feat: add readonly dropdown

packages/react/__tests__/__snapshots__/PublicAPI-test.js.snap

@@ -2757,6 +2757,9 @@ Map {
       "onChange": Object {
         "type": "func",
       },
+      "readOnly": Object {
+        "type": "bool",
+      },
       "renderSelectedItem": Object {
         "type": "func",
       },

packages/react/src/components/Dropdown/Dropdown-test.js

@@ -144,6 +144,19 @@ describe('Dropdown', () => {
     });
   });
 
+  it('should respect readOnly prop', () => {
+    render(<Dropdown {...mockProps} readOnly={true} />);
+    openMenu(); // menu should not open
+    assertMenuClosed();
+
+    openMenu(); // menu should not open
+    expect(screen.queryByText('Item 0')).toBeNull();
+    expect(mockProps.onChange).toHaveBeenCalledTimes(0);
+    assertMenuClosed();
+
+    mockProps.onChange.mockClear();
+  });
+
   describe('should display initially selected item found in `initialSelectedItem`', () => {
     it('using an object type for the `initialSelectedItem` prop', () => {
       render(

packages/react/src/components/Dropdown/Dropdown.js

@@ -56,6 +56,7 @@ const Dropdown = React.forwardRef(function Dropdown(
     initialSelectedItem,
     selectedItem: controlledSelectedItem,
     downshiftProps,
+    readOnly,
     ...other
   },
   ref
@@ -102,6 +103,7 @@ const Dropdown = React.forwardRef(function Dropdown(
       [`${prefix}--dropdown--inline`]: inline,
       [`${prefix}--dropdown--disabled`]: disabled,
       [`${prefix}--dropdown--light`]: light,
+      [`${prefix}--dropdown--readonly`]: readOnly,
       [`${prefix}--dropdown--${size}`]: size,
       [`${prefix}--list-box--up`]: direction === 'top',
     }
@@ -152,6 +154,24 @@ const Dropdown = React.forwardRef(function Dropdown(
     setIsFocused(evt.type === 'focus' ? true : false);
   };
 
+  const readOnlyEventHandlers = readOnly
+    ? {
+        onClick: (evt) => {
+          // NOTE: does not prevent click
+          evt.preventDefault();
+          // focus on the element as per readonly input behavior
+          evt.target.focus();
+        },
+        onKeyDown: (evt) => {
+          const selectAccessKeys = ['ArrowDown', 'ArrowUp', ' ', 'Enter'];
+          // This prevents the select from opening for the above keys
+          if (selectAccessKeys.includes(evt.key)) {
+            evt.preventDefault();
+          }
+        },
+      }
+    : {};
+
   return (
     <div className={wrapperClasses} {...other}>
       {titleText && (
@@ -184,9 +204,10 @@ const Dropdown = React.forwardRef(function Dropdown(
           type="button"
           className={`${prefix}--list-box__field`}
           disabled={disabled}
-          aria-disabled={disabled}
+          aria-disabled={readOnly ? true : undefined} // aria-disabled to remain focusable
           title={selectedItem ? itemToString(selectedItem) : label}
           {...toggleButtonProps}
+          {...readOnlyEventHandlers}
           ref={mergeRefs(toggleButtonProps.ref, ref)}>
           <span className={`${prefix}--list-box__label`}>
             {selectedItem
@@ -341,6 +362,11 @@ Dropdown.propTypes = {
    */
   onChange: PropTypes.func,
 
+  /**
+   * Whether or not the Dropdown is readonly
+   */
+  readOnly: PropTypes.bool,
+
   /**
    * An optional callback to render the currently selected item as a react element instead of only
    * as a string.

packages/react/src/components/MultiSelect/MultiSelect.stories.js

@@ -65,6 +65,9 @@ export default {
     open: {
       table: { disable: true },
     },
+    readOnly: {
+      control: { type: 'boolean' },
+    },
     title: {
       table: { disable: true },
     },

packages/styles/scss/components/dropdown/_dropdown.scss

@@ -473,4 +473,19 @@
   .#{$prefix}--list-box__menu-item__selected-icon {
     @include high-contrast-mode('icon-fill');
   }
+
+  // readonly
+  .#{$prefix}--dropdown--readonly,
+  .#{$prefix}--dropdown--readonly:hover {
+    background-color: transparent;
+  }
+
+  .#{$prefix}--dropdown--readonly .#{$prefix}--list-box__field,
+  .#{$prefix}--dropdown--readonly .#{$prefix}--list-box__menu-icon {
+    cursor: default;
+  }
+
+  .#{$prefix}--dropdown--readonly .#{$prefix}--list-box__menu-icon svg {
+    fill: $icon-disabled;
+  }
 }