* refactor(overlays): overlays now are enabled via ionViewDidEnter (#6811) closes #6753

overalys now are enabled via ionViewDidEnter

* style(overlays): fixed tslint error

fixed tslint error

* style(overlays): formatting

formatting

* refactor(overlays): minor refactor to match style

minor refactor to match style

src/util/key.ts

@@ -0,0 +1,5 @@
+export enum Key {
+  ENTER = <any> 13,
+  ESCAPE = <any> 27,
+  TAB = <any> 9
+};

src/util/keyboard.ts

@@ -3,6 +3,7 @@ import {Injectable, NgZone} from '@angular/core';
 import {Config} from '../config/config';
 import {Form} from './form';
 import {hasFocusedTextInput, nativeRaf, rafFrames, nativeTimeout} from './dom';
+import {Key} from './key';
 
 /**
  * @name Keyboard
@@ -152,7 +153,7 @@ export class Keyboard {
 
     // default is to add the focus-outline when the tab key is used
     function keyDown(ev: KeyboardEvent) {
-      if (!isKeyInputEnabled && ev.keyCode === 9) {
+      if (!isKeyInputEnabled && ev.keyCode === Key.TAB) {
         isKeyInputEnabled = true;
         enableKeyInput();
       }