.find('[data-test-subj="lnsDragDrop"]').simulate('dragover', { preventDefault });
 
@@ -51,7 +59,7 @@ describe('DragDrop', () => {
     const component = mount(
       <ChildDragDropProvider dragging={value} setDragging={setDragging}>
         <DragDrop value={value} draggable={true} label="drag label">
-          Hello!
+          <button>Hello!</button>
         </DragDrop>
       </ChildDragDropProvider>
     );
@@ -74,7 +82,7 @@ describe('DragDrop', () => {
     const component = mount(
       <ChildDragDropProvider dragging="hola" setDragging={setDragging}>
         <DragDrop onDrop={onDrop} droppable={true} value={value}>
-          Hello!
+          <button>Hello!</button>
         </DragDrop>
       </ChildDragDropProvider>
     );
@@ -98,7 +106,7 @@ describe('DragDrop', () => {
     const component = mount(
       <ChildDragDropProvider dragging="hola" setDragging={setDragging}>
         <DragDrop onDrop={onDrop} droppable={false} value={{}}>
-          Hello!
+          <button>Hello!</button>
         </DragDrop>
       </ChildDragDropProvider>
     );
@@ -121,7 +129,7 @@ describe('DragDrop', () => {
         }}
         droppable
       >
-        Hello!
+        <button>Hello!</button>
       </DragDrop>
     );
 
@@ -132,10 +140,10 @@ describe('DragDrop', () => {
     const component = mount(
       <ChildDragDropProvider dragging={'ignored'} setDragging={() => {}}>
         <DragDrop value="ignored" draggable={true} label="a">
-          Ignored
+          <button>Hello!</button>
         </DragDrop>
         <DragDrop onDrop={(x: unknown) => {}} droppable={false}>
-          Hello!
+          <button>Hello!</button>
         </DragDrop>
       </ChildDragDropProvider>
     );
@@ -154,14 +162,14 @@ describe('DragDrop', () => {
         }}
       >
         <DragDrop value="ignored" draggable={true} label="a">
-          Ignored
+          <button>Hello!</button>
         </DragDrop>
         <DragDrop
           onDrop={(x: unknown) => {}}
           droppable
           getAdditionalClassesOnEnter={getAdditionalClasses}
         >
-          Hello!
+          <button>Hello!</button>
         </DragDrop>
       </ChildDragDropProvider>
     );