GraphNG: Fix issues with plugins not retrieving plot instance (#29585)

* Fix issues with plugins not retrieving plot instance

* Review

packages/grafana-ui/src/components/uPlot/Plot.tsx

@@ -23,10 +23,6 @@ export const UPlotChart: React.FC<PlotProps> = props => {
     props.config
   );
   const getPlotInstance = useCallback(() => {
-    if (!plotInstance.current) {
-      throw new Error("Plot hasn't initialised yet");
-    }
-
     return plotInstance.current;
   }, []);
 
@@ -72,13 +68,15 @@ export const UPlotChart: React.FC<PlotProps> = props => {
 
   // Memoize plot context
   const plotCtx = useMemo(() => {
-    return buildPlotContext(Boolean(plotInstance.current), canvasRef, props.data, registerPlugin, getPlotInstance);
+    return buildPlotContext(canvasRef, props.data, registerPlugin, getPlotInstance);
   }, [plotInstance, canvasRef, props.data, registerPlugin, getPlotInstance]);
 
   return (
     <PlotContext.Provider value={plotCtx}>
-      <div ref={plotCtx.canvasRef} data-testid="uplot-main-div" />
-      {props.children}
+      <div style={{ position: 'relative' }}>
+        <div ref={plotCtx.canvasRef} data-testid="uplot-main-div" />
+        {props.children}
+      </div>
     </PlotContext.Provider>
   );
 };

packages/grafana-ui/src/components/uPlot/context.ts

@@ -21,8 +21,7 @@ interface PlotPluginsContextType {
 }
 
 interface PlotContextType extends PlotPluginsContextType {
-  isPlotReady: boolean;
-  getPlotInstance: () => uPlot;
+  getPlotInstance: () => uPlot | undefined;
   getSeries: () => Series[];
   getCanvas: () => PlotCanvasContextType;
   canvasRef: any;
@@ -127,28 +126,31 @@ export const usePlotData = (): PlotDataAPI => {
 };
 
 export const buildPlotContext = (
-  isPlotReady: boolean,
   canvasRef: any,
   data: AlignedFrameWithGapTest,
   registerPlugin: any,
-  getPlotInstance: () => uPlot
+  getPlotInstance: () => uPlot | undefined
 ): PlotContextType => {
   return {
-    isPlotReady,
     canvasRef,
     data,
     registerPlugin,
     getPlotInstance,
-    getSeries: () => getPlotInstance().series,
-    getCanvas: () => ({
-      width: getPlotInstance().width,
-      height: getPlotInstance().height,
-      plot: {
-        width: getPlotInstance().bbox.width / window.devicePixelRatio,
-        height: getPlotInstance().bbox.height / window.devicePixelRatio,
-        top: getPlotInstance().bbox.top / window.devicePixelRatio,
-        left: getPlotInstance().bbox.left / window.devicePixelRatio,
-      },
-    }),
+    getSeries: () => getPlotInstance()!.series,
+    getCanvas: () => {
+      const plotInstance = getPlotInstance()!;
+      const bbox = plotInstance.bbox;
+      const pxRatio = window.devicePixelRatio;
+      return {
+        width: plotInstance.width,
+        height: plotInstance.height,
+        plot: {
+          width: bbox.width / pxRatio,
+          height: bbox.height / pxRatio,
+          top: bbox.top / pxRatio,
+          left: bbox.left / pxRatio,
+        },
+      };
+    },
   };
 };

packages/grafana-ui/src/components/uPlot/geometries/EventsCanvas.tsx

@@ -18,8 +18,7 @@ export function EventsCanvas<T>({ id, events, renderEventMarker, mapEventToXYCoo
 
   const eventMarkers = useMemo(() => {
     const markers: React.ReactNode[] = [];
-
-    if (!plotCtx.isPlotReady || events.length === 0) {
+    if (!plotCtx.getPlotInstance() || events.length === 0) {
       return markers;
     }
 
@@ -41,9 +40,9 @@ export function EventsCanvas<T>({ id, events, renderEventMarker, mapEventToXYCoo
     }
 
     return <>{markers}</>;
-  }, [events, renderEventMarker, renderToken, plotCtx.isPlotReady]);
+  }, [events, renderEventMarker, renderToken, plotCtx]);
 
-  if (!plotCtx.isPlotReady) {
+  if (!plotCtx.getPlotInstance()) {
     return null;
   }
 

packages/grafana-ui/src/components/uPlot/geometries/XYCanvas.tsx

@@ -10,8 +10,9 @@ interface XYCanvasProps {}
  */
 export const XYCanvas: React.FC<XYCanvasProps> = ({ children }) => {
   const plotContext = usePlotContext();
+  const plotInstance = plotContext.getPlotInstance();
 
-  if (!plotContext.isPlotReady) {
+  if (!plotInstance) {
     return null;
   }
 
