[EuiColorPicker] Add isClearable and placeholder options

src-docs/src/views/color_picker/color_picker_example.js

@@ -171,6 +171,17 @@ const customBadgeSnippet = `// Be sure to provide relevant accessibility to unma
 />
 `;
 
+import Empty from './empty_state';
+const emptySource = require('!!raw-loader!./empty_state');
+const emptyHtml = renderToHtml(CustomButton);
+const emptySnippet = `<EuiColorPicker
+  onChange={handleChange}
+  color={chosenColor}
+  placeholder="Auto"
+  isClearable={true}
+/>
+`;
+
 import Modes from './modes';
 const modesSource = require('!!raw-loader!./modes');
 const modesHtml = renderToHtml(Modes);
@@ -551,6 +562,32 @@ export const ColorPickerExample = {
       snippet: [customButtonSnippet, customBadgeSnippet],
       demo: <CustomButton />,
     },
+    {
+      title: 'Empty state',
+      source: [
+        {
+          type: GuideSectionTypes.JS,
+          code: emptySource,
+        },
+        {
+          type: GuideSectionTypes.HTML,
+          code: emptyHtml,
+        },
+      ],
+      text: (
+        <>
+          <p>
+            For instances where an &quot;empty&quot; color picker has meaning
+            other than transparent color value, use the{' '}
+            <EuiCode>placeholder</EuiCode> prop to provide context. Removing
+            color selection and returning to the default state can be made
+            easier by setting <EuiCode>isClearable=true</EuiCode>.
+          </p>
+        </>
+      ),
+      snippet: emptySnippet,
+      demo: <Empty />,
+    },
     {
       title: 'Inline',
       source: [

src-docs/src/views/color_picker/empty_state.js

@@ -0,0 +1,27 @@
+import React, { useMemo } from 'react';
+
+import { EuiColorPicker, EuiFormRow } from '../../../../src/components';
+
+import { useColorPickerState } from '../../../../src/services';
+
+export default () => {
+  const [color, setColor, errors] = useColorPickerState();
+  const isInvalid = useMemo(() => color !== '' && !!errors, [color, errors]);
+
+  const customSwatches = ['#333', '#666', '#999', '#CCC'];
+
+  return (
+    <React.Fragment>
+      <EuiFormRow label="Pick a color" isInvalid={isInvalid} error={errors}>
+        <EuiColorPicker
+          onChange={setColor}
+          color={color}
+          isInvalid={isInvalid}
+          swatches={customSwatches}
+          placeholder="Auto"
+          isClearable={true}
+        />
+      </EuiFormRow>
+    </React.Fragment>
+  );
+};

src/components/color_picker/__snapshots__/color_picker.test.tsx.snap

@@ -65,6 +65,81 @@ exports[`renders EuiColorPicker 1`] = `
 </div>
 `;
 
