fix(nav): push-pop pages too quickly

fixes #8319

src/navigation/nav-controller-base.ts

@@ -623,7 +623,7 @@ export class NavControllerBase extends Ion implements NavController {
     const duration = trns.getDuration();
 
     // set that this nav is actively transitioning
-    this.setTransitioning(true, duration);
+    this.setTransitioning(true, duration + ACTIVE_TRANSITION_OFFSET);
 
     if (!trns.parent) {
       // this is the top most, or only active transition, so disable the app
@@ -959,3 +959,4 @@ let ctrlIds = -1;
 
 const DISABLE_APP_MINIMUM_DURATION = 64;
 const ACTIVE_TRANSITION_MAX_TIME = 5000;
+const ACTIVE_TRANSITION_OFFSET = 200;

src/navigation/view-controller.ts

@@ -30,7 +30,7 @@ export class ViewController {
   private _cntRef: ElementRef;
   private _hdrDir: Header;
   private _ftrDir: Footer;
-  private _hidden: string;
+  private _isHidden: boolean = false;
   private _leavingOpts: NavOptions;
   private _nb: Navbar;
   private _onDidDismiss: Function;
@@ -273,10 +273,11 @@ export class ViewController {
     // doing checks to make sure we only update the DOM when actually needed
     if (this._cmp) {
       // if it should render, then the hidden attribute should not be on the element
-      if (shouldShow && this._hidden === '' || !shouldShow && this._hidden !== '') {
-        this._hidden = (shouldShow ? null : '');
+      if (shouldShow === this._isHidden) {
+        this._isHidden = !shouldShow;
+        let value = (shouldShow ? null : '');
         // ******** DOM WRITE ****************
-        renderer.setElementAttribute(this.pageRef().nativeElement, 'hidden', this._hidden);
+        renderer.setElementAttribute(this.pageRef().nativeElement, 'hidden', value);
       }
     }
   }