@@ -20,8 +21,8 @@ export const XYCanvas: React.FC<XYCanvasProps> = ({ children }) => {
       className={css`
         position: absolute;
         overflow: visible;
-        left: ${plotContext.getPlotInstance().bbox.left / window.devicePixelRatio}px;
-        top: ${plotContext.getPlotInstance().bbox.top / window.devicePixelRatio}px;
+        left: ${plotInstance.bbox.left / window.devicePixelRatio}px;
+        top: ${plotInstance.bbox.top / window.devicePixelRatio}px;
       `}
     >
       {children}

packages/grafana-ui/src/components/uPlot/plugins/SelectionPlugin.tsx

@@ -75,7 +75,7 @@ export const SelectionPlugin: React.FC<SelectionPluginProps> = ({ onSelect, onDi
     };
   }, []);
 
-  if (!plotCtx.isPlotReady || !children || !selection) {
+  if (!plotCtx.getPlotInstance() || !children || !selection) {
     return null;
   }
 

packages/grafana-ui/src/components/uPlot/plugins/TooltipPlugin.tsx

@@ -25,7 +25,7 @@ export const TooltipPlugin: React.FC<TooltipPluginProps> = ({ mode = 'single', t
   return (
     <CursorPlugin id={pluginId}>
       {({ focusedSeriesIdx, focusedPointIdx, coords }) => {
-        if (!plotContext.isPlotReady) {
+        if (!plotContext.getPlotInstance()) {
           return null;
         }
 

public/app/plugins/panel/graph3/plugins/AnnotationsPlugin.tsx

@@ -32,7 +32,7 @@ export const AnnotationsPlugin: React.FC<AnnotationsPluginProps> = ({ annotation
   );
 
   useEffect(() => {
-    if (plotCtx.isPlotReady) {
+    if (plotCtx.getPlotInstance()) {
       const views: Array<DataFrameView<AnnotationsDataFrameViewDTO>> = [];
 
       for (const frame of annotations) {
@@ -41,7 +41,7 @@ export const AnnotationsPlugin: React.FC<AnnotationsPluginProps> = ({ annotation
 
       annotationsRef.current = views;
     }
-  }, [plotCtx.isPlotReady, annotations]);
+  }, [plotCtx, annotations]);
 
   useEffect(() => {
     const unregister = plotCtx.registerPlugin({
@@ -93,13 +93,14 @@ export const AnnotationsPlugin: React.FC<AnnotationsPluginProps> = ({ annotation
 
   const mapAnnotationToXYCoords = useCallback(
     (annotation: AnnotationsDataFrameViewDTO) => {
-      if (!annotation.time) {
+      const plotInstance = plotCtx.getPlotInstance();
+      if (!annotation.time || !plotInstance) {
         return undefined;
       }
 
       return {
-        x: plotCtx.getPlotInstance().valToPos(annotation.time / 1000, 'x'),
-        y: plotCtx.getPlotInstance().bbox.height / window.devicePixelRatio + 4,
+        x: plotInstance.valToPos(annotation.time, 'x'),
+        y: plotInstance.bbox.height / window.devicePixelRatio + 4,
       };
     },
     [plotCtx.getPlotInstance]

public/app/plugins/panel/graph3/plugins/ExemplarsPlugin.tsx

@@ -42,7 +42,7 @@ export const ExemplarsPlugin: React.FC<ExemplarsPluginProps> = ({ exemplars, tim
 
   // THIS EVENT ONLY MOCKS EXEMPLAR Y VALUE!!!! TO BE REMOVED WHEN WE GET CORRECT EXEMPLARS SHAPE VIA PROPS
   useEffect(() => {
-    if (plotCtx.isPlotReady) {
+    if (plotCtx.getPlotInstance()) {
       const mocks: DataFrame[] = [];
 
       for (const frame of exemplars) {
@@ -61,18 +61,19 @@ export const ExemplarsPlugin: React.FC<ExemplarsPluginProps> = ({ exemplars, tim
 
       setExemplarsMock(mocks);
     }
-  }, [plotCtx.isPlotReady, exemplars]);
+  }, [plotCtx, exemplars]);
 
   const mapExemplarToXYCoords = useCallback(
     (exemplar: ExemplarsDataFrameViewDTO) => {
-      if (!exemplar.time) {
+      const plotInstance = plotCtx.getPlotInstance();
+      if (!exemplar.time || !plotInstance) {
         return undefined;
       }
 
       return {
-        x: plotCtx.getPlotInstance().valToPos(exemplar.time / 1000, 'x'),
+        x: plotInstance.valToPos(exemplar.time / 1000, 'x'),
         // exemplar.y is a temporary mock for an examplar. This Needs to be calculated according to examplar scale!
-        y: Math.floor((exemplar.y * plotCtx.getPlotInstance().bbox.height) / window.devicePixelRatio),
+        y: Math.floor((exemplar.y * plotInstance.bbox.height) / window.devicePixelRatio),
       };
     },
     [plotCtx.getPlotInstance]