From 70be747e9da5d9b69aa7381f2269c9641c1df80b Mon Sep 17 00:00:00 2001
From: Simon Lamon <32477463+silamon@users.noreply.github.com>
Date: Tue, 31 Mar 2026 13:27:22 +0200
Subject: [PATCH] Gauge improvements (#30368)

* Gauge last improvements

* Change needle

* Fixup

* Feedback comments

* Update src/components/ha-gauge.ts

---------

Co-authored-by: Petar Petrov <MindFreeze@users.noreply.github.com>
---
 gallery/src/pages/lovelace/gauge-card.ts    |  15 ++
 src/components/ha-gauge.ts                  | 186 ++++++++++++--------
 src/panels/lovelace/cards/hui-gauge-card.ts |   4 +-
 3 files changed, 125 insertions(+), 80 deletions(-)

diff --git a/gallery/src/pages/lovelace/gauge-card.ts b/gallery/src/pages/lovelace/gauge-card.ts
index c79a3def95..5472b7f02b 100644
--- a/gallery/src/pages/lovelace/gauge-card.ts
+++ b/gallery/src/pages/lovelace/gauge-card.ts
@@ -134,6 +134,21 @@ const CONFIGS = [
   entity: sensor.not_working
     `,
   },
+  {
+    heading: "Lower minimum",
+    config: `
+- type: gauge
+  entity: sensor.brightness_high
+  needle: true
+  severity:
+    green: 0
+    yellow: 0.45
+    red: 0.9
+  min: -0.05
+  name: " "
+  max: 1.9
+  unit: GBP/h`,
+  },
 ];
 
 @customElement("demo-lovelace-gauge-card")
diff --git a/src/components/ha-gauge.ts b/src/components/ha-gauge.ts
index 78b0c84be1..61d08bc58a 100644
--- a/src/components/ha-gauge.ts
+++ b/src/components/ha-gauge.ts
@@ -1,4 +1,4 @@
-import type { PropertyValues, TemplateResult } from "lit";
+import type { PropertyValues } from "lit";
 import { css, LitElement, svg } from "lit";
 import { customElement, property, state } from "lit/decorators";
 import { styleMap } from "lit/directives/style-map";
@@ -54,6 +54,7 @@ export class HaGauge extends LitElement {
         this._angle = getAngle(this.value, this.min, this.max);
       }
       this._segment_label = this._getSegmentLabel();
+      this._rescaleSvg();
     });
   }
 
@@ -70,6 +71,7 @@ export class HaGauge extends LitElement {
     }
     this._angle = getAngle(this.value, this.min, this.max);
     this._segment_label = this._getSegmentLabel();
+    this._rescaleSvg();
   }
 
   protected render() {
@@ -88,87 +90,91 @@ export class HaGauge extends LitElement {
         />
 
 
-  ${
-    this.levels
-      ? [...this.levels]
-          .sort((a, b) => a.level - b.level)
-          .map((level, i, arr) => {
-            const startLevel = i === 0 ? this.min : arr[i].level;
-            const endLevel = i + 1 < arr.length ? arr[i + 1].level : this.max;
+        ${
+          this.levels
+            ? (() => {
+                const sortedLevels = [...this.levels].sort(
+                  (a, b) => a.level - b.level
+                );
 
-            const startAngle = getAngle(startLevel, this.min, this.max);
-            const endAngle = getAngle(endLevel, this.min, this.max);
-            const largeArc = endAngle - startAngle > 180 ? 1 : 0;
+                if (
+                  sortedLevels.length > 0 &&
+                  sortedLevels[0].level !== this.min
+                ) {
+                  sortedLevels.unshift({
+                    level: this.min,
+                    stroke: "var(--info-color)",
+                  });
+                }
 
-            const x1 = -arcRadius * Math.cos((startAngle * Math.PI) / 180);
-            const y1 = -arcRadius * Math.sin((startAngle * Math.PI) / 180);
-            const x2 = -arcRadius * Math.cos((endAngle * Math.PI) / 180);
-            const y2 = -arcRadius * Math.sin((endAngle * Math.PI) / 180);
+                return sortedLevels.map((level, i, arr) => {
+                  const startLevel = level.level;
+                  const endLevel =
+                    i + 1 < arr.length ? arr[i + 1].level : this.max;
 
