Added back button and escape listeners for closing the full screen popup

lib/FullScreen.js

@@ -69,6 +69,11 @@ function (_ImageViewer) {
         display: 'none'
       }); // enable scroll
 
+      // escape listener
+      document.removeEventListener('keyup', _this._events.escapeListener);
+      // Android back button listener
+      document.removeEventListener('backbutton', _this._events.androidBackButtonListener);
+
       (0, _util.removeCss)(document.querySelector('html'), 'overflow'); // remove window event
 
       _this._events.onWindowResize();
@@ -101,6 +106,21 @@ function (_ImageViewer) {
         this.load(imageSrc, hiResImageSrc);
       } // handle window resize
 
+      // escape listener
+      this._events.escapeListener = (e) => {
+        if (e.keyCode === 27 || e.key === 'Escape') {
+          this.hide();
+          e.preventDefault();
+        }
+      }
+      document.addEventListener('keyup', this._events.escapeListener);
+
+      // Android back button listener
+      this._events.androidBackButtonListener = (e) => {
+        this.hide();
+        e.preventDefault();
+      }
+      document.addEventListener('backbutton', this._events.androidBackButtonListener);
 
       this._events.onWindowResize = (0, _util.assignEvent)(window, 'resize', this.refresh); // disable scroll on html
 
@@ -124,4 +144,4 @@ function (_ImageViewer) {
 }(_ImageViewer2.default);
 
 var _default = FullScreenViewer;
-exports.default = _default;
+exports.default = _default;