Keep the currently selected item selected in the dropdown in single selection mode

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## [`master`](https://github.com/elastic/eui/tree/master)
 
 - Convert the other of the services to TypeScript ([#1392](https://github.com/elastic/eui/pull/1392))
+- Changed single selection to select existing option in the list ([#1391](https://github.com/elastic/eui/pull/1391))
 
 ## [`6.0.1`](https://github.com/elastic/eui/tree/v6.0.1)
 

src/components/combo_box/__snapshots__/combo_box.test.js.snap

@@ -380,7 +380,7 @@ exports[`props singleSelection is rendered 1`] = `
   <EuiComboBoxInput
     autoSizeInputRef={[Function]}
     compressed={false}
-    focusedOptionId={null}
+    focusedOptionId="htmlid__option-2"
     fullWidth={false}
     hasSelectedOptions={true}
     inputRef={[Function]}
@@ -409,3 +409,141 @@ exports[`props singleSelection is rendered 1`] = `
   />
 </div>
 `;
+
+exports[`props singleSelection selects existing option when opened 1`] = `
+<div
+  aria-expanded={true}
+  aria-haspopup="listbox"
+  className="euiComboBox euiComboBox-isOpen"
+  onBlur={[Function]}
+  onKeyDown={[Function]}
+  role="combobox"
+>
+  <EuiComboBoxInput
+    autoSizeInputRef={[Function]}
+    compressed={false}
+    focusedOptionId="htmlid__option-2"
+    fullWidth={false}
+    hasSelectedOptions={true}
+    inputRef={[Function]}
+    isListOpen={true}
+    noIcon={false}
+    onChange={[Function]}
+    onClear={[Function]}
+    onClick={[Function]}
+    onCloseListClick={[Function]}
+    onFocus={[Function]}
+    onOpenListClick={[Function]}
+    onRemoveOption={[Function]}
+    rootId={[Function]}
+    searchValue=""
+    selectedOptions={
+      Array [
+        Object {
+          "label": "Mimas",
+        },
+      ]
+    }
+    singleSelection={true}
+    toggleButtonRef={[Function]}
+    updatePosition={[Function]}
+    value="Mimas"
+  />
+  <EuiPortal>
+    <EuiComboBoxOptionsList
+      activeOptionIndex={2}
+      areAllOptionsSelected={false}
+      data-test-subj=""
+      fullWidth={false}
+      getSelectedOptionForSearchValue={[Function]}
+      listRef={[Function]}
+      matchingOptions={
+        Array [
+          Object {
+            "data-test-subj": "titanOption",
+            "label": "Titan",
+          },
+          Object {
+            "label": "Enceladus",
+          },
+          Object {
+            "label": "Mimas",
+          },
+          Object {
+            "label": "Dione",
+          },
+          Object {
+            "label": "Iapetus",
+          },
+          Object {
+            "label": "Phoebe",
+          },
+          Object {
+            "label": "Rhea",
+          },
+          Object {
+            "label": "Pandora is one of Saturn's moons, named for a Titaness of Greek mythology",
+          },
+          Object {
+            "label": "Tethys",
+          },
+          Object {
+            "label": "Hyperion",
+          },
+        ]
+      }
+      onOptionClick={[Function]}
+      onOptionEnterKey={[Function]}
+      optionRef={[Function]}
+      options={
+        Array [
+          Object {
+            "data-test-subj": "titanOption",
+            "label": "Titan",
+          },
+          Object {
+            "label": "Enceladus",
+          },
+          Object {
+            "label": "Mimas",
+          },
+          Object {
+            "label": "Dione",
+          },
+          Object {
+            "label": "Iapetus",
+          },
+          Object {
+            "label": "Phoebe",
+          },
+          Object {
+            "label": "Rhea",
+          },
+          Object {
+            "label": "Pandora is one of Saturn's moons, named for a Titaness of Greek mythology",
+          },
+          Object {
+            "label": "Tethys",
+          },
+          Object {
+            "label": "Hyperion",
+          },
+        ]
+      }
+      position="bottom"
+      rootId={[Function]}
+      rowHeight={27}
+      scrollToIndex={2}
+      searchValue=""
+      selectedOptions={
+        Array [
+          Object {
+            "label": "Mimas",
+          },
+        ]
+      }
+      updatePosition={[Function]}
+    />
+  </EuiPortal>
+</div>
+`;