-            const firstSegment = i === 0;
-            const lastSegment = i === arr.length - 1;
+                  const startAngle = getAngle(startLevel, this.min, this.max);
+                  const endAngle = getAngle(endLevel, this.min, this.max);
+                  const largeArc = endAngle - startAngle > 180 ? 1 : 0;
 
-            const paths: TemplateResult[] = [];
+                  const x1 =
+                    -arcRadius * Math.cos((startAngle * Math.PI) / 180);
+                  const y1 =
+                    -arcRadius * Math.sin((startAngle * Math.PI) / 180);
+                  const x2 = -arcRadius * Math.cos((endAngle * Math.PI) / 180);
+                  const y2 = -arcRadius * Math.sin((endAngle * Math.PI) / 180);
 
-            if (firstSegment) {
-              paths.push(svg`
-              <path
-                class="level"
-                stroke="${level.stroke}"
-                style="stroke-linecap: round"
-                d="M ${x1} ${y1} A ${arcRadius} ${arcRadius} 0 ${largeArc} 1 ${x2} ${y2}"
-              />
-            `);
-            } else if (lastSegment) {
-              const offsetAngle = 0.5;
-              const midAngle = endAngle - offsetAngle;
-              const xm = -arcRadius * Math.cos((midAngle * Math.PI) / 180);
-              const ym = -arcRadius * Math.sin((midAngle * Math.PI) / 180);
+                  const isFirst = i === 0;
+                  const isLast = i === arr.length - 1;
 
-              paths.push(svg`
-                <path
-                  class="level"
-                  stroke="${level.stroke}"
-                  style="stroke-linecap: butt"
-                  d="M ${x1} ${y1} A ${arcRadius} ${arcRadius} 0 ${largeArc} 1 ${xm} ${ym}"
-                />
-              `);
+                  if (isFirst) {
+                    return svg`
+                      <path
+                        class="level"
+                        stroke="${level.stroke}"
+                        style="stroke-linecap: butt"
+                        d="M ${x1} ${y1} A ${arcRadius} ${arcRadius} 0 ${largeArc} 1 ${x2} ${y2}"
+                      />
+                    `;
+                  }
 
-              paths.push(svg`
-                <path
-                  class="level"
-                  stroke="${level.stroke}"
-                  style="stroke-linecap: round"
-                  d="M ${xm} ${ym} A ${arcRadius} ${arcRadius} 0 0 1 ${x2} ${y2}"
-                />
-              `);
-            } else {
-              paths.push(svg`
-                <path
-                  class="level"
-                  stroke="${level.stroke}"
-                  style="stroke-linecap: butt"
-                  d="M ${x1} ${y1} A ${arcRadius} ${arcRadius} 0 ${largeArc} 1 ${x2} ${y2}"
-                />
-              `);
-            }
+                  if (isLast) {
+                    const offsetAngle = 0.5;
+                    const midAngle = endAngle - offsetAngle;
+                    const xm =
+                      -arcRadius * Math.cos((midAngle * Math.PI) / 180);
+                    const ym =
+                      -arcRadius * Math.sin((midAngle * Math.PI) / 180);
 
-            return paths;
-          })
-      : ""
-  }
+                    return svg`
+                        <path class="level" stroke="${level.stroke}" style="stroke-linecap: butt"
+                              d="M ${x1} ${y1} A ${arcRadius} ${arcRadius} 0 ${largeArc} 1 ${xm} ${ym}" />
+                        <path class="level" stroke="${level.stroke}" style="stroke-linecap: butt"
+                              d="M ${xm} ${ym} A ${arcRadius} ${arcRadius} 0 0 1 ${x2} ${y2}" />
+                    `;
+                  }
+
+                  return svg`
+                    <path
+                      class="level"
+                      stroke="${level.stroke}"
+                      style="stroke-linecap: butt"
+                      d="M ${x1} ${y1} A ${arcRadius} ${arcRadius} 0 ${largeArc} 1 ${x2} ${y2}"
+                    ></path>
+                  `;
+                });
+              })()
+            : ""
+        }
 
