Added destroy method

src/lib/@types/index.d.ts

@@ -220,6 +220,11 @@ declare module 'simple-keyboard' {
      * @param  {string} button The button layout name to select
      */
     getButtonElement(button: string): HTMLElement | HTMLElement[];
+
+    /**
+     * Clears keyboard listeners and DOM elements.
+     */
+    destroy(): void;
   }
 
   export default Keyboard;

src/lib/components/Keyboard.js

@@ -64,6 +64,7 @@ class SimpleKeyboard {
      * @property {boolean} useTouchEvents Instructs simple-keyboard to use touch events instead of click events.
      * @property {boolean} autoUseTouchEvents Enable useTouchEvents automatically when touch device is detected.
      * @property {boolean} useMouseEvents Opt out of PointerEvents handling, falling back to the prior mouse event logic.
+     * @property {function} destroy Clears keyboard listeners and DOM elements.
      */
     this.options = options;
     this.options.layoutName = this.options.layoutName || "default";
@@ -646,6 +647,23 @@ class SimpleKeyboard {
     });
   }
 
+  /**
+   * Destroy keyboard listeners and DOM elements
+   */
+  destroy() {
+    /**
+     * Remove listeners
+     */
+    document.removeEventListener("keyup", this.caretEventHandler);
+    document.removeEventListener("mouseup", this.caretEventHandler);
+    document.removeEventListener("touchend", this.caretEventHandler);
+
+    /**
+     * Clear DOM
+     */
+    this.clear();
+  }
+
   /**
    * Process buttonTheme option
    */

src/lib/components/tests/Keyboard.test.js

@@ -1222,4 +1222,14 @@ it('Keyboard inputName change will trigget caretPosition reset', () => {
   keyboard.getButtonElement("b").onpointerdown();
 
   expect(keyboard.caretPosition).toBe(null);
+});
+
+it('Keyboard destroy will work', () => {
+  testUtil.setDOM();
+
+  let keyboard = new Keyboard();
+
+  keyboard.destroy();
+
+  expect(keyboard.keyboardDOM.innerHTML).toBeFalsy();
 });