+exports[`renders EuiColorPicker with a clearable input 1`] = `
+<div
+  class="euiPopover euiPopover--anchorDownLeft euiPopover--displayBlock euiColorPicker__popoverAnchor"
+>
+  <div
+    class="euiPopover__anchor"
+  >
+    <div
+      class="euiFormControlLayout"
+    >
+      <div
+        class="euiFormControlLayout__childrenWrapper"
+      >
+        <div
+          style="color:rgb(255,238,221)"
+        >
+          <div
+            class="euiFormControlLayout"
+          >
+            <div
+              class="euiFormControlLayout__childrenWrapper"
+            >
+              <input
+                aria-label="Press the down key to open a popover containing color options"
+                autocomplete="off"
+                class="euiFieldText euiColorPicker__input euiFieldText--withIcon"
+                data-test-subj="colorPickerAnchor"
+                type="text"
+                value="#FFEEDD"
+              />
+              <div
+                class="euiFormControlLayoutIcons"
+              >
+                <span
+                  class="euiFormControlLayoutCustomIcon"
+                >
+                  <div
+                    aria-hidden="true"
+                    class="euiFormControlLayoutCustomIcon__icon"
+                    data-euiicon-type="swatchInput"
+                  />
+                </span>
+              </div>
+            </div>
+          </div>
+        </div>
+        <div
+          class="euiFormControlLayoutIcons euiFormControlLayoutIcons--right"
+        >
+          <button
+            aria-label="Clear input"
+            class="euiFormControlLayoutClearButton"
+            type="button"
+          >
+            <div
+              class="euiFormControlLayoutClearButton__icon"
+              data-euiicon-type="cross"
+            />
+          </button>
+          <span
+            class="euiFormControlLayoutCustomIcon"
+          >
+            <div
+              aria-hidden="true"
+              class="euiFormControlLayoutCustomIcon__icon"
+              data-euiicon-type="arrowDown"
+            />
+          </span>
+        </div>
+      </div>
+    </div>
+  </div>
+</div>
+`;
+
 exports[`renders EuiColorPicker with a color swatch when color is defined 1`] = `
 <div
   class="euiPopover euiPopover--anchorDownLeft euiPopover--displayBlock euiColorPicker__popoverAnchor"
@@ -130,6 +205,70 @@ exports[`renders EuiColorPicker with a color swatch when color is defined 1`] =
 </div>
 `;
 
+exports[`renders EuiColorPicker with a custom placeholder 1`] = `
+<div
+  class="euiPopover euiPopover--anchorDownLeft euiPopover--displayBlock euiColorPicker__popoverAnchor"
+>
+  <div
+    class="euiPopover__anchor"
+  >
+    <div
+      class="euiFormControlLayout"
+    >
+      <div
+        class="euiFormControlLayout__childrenWrapper"
+      >
+        <div>
+          <div
+            class="euiFormControlLayout"
+          >
+            <div
+              class="euiFormControlLayout__childrenWrapper"
+            >
+              <input
+                aria-label="Press the down key to open a popover containing color options"
+                autocomplete="off"
+                class="euiFieldText euiColorPicker__input euiFieldText--withIcon"
+                data-test-subj="colorPickerAnchor"
+                placeholder="Auto"
+                type="text"
+                value=""
+              />
+              <div
+                class="euiFormControlLayoutIcons"
+              >
+                <span
+                  class="euiFormControlLayoutCustomIcon"
+                >
+                  <div
+                    aria-hidden="true"
+                    class="euiFormControlLayoutCustomIcon__icon"
+                    data-euiicon-type="stopSlash"
+                  />
+                </span>
+              </div>
+            </div>
+          </div>
+        </div>
+        <div
+          class="euiFormControlLayoutIcons euiFormControlLayoutIcons--right"
+        >
+          <span
+            class="euiFormControlLayoutCustomIcon"
+          >
+            <div
+              aria-hidden="true"
+              class="euiFormControlLayoutCustomIcon__icon"
+              data-euiicon-type="arrowDown"
+            />
+          </span>
+        </div>
+      </div>
+    </div>
+  </div>
+</div>
+`;
+
 exports[`renders EuiColorPicker with an empty swatch when color is "" 1`] = `
 <div
   class="euiPopover euiPopover--anchorDownLeft euiPopover--displayBlock euiColorPicker__popoverAnchor"

src/components/color_picker/color_picker.test.tsx

@@ -145,6 +145,25 @@ test('renders EuiColorPicker with a color swatch when color is defined', () => {
   expect(colorPicker).toMatchSnapshot();
 });
 
