From 833e4ceb4a7c17b0ad72b0f03ba2ba7e0e6b8db0 Mon Sep 17 00:00:00 2001
From: stockiNail <stocki.nail@gmail.com>
Date: Fri, 19 Aug 2022 12:46:19 +0200
Subject: [PATCH] Manage line label visibility when not inside chart area

---
 src/types/label.js | 5 +++--
 src/types/line.js  | 9 +++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/types/label.js b/src/types/label.js
index 781fd6911..8c6c6c1d8 100644
--- a/src/types/label.js
+++ b/src/types/label.js
@@ -1,6 +1,6 @@
 import {Element} from 'chart.js';
 import {drawBox, drawLabel, measureLabelSize, getChartPoint, toPosition, setBorderStyle, getSize, inBoxRange, isBoundToPoint, resolveBoxProperties, getRelativePosition, translate, rotated, getElementCenterPoint} from '../helpers';
-import {toPadding, toRadians, distanceBetweenPoints} from 'chart.js/helpers';
+import {toPadding, toRadians, distanceBetweenPoints, defined} from 'chart.js/helpers';
 
 const positions = ['left', 'bottom', 'top', 'right'];
 
@@ -17,7 +17,8 @@ export default class LabelAnnotation extends Element {
 
   draw(ctx) {
     const options = this.options;
-    if (!options.display || !options.content) {
+    const visible = !defined(this._visible) || this._visible;
+    if (!options.display || !options.content || !visible) {
       return;
     }
     ctx.save();
diff --git a/src/types/line.js b/src/types/line.js
index 78504d45f..8a7ddc8b9 100644
--- a/src/types/line.js
+++ b/src/types/line.js
@@ -89,13 +89,14 @@ export default class LineAnnotation extends Element {
       : {x, y, x2, y2, width: Math.abs(x2 - x), height: Math.abs(y2 - y)};
     properties.centerX = (x2 + x) / 2;
     properties.centerY = (y2 + y) / 2;
-    if (!inside) {
-      options.label.display = false;
-    }
+    const labelProperties = resolveLabelElementProperties(chart, properties, options.label);
+    // additonal prop to manage zoom/pan
+    labelProperties._visible = inside;
+
     properties.elements = [{
       type: 'label',
       optionScope: 'label',
-      properties: resolveLabelElementProperties(chart, properties, options.label)
+      properties: labelProperties
     }];
     return properties;
   }