Geomap: Add color scale in legend (#47803)

Added color scale in geomap legend

public/app/core/components/ColorScale/ColorScale.tsx

@@ -11,6 +11,7 @@ type Props = {
   // Show a value as string -- when not defined, the raw values will not be shown
   display?: (v: number) => string;
   hoverValue?: number;
+  useStopsPercentage?: boolean;
 };
 
 type HoverState = {
@@ -19,8 +20,9 @@ type HoverState = {
 };
 
 const LEFT_OFFSET = 2;
+const GRADIENT_STOPS = 10;
 
-export const ColorScale = ({ colorPalette, min, max, display, hoverValue }: Props) => {
+export const ColorScale = ({ colorPalette, min, max, display, hoverValue, useStopsPercentage }: Props) => {
   const [colors, setColors] = useState<string[]>([]);
   const [scaleHover, setScaleHover] = useState<HoverState>({ isShown: false, value: 0 });
   const [percent, setPercent] = useState<number | null>(null);
@@ -29,8 +31,8 @@ export const ColorScale = ({ colorPalette, min, max, display, hoverValue }: Prop
   const styles = getStyles(theme, colors);
 
   useEffect(() => {
-    setColors(getGradientStops({ colorArray: colorPalette }));
-  }, [colorPalette]);
+    setColors(getGradientStops({ colorArray: colorPalette, stops: GRADIENT_STOPS, useStopsPercentage }));
+  }, [colorPalette, useStopsPercentage]);
 
   const onScaleMouseMove = (event: React.MouseEvent<HTMLDivElement>) => {
     const divOffset = event.nativeEvent.offsetX;
@@ -79,9 +81,17 @@ export const ColorScale = ({ colorPalette, min, max, display, hoverValue }: Prop
   );
 };
 
-const getGradientStops = ({ colorArray, stops = 10 }: { colorArray: string[]; stops?: number }): string[] => {
+const getGradientStops = ({
+  colorArray,
+  stops,
+  useStopsPercentage = true,
+}: {
+  colorArray: string[];
+  stops: number;
+  useStopsPercentage?: boolean;
+}): string[] => {
   const colorCount = colorArray.length;
-  if (colorCount <= 20) {
+  if (useStopsPercentage && colorCount <= 20) {
     const incr = (1 / colorCount) * 100;
     let per = 0;
     const stops: string[] = [];
@@ -114,8 +124,6 @@ const getStyles = (theme: GrafanaTheme2, colors: string[]) => ({
   scaleWrapper: css`
     width: 100%;
     max-width: 300px;
-    margin-left: 25px;
-    padding: 10px 0;
     font-size: 11px;
     opacity: 1;
   `,

public/app/plugins/panel/geomap/GeomapPanel.tsx

@@ -33,11 +33,12 @@ import { DebugOverlay } from './components/DebugOverlay';
 import { getGlobalStyles } from './globalStyles';
 import { Global } from '@emotion/react';
 import { GeomapHoverPayload, GeomapLayerHover } from './event';
-import { Subscription } from 'rxjs';
+import { Subject, Subscription } from 'rxjs';
 import { PanelEditExitedEvent } from 'app/types/events';
 import { defaultMarkersConfig, MARKERS_LAYER_ID } from './layers/data/markersLayer';
 import { cloneDeep } from 'lodash';
 import { GeomapTooltip } from './GeomapTooltip';
+import { FeatureLike } from 'ol/Feature';
 
 // Allows multiple panels to share the same view instance
 let sharedView: View | undefined = undefined;
@@ -313,7 +314,7 @@ export class GeomapPanel extends Component<Props, State> {
       this.props.eventBus.publish(new DataHoverClearEvent());
     });
 
-    // Notify the the panel editor
+    // Notify the panel editor
     if (this.panelContext.onInstanceStateChange) {
       this.panelContext.onInstanceStateChange({
         map: this.map,
@@ -371,6 +372,7 @@ export class GeomapPanel extends Component<Props, State> {
     this.map.forEachFeatureAtPixel(
       pixel,
       (feature, layer, geo) => {
+        const s: MapLayerState = (layer as any).__state;
         //match hover layer to layer in layers
         //check if the layer show tooltip is enabled
         //then also pass the list of tooltip fields if exists
@@ -382,9 +384,12 @@ export class GeomapPanel extends Component<Props, State> {
             hoverPayload.data = ttip.data = frame as DataFrame;
             hoverPayload.rowIndex = ttip.rowIndex = props['rowIndex'];
           }
+
+          if (s?.mouseEvents) {
+            s.mouseEvents.next(feature);
+          }
         }
 