+test('renders EuiColorPicker with a custom placeholder', () => {
+  const colorPicker = render(
+    <EuiColorPicker onChange={onChange} placeholder="Auto" {...requiredProps} />
+  );
+  expect(colorPicker).toMatchSnapshot();
+});
+
+test('renders EuiColorPicker with a clearable input', () => {
+  const colorPicker = render(
+    <EuiColorPicker
+      onChange={onChange}
+      color={'#ffeedd'}
+      isClearable={true}
+      {...requiredProps}
+    />
+  );
+  expect(colorPicker).toMatchSnapshot();
+});
+
 test('popover color selector is not shown by default', () => {
   const colorPicker = mount(
     <EuiColorPicker onChange={onChange} color="#ffeedd" {...requiredProps} />
@@ -282,6 +301,25 @@ test('Setting a new alpha value calls onChange', () => {
   });
 });
 
+test('Clicking the "clear" button calls onChange', () => {
+  const colorPicker = mount(
+    <EuiColorPicker
+      onChange={onChange}
+      color="#ffeedd"
+      isClearable={true}
+      {...requiredProps}
+    />
+  );
+
+  colorPicker.find('.euiFormControlLayoutClearButton').simulate('click');
+  expect(onChange).toBeCalled();
+  expect(onChange).toBeCalledWith('', {
+    hex: '',
+    isValid: false,
+    rgba: [NaN, NaN, NaN, 1],
+  });
+});
+
 test('default mode does renders child components', () => {
   const colorPicker = mount(
     <EuiColorPicker onChange={onChange} color="#ffeedd" {...requiredProps} />

src/components/color_picker/color_picker.tsx

@@ -145,6 +145,14 @@ export interface EuiColorPickerProps
    * Placement option for a secondary color value input.
    */
   secondaryInputDisplay?: 'top' | 'bottom' | 'none';
+  /**
+   * Add a button to the primary input to clear its value.
+   */
+  isClearable?: boolean;
+  /**
+   * Text to repalce the default 'Transparent' placeholder for unset color values.
+   */
+  placeholder?: string;
 }
 
 function isKeyboardEvent(
@@ -207,6 +215,8 @@ export const EuiColorPicker: FunctionComponent<EuiColorPickerProps> = ({
   showAlpha = false,
   format,
   secondaryInputDisplay = 'none',
+  isClearable = false,
+  placeholder,
 }) => {
   const preferredFormat = useMemo(() => {
     if (format) return format;
@@ -361,6 +371,13 @@ export const EuiColorPicker: FunctionComponent<EuiColorPickerProps> = ({
     }
   };
 
+  const handleClearInput = () => {
+    handleOnChange('');
+    if (isColorSelectorShown) {
+      closeColorSelector();
+    }
+  };
+
   const updateWithHsv = (hsv: ColorSpaces['hsv']) => {
     const color = chroma.hsv(...hsv).alpha(alphaChannel);
     let formatted;
@@ -439,7 +456,7 @@ export const EuiColorPicker: FunctionComponent<EuiColorPickerProps> = ({
           <EuiFieldText
             compressed={true}
             value={color ? color.toUpperCase() : HEX_FALLBACK}
-            placeholder={!color ? transparent : undefined}
+            placeholder={!color ? placeholder || transparent : undefined}
             onChange={handleColorInput}
             isInvalid={isInvalid}
             disabled={disabled}
@@ -557,6 +574,11 @@ export const EuiColorPicker: FunctionComponent<EuiColorPickerProps> = ({
               }
             : undefined
         }
+        clear={
+          isClearable && color && !readOnly && !disabled
+            ? { onClick: handleClearInput }
+            : undefined
+        }
         readOnly={readOnly}
         fullWidth={fullWidth}
         compressed={compressed}
@@ -585,7 +607,7 @@ export const EuiColorPicker: FunctionComponent<EuiColorPickerProps> = ({
                 onClick={handleInputActivity}
                 onKeyDown={handleInputActivity}
                 value={color ? color.toUpperCase() : HEX_FALLBACK}
-                placeholder={!color ? transparent : undefined}
+                placeholder={!color ? placeholder || transparent : undefined}
                 id={id}
                 onChange={handleColorInput}
                 icon={chromaColor ? 'swatchInput' : 'stopSlash'}