[Discover] Fix Fields flyout and Create Field flyouts on mobile (elas…

…tic#145650)

## Summary

@jughosta flagged several responsive issues in
elastic#144845 (review).
Two of these were existing issues in Kibana main and need to be
backported to 8.6, hence the separate PR.

I recommend turning off whitespace changes when viewing the diff, as
much of the wrapped/unwrapped code remained the same except for
indentation.

### Create Field flyout:

#### Before:
<img width="760" alt=""
src="https://user-images.githubusercontent.com/549407/202580476-610e3f54-eabb-4859-a49d-19d0608be787.png">

#### After:
<img width="779" alt=""
src="https://user-images.githubusercontent.com/549407/202580282-886435e7-00cc-4569-943d-fff471b3af7b.png">

### Fields flyout (mobile only):

#### Before:
<img width="754" alt=""
src="https://user-images.githubusercontent.com/549407/202580465-917ef121-d0eb-4188-bcf7-2b08edb5dd49.png">

#### After:
<img width="761" alt=""
src="https://user-images.githubusercontent.com/549407/202580275-820b9420-a8da-458e-bbb4-5f1cfb57ba99.png">

### Checklist

- [x] This renders correctly on smaller devices using a responsive
layout. (You can test this [in your
browser](https://www.browserstack.com/guide/responsive-testing-on-local-server))
- [x] This was checked for [cross-browser
compatibility](https://www.elastic.co/support/matrix#matrix_browsers)

Co-authored-by: Kibana Machine <[email protected]>
Co-authored-by: Julia Rechkunova <[email protected]>

src/plugins/data_view_field_editor/public/components/field_editor_flyout_content.tsx

@@ -13,6 +13,7 @@ import {
   EuiFlexItem,
   EuiText,
   EuiTitle,
+  useIsWithinMaxBreakpoint,
 } from '@elastic/eui';
 import { i18n } from '@kbn/i18n';
 import { FormattedMessage } from '@kbn/i18n-react';
@@ -72,6 +73,8 @@ const FieldEditorFlyoutContentComponent = ({
   const isEditingExistingField = !!fieldToEdit;
   const { dataView, subfields$ } = useFieldEditorContext();
 
+  const isMobile = useIsWithinMaxBreakpoint('s');
+
   const {
     panel: { isVisible: isPanelVisible },
   } = useFieldPreviewContext();
@@ -198,7 +201,7 @@ const FieldEditorFlyoutContentComponent = ({
     <>
       <FlyoutPanels.Group
         flyoutClassName={euiFlyoutClassname}
-        maxWidth={1180}
+        maxWidth={isMobile ? false : 1180}
         data-test-subj="fieldEditor"
         fixedPanelWidths
       >

src/plugins/data_view_field_editor/public/components/flyout_panels/flyout_panels.tsx

@@ -14,7 +14,7 @@ import React, {
   useMemo,
   useLayoutEffect,
 } from 'react';
-import { EuiFlexGroup, EuiFlexGroupProps } from '@elastic/eui';
+import { EuiFlexGroup, EuiFlexGroupProps, EuiFlyoutProps } from '@elastic/eui';
 
 import './flyout_panels.scss';
 
@@ -47,7 +47,7 @@ export interface Props {
    * The total max width with all the panels in the DOM
    * Corresponds to the "maxWidth" prop passed to the EuiFlyout
    */
-  maxWidth: number;
+  maxWidth: EuiFlyoutProps['maxWidth'];
   /** The className selector of the flyout */
   flyoutClassName: string;
   /** The size between the panels. Corresponds to EuiFlexGroup gutterSize */
@@ -110,20 +110,27 @@ export const Panels: React.FC<Props> = ({
 
     let currentWidth: number;
 
