bug: (angular) gesture partial back

Bug Report

Ionic version:

[x] 4.x

Current behavior: When viewing a Detail view you can swipe back to return to the List view you came from. However if you only drag your finger partially across the screen and return back to the Detail view without removing your finger, the view begins to behave strangely. The List view is now visible. Expected behavior: If you start to swipe right to back out of a view and gesture back to pull the page back into view. The previous page should be hidden

Steps to reproduce:

1. From the home view, tap on push me button
2. Drag your finger from left to right, stopping in the middle of the screen
3. Without removing your finger, drag your finger back to the left which will return you to the “other” page Related code: https://github.com/Kadinvanvalin/ionic-gesture-back

// stack-controller.ts
// I was able to fix locally by adding the else statement.

  endBackTransition(shouldComplete: boolean) {
    if (shouldComplete) {
      this.skipTransition = true;
      this.pop(1);
    } else {
      const leavingView = this.activeView;
      const viewsSnapshot = this.views.slice();
      if (leavingView) { cleanupAsync(leavingView, this.views, viewsSnapshot, this.location); }
    }
  }

Other information:

.ion-page-hidden is removed when you start the gesture, but isn’t reapplied at the end of the gesture if you end on the “wrong page” Ionic info:

Ionic:

   ionic (Ionic CLI)             : 4.3.1 (/Users/kadin/.nvm/versions/node/v11.1.0/lib/node_modules/ionic)
   Ionic Framework               : @ionic/angular 4.4.2
   @angular-devkit/build-angular : 0.13.9
   @angular-devkit/schematics    : 7.3.9
   @angular/cli                  : 7.3.9
   @ionic/angular-toolkit        : 1.5.1

System:

   NodeJS : v11.1.0 (/Users/kadin/.nvm/versions/node/v11.1.0/bin/node)
   npm    : 6.9.0
   OS     : macOS

[dansiemens]

@joshstrange seems overkill…better solution would be to just reapply .ion-page-hidden at the end of the gesture as @Kadinvanvalin suggested in the bug report.

[AndreasGassmann]

I can confirm this issue. In my case, I am using the cordova-plugin-camera-preview plugin on a subpage and have to make the whole content transparent. Everything works fine until I use swipe to go back.

The behaviour is very weird:

• The sub-page becomes transparent, showing the parent page.
• “Scrolling” gets applied to the parent page, the sub-page does not move
• We have a drawing are on the sub-page, touch events still get registered there, but they also scroll the parent page.
• Using swipe-back fixes the issue (by going back to the parent page).

We are currently migrating our app to Ionic 4 and this branch is not public yet. But if it would help you in reproducing the error, I can try to make it public.

Here is a video: https://streamable.com/tt8p9

EDIT: My temporary solution is to simply disable swipe to go back in the whole application. Ideally I would like to only disable it on some pages, but I couldn’t find any docs for it. Is there a way to do that?