Set unicode.activeVersion when loading UnicodeGraphemeProvider.

addons/xterm-addon-unicode-graphemes/README.md

@@ -19,7 +19,4 @@ import { UnicodeGraphemeAddon } from 'xterm-addon-unicode-graphemes';
 const terminal = new Terminal();
 const unicodeGraphemeAddon = new UnicodeGraphemeAddon();
 terminal.loadAddon(unicodeGraphemeAddon);
-
-// activate the new version
-terminal.unicode.activeVersion = '15';
 ```

addons/xterm-addon-unicode-graphemes/src/UnicodeGraphemesAddon.ts

@@ -5,13 +5,29 @@
  * UnicodeVersionProvider for V15 with grapeme cluster handleing.
  */
 
-import { Terminal, ITerminalAddon } from 'xterm';
+import { Terminal, ITerminalAddon, IUnicodeHandling } from 'xterm';
 import { UnicodeGraphemeProvider } from './UnicodeGraphemeProvider';
 
 
 export class UnicodeGraphemesAddon implements ITerminalAddon {
+  private _provider?: UnicodeGraphemeProvider;
+  private _unicode?: IUnicodeHandling;
+  private _oldVersion: string = '';
+
   public activate(terminal: Terminal): void {
-    terminal.unicode.register(new UnicodeGraphemeProvider());
+    if (! this._provider) {
+      this._provider = new UnicodeGraphemeProvider();
+    }
+    const unicode = terminal.unicode;
+    this._unicode = unicode;
+    unicode.register(this._provider);
+    this._oldVersion = unicode.activeVersion;
+    unicode.activeVersion = '15-graphemes';
+  }
+
+  public dispose(): void {
+    if (this._unicode) {
+      this._unicode.activeVersion = this._oldVersion;
+    }
   }
-  public dispose(): void { }
 }