Flame graph: Add context menu (#62705)

* Context menu

* Flame graph context menu improvements

* Move context menu state into flame graph

* Simplify logic

* Add test and rename to ContextMenuData

public/app/plugins/panel/flamegraph/components/FlameGraph/FlameGraph.test.tsx

@@ -1,4 +1,4 @@
-import { screen } from '@testing-library/dom';
+import { fireEvent, screen } from '@testing-library/dom';
 import { render } from '@testing-library/react';
 import React, { useState } from 'react';
 
@@ -9,6 +9,7 @@ import { SelectedView } from '../types';
 import FlameGraph from './FlameGraph';
 import { Item, nestedSetToLevels } from './dataTransform';
 import { data } from './testData/dataNestedSet';
+
 import 'jest-canvas-mock';
 
 jest.mock('react-use', () => ({
@@ -67,4 +68,18 @@ describe('FlameGraph', () => {
     render(<FlameGraphWithProps />);
     expect(screen.getByText('16.5 Bil (100%) of 16,460,000,000 total samples (Count)')).toBeDefined();
   });
+
+  it('should render context menu', async () => {
+    const event = new MouseEvent('click');
+    Object.defineProperty(event, 'offsetX', { get: () => 10 });
+    Object.defineProperty(event, 'offsetY', { get: () => 10 });
+    Object.defineProperty(HTMLCanvasElement.prototype, 'clientWidth', { configurable: true, value: 500 });
+
+    const screen = render(<FlameGraphWithProps />);
+    const canvas = screen.getByTestId('flameGraph') as HTMLCanvasElement;
+    expect(canvas).toBeInTheDocument();
+    expect(screen.queryByTestId('contextMenu')).not.toBeInTheDocument();
+    fireEvent(canvas, event);
+    expect(screen.getByTestId('contextMenu')).toBeInTheDocument();
+  });
 });

public/app/plugins/panel/flamegraph/components/FlameGraph/FlameGraph.tsx

@@ -24,8 +24,9 @@ import { useMeasure } from 'react-use';
 import { CoreApp, createTheme, DataFrame, FieldType, getDisplayProcessor } from '@grafana/data';
 
 import { PIXELS_PER_LEVEL } from '../../constants';
-import { TooltipData, SelectedView } from '../types';
+import { TooltipData, SelectedView, ContextMenuData } from '../types';
 
+import FlameGraphContextMenu from './FlameGraphContextMenu';
 import FlameGraphMetadata from './FlameGraphMetadata';
 import FlameGraphTooltip, { getTooltipData } from './FlameGraphTooltip';
 import { ItemWithStart } from './dataTransform';
@@ -77,18 +78,7 @@ const FlameGraph = ({
   const graphRef = useRef<HTMLCanvasElement>(null);
   const tooltipRef = useRef<HTMLDivElement>(null);
   const [tooltipData, setTooltipData] = useState<TooltipData>();
-  const [showTooltip, setShowTooltip] = useState(false);
-
-  // Convert pixel coordinates to bar coordinates in the levels array so that we can add mouse events like clicks to
-  // the canvas.
-  const convertPixelCoordinatesToBarCoordinates = useCallback(
-    (x: number, y: number, pixelsPerTick: number) => {
-      const levelIndex = Math.floor(y / (PIXELS_PER_LEVEL / window.devicePixelRatio));
-      const barIndex = getBarIndex(x, levels[levelIndex], pixelsPerTick, totalTicks, rangeMin);
-      return { levelIndex, barIndex };
-    },
-    [levels, totalTicks, rangeMin]
-  );
+  const [contextMenuData, setContextMenuData] = useState<ContextMenuData>();
 
   const [ufuzzy] = useState(() => {
     return new uFuzzy();
@@ -152,25 +142,37 @@ const FlameGraph = ({
       const pixelsPerTick = (wrapperWidth * window.devicePixelRatio) / totalTicks / (rangeMax - rangeMin);
       render(pixelsPerTick);
 
-      // Clicking allows user to "zoom" into the flamegraph. Zooming means the x axis gets smaller so that the clicked
-      // bar takes 100% of the x axis.
       graphRef.current.onclick = (e) => {
+        setTooltipData(undefined);
         const pixelsPerTick = graphRef.current!.clientWidth / totalTicks / (rangeMax - rangeMin);
-        const { levelIndex, barIndex } = convertPixelCoordinatesToBarCoordinates(e.offsetX, e.offsetY, pixelsPerTick);
+        const { levelIndex, barIndex } = convertPixelCoordinatesToBarCoordinates(
+          e,
+          pixelsPerTick,
+          levels,
+          totalTicks,
+          rangeMin
+        );
 