-    if (fixedPanelWidths) {
-      const totalWidth = Object.values(panels).reduce((acc, { width = 0 }) => acc + width, 0);
-      currentWidth = Math.min(maxWidth, totalWidth);
-      // As EUI declares both min-width and max-width on the .euiFlyout CSS class
-      // we need to override  both values
-      flyoutDOMelement.style.minWidth = `${limitWidthToWindow(currentWidth, window)}px`;
-      flyoutDOMelement.style.maxWidth = `${limitWidthToWindow(currentWidth, window)}px`;
+    if (typeof maxWidth === 'number') {
+      if (fixedPanelWidths) {
+        const totalWidth = Object.values(panels).reduce((acc, { width = 0 }) => acc + width, 0);
+        currentWidth = Math.min(maxWidth, totalWidth);
+        // As EUI declares both min-width and max-width on the .euiFlyout CSS class
+        // we need to override  both values
+        flyoutDOMelement.style.minWidth = `${limitWidthToWindow(currentWidth, window)}px`;
+        flyoutDOMelement.style.maxWidth = `${limitWidthToWindow(currentWidth, window)}px`;
+      } else {
+        const totalPercentWidth = Math.min(
+          100,
+          Object.values(panels).reduce((acc, { width = 0 }) => acc + width, 0)
+        );
+        currentWidth = (maxWidth * totalPercentWidth) / 100;
+        flyoutDOMelement.style.maxWidth = `${limitWidthToWindow(currentWidth, window)}px`;
+      }
     } else {
-      const totalPercentWidth = Math.min(
-        100,
-        Object.values(panels).reduce((acc, { width = 0 }) => acc + width, 0)
-      );
-      currentWidth = (maxWidth * totalPercentWidth) / 100;
-      flyoutDOMelement.style.maxWidth = `${limitWidthToWindow(currentWidth, window)}px`;
+      // maxWidth is false on smaller mobile screens when the preview panel is unused.
+      // Unset custom min/max widths and let EUI's default 90vw width be used
+      flyoutDOMelement.style.minWidth = '';
+      flyoutDOMelement.style.maxWidth = '';
     }
   }, [panels, maxWidth, fixedPanelWidths, flyoutClassName, flyoutDOMelement]);
 

src/plugins/discover/public/application/main/components/sidebar/discover_sidebar.scss

@@ -8,7 +8,7 @@
 
   @include euiBreakpoint('xs', 's') {
     width: 100%;
-    padding: $euiSize $euiSize 0 $euiSize;
+    padding: $euiSize;
     background-color: $euiPageBackgroundColor;
   }
 }

src/plugins/discover/public/application/main/components/sidebar/discover_sidebar_responsive.tsx

@@ -320,22 +320,19 @@ export function DiscoverSidebarResponsive(props: DiscoverSidebarResponsiveProps)
                   </h2>
                 </EuiTitle>
               </EuiFlyoutHeader>
-              {/* Using only the direct flyout body class because we maintain scroll in a lower sidebar component. Needs a fix on the EUI side */}
-              <div className="euiFlyoutBody">
-                <DiscoverSidebar
-                  {...props}
-                  documents={documentState.result}
-                  fieldCounts={fieldCounts.current}
-                  fieldFilter={fieldFilter}
-                  setFieldFilter={setFieldFilter}
-                  alwaysShowActionButtons={true}
-                  setFieldEditorRef={setFieldEditorRef}
-                  closeFlyout={closeFlyout}
-                  editField={editField}
-                  createNewDataView={createNewDataView}
-                  showDataViewPicker={true}
-                />
-              </div>
+              <DiscoverSidebar
+                {...props}
+                documents={documentState.result}
+                fieldCounts={fieldCounts.current}
+                fieldFilter={fieldFilter}
+                setFieldFilter={setFieldFilter}
+                alwaysShowActionButtons={true}
+                setFieldEditorRef={setFieldEditorRef}
+                closeFlyout={closeFlyout}
+                editField={editField}
+                createNewDataView={createNewDataView}
+                showDataViewPicker={true}
+              />
             </EuiFlyout>
           </EuiPortal>
         )}