DashboardGrid: Add LayoutItemContext to affect zIndex from panels (#8…

…0116)

packages/grafana-ui/src/components/Layout/LayoutItemContext.ts

@@ -0,0 +1,21 @@
+import { createContext } from 'react';
+
+export interface LayoutItemContextProps {
+  boostZIndex(): () => void;
+}
+
+/**
+ * Provides an API for downstream components (e.g. within panels) to inform the layout
+ * that anchored tooltips or context menus could overflow the panel bounds. The layout
+ * system can then boost the z-index of items with any anchored contents to prevent the overflown
+ * content from rendering underneath adjacent layout items (e.g. other panels) that naturally
+ * render later/higher in the stacking order
+ *
+ * This is used by VizTooltips and Annotations, which anchor to data points or time range within
+ * the viz drawing area
+ *
+ * @internal
+ */
+export const LayoutItemContext = createContext<LayoutItemContextProps>({
+  boostZIndex: () => () => {},
+});

packages/grafana-ui/src/components/index.ts

@@ -264,6 +264,8 @@ export { Avatar } from './UsersIndicator/Avatar';
 export { InlineFormLabel } from './FormLabel/FormLabel';
 export { Divider } from './Divider/Divider';
 
+export { LayoutItemContext, type LayoutItemContextProps } from './Layout/LayoutItemContext';
+
 /** @deprecated Please use non-legacy versions of these components */
 const LegacyForms = {
   SecretFormField,

public/app/features/dashboard/dashgrid/DashboardGrid.tsx

@@ -1,10 +1,12 @@
 import classNames from 'classnames';
-import React, { PureComponent, CSSProperties } from 'react';
+import React, { PureComponent, CSSProperties, useRef, useCallback, useReducer, useMemo } from 'react';
 import ReactGridLayout, { ItemCallback } from 'react-grid-layout';
 import AutoSizer from 'react-virtualized-auto-sizer';
 import { Subscription } from 'rxjs';
 
+import { zIndex } from '@grafana/data/src/themes/zIndex';
 import { config } from '@grafana/runtime';
+import { LayoutItemContext } from '@grafana/ui';
 import appEvents from 'app/core/app_events';
 import { GRID_CELL_HEIGHT, GRID_CELL_VMARGIN, GRID_COLUMN_COUNT } from 'app/core/constants';
 import { contextSrv } from 'app/core/services/context_srv';
@@ -383,6 +385,21 @@ const GrafanaGridItem = React.forwardRef<HTMLDivElement, GrafanaGridItemProps>((
   let width = 100;
   let height = 100;
 
+  const boostedCount = useRef(0);
+  const [_, forceUpdate] = useReducer((x) => x + 1, 0);
+
+  const boostZIndex = useCallback(() => {
+    boostedCount.current += 1;
+    forceUpdate();
+
+    return () => {
+      boostedCount.current -= 1;
+      forceUpdate();
+    };
+  }, [forceUpdate]);
+
+  const ctxValue = useMemo(() => ({ boostZIndex }), [boostZIndex]);
+
   const { gridWidth, gridPos, isViewing, windowHeight, windowWidth, descendingOrderIndex, ...divProps } = props;
   const style: CSSProperties = props.style ?? {};
 
@@ -413,10 +430,17 @@ const GrafanaGridItem = React.forwardRef<HTMLDivElement, GrafanaGridItemProps>((
 
   // props.children[0] is our main children. RGL adds the drag handle at props.children[1]
   return (
-    <div {...divProps} style={{ ...divProps.style, zIndex: descendingOrderIndex }} ref={ref}>
-      {/* Pass width and height to children as render props */}
-      {[props.children[0](width, height), props.children.slice(1)]}
-    </div>
+    <LayoutItemContext.Provider value={ctxValue}>
+      <div
+        {...divProps}
+        // .context-menu-open === $zindex-dropdown === 1030 (zIndex.ts)
+        style={{ ...divProps.style, zIndex: boostedCount.current === 0 ? descendingOrderIndex : zIndex.dropdown }}
+        ref={ref}
+      >
+        {/* Pass width and height to children as render props */}
+        {[props.children[0](width, height), props.children.slice(1)]}
+      </div>
+    </LayoutItemContext.Provider>
   );
 });