Refactor SplitPaneWrapper to be more centralized component, refactor PanelEditor to use it (#58380)

* Move layout to paneleditor, make SplitPaneWrapper more generic

* Read/write the size ratio in local storage

* Add min height to enable scrollbar

* Enable show/hide panel options

* Change back variable name

public/app/core/components/SplitPaneWrapper/SplitPaneWrapper.tsx

@@ -1,28 +1,23 @@
 import { css, cx } from '@emotion/css';
-import React, { createRef, MutableRefObject, PureComponent, ReactNode } from 'react';
-import SplitPane from 'react-split-pane';
+import React, { createRef, MutableRefObject, PureComponent } from 'react';
+import SplitPane, { Split } from 'react-split-pane';
 
 import { GrafanaTheme2 } from '@grafana/data';
 import { config } from 'app/core/config';
 
-enum Pane {
-  Right,
-  Top,
-}
-
 interface Props {
-  leftPaneComponents: ReactNode[] | ReactNode;
-  rightPaneComponents: ReactNode;
-  uiState: { topPaneSize: number; rightPaneSize: number };
-  rightPaneVisible?: boolean;
-  updateUiState: (uiState: { topPaneSize?: number; rightPaneSize?: number }) => void;
+  splitOrientation?: Split;
+  paneSize: number;
+  splitVisible?: boolean;
+  maxSize?: number;
+  primary?: 'first' | 'second';
+  onDragFinished?: (size?: number) => void;
+  secondaryPaneStyle?: React.CSSProperties;
 }
 
 export class SplitPaneWrapper extends PureComponent<Props> {
+  //requestAnimationFrame reference
   rafToken: MutableRefObject<number | null> = createRef();
-  static defaultProps = {
-    rightPaneVisible: true,
-  };
 
   componentDidMount() {
     window.addEventListener('resize', this.updateSplitPaneSize);
@@ -41,86 +36,41 @@ export class SplitPaneWrapper extends PureComponent<Props> {
     });
   };
 
-  onDragFinished = (pane: Pane, size?: number) => {
+  onDragFinished = (size?: number) => {
     document.body.style.cursor = 'auto';
 
-    // When the drag handle is just clicked size is undefined
-    if (!size) {
-      return;
-    }
-
-    const { updateUiState } = this.props;
-    if (pane === Pane.Top) {
-      updateUiState({
-        topPaneSize: size / window.innerHeight,
-      });
-    } else {
-      updateUiState({
-        rightPaneSize: size / window.innerWidth,
-      });
+    if (this.props.onDragFinished && size !== undefined) {
+      this.props.onDragFinished(size);
     }
   };
 
   onDragStarted = () => {
-    document.body.style.cursor = 'row-resize';
+    document.body.style.cursor = this.props.splitOrientation === 'horizontal' ? 'row-resize' : 'col-resize';
   };
 
-  renderHorizontalSplit() {
-    const { leftPaneComponents, uiState } = this.props;
-    const styles = getStyles(config.theme2);
-    const topPaneSize = uiState.topPaneSize >= 1 ? uiState.topPaneSize : uiState.topPaneSize * window.innerHeight;
-
-    /*
-      Guesstimate the height of the browser window minus
-      panel toolbar and editor toolbar (~120px). This is to prevent resizing
-      the preview window beyond the browser window.
-     */
-
-    if (Array.isArray(leftPaneComponents)) {
-      return (
-        <SplitPane
-          split="horizontal"
-          maxSize={-200}
-          primary="first"
-          size={topPaneSize}
-          pane2Style={{ minHeight: 0 }}
-          resizerClassName={styles.resizerH}
-          onDragStarted={this.onDragStarted}
-          onDragFinished={(size) => this.onDragFinished(Pane.Top, size)}
-        >
-          {leftPaneComponents}
-        </SplitPane>
-      );
-    }
-
-    return <div className={styles.singleLeftPane}>{leftPaneComponents}</div>;
-  }
-
   render() {
-    const { rightPaneVisible, rightPaneComponents, uiState } = this.props;
+    const { paneSize, splitOrientation, maxSize, primary, secondaryPaneStyle } = this.props;
     // Limit options pane width to 90% of screen.
     const styles = getStyles(config.theme2);
 