+        // if clicking on a block in the canvas
         if (barIndex !== -1 && !isNaN(levelIndex) && !isNaN(barIndex)) {
-          setTopLevelIndex(levelIndex);
-          setSelectedBarIndex(barIndex);
-          setRangeMin(levels[levelIndex][barIndex].start / totalTicks);
-          setRangeMax((levels[levelIndex][barIndex].start + levels[levelIndex][barIndex].value) / totalTicks);
+          setContextMenuData({ e, levelIndex, barIndex });
+        } else {
+          // if clicking on the canvas but there is no block beneath the cursor
+          setContextMenuData(undefined);
         }
       };
 
       graphRef.current!.onmousemove = (e) => {
-        if (tooltipRef.current) {
-          setShowTooltip(false);
+        if (tooltipRef.current && contextMenuData === undefined) {
+          setTooltipData(undefined);
           const pixelsPerTick = graphRef.current!.clientWidth / totalTicks / (rangeMax - rangeMin);
-          const { levelIndex, barIndex } = convertPixelCoordinatesToBarCoordinates(e.offsetX, e.offsetY, pixelsPerTick);
+          const { levelIndex, barIndex } = convertPixelCoordinatesToBarCoordinates(
+            e,
+            pixelsPerTick,
+            levels,
+            totalTicks,
+            rangeMin
+          );
 
           if (barIndex !== -1 && !isNaN(levelIndex) && !isNaN(barIndex)) {
             tooltipRef.current.style.left = e.clientX + 10 + 'px';
@@ -179,18 +181,16 @@ const FlameGraph = ({
             const bar = levels[levelIndex][barIndex];
             const tooltipData = getTooltipData(valueField, bar.label, bar.value, bar.self, totalTicks);
             setTooltipData(tooltipData);
-            setShowTooltip(true);
           }
         }
       };
 
       graphRef.current!.onmouseleave = () => {
-        setShowTooltip(false);
+        setTooltipData(undefined);
       };
     }
   }, [
     render,
-    convertPixelCoordinatesToBarCoordinates,
     levels,
     rangeMin,
     rangeMax,
@@ -203,8 +203,22 @@ const FlameGraph = ({
     selectedView,
     valueField,
     setSelectedBarIndex,
+    setContextMenuData,
+    contextMenuData,
   ]);
 
+  // hide context menu if outside of the flame graph canvas is clicked
+  useEffect(() => {
+    const handleOnClick = (e: MouseEvent) => {
+      // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
+      if ((e.target as HTMLElement).parentElement?.id !== 'flameGraphCanvasContainer') {
+        setContextMenuData(undefined);
+      }
+    };
+    window.addEventListener('click', handleOnClick);
+    return () => window.removeEventListener('click', handleOnClick);
+  }, [setContextMenuData]);
+
   return (
     <div className={styles.graph} ref={sizeRef}>
       <FlameGraphMetadata
@@ -214,15 +228,29 @@ const FlameGraph = ({
         valueField={valueField}
         totalTicks={totalTicks}
       />
+      <div className={styles.canvasContainer} id="flameGraphCanvasContainer">
         <canvas ref={graphRef} data-testid="flameGraph" />
-      <FlameGraphTooltip tooltipRef={tooltipRef} tooltipData={tooltipData!} showTooltip={showTooltip} />
+      </div>
+      <FlameGraphTooltip tooltipRef={tooltipRef} tooltipData={tooltipData!} />
+      {contextMenuData && (
+        <FlameGraphContextMenu
+          contextMenuData={contextMenuData!}
+          levels={levels}
+          totalTicks={totalTicks}
+          graphRef={graphRef}
+          setContextMenuData={setContextMenuData}
+          setTopLevelIndex={setTopLevelIndex}
+          setSelectedBarIndex={setSelectedBarIndex}
+          setRangeMin={setRangeMin}
+          setRangeMax={setRangeMax}
+        />
+      )}
     </div>
   );
 };
 
 const getStyles = (selectedView: SelectedView, app: CoreApp, flameGraphHeight: number | undefined) => ({
   graph: css`
-    cursor: pointer;
     float: left;
     overflow: scroll;
     width: ${selectedView === SelectedView.FlameGraph ? '100%' : '50%'};
@@ -230,8 +258,25 @@ const getStyles = (selectedView: SelectedView, app: CoreApp, flameGraphHeight: n
       ? `height: calc(${flameGraphHeight}px - 50px)`
       : ''}; // 50px to adjust for header pushing content down
   `,
+  canvasContainer: css`
+    cursor: pointer;
+  `,
 });
 
