feat(chart_state): add render change event

src/chart_types/xy_chart/store/chart_state.test.ts

@@ -314,6 +314,33 @@ describe('Chart Store', () => {
     expect(store.onCursorUpdateListener).toEqual(listener);
   });
 
+  test('can set a render change listener', () => {
+    const listener = (): void => {
+      return;
+    };
+    store.setOnRenderChangeListener(listener);
+
+    expect(store.onRenderChangeListener).toEqual(listener);
+  });
+
+  test('should observe chartInitialized value', () => {
+    const listener = jest.fn();
+    store.chartInitialized.set(false);
+    store.setOnRenderChangeListener(listener);
+    store.chartInitialized.set(true);
+
+    expect(listener).toBeCalledWith(true);
+  });
+
+  test('should observe chartInitialized value only on change', () => {
+    const listener = jest.fn();
+    store.chartInitialized.set(false);
+    store.setOnRenderChangeListener(listener);
+    store.chartInitialized.set(false);
+
+    expect(listener).not.toBeCalled();
+  });
+
   test('can remove listeners', () => {
     store.removeElementClickListener();
     expect(store.onElementClickListener).toBeUndefined();
@@ -335,6 +362,9 @@ describe('Chart Store', () => {
 
     store.removeOnCursorUpdateListener();
     expect(store.onCursorUpdateListener).toBeUndefined();
+
+    store.removeOnRenderChangeListener();
+    expect(store.onRenderChangeListener).toBeUndefined();
   });
 
   test('can respond to a brush end event', () => {

src/chart_types/xy_chart/store/chart_state.ts

@@ -106,6 +106,8 @@ export type ElementOverListener = (values: GeometryValue[]) => void;
 export type BrushEndListener = (min: number, max: number) => void;
 export type LegendItemListener = (dataSeriesIdentifiers: DataSeriesColorsValues | null) => void;
 export type CursorUpdateListener = (event?: CursorEvent) => void;
+export type RenderChangeListener = (isRendered: boolean) => void;
+export type BasicListener = () => undefined | void;
 
 export class ChartStore {
   constructor(id?: string) {
@@ -206,15 +208,16 @@ export class ChartStore {
 
   onElementClickListener?: ElementClickListener;
   onElementOverListener?: ElementOverListener;
-  onElementOutListener?: () => undefined | void;
+  onElementOutListener?: BasicListener;
   onBrushEndListener?: BrushEndListener;
   onLegendItemOverListener?: LegendItemListener;
-  onLegendItemOutListener?: () => undefined | void;
+  onLegendItemOutListener?: BasicListener;
   onLegendItemClickListener?: LegendItemListener;
   onLegendItemPlusClickListener?: LegendItemListener;
   onLegendItemMinusClickListener?: LegendItemListener;
   onLegendItemVisibilityToggleClickListener?: LegendItemListener;
   onCursorUpdateListener?: CursorUpdateListener;
+  onRenderChangeListener?: RenderChangeListener;
 
   geometries: {
     points: PointGeometry[];
@@ -698,7 +701,7 @@ export class ChartStore {
   setOnElementOverListener(listener: ElementOverListener) {
     this.onElementOverListener = listener;
   }
-  setOnElementOutListener(listener: () => undefined | void) {
+  setOnElementOutListener(listener: BasicListener) {
     this.onElementOutListener = listener;
   }
   setOnBrushEndListener(listener: BrushEndListener) {
@@ -707,7 +710,7 @@ export class ChartStore {
   setOnLegendItemOverListener(listener: LegendItemListener) {
     this.onLegendItemOverListener = listener;
   }
-  setOnLegendItemOutListener(listener: () => undefined | void) {
+  setOnLegendItemOutListener(listener: BasicListener) {
     this.onLegendItemOutListener = listener;
   }
   setOnLegendItemClickListener(listener: LegendItemListener) {
@@ -722,6 +725,15 @@ export class ChartStore {
   setOnCursorUpdateListener(listener: CursorUpdateListener) {
     this.onCursorUpdateListener = listener;
   }
+  setOnRenderChangeListener(listener: RenderChangeListener) {
+    this.onRenderChangeListener = listener;
+
+    this.chartInitialized.observe(({ newValue, oldValue }) => {
+      if (this.onRenderChangeListener && newValue !== oldValue) {
+        this.onRenderChangeListener(newValue);
+      }
+    });
+  }
   removeElementClickListener() {
     this.onElementClickListener = undefined;
   }
@@ -746,6 +758,9 @@ export class ChartStore {
   removeOnCursorUpdateListener() {
     this.onCursorUpdateListener = undefined;
   }
+  removeOnRenderChangeListener() {
+    this.onRenderChangeListener = undefined;
+  }
 
   isBrushEnabled(): boolean {
     if (!this.xScale) {

src/index.ts

@@ -33,4 +33,7 @@ export {
   ElementClickListener,
   ElementOverListener,
   LegendItemListener,
+  CursorUpdateListener,
+  RenderChangeListener,
+  BasicListener,
 } from './chart_types/xy_chart/store/chart_state';

src/specs/settings.test.tsx

@@ -128,6 +128,9 @@ describe('Settings spec component', () => {
     const onCursorUpdateEvent = (): void => {
       return;
     };
+    const onRenderChangeEvent = (): void => {
+      return;
+    };
 
