From a09fa311888db5735b2f62b2d112a07058e73ffb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=81lvaro=20Velad=20Galv=C3=A1n?= <alvaro.velad@mirada.tv>
Date: Wed, 26 May 2021 20:31:36 +0200
Subject: [PATCH] fix: Force update captions when element resizes (#3426)

---
 lib/text/ui_text_displayer.js | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/lib/text/ui_text_displayer.js b/lib/text/ui_text_displayer.js
index 60b36ecbc8..cda645f159 100644
--- a/lib/text/ui_text_displayer.js
+++ b/lib/text/ui_text_displayer.js
@@ -82,6 +82,15 @@ shaka.text.UITextDisplayer = class {
     this.eventManager_.listen(document, 'fullscreenchange', () => {
       this.updateCaptions_(/* forceUpdate= */ true);
     });
+
+    /** @private {ResizeObserver} */
+    this.resizeObserver_ = null;
+    if ('ResizeObserver' in window) {
+      this.resizeObserver_ = new ResizeObserver(() => {
+        this.updateCaptions_(/* forceUpdate= */ true);
+      });
+      this.resizeObserver_.observe(this.textContainer_);
+    }
   }
 
 
@@ -132,6 +141,11 @@ shaka.text.UITextDisplayer = class {
       this.eventManager_.release();
       this.eventManager_ = null;
     }
+
+    if (this.resizeObserver_) {
+      this.resizeObserver_.disconnect();
+      this.resizeObserver_ = null;
+    }
   }