+// Convert pixel coordinates to bar coordinates in the levels array so that we can add mouse events like clicks to
+// the canvas.
+const convertPixelCoordinatesToBarCoordinates = (
+  e: MouseEvent,
+  pixelsPerTick: number,
+  levels: ItemWithStart[][],
+  totalTicks: number,
+  rangeMin: number
+) => {
+  const levelIndex = Math.floor(e.offsetY / (PIXELS_PER_LEVEL / window.devicePixelRatio));
+  const barIndex = getBarIndex(e.offsetX, levels[levelIndex], pixelsPerTick, totalTicks, rangeMin);
+  return { levelIndex, barIndex };
+};
+
 /**
  * Binary search for a bar in a level, based on the X pixel coordinate. Useful for detecting which bar did user click
  * on.

public/app/plugins/panel/flamegraph/components/FlameGraph/FlameGraphContextMenu.tsx

@@ -0,0 +1,82 @@
+import React from 'react';
+
+import { MenuItem, ContextMenu } from '@grafana/ui';
+
+import { ContextMenuData } from '../types';
+
+import { ItemWithStart } from './dataTransform';
+
+type Props = {
+  contextMenuData: ContextMenuData;
+  levels: ItemWithStart[][];
+  totalTicks: number;
+  graphRef: React.RefObject<HTMLCanvasElement>;
+  setContextMenuData: (event: ContextMenuData | undefined) => void;
+  setTopLevelIndex: (level: number) => void;
+  setSelectedBarIndex: (bar: number) => void;
+  setRangeMin: (range: number) => void;
+  setRangeMax: (range: number) => void;
+};
+
+const FlameGraphContextMenu = ({
+  contextMenuData,
+  graphRef,
+  totalTicks,
+  levels,
+  setContextMenuData,
+  setTopLevelIndex,
+  setSelectedBarIndex,
+  setRangeMin,
+  setRangeMax,
+}: Props) => {
+  const renderMenuItems = () => {
+    return (
+      <>
+        <MenuItem
+          label="Focus block"
+          icon={'eye'}
+          onClick={() => {
+            if (graphRef.current && contextMenuData) {
+              setTopLevelIndex(contextMenuData.levelIndex);
+              setSelectedBarIndex(contextMenuData.barIndex);
+              setRangeMin(levels[contextMenuData.levelIndex][contextMenuData.barIndex].start / totalTicks);
+              setRangeMax(
+                (levels[contextMenuData.levelIndex][contextMenuData.barIndex].start +
+                  levels[contextMenuData.levelIndex][contextMenuData.barIndex].value) /
+                  totalTicks
+              );
+              setContextMenuData(undefined);
+            }
+          }}
+        />
+        <MenuItem
+          label="Copy function name"
+          icon={'copy'}
+          onClick={() => {
+            if (graphRef.current && contextMenuData) {
+              const bar = levels[contextMenuData.levelIndex][contextMenuData.barIndex];
+              navigator.clipboard.writeText(bar.label).then(() => {
+                setContextMenuData(undefined);
+              });
+            }
+          }}
+        />
+      </>
+    );
+  };
+
+  return (
+    <div data-testid="contextMenu">
+      {contextMenuData.e.clientX && contextMenuData.e.clientY && (
+        <ContextMenu
+          renderMenuItems={() => renderMenuItems()}
+          x={contextMenuData.e.clientX + 10}
+          y={contextMenuData.e.clientY}
+          focusOnOpen={false}
+        ></ContextMenu>
+      )}
+    </div>
+  );
+};
+
+export default FlameGraphContextMenu;

public/app/plugins/panel/flamegraph/components/FlameGraph/FlameGraphTooltip.tsx

@@ -9,15 +9,14 @@ import { TooltipData, SampleUnit } from '../types';
 type Props = {
   tooltipRef: LegacyRef<HTMLDivElement>;
   tooltipData: TooltipData;
-  showTooltip: boolean;
 };
 
-const FlameGraphTooltip = ({ tooltipRef, tooltipData, showTooltip }: Props) => {
+const FlameGraphTooltip = ({ tooltipRef, tooltipData }: Props) => {
   const styles = useStyles2(getStyles);
 
   return (
     <div ref={tooltipRef} className={styles.tooltip}>
-      {tooltipData && showTooltip && (
+      {tooltipData && (
         <Tooltip
           content={
             <div>

public/app/plugins/panel/flamegraph/components/types.ts

@@ -8,6 +8,12 @@ export type TooltipData = {
   samples: string;
 };
 
+export type ContextMenuData = {
+  e: MouseEvent;
+  levelIndex: number;
+  barIndex: number;
+};
+
 export type Metadata = {
   percentValue: number;
   unitTitle: string;