How to add “Go Back” function in WebView inside Fragment?

Question

UPDATE: Solved! Problem was related to my Viewpager not WebView.

I\'m trying to add a \"Go Back\" function to my WebView which is insid

Answer 1

First of all get back pressed in fragment

 mContentView.setFocusableInTouchMode(true);
 mContentView.requestFocus();
 mContentView.setOnKeyListener( new OnKeyListener()
 {
   @Override
   public boolean onKey( View v, int keyCode, KeyEvent event )
  {
      if( keyCode == KeyEvent.KEYCODE_BACK && mWebView.canGoBack())
      {                                                    
            mWebView.goBack();
            return true;
      }
      return false;
  }
 } );

hope it will works.

Answer 2

In WebViewActivity.java, I added 1 method:

@Override
public void onBackPressed() {

    WebViewFragment fragment = (WebViewFragment)
            getSupportFragmentManager().findFragmentById(R.id.fragmentContainer);
    if (fragment.canGoBack()) {
        fragment.goBack();
    } else {
        super.onBackPressed();
    }
}

In WebViewFragment.java, I added 2 methods:

public boolean canGoBack() {
    return mWebView.canGoBack();
}

public void goBack() {
    mWebView.goBack();
}

Answer 3

I've created a simple interface:

public interface IOnBackPressed {
    boolean onBackPressed();
}

in the Activity:

public class MyActivity extends Activity {
    @Override public void onBackPressed() {
    Fragment fragment = getSupportFragmentManager().findFragmentById(R.id.main_container);
       if (!(fragment instanceof IOnBackPressed) || !((IOnBackPressed) fragment).onBackPressed()) {
          super.onBackPressed();
       }
    }
}

in the Fragment:

public class MyFragment extends Fragment implements IOnBackPressed {
   @Override
    public boolean onBackPressed() {
        if (webview.canGoBack()) {
            webview.goBack();
            // backpress is not considered in the Activity
            return true;
        } else {
            // activity will act normal
            return false;
        }
    }
}

Answer 4

This is how I did in my app. I consume back press event till web view can go back. Once web view cant go back I show hint to user that if he keep on pressing back then app will exit.

It will give user a chance to stay in your app when webview cant go back. I felt it more user friendly:

          //time passed between two back presses.
          private val TIME_INTERVAL = 200 
           // variable to keep track of last back press
          private var mBackPressed: Long = 0


        webView!!.requestFocus()
        webView.setOnKeyListener(View.OnKeyListener { v, keyCode, event ->
            if (keyCode == KeyEvent.KEYCODE_BACK
                    && event.action == MotionEvent.ACTION_UP
                  ) {
                if(webView.canGoBack()) {
                    //go back in previous page
                    webView.goBack()
                    return@OnKeyListener true
                }
                else
                {
                    if (mBackPressed + TIME_INTERVAL > System.currentTimeMillis())
                    {   // dont consume back press and pass to super
                        return@OnKeyListener false
                    }
                    else {
                        // show hint for double back press
                        Toast.makeText(context, " Double Tap back button to exit the demo", Toast.LENGTH_SHORT).show();
                        mBackPressed = System.currentTimeMillis();
                        return@OnKeyListener true
                    }
                }
            }
            return@OnKeyListener false

        })

Answer 5

There is a simple way with BackPressedDispatcher

Fragment:

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    val callback = object : OnBackPressedCallback(true) {
        override fun handleOnBackPressed() {
            if(webView.canGoBack()){
               webView.goBack()
            } else {
                isEnabled = false
                requireActivity().onBackPressed()
            }
        }
    }
    requireActivity().onBackPressedDispatcher.addCallback(this,callback)
}

Activity :

override fun onBackPressed() {
    val fragment = supportFragmentManager.findFragmentByTag("WebViewFragment")
    if (WebViewFragment::class.java.isInstance(fragment)) {
        if (onBackPressedDispatcher.hasEnabledCallbacks()) {
            onBackPressedDispatcher.onBackPressed()
            return
        }
        super.onBackPressed()
    }
}

Maybe these codes can be improved, but it works very well for me. For more information visit here.

Answer 6

You can check this code :

    webView.canGoBack();
    webView.setOnKeyListener(new View.OnKeyListener() {

        public boolean onKey(View v, int keyCode, KeyEvent event) {
            if (keyCode == KeyEvent.KEYCODE_BACK
                    && event.getAction() == MotionEvent.ACTION_UP
                    && webView.canGoBack()) {
                webView.goBack();
                return true;
            }
            return false;
        }
    });