     const chartStoreListeners = {
       onElementClick,
@@ -140,6 +143,7 @@ describe('Settings spec component', () => {
       onLegendItemPlusClick: onLegendEvent,
       onLegendItemMinusClick: onLegendEvent,
       onCursorUpdate: onCursorUpdateEvent,
+      onRenderChange: onRenderChangeEvent,
     };
 
     mount(<SettingsComponent chartStore={chartStore} {...chartStoreListeners} />);
@@ -153,6 +157,7 @@ describe('Settings spec component', () => {
     expect(chartStore.onLegendItemPlusClickListener).toEqual(onLegendEvent);
     expect(chartStore.onLegendItemMinusClickListener).toEqual(onLegendEvent);
     expect(chartStore.onCursorUpdateListener).toEqual(onCursorUpdateEvent);
+    expect(chartStore.onRenderChangeListener).toEqual(onRenderChangeEvent);
   });
 
   test('should allow partial theme', () => {

src/specs/settings.tsx

@@ -12,6 +12,7 @@ import {
   ElementOverListener,
   LegendItemListener,
   CursorUpdateListener,
+  RenderChangeListener,
 } from '../chart_types/xy_chart/store/chart_state';
 import { ScaleTypes } from '../utils/scales/scales';
 import { LIGHT_THEME } from '../utils/themes/light_theme';
@@ -87,6 +88,7 @@ export interface SettingSpecProps {
   onLegendItemPlusClick?: LegendItemListener;
   onLegendItemMinusClick?: LegendItemListener;
   onCursorUpdate?: CursorUpdateListener;
+  onRenderChange?: RenderChangeListener;
   xDomain?: Domain | DomainRange;
   resizeDebounce?: number;
 }
@@ -123,6 +125,7 @@ function updateChartStore(props: SettingSpecProps) {
     onLegendItemClick,
     onLegendItemMinusClick,
     onLegendItemPlusClick,
+    onRenderChange,
     onCursorUpdate,
     debug,
     xDomain,
@@ -187,6 +190,9 @@ function updateChartStore(props: SettingSpecProps) {
   if (onCursorUpdate) {
     chartStore.setOnCursorUpdateListener(onCursorUpdate);
   }
+  if (onRenderChange) {
+    chartStore.setOnRenderChangeListener(onRenderChange);
+  }
 }
 
 export class SettingsComponent extends PureComponent<SettingSpecProps> {

stories/interactions.tsx

@@ -44,6 +44,9 @@ const onLegendItemListeners = {
   onLegendItemMinusClick: action('onLegendItemMinusClick'),
 };
 
+const onRenderChange = action('onRenderChange');
+const onCursorUpdate = action('onCursorUpdate');
+
 storiesOf('Interactions', module)
   .add('bar clicks and hovers', () => {
     const headerFormatter: TooltipValueFormatter = (tooltipData: TooltipValue) => {
@@ -573,4 +576,63 @@ storiesOf('Interactions', module)
         />
       </Chart>
     );
-  });
+  })
+  .add(
+    'Render change action',
+    () => {
+      return (
+        <Chart className={'story-chart'}>
+          <Settings showLegend={true} legendPosition={Position.Right} onRenderChange={onRenderChange} />
+          <Axis id={getAxisId('bottom')} position={Position.Bottom} title={'Bottom axis'} showOverlappingTicks={true} />
+          <Axis
+            id={getAxisId('left2')}
+            title={'Left axis'}
+            position={Position.Left}
+            tickFormat={(d) => Number(d).toFixed(2)}
+          />
+
+          <BarSeries
+            id={getSpecId('bars')}
+            xScaleType={ScaleType.Linear}
+            yScaleType={ScaleType.Linear}
+            xAccessor="x"
+            yAccessors={['y']}
+            data={[{ x: 0, y: 2 }, { x: 1, y: 7 }, { x: 2, y: 3 }, { x: 3, y: 6 }]}
+          />
+        </Chart>
+      );
+    },
+    {
+      info:
+        'Sends an event every time the chart render state changes. This is provided to bind attributes to the chart for visulaization loading checks.',
+    },
+  )
+  .add(
+    'Cursor update action',
+    () => {
+      return (
+        <Chart className={'story-chart'}>
+          <Settings showLegend={true} legendPosition={Position.Right} onCursorUpdate={onCursorUpdate} />
+          <Axis id={getAxisId('bottom')} position={Position.Bottom} title={'Bottom axis'} showOverlappingTicks={true} />
+          <Axis
+            id={getAxisId('left2')}
+            title={'Left axis'}
+            position={Position.Left}
+            tickFormat={(d) => Number(d).toFixed(2)}
+          />
+
+          <BarSeries
+            id={getSpecId('bars')}
+            xScaleType={ScaleType.Linear}
+            yScaleType={ScaleType.Linear}
+            xAccessor="x"
+            yAccessors={['y']}
+            data={[{ x: 0, y: 2 }, { x: 1, y: 7 }, { x: 2, y: 3 }, { x: 3, y: 6 }]}
+          />
+        </Chart>
+      );
+    },
+    {
+      info: 'Sends an event every time the cursor changes. This is provided to sync cursors between multiple charts.',
+    },
+  );