From a67e26fb1c696e331f62d5af0313800f8809ec91 Mon Sep 17 00:00:00 2001
From: jahorton <jahorton@sil.org>
Date: Fri, 29 Jan 2021 12:54:50 +0700
Subject: [PATCH] fix(web): removes stylesheets from unloaded keyboards

---
 web/source/osk/oskManager.ts     | 7 ++++++-
 web/source/osk/visualKeyboard.ts | 9 +++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/web/source/osk/oskManager.ts b/web/source/osk/oskManager.ts
index d0a2d98754..2e56761f18 100644
--- a/web/source/osk/oskManager.ts
+++ b/web/source/osk/oskManager.ts
@@ -197,8 +197,10 @@ namespace com.keyman.osk {
         s.fontSize = fontScale + 'em';
       }
 
+      if(this.vkbd) {
+        this.vkbd.shutdown();
+      }
       this.vkbd = null;
-      // TODO:  Consider a 'vkbd.release()' method?
 
       // Instantly resets the OSK container, erasing / delinking the previously-loaded keyboard.
       this._Box.innerHTML = '';
@@ -311,6 +313,9 @@ namespace com.keyman.osk {
      * Description  Generates the visual keyboard element and attaches it to KMW
      */
     private _GenerateVisualKeyboard(keyboard: keyboards.Keyboard) {
+      if(this.vkbd) {
+        this.vkbd.shutdown();
+      }
       this.vkbd = new com.keyman.osk.VisualKeyboard(keyboard);
       let util = com.keyman.singleton.util;
 
diff --git a/web/source/osk/visualKeyboard.ts b/web/source/osk/visualKeyboard.ts
index d32690d586..7e1e3fc14b 100644
--- a/web/source/osk/visualKeyboard.ts
+++ b/web/source/osk/visualKeyboard.ts
@@ -2763,5 +2763,14 @@ namespace com.keyman.osk {
       }, 5000);
       return false;
     };
+
+    shutdown() {
+      let keyman = com.keyman.singleton;
+
+      // Prevents style-sheet pollution from multiple keyboard swaps.
+      if(this.styleSheet) {
+        keyman.util.removeStyleSheet(this.styleSheet);
+      }
+    }
   }
 }