-        const s: MapLayerState = (layer as any).__state;
         if (s) {
           let h = layerLookup.get(s);
           if (!h) {
@@ -406,6 +411,14 @@ export class GeomapPanel extends Component<Props, State> {
     this.props.eventBus.publish(this.hoverEvent);
 
     this.setState({ ttip: { ...hoverPayload } });
+
+    if (!layers.length) {
+      // clear mouse events
+      this.layers.forEach((layer) => {
+        layer.mouseEvents.next(undefined);
+      });
+    }
+
     return layers.length ? true : false;
   };
 
@@ -508,6 +521,7 @@ export class GeomapPanel extends Component<Props, State> {
       options,
       layer,
       handler,
+      mouseEvents: new Subject<FeatureLike | undefined>(),
 
       getName: () => UID,
 

public/app/plugins/panel/geomap/layers/data/MarkersLegend.tsx

@@ -1,6 +1,6 @@
-import React from 'react';
+import React, { useMemo } from 'react';
 import { Label, stylesFactory, useTheme2, VizLegendItem } from '@grafana/ui';
-import { formattedValueToString, getFieldColorModeForField, GrafanaTheme2 } from '@grafana/data';
+import { DataFrame, formattedValueToString, getFieldColorModeForField, GrafanaTheme2 } from '@grafana/data';
 import { css } from '@emotion/css';
 import { config } from 'app/core/config';
 import { DimensionSupplier } from 'app/features/dimensions';
@@ -8,26 +8,50 @@ import { getThresholdItems } from 'app/plugins/panel/state-timeline/utils';
 import { getMinMaxAndDelta } from '@grafana/data/src/field/scale';
 import SVG from 'react-inlinesvg';
 import { StyleConfigState } from '../../style/types';
+import { ColorScale } from 'app/core/components/ColorScale/ColorScale';
+import { useObservable } from 'react-use';
+import { of } from 'rxjs';
+import BaseLayer from 'ol/layer/Base';
+import { MapLayerState } from '../../types';
 
 export interface MarkersLegendProps {
   size?: DimensionSupplier<number>;
   layerName?: string;
   styleConfig?: StyleConfigState;
+  layer?: BaseLayer;
 }
 
 export function MarkersLegend(props: MarkersLegendProps) {
-  const { layerName, styleConfig } = props;
+  const { layerName, styleConfig, layer } = props;
   const theme = useTheme2();
   const style = getStyles(theme);
 
+  const hoverEvent = useObservable(((layer as any)?.__state as MapLayerState)?.mouseEvents ?? of(undefined));
+
+  const colorField = styleConfig?.dims?.color?.field;
+  const hoverValue = useMemo(() => {
+    if (!colorField || !hoverEvent) {
+      return undefined;
+    }
+
+    const props = hoverEvent.getProperties();
+    const frame = props.frame as DataFrame;
+
+    if (!frame) {
+      return undefined;
+    }
+
+    const rowIndex = props.rowIndex as number;
+    return colorField.values.get(rowIndex);
+  }, [hoverEvent, colorField]);
+
   if (!styleConfig) {
     return <></>;
   }
+
   const { color, opacity} = styleConfig?.base ?? {};
   const symbol = styleConfig?.config.symbol?.fixed;
 
-  const colorField = styleConfig.dims?.color?.field;
-
   if (color && symbol && !colorField) {
     return (
       <div className={style.infoWrap}>
@@ -48,7 +72,6 @@ export function MarkersLegend(props: MarkersLegendProps) {
     return <></>;
   }
 
-  const fmt = (v: any) => `${formattedValueToString(colorField.display!(v))}`;
   const colorMode = getFieldColorModeForField(colorField);
 
   if (colorMode.isContinuous && colorMode.getColors) {
@@ -65,15 +88,15 @@ export function MarkersLegend(props: MarkersLegendProps) {
     //   ]
     // })
 
+    const display = colorField.display ? (v: number) => formattedValueToString(colorField.display!(v)) : (v: number) => `${v}`;
     return (
       <>
-        <Label>{colorField?.name}</Label>
-        <div
-          className={style.gradientContainer}
-          style={{ backgroundImage: `linear-gradient(to right, ${colors.map((c) => c).join(', ')}` }}
-        >
-          <div style={{ color: theme.colors.getContrastText(colors[0]) }}>{fmt(colorRange.min)}</div>
-          <div style={{ color: theme.colors.getContrastText(colors[colors.length - 1]) }}>{fmt(colorRange.max)}</div>
+        <div className={style.labelsWrapper}>
+          <Label>{layerName}</Label>
+          <Label>{colorField?.name}</Label>
+        </div>
+        <div className={style.colorScaleWrapper}>
+          <ColorScale hoverValue={hoverValue} colorPalette={colors} min={colorRange.min as number} max={colorRange.max as number} display={display} useStopsPercentage={false}/>
         </div>
       </>
     );
@@ -132,11 +155,13 @@ const getStyles = stylesFactory((theme: GrafanaTheme2) => ({
     margin: auto;
     margin-right: 4px;
   `,
-  gradientContainer: css`
+  colorScaleWrapper: css`
     min-width: 200px;
-    display: flex;
-    justify-content: space-between;
     font-size: ${theme.typography.bodySmall.fontSize};
     padding: ${theme.spacing(0, 0.5)};
   `,
+  labelsWrapper: css`
+    display: flex;
+    justify-content: space-between;
+  `
 }));

public/app/plugins/panel/geomap/layers/data/markersLayer.tsx

@@ -67,12 +67,6 @@ export const markersLayer: MapLayerRegistryItem<MarkersConfig> = {
       ...options?.config,
     };
 
-    const legendProps = new ReplaySubject<MarkersLegendProps>(1);
-    let legend: ReactNode = null;
-    if (config.showLegend) {
-      legend = <ObservablePropsWrapper watch={legendProps} initialSubProps={{}} child={MarkersLegend} />;
-    }
-
     const style = await getStyleConfigState(config.style);
     const location = await getLocationMatchers(options.location);
     const source = new FrameVectorSource(location);
@@ -80,6 +74,12 @@ export const markersLayer: MapLayerRegistryItem<MarkersConfig> = {
       source,
     });
 
+    const legendProps = new ReplaySubject<MarkersLegendProps>(1);
+    let legend: ReactNode = null;
+    if (config.showLegend) {
+      legend = <ObservablePropsWrapper watch={legendProps} initialSubProps={{}} child={MarkersLegend} />;
+    }
+
     if (!style.fields) {
       // Set a global style
       vectorLayer.setStyle(style.maker(style.base));
@@ -142,6 +142,7 @@ export const markersLayer: MapLayerRegistryItem<MarkersConfig> = {
               styleConfig: style,
               size: style.dims?.size,
               layerName: options.name,
+              layer: vectorLayer,
             });
           }
 

public/app/plugins/panel/geomap/types.ts

@@ -5,6 +5,8 @@ import BaseLayer from 'ol/layer/Base';
 import Units from 'ol/proj/Units';
 import { StyleConfig } from './style/types';
 import { MapCenterID } from './view';
+import { Subject } from 'rxjs';
+import { FeatureLike } from 'ol/Feature';
 
 export interface ControlsOptions {
   // Zoom (upper left)
@@ -80,4 +82,5 @@ export interface MapLayerState<TConfig = any> extends LayerElement {
   layer: BaseLayer; // the openlayers instance
   onChange: (cfg: MapLayerOptions<TConfig>) => void;
   isBasemap?: boolean;
+  mouseEvents: Subject<FeatureLike | undefined>;
 }

public/app/plugins/panel/heatmap-new/HeatmapPanel.tsx

@@ -18,7 +18,7 @@ import { quantizeScheme } from './palettes';
 import { HeatmapHoverEvent, prepConfig } from './utils';
 import { HeatmapHoverView } from './HeatmapHoverView';
 import { CloseButton } from 'app/core/components/CloseButton/CloseButton';
-import { ColorScale } from './ColorScale';
+import { ColorScale } from 'app/core/components/ColorScale/ColorScale';
 
 interface HeatmapPanelProps extends PanelProps<PanelOptions> {}
 
@@ -113,7 +113,9 @@ export const HeatmapPanel: React.FC<HeatmapPanelProps> = ({
 
     return (
       <VizLayout.Legend placement="bottom" maxHeight="20%">
-        <ColorScale hoverValue={hoverValue} colorPalette={palette} min={min} max={max} display={info.display} />
+        <div className={styles.colorScaleWrapper}>
+          <ColorScale hoverValue={hoverValue} colorPalette={palette} min={min} max={max} display={info.display} />
+        </div>
       </VizLayout.Legend>
     );
   };
@@ -164,4 +166,8 @@ const getStyles = (theme: GrafanaTheme2) => ({
   closeButtonSpacer: css`
     margin-bottom: 15px;
   `,
+  colorScaleWrapper: css`
+    margin-left: 25px;
+    padding: 10px 0;
+  `,
 });

public/app/plugins/panel/heatmap-new/module.tsx

@@ -15,7 +15,7 @@ import { heatmapChangedHandler } from './migrations';
 import { addHeatmapCalculationOptions } from 'app/features/transformers/calculateHeatmap/editor/helper';
 import { colorSchemes, quantizeScheme } from './palettes';
 import { config } from '@grafana/runtime';
-import { ColorScale } from './ColorScale';
+import { ColorScale } from 'app/core/components/ColorScale/ColorScale';
 
 export const plugin = new PanelPlugin<PanelOptions, GraphFieldConfig>(HeatmapPanel)
   .useFieldConfig()