src/components/combo_box/combo_box.js

@@ -63,17 +63,24 @@ export class EuiComboBox extends Component {
     super(props);
 
     const initialSearchValue = '';
-    const { options, selectedOptions } = props;
+    const { options, selectedOptions, singleSelection } = props;
 
     this.state = {
-      matchingOptions: getMatchingOptions(options, selectedOptions, initialSearchValue, props.async),
+      matchingOptions: getMatchingOptions(options, selectedOptions, initialSearchValue, props.async, singleSelection),
       listElement: undefined,
       searchValue: initialSearchValue,
       isListOpen: false,
       listPosition: 'bottom',
       activeOptionIndex: undefined,
     };
 
+    // ensure that the currently selected single option is active if it is in the matchingOptions
+    if (singleSelection && selectedOptions.length === 1) {
+      if (this.state.matchingOptions.includes(selectedOptions[0])) {
+        this.state.activeOptionIndex = this.state.matchingOptions.indexOf(selectedOptions[0]);
+      }
+    }
+
     this.rootId = htmlIdGenerator();
 
     // Refs.
@@ -396,8 +403,15 @@ export class EuiComboBox extends Component {
   onComboBoxClick = () => {
     // When the user clicks anywhere on the box, enter the interaction state.
     this.searchInput.focus();
-    // If the user does this from a state in which an option has focus, then we need to clear it.
-    this.clearActiveOption();
+
+    // If the user does this from a state in which an option has focus, then we need to reset it or clear it.
+    if (this.props.singleSelection && this.props.selectedOptions.length === 1) {
+      this.setState({
+        activeOptionIndex: this.state.matchingOptions.indexOf(this.props.selectedOptions[0]),
+      });
+    } else {
+      this.clearActiveOption();
+    }
   };
 
   onOpenListClick = () => {
@@ -457,18 +471,27 @@ export class EuiComboBox extends Component {
   }
 
   static getDerivedStateFromProps(nextProps, prevState) {
-    const { options, selectedOptions } = nextProps;
+    const { options, selectedOptions, singleSelection } = nextProps;
     const { searchValue } = prevState;
 
     // Calculate and cache the options which match the searchValue, because we use this information
     // in multiple places and it would be expensive to calculate repeatedly.
-    const matchingOptions = getMatchingOptions(options, selectedOptions, searchValue, nextProps.async);
+    const matchingOptions = getMatchingOptions(options, selectedOptions, searchValue, nextProps.async, singleSelection);
+    // ensure that the currently selected single option is active if it is in the matchingOptions
+    if (singleSelection && selectedOptions.length === 1) {
+      let nextActiveOptionIndex;
+      if (matchingOptions.includes(selectedOptions[0])) {
+        nextActiveOptionIndex = matchingOptions.indexOf(selectedOptions[0]);
+      }
+      return { matchingOptions, activeOptionIndex: nextActiveOptionIndex };
+    }
 
     return { matchingOptions };
   }
 
   updateMatchingOptionsIfDifferent(newMatchingOptions) {
-    const { matchingOptions } = this.state;
+    const { matchingOptions, activeOptionIndex } = this.state;
+    const { singleSelection, selectedOptions } = this.props;
 
     let areOptionsDifferent = false;
 
@@ -485,7 +508,14 @@ export class EuiComboBox extends Component {
 
     if (areOptionsDifferent) {
       this.options = [];
-      this.setState({ matchingOptions: newMatchingOptions });
+      let nextActiveOptionIndex = activeOptionIndex;
+      // ensure that the currently selected single option is active if it is in the matchingOptions
+      if (singleSelection && selectedOptions.length === 1) {
+        if (newMatchingOptions.includes(selectedOptions[0])) {
+          nextActiveOptionIndex = newMatchingOptions.indexOf(selectedOptions[0]);
+        }
+      }
+      this.setState({ matchingOptions: newMatchingOptions, activeOptionIndex: nextActiveOptionIndex });
 
       if (!newMatchingOptions.length) {
         // Prevent endless setState -> componentWillUpdate -> setState loop.
@@ -497,13 +527,13 @@ export class EuiComboBox extends Component {
   }
 
   componentDidUpdate() {
-    const { options, selectedOptions } = this.props;
+    const { options, selectedOptions, singleSelection } = this.props;
     const { searchValue } = this.state;
 
