CODEWITHSUNDEEP
androidandroid-webview
zvzej
zvzej

Reputation: 6336

How to go back to previous page if back button is pressed in WebView?

I have an app in which I have a WebView where I display some websites. It works, clicking a link in the webpage goes to the next page in the website inside my app. But when I click the phone's back button, it takes me straight into my app. I want to go back to the previous page in the website instead. How can I do this?

Here is the code sample I'm using:

public class Webdisplay extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);

        this.getWindow().requestFeature(Window.FEATURE_PROGRESS);
        setContentView(R.layout.webdisplay);

        getWindow().setFeatureInt(Window.FEATURE_PROGRESS,
                Window.PROGRESS_VISIBILITY_ON); 

        Toast loadingmess = Toast.makeText(this,
                "Cargando El Diario de Hoy", Toast.LENGTH_SHORT);
        loadingmess.show();

        WebView myWebView;

        myWebView = (WebView) findViewById(R.id.webview);
        myWebView.getSettings().setJavaScriptEnabled(true);
        myWebView.loadUrl("http://www.elsalvador.com");
        myWebView.setWebViewClient(new WebViewClient());
        myWebView.setInitialScale(1);
        myWebView.getSettings().setBuiltInZoomControls(true);
        myWebView.getSettings().setUseWideViewPort(true);

        final Activity MyActivity = this;
        myWebView.setWebChromeClient(new WebChromeClient() 
        {
            public void onProgressChanged(WebView view, int progress)   
            {
                MyActivity.setTitle("Loading...");
                MyActivity.setProgress(progress * 100); 

                if(progress == 100)
                    MyActivity.setTitle(R.string.app_name);
            }
        });
    }
}

Upvotes: 407

Views: 331156

Answers (19)

steven smith
steven smith

Reputation: 1577

In Kotlin friederbluemle's answer is:

webView.setOnKeyListener { v, keyCode, event ->
            var rv = