bug: WKWebView is not resized properly after the native Share modal has been closed

[ChristopherTotty]

Bug Report

Plugin(s)

capacitor/share v1.1.0

Capacitor Version

💊   Capacitor Doctor  💊 

Latest Dependencies:

  @capacitor/cli: 3.4.1
  @capacitor/core: 3.4.1
  @capacitor/android: 3.4.1
  @capacitor/ios: 3.4.1

Installed Dependencies:

  @capacitor/android: not installed
  @capacitor/core: 3.4.1
  @capacitor/cli: 3.4.1
  @capacitor/ios: 3.4.1

[success] iOS looking great! 👌

Platform(s)

iOS, confirmed on hardware iPhone XR and iPhone 12 Pro. iOS Simulator does not replicate.

Current Behavior

Using the Share sheet functionality, then calling for a share to the Messages app causes the app view to resize. After completing or cancelling the share, the app view does not return to its original size/origin.

Expected Behavior

After completing or cancelling the share, the app view should return to its original size/origin.

Code Reproduction

https://github.com/ChristopherTotty/capacitor-share-replication

Other Technical Details

Unsure on replication as the device will sometimes work but then after a power cycle the issue will present again.

Additional Context

See:
ionic-team/capacitor#2979
ionic-team/capacitor#2955

RPReplay_Final1645561625.mov

[jcesarmobile]

Adding another repository that proves that the issue is on keyboard plugin instead of share plugin
https://github.com/nprather/toolbar-dissappearing.git

workarounds are to uninstall @capacitor/keyboard until the bug is fixed or configure the resize mode to anything other than native. i.e

"plugins": {
    "Keyboard": {
        "resize": "ionic"
    }
}

[drakedeatonuk]

I've noticed similar issues the webview not resizing, but related to the keyboard closing.

@ChristopherTotty I've opened a similar ticket here: #23

[dabaaaz]

Do you know if Keyboard with Share will be OK soon ?

"resize": "ionic" is not working for me :/

Thanks to @ChristopherTotty : https://github.com/ionic-team/capacitor-plugins/pull/832/files
I've added the fix for frame.size.width & frame.origin.x too :) !

self?.bridge?.webView?.frame.size.height = UIScreen.main.bounds.size.height
self?.bridge?.webView?.frame.size.width = UIScreen.main.bounds.size.width
self?.bridge?.webView?.frame.origin.y = 0
self?.bridge?.webView?.frame.origin.x = 0

[devkhan1]

WKWebView didn’t resize after keyboard closed — what caused it & how we fixed it..

Symptoms

On iOS (and sometimes Android), when the native keyboard closed, the webview left a big empty gap where the keyboard had been.

After it happened once, subsequent open/close cycles kept the wrong height until the app was restarted.

It was sporadic (more frequent under low-power / throttled conditions).

Root cause (per the thread + our repros)

Using Capacitor Keyboard “native” resize mode (and especially toggling resize modes at runtime) can desync WKWebView’s frame from the actual viewport height. When the keyboard dismisses, WKWebView sometimes doesn’t restore its frame, so the page thinks it’s shorter than it really is. This matches the discussion in the linked issue: switching away from native resize made the problem disappear.

The fix that worked for us

We eliminated native resize entirely and let the system do a traditional adjustResize, with a couple of small safety nudges. No other invasive UI changes were needed.

Don’t use KeyboardResize.Native.
In capacitor.config.ts:

plugins: {
Keyboard: {
resize: KeyboardResize.Body, // not Native
},
}

Keep Android in resize mode, no toggling.
AndroidManifest:

<activity
android:windowSoftInputMode="stateHidden|adjustResize"
... />

MainActivity.java:

@OverRide public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
WindowCompat.setDecorFitsSystemWindows(getWindow(), true);
getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE);
}

@OverRide public void onResume() {
super.onResume();
// gentle nudge in case the system forgot to restore after IME hide
getWindow().getDecorView().post(() ->
getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE)
);
}

Key point: we don’t call Keyboard.setResizeMode(...) at runtime anymore. No switching resize modes while the keyboard is open.

Tiny UI safeties (optional but helped stability):

We listen for Capacitor keyboard keyboardWillHide/DidHide and do a one-shot “stick to bottom” resnap in our chat viewport after ~60ms (only if the user is already near the bottom).

We use a --vh CSS variable synced to visualViewport.height so mobile “100vh” isn’t stale when the keyboard comes/goes.

Result

After removing native resize and stopping runtime mode toggles, the “stuck gap” stopped reproducing on Android (tested Samsung S10+ and Huawei Nova 5T). The occasional post-hide resnap simply keeps the chat scrolled to bottom — it doesn’t paper over a broken layout anymore because the layout itself is now consistent.