     // Need to handle when width is relative. ie a percentage of the viewport
-    const rightPaneSize =
-      uiState.rightPaneSize <= 1 ? uiState.rightPaneSize * window.innerWidth : uiState.rightPaneSize;
-
-    if (!rightPaneVisible) {
-      return this.renderHorizontalSplit();
-    }
+    const paneSizePx =
+      paneSize <= 1
+        ? paneSize * (splitOrientation === 'horizontal' ? window.innerHeight : window.innerWidth)
+        : paneSize;
 
     return (
       <SplitPane
-        split="vertical"
-        maxSize={-300}
-        size={rightPaneSize}
-        primary="second"
-        resizerClassName={styles.resizerV}
-        onDragStarted={() => (document.body.style.cursor = 'col-resize')}
-        onDragFinished={(size) => this.onDragFinished(Pane.Right, size)}
+        split={splitOrientation}
+        maxSize={maxSize}
+        size={paneSizePx}
+        primary={primary}
+        resizerClassName={splitOrientation === 'horizontal' ? styles.resizerH : styles.resizerV}
+        onDragStarted={() => this.onDragStarted()}
+        onDragFinished={(size) => this.onDragFinished(size)}
+        pane2Style={secondaryPaneStyle}
       >
-        {this.renderHorizontalSplit()}
-        {rightPaneComponents}
+        {this.props.children}
       </SplitPane>
     );
   }

public/app/features/dashboard/components/PanelEditor/PanelEditor.tsx

@@ -47,7 +47,7 @@ import { PanelEditorTableView } from './PanelEditorTableView';
 import { PanelEditorTabs } from './PanelEditorTabs';
 import { VisualizationButton } from './VisualizationButton';
 import { discardPanelChanges, initPanelEditor, updatePanelEditorUIState } from './state/actions';
-import { toggleTableView } from './state/reducers';
+import { PanelEditorUIState, toggleTableView } from './state/reducers';
 import { getPanelEditorTabs } from './state/selectors';
 import { DisplayMode, displayModes, PanelEditorTab } from './types';
 import { calculatePanelSize } from './utils';
@@ -438,8 +438,27 @@ export class PanelEditorUnconnected extends PureComponent<Props> {
     );
   }
 
+  renderHorizontalSplit(uiState: PanelEditorUIState, styles: EditorStyles) {
+    return (
+      <SplitPaneWrapper
+        splitOrientation="horizontal"
+        maxSize={-200}
+        paneSize={uiState.topPaneSize}
+        primary="first"
+        secondaryPaneStyle={{ minHeight: 0 }}
+        onDragFinished={(size) => {
+          if (size) {
+            updatePanelEditorUIState({ topPaneSize: size / window.innerHeight });
+          }
+        }}
+      >
+        {this.renderPanelAndEditor(styles)}
+      </SplitPaneWrapper>
+    );
+  }
+
   render() {
-    const { initDone, updatePanelEditorUIState, uiState, theme, sectionNav, pageNav, className } = this.props;
+    const { initDone, uiState, theme, sectionNav, pageNav, className, updatePanelEditorUIState } = this.props;
     const styles = getStyles(theme, this.props);
 
     if (!initDone) {
@@ -457,13 +476,24 @@ export class PanelEditorUnconnected extends PureComponent<Props> {
       >
         <div className={styles.wrapper}>
           <div className={styles.verticalSplitPanesWrapper}>
-            <SplitPaneWrapper
-              leftPaneComponents={this.renderPanelAndEditor(styles)}
-              rightPaneComponents={this.renderOptionsPane()}
-              uiState={uiState}
-              updateUiState={updatePanelEditorUIState}
-              rightPaneVisible={uiState.isPanelOptionsVisible}
-            />
+            {!uiState.isPanelOptionsVisible ? (
+              this.renderHorizontalSplit(uiState, styles)
+            ) : (
+              <SplitPaneWrapper
+                splitOrientation="vertical"
+                maxSize={-300}
+                paneSize={uiState.rightPaneSize}
+                primary="second"
+                onDragFinished={(size) => {
+                  if (size) {
+                    updatePanelEditorUIState({ rightPaneSize: size / window.innerWidth });
+                  }
+                }}
+              >
+                {this.renderHorizontalSplit(uiState, styles)}
+                {this.renderOptionsPane()}
+              </SplitPaneWrapper>
+            )}
           </div>
           {this.state.showSaveLibraryPanelModal && (
             <SaveLibraryPanelModal