Allow locking of EuiNavDrawer in the expanded state

src/components/list_group/list_group_item.tsx

@@ -156,11 +156,15 @@ export const EuiListGroupItem: FunctionComponent<EuiListGroupItemProps> = ({
   let extraActionNode;
 
   if (extraAction) {
-    const { iconType, alwaysShow, ...rest } = extraAction;
-
-    const extraActionClasses = classNames('euiListGroupItem__extraAction', {
-      'euiListGroupItem__extraAction-alwaysShow': alwaysShow,
-    });
+    const { iconType, alwaysShow, className, ...rest } = extraAction;
+
+    const extraActionClasses = classNames(
+      'euiListGroupItem__extraAction',
+      {
+        'euiListGroupItem__extraAction-alwaysShow': alwaysShow,
+      },
+      className
+    );
 
     extraActionNode = (
       <EuiButtonIconTyped

src/components/nav_drawer/_nav_drawer.scss

@@ -118,3 +118,31 @@
     margin-left: 0;
   }
 }
+
+@include euiBreakpoint('xs', 's', 'm', 'l') {
+  .euiNavDrawer__expandButtonLockAction {
+    display: none;
+  }
+}
+
+@include euiBreakpoint('xl') {
+  .euiNavDrawer-isLocked {
+    + .euiNavDrawerPage .euiNavDrawerPage__pageBody {
+      // Shrink the content from the left so it's no longer overlapped by the nav drawer (ALWAYS)
+      margin-left: $euiNavDrawerWidthExpanded !important; // sass-lint:disable-line no-important
+      transition: margin $euiAnimSpeedFast $euiAnimSlightResistance;
+    }
+
+    &.euiNavDrawer-flyoutIsExpanded {
+      // Instead of one collapsed and one expanded, they're now both expanded
+      // Double the width of expanded sidebars
+      width: $euiNavDrawerWidthExpanded * 2 !important; // sass-lint:disable-line no-important
+    }
+  }
+
+  // In case they unlock while the flyout is expanded,
+  // the nav drawer doesn't actually get collapsed until an interaction
+  .euiNavDrawer-isExpanded.euiNavDrawer-flyoutIsExpanded {
+    width: $euiNavDrawerWidthExpanded * 2 !important; // sass-lint:disable-line no-important
+  }
+}

src/components/nav_drawer/nav_drawer.js

@@ -7,22 +7,56 @@ import { EuiNavDrawerGroup } from './nav_drawer_group';
 import { EuiOutsideClickDetector } from '../outside_click_detector';
 import { EuiI18n } from '../i18n';
 import { EuiFlexItem } from '../flex';
+import { throttle } from '../color_picker/utils';
 
 export class EuiNavDrawer extends Component {
   constructor(props) {
     super(props);
 
     this.state = {
-      isCollapsed: true,
+      isLocked: props.isLocked,
+      isCollapsed: !props.isLocked,
       flyoutIsCollapsed: true,
       outsideClickDisabled: true,
       isManagingFocus: false,
       toolTipsEnabled: true,
     };
   }
 
+  componentDidMount() {
+    if (this.props.isLocked) {
+      window.addEventListener('resize', this.functionToCallOnWindowResize);
+    }
+  }
+
+  componentWillUnmount() {
+    window.removeEventListener('resize', this.functionToCallOnWindowResize);
+  }
+
+  functionToCallOnWindowResize = throttle(() => {
+    if (window.innerWidth < 1200) {
+      this.collapseDrawer();
+      this.collapseFlyout();
+    }
+    // reacts every 50ms to resize changes and always gets the final update
+  }, 50);
+
   timeoutID;
 
+  sideNavLockClicked = () => {
+    if (this.state.isLocked) {
+      window.removeEventListener('resize', this.functionToCallOnWindowResize);
+    } else {
+      window.addEventListener('resize', this.functionToCallOnWindowResize);
+    }
+
+    this.setState({
+      isLocked: !this.state.isLocked,
+      isCollapsed: false,
+      outsideClickDisabled: true,
+    });
+  };
+
   toggleOpen = () => {
     this.setState({
       isCollapsed: !this.state.isCollapsed,
@@ -36,6 +70,16 @@ export class EuiNavDrawer extends Component {
     }, 150);
   };
 