     // React 16.3 has a bug (fixed in 16.4) where getDerivedStateFromProps
     // isn't called after a state change, and we track `searchValue` in state
     // instead we need to react to a change in searchValue here
-    this.updateMatchingOptionsIfDifferent(getMatchingOptions(options, selectedOptions, searchValue, this.props.async));
+    this.updateMatchingOptionsIfDifferent(getMatchingOptions(options, selectedOptions, searchValue, this.props.async, singleSelection));
   }
 
   componentWillUnmount() {

src/components/combo_box/combo_box.test.js

@@ -97,16 +97,30 @@ describe('props', () => {
     });
   });
 
-  test('singleSelection is rendered', () => {
-    const component = shallow(
-      <EuiComboBox
-        options={options}
-        selectedOptions={[options[2]]}
-        singleSelection={true}
-      />
-    );
+  describe('singleSelection', () => {
+    test('is rendered', () => {
+      const component = shallow(
+        <EuiComboBox
+          options={options}
+          selectedOptions={[options[2]]}
+          singleSelection={true}
+        />
+      );
 
-    expect(component).toMatchSnapshot();
+      expect(component).toMatchSnapshot();
+    });
+    test('selects existing option when opened', () => {
+      const component = shallow(
+        <EuiComboBox
+          options={options}
+          selectedOptions={[options[2]]}
+          singleSelection={true}
+        />
+      );
+
+      component.setState({ isListOpen: true });
+      expect(component).toMatchSnapshot();
+    });
   });
 
   test('isDisabled is rendered', () => {

src/components/combo_box/matching_options.js

@@ -14,10 +14,10 @@ export const getSelectedOptionForSearchValue = (searchValue, selectedOptions) =>
   return selectedOptions.find(option => option.label.toLowerCase() === normalizedSearchValue);
 };
 
-const collectMatchingOption = (accumulator, option, selectedOptions, normalizedSearchValue, isPreFiltered) => {
-  // Only show options which haven't yet been selected.
+const collectMatchingOption = (accumulator, option, selectedOptions, normalizedSearchValue, isPreFiltered, showPrevSelected) => {
+  // Only show options which haven't yet been selected unless requested.
   const selectedOption = getSelectedOptionForSearchValue(option.label, selectedOptions);
-  if (selectedOption) {
+  if (selectedOption && !showPrevSelected) {
     return false;
   }
 
@@ -38,15 +38,22 @@ const collectMatchingOption = (accumulator, option, selectedOptions, normalizedS
   }
 };
 
-export const getMatchingOptions = (options, selectedOptions, searchValue, isPreFiltered) => {
+export const getMatchingOptions = (options, selectedOptions, searchValue, isPreFiltered, showPrevSelected) => {
   const normalizedSearchValue = searchValue.trim().toLowerCase();
   const matchingOptions = [];
 
   options.forEach(option => {
     if (option.options) {
       const matchingOptionsForGroup = [];
       option.options.forEach(groupOption => {
-        collectMatchingOption(matchingOptionsForGroup, groupOption, selectedOptions, normalizedSearchValue, isPreFiltered);
+        collectMatchingOption(
+          matchingOptionsForGroup,
+          groupOption,
+          selectedOptions,
+          normalizedSearchValue,
+          isPreFiltered,
+          showPrevSelected
+        );
       });
       if (matchingOptionsForGroup.length > 0) {
         // Add option for group label
@@ -55,7 +62,7 @@ export const getMatchingOptions = (options, selectedOptions, searchValue, isPreF
         matchingOptions.push(...matchingOptionsForGroup);
       }
     } else {
-      collectMatchingOption(matchingOptions, option, selectedOptions, normalizedSearchValue, isPreFiltered);
+      collectMatchingOption(matchingOptions, option, selectedOptions, normalizedSearchValue, isPreFiltered, showPrevSelected);
     }
   });
   return matchingOptions;