From 49c7dad6eb257c067e9182d75583beb8fefeca89 Mon Sep 17 00:00:00 2001
From: Petar Petrov <MindFreeze@users.noreply.github.com>
Date: Fri, 8 Aug 2025 09:43:59 +0300
Subject: [PATCH] Font improvements for Sankey chart (#26438)

* Use theme vars for sankey chart font

* improve font size calculation
---
 src/components/chart/ha-chart-base.ts   | 7 +++++++
 src/components/chart/ha-sankey-chart.ts | 7 ++-----
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/components/chart/ha-chart-base.ts b/src/components/chart/ha-chart-base.ts
index 9c12fb904c..3d5ae876b5 100644
--- a/src/components/chart/ha-chart-base.ts
+++ b/src/components/chart/ha-chart-base.ts
@@ -598,6 +598,13 @@ export class HaChartBase extends LitElement {
           textBorderWidth: 2,
         },
       },
+      sankey: {
+        label: {
+          color: style.getPropertyValue("--primary-text-color"),
+          textBorderColor: style.getPropertyValue("--primary-background-color"),
+          textBorderWidth: 2,
+        },
+      },
       categoryAxis: {
         axisLine: { show: false },
         axisTick: { show: false },
diff --git a/src/components/chart/ha-sankey-chart.ts b/src/components/chart/ha-sankey-chart.ts
index 67ba9a4f12..b10e3c19e2 100644
--- a/src/components/chart/ha-sankey-chart.ts
+++ b/src/components/chart/ha-sankey-chart.ts
@@ -197,12 +197,9 @@ export class HaSankeyChart extends LitElement {
           };
         }
 
-        // estimate the number of lines after the label is wrapped
-        // this is a very rough estimate, but it works for now
-        const lineCount = Math.ceil(params.labelRect.width / labelSpace);
-        // `overflow: "break"` allows the label to overflow outside its height, so we need to account for that
+        const availableHeight = params.rect.height + 8; // account for the margin
         const fontSize = Math.min(
-          (params.rect.height / lineCount) * FONT_SIZE,
+          (availableHeight / params.labelRect.height) * FONT_SIZE,
           FONT_SIZE
         );
         return {