+  collapseButtonClick = () => {
+    if (this.state.isCollapsed) {
+      this.expandDrawer();
+    } else {
+      this.collapseDrawer();
+    }
+
+    this.collapseFlyout();
+  };
+
   expandDrawer = () => {
     this.setState({
       isCollapsed: false,
@@ -54,6 +98,7 @@ export class EuiNavDrawer extends Component {
       isCollapsed: true,
       outsideClickDisabled: this.state.flyoutIsCollapsed ? true : false,
       toolTipsEnabled: true,
+      isLocked: false,
     });
 
     // Scrolls the menu and flyout back to top when the nav drawer collapses
@@ -103,7 +148,7 @@ export class EuiNavDrawer extends Component {
         flyoutIsCollapsed: false,
         navFlyoutTitle: title,
         navFlyoutContent: content,
-        isCollapsed: true,
+        isCollapsed: this.state.isLocked ? false : true,
         toolTipsEnabled: false,
         outsideClickDisabled: false,
       });
@@ -115,12 +160,12 @@ export class EuiNavDrawer extends Component {
       flyoutIsCollapsed: true,
       navFlyoutTitle: null,
       navFlyoutContent: null,
-      toolTipsEnabled: true,
+      toolTipsEnabled: this.state.isLocked ? false : true,
     });
   };
 
   closeBoth = () => {
-    this.collapseDrawer();
+    if (!this.state.isLocked) this.collapseDrawer();
     this.collapseFlyout();
   };
 
@@ -158,6 +203,7 @@ export class EuiNavDrawer extends Component {
       {
         'euiNavDrawer-isCollapsed': this.state.isCollapsed,
         'euiNavDrawer-isExpanded': !this.state.isCollapsed,
+        'euiNavDrawer-isLocked': this.state.isLocked,
         'euiNavDrawer-flyoutIsCollapsed': this.state.flyoutIsCollapsed,
         'euiNavDrawer-flyoutIsExpanded': !this.state.flyoutIsCollapsed,
       },
@@ -172,22 +218,40 @@ export class EuiNavDrawer extends Component {
             tokens={[
               'euiNavDrawer.sideNavCollapse',
               'euiNavDrawer.sideNavExpand',
+              'euiNavDrawer.sideNavLockExpanded',
+              'euiNavDrawer.sideNavLockCollapsed',
             ]}
-            defaults={['Collapse', 'Expand']}>
-            {([sideNavCollapse, sideNavExpand]) => (
+            defaults={[
+              'Collapse',
+              'Expand',
+              'Lock navigation open',
+              'Unlock navigation',
+            ]}>
+            {([
+              sideNavCollapse,
+              sideNavExpand,
+              sideNavLockExpanded,
+              sideNavLockCollapsed,
+            ]) => (
               <EuiListGroupItem
                 label={this.state.isCollapsed ? sideNavExpand : sideNavCollapse}
                 iconType={this.state.isCollapsed ? 'menuRight' : 'menuLeft'}
                 size="s"
                 showToolTip={this.state.isCollapsed}
-                onClick={
-                  this.state.isCollapsed
-                    ? () => {
-                        this.expandDrawer();
-                        this.collapseFlyout();
-                      }
-                    : () => this.collapseDrawer()
-                }
+                extraAction={{
+                  className: 'euiNavDrawer__expandButtonLockAction',
+                  color: 'text',
+                  onClick: this.sideNavLockClicked,
+                  iconType: this.state.isLocked ? 'lockOpen' : 'lock',
+                  iconSize: 's',
+                  'aria-label': sideNavLockExpanded,
+                  title: this.state.isLocked
+                    ? sideNavLockCollapsed
+                    : sideNavLockExpanded,
+                  'aria-checked': this.state.isLocked ? true : false,
+                  role: 'switch',
+                }}
+                onClick={this.collapseButtonClick}
                 data-test-subj={
                   this.state.isCollapsed
                     ? 'navDrawerExpandButton-isCollapsed'
@@ -273,6 +337,11 @@ EuiNavDrawer.propTypes = {
    * Display tooltips on side nav items
    */
   showToolTips: PropTypes.bool,
+
+  /**
+   * Keep drawer locked open by default
+   */
+  isLocked: PropTypes.bool,
 };
 
 EuiNavDrawer.defaultProps = {