         ${
           this.needle
             ? svg`
-                <line
-                  class="needle"
-                  x1="-35.0"
-                  y1="0"
-                  x2="-45.0"
-                  y2="0"
-                  style=${styleMap({ transform: `rotate(${this._angle}deg)` })}
-                />
+                <path
+                class="needle"
+                d="M -36,-2 L -44,-1 A 1,1,0,0,0,-44,1 L -36,2 A 2,2,0,0,0,-36,-2 Z"
+
+                style=${styleMap({ transform: `rotate(${this._angle}deg)` })}
+              />
               `
             : svg`
                 <path
@@ -179,7 +185,8 @@ export class HaGauge extends LitElement {
                 />
               `
         }
-
+      </svg>
+      <svg class="text">
         <text
           class="value-text"
           x="0"
@@ -204,6 +211,18 @@ export class HaGauge extends LitElement {
     `;
   }
 
+  private _rescaleSvg() {
+    // Set the viewbox of the SVG containing the value to perfectly
+    // fit the text
+    // That way it will auto-scale correctly
+    const svgRoot = this.shadowRoot!.querySelector(".text")!;
+    const box = svgRoot.querySelector("text")!.getBBox()!;
+    svgRoot.setAttribute(
+      "viewBox",
+      `${box.x} ${box.y} ${box.width} ${box.height}`
+    );
+  }
+
   private _getSegmentLabel() {
     if (this.levels) {
       [...this.levels].sort((a, b) => a.level - b.level);
@@ -224,32 +243,43 @@ export class HaGauge extends LitElement {
     .levels-base {
       fill: none;
       stroke: var(--primary-background-color);
-      stroke-width: 8;
-      stroke-linecap: round;
+      stroke-width: 6;
+      stroke-linecap: butt;
     }
 
     .level {
       fill: none;
-      stroke-width: 8;
+      stroke-width: 6;
       stroke-linecap: butt;
     }
 
     .value {
       fill: none;
-      stroke-width: 8;
+      stroke-width: 6;
       stroke: var(--gauge-color);
-      stroke-linecap: round;
+      stroke-linecap: butt;
       transition: stroke-dashoffset 1s ease 0s;
     }
 
     .needle {
-      stroke: var(--primary-text-color);
-      stroke-width: 2;
+      fill: var(--primary-text-color);
+      stroke: var(--card-background-color);
+      color: var(--primary-text-color);
+      stroke-width: 1;
       stroke-linecap: round;
       transform-origin: 0 0;
       transition: all 1s ease 0s;
     }
 
+    .text {
+      position: absolute;
+      max-height: 40%;
+      max-width: 55%;
+      left: 50%;
+      bottom: 10%;
+      transform: translate(-50%, 0%);
+    }
+
     .value-text {
       font-size: var(--ha-font-size-l);
       fill: var(--primary-text-color);
diff --git a/src/panels/lovelace/cards/hui-gauge-card.ts b/src/panels/lovelace/cards/hui-gauge-card.ts
index 7bc8ef8479..b157b0bfee 100644
--- a/src/panels/lovelace/cards/hui-gauge-card.ts
+++ b/src/panels/lovelace/cards/hui-gauge-card.ts
@@ -303,9 +303,8 @@ class HuiGaugeCard extends LitElement implements LovelaceCard {
 
     .title {
       width: 100%;
-      font-size: var(--ha-font-size-l);
+      font-size: var(--ha-font-size-m);
       line-height: var(--ha-line-height-expanded);
-      padding: 0px 0px var(--ha-space-2) 0px;
       margin: 0;
       text-align: center;
       box-sizing: border-box;
@@ -318,6 +317,7 @@ class HuiGaugeCard extends LitElement implements LovelaceCard {
 
     ha-gauge {
       width: 100%;
+      max-width: 250px;
     }
   `;
 }