[webview_flutter]Add pinch to zoom for Android

[FisherWL]

Description

By using webview_flutter, pinch to zoom is enabled by default on ios, but not on android platform. This PR adds pinch to zoom for android, and hide the distracting +/- buttons..

Related Issues

flutter/flutter#48283

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[cetorres]

@amirh Please approve this PR. This is a very important feature that's missing on Android. Thank you. And thank you @FisherWL for the great work!

[eltonmorais]

Please, we need this!

[otaviogrrd]

Thanks @FisherWL , we need this!

for those needing to fix this and can't wait for the official version, just download @FisherWL repository,
copy the folder webview_flutter located inside packages to your project root folder,
then on the pubspec.yaml add the dependecie as a folder like this:

  webview_flutter:
    path: ./webview_flutter

[bparrishMines]

Hi @FisherWL,

Thanks for the contribution! For this solution, I think we would want this to be configurable. Most likely somewhere in WebViewController. It could then be a no-op on iOS.

This change would also require tests.

cc @cyanglaz @amirh

[hongbiangoal]

The pr will merged in which version? This pr is very important for android~

[tal412]

The ability to set something like "withZoom=true" and "useWideViewPort=true" is extremely important... Many sites need to have those settings enabled in order to work properly.

[panudetjt]

I need this too

[bkonyi]

@bparrishMines @amirh can we pick this change up ourselves if it requires testing and configurability? This is pretty critical functionality that makes WebView on Android useless in many circumstances.

[GreenHatHG]

Is there any progress up to now？
Will the official use the function of flutter_webview_plugin directly

[stuartmorgan]

Thanks for the submission! We’re currently working through a large backlog of PRs, and this is not ready for review and landing as is (due to lack of configurability and tests, per earlier review comments). As explained in CONTRIBUTING.md, votes for the corresponding issue are the primary way we’re prioritizing non-trivial reviews, so we encourage anyone interested in this PR to vote for the corresponding issue.

@FisherWL If you are interested in addressing the review comments before someone on the team has time to look into potentially adding the tests, please update the PR and let us know, and we can work on getting it reviewed.

We apologize for the long delay in triaging this PR. We’re in the process of overhauling our PR triage system to respond much more quickly, as well as working through the backlog.

[stuartmorgan]

Closing, as this was obsoleted by #3325.