How can I write my normal code into a Fragment?

Question

I am coding an app with Android Studio. I started a few days ago. I want to put a WebView in a fragment. Because I use Fragment to present WebView I cannot override onBackPressed to handle back button events. I'm trying to achieve the behaviour of opening previous page of WebView when back button pressed. I found this code:

    @Override
    public void onBackPressed(){
        if(webView.canGoBack()){
            webView.goBack();
        }
        else{
            super.onBackPressed();
        }
    }

But this doesn't work in a fragment. Can someone help me with this example or in general how I could write my normal code in the fragment class.

A solution to consider: https://stackoverflow.com/a/14530879/7210237 — Jenea Vranceanu, Jul 09 '20 at 15:22

score 0 · Answer 1 · answered Jul 09 '20 at 15:37

you can use backPressDispacher like this:

 @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        requireActivity().getOnBackPressedDispatcher().addCallback(getViewLifecycleOwner(), new OnBackPressedCallback(true) {
            @Override
            public void handleOnBackPressed() {
                if(webView.canGoBack()){
                   webView.goBack();
                 }else{
                    navigationController.popBackStack() // I'm assuming you are using navigation component
                  }
            }
        });
    }

If you are not using navigation component this should work fine if not handle your backpress as you need inside else block

Michael · Answer 2 · 2020-07-09T16:35:07.620

try this code inside your onCreateView method in Fragment

webView.setOnKeyListener(new View.OnKeyListener() {
        @Override
        public boolean onKey(View v, int keyCode, KeyEvent event) {

            if (event.getAction() == android.view.KeyEvent.ACTION_DOWN) {
                if ((keyCode == android.view.KeyEvent.KEYCODE_BACK)) {
                    if(webView!=null)
                    {
                        if(webView.canGoBack())
                        {
                            webView.goBack();
                        }  else {
                            getActivity().onBackPressed();
                        }
                    }
                }
            }

            return true;
        }
    });

How can I write my normal code into a Fragment?

2 Answers2