Fix #3900: [FEATURE] Histograms

src/controllers/controller.histogram.js

@@ -0,0 +1,55 @@
+import BarController from './controller.bar.js';
+
+/**
+ * @typedef { import('../types.js').ChartMeta } ChartMeta
+ * @typedef { import('../types.js').Point } Point
+ */
+
+export default class HistogramController extends BarController {
+
+  static id = 'histogram';
+
+  /**
+   * @type {any}
+   */
+  static defaults = {
+    datasetElementType: false,
+    dataElementType: 'bar',
+
+    // Bars fill the entire category width with no gaps between them,
+    // which is the expected appearance for a histogram.
+    barPercentage: 1,
+    categoryPercentage: 1,
+
+    grouped: false,
+
+    animations: {
+      numbers: {
+        type: 'number',
+        properties: ['x', 'y', 'base', 'width', 'height']
+      }
+    }
+  };
+
+  /**
+   * @type {any}
+   */
+  static overrides = {
+    scales: {
+      // A linear index axis is required so bars are positioned and sized
+      // according to their numeric x values rather than by category index.
+      _index_: {
+        type: 'linear',
+        offset: false,
+        grid: {
+          offset: false
+        }
+      },
+      _value_: {
+        type: 'linear',
+        beginAtZero: true,
+      }
+    }
+  };
+
+}

src/controllers/index.js

@@ -1,5 +1,6 @@
 export {default as BarController} from './controller.bar.js';
 export {default as BubbleController} from './controller.bubble.js';
+export {default as HistogramController} from './controller.histogram.js';
 export {default as DoughnutController} from './controller.doughnut.js';
 export {default as LineController} from './controller.line.js';
 export {default as PolarAreaController} from './controller.polarArea.js';

src/types.ts

@@ -11,6 +11,7 @@ export {
   BarController,
   BubbleController,
   DoughnutController,
+  HistogramController,
   LineController,
   PieController,
   PolarAreaController,

src/types/index.d.ts

@@ -159,6 +159,15 @@ export declare const BarController: ChartComponent & {
   new (chart: Chart, datasetIndex: number): BarController;
 };
 
+export type HistogramControllerDatasetOptions = BarControllerDatasetOptions;
+export type HistogramControllerChartOptions = BarControllerChartOptions;
+
+export type HistogramController = BarController
+export declare const HistogramController: ChartComponent & {
+  prototype: HistogramController;
+  new (chart: Chart, datasetIndex: number): HistogramController;
+};
+
 export interface BubbleControllerDatasetOptions
   extends ControllerDatasetOptions,
   ScriptableAndArrayOptions<PointOptions, ScriptableContext<'bubble'>>,
@@ -3716,6 +3725,14 @@ export interface ChartTypeRegistry {
     parsedDataType: BarParsedData,
     scales: keyof CartesianScaleTypeRegistry;
   };
+  histogram: {
+    chartOptions: HistogramControllerChartOptions;
+    datasetOptions: HistogramControllerDatasetOptions;
+    defaultDataPoint: ScatterDataPoint | number | null;
+    metaExtensions: {};
+    parsedDataType: BarParsedData;
+    scales: keyof CartesianScaleTypeRegistry;
+  };
   line: {
     chartOptions: LineControllerChartOptions;
     datasetOptions: LineControllerDatasetOptions & FillerControllerDatasetOptions;