From a297077b4e75b74a6decbb03b623e898a46ede5e Mon Sep 17 00:00:00 2001
From: Mario Hros <966992+k3a@users.noreply.github.com>
Date: Fri, 22 Sep 2023 17:13:02 +0200
Subject: [PATCH] Handle clicking on a label of a timeline history graph card
 and display more info for the displayed entity

---
 src/components/chart/ha-chart-base.ts        | 66 ++++++++++++++++++++
 src/components/chart/state-history-charts.ts | 14 +++++
 2 files changed, 80 insertions(+)

diff --git a/src/components/chart/ha-chart-base.ts b/src/components/chart/ha-chart-base.ts
index 60d0d039f8d5..01c260ffdbf6 100644
--- a/src/components/chart/ha-chart-base.ts
+++ b/src/components/chart/ha-chart-base.ts
@@ -12,6 +12,7 @@ import { styleMap } from "lit/directives/style-map";
 import { clamp } from "../../common/number/clamp";
 import { computeRTL } from "../../common/util/compute_rtl";
 import { HomeAssistant } from "../../types";
+import { fireEvent } from "../../common/dom/fire_event";
 
 export const MIN_TIME_BETWEEN_UPDATES = 60 * 5 * 1000;
 
@@ -271,6 +272,46 @@ export class HaChartBase extends LitElement {
     };
   }
 
+  private _findLabel(evt): { label: string; index: number } | null {
+    let res: { label: string; index: number } | null = null;
+
+    const scales = this.chart?.scales ?? [];
+
+    const scaleDetails = Object.values(scales).map((s: any) => ({
+      scaleId: s.id,
+      labels: s?._labelItems?.map(
+        (e, i) =>
+          ({
+            x: e.options.translation[0] - (s?._labelSizes?.widths[i] ?? 0),
+            x2: e.options.translation[0] + (s?._labelSizes?.widths[i] ?? 0) / 2,
+            y: e.options.translation[1] - (s?._labelSizes?.heights[i] ?? 0) / 2,
+            y2:
+              e.options.translation[1] + (s?._labelSizes?.heights[i] ?? 0) / 2,
+            label: e.label,
+            index: i,
+          }) ?? []
+      ),
+    }));
+
+    scaleDetails.forEach((l) => {
+      l.labels.forEach((label, index) => {
+        if (
+          evt.x > label.x &&
+          evt.x < label.x2 &&
+          evt.y > label.y &&
+          evt.y < label.y2
+        ) {
+          res = {
+            label: label.label,
+            index,
+          };
+        }
+      });
+    });
+
+    return res;
+  }
+
   private _createPlugins() {
     return [
       ...(this.plugins || []),
@@ -288,6 +329,25 @@ export class HaChartBase extends LitElement {
           display: false,
         },
       },
+      {
+        id: "labelClickHandler",
+        afterEvent: (chart: Chart, event) => {
+          const evt = event.event;
+
+          if (evt.type !== "click" || event.inChartArea) {
+            return;
+          }
+
+          const labelInfo = this._findLabel(evt);
+
+          if (labelInfo) {
+            fireEvent(this, "label-click", {
+              label: labelInfo.label,
+              index: labelInfo.index,
+            });
+          }
+        },
+      },
     ];
   }
 
@@ -451,4 +511,10 @@ declare global {
   interface HTMLElementTagNameMap {
     "ha-chart-base": HaChartBase;
   }
+  interface HASSDomEvents {
+    "label-click": {
+      label: string;
+      index: number;
+    };
+  }
 }
diff --git a/src/components/chart/state-history-charts.ts b/src/components/chart/state-history-charts.ts
index d9dd0d983e21..001aed9c5462 100644
--- a/src/components/chart/state-history-charts.ts
+++ b/src/components/chart/state-history-charts.ts
@@ -13,6 +13,7 @@ import {
   queryAll,
   state,
 } from "lit/decorators";
+import { fireEvent } from "../../common/dom/fire_event";
 import { isComponentLoaded } from "../../common/config/is_component_loaded";
 import { restoreScroll } from "../../common/decorators/restore-scroll";
 import {
@@ -198,6 +199,7 @@ export class StateHistoryCharts extends LitElement {
         .paddingYAxis=${this._maxYWidth}
         .chartIndex=${index}
         @y-width-changed=${this._yWidthChanged}
+        @label-click=${this._labelClicked}
       ></state-history-chart-timeline>
     </div> `;
   };
@@ -236,6 +238,18 @@ export class StateHistoryCharts extends LitElement {
     this._maxYWidth = Math.max(...Object.values(this._childYWidths), 0);
   }
 
+  private _labelClicked(e: CustomEvent<HASSDomEvents["label-click"]>) {
+    const timeline = this.historyData?.timeline;
+
+    if (timeline) {
+      const entityId = timeline[e.detail.index]?.entity_id;
+
+      if (entityId) {
+        fireEvent(this, "hass-more-info", { entityId });
+      }
+    }
+  }
+
   private _isHistoryEmpty(): boolean {
     const historyDataEmpty =
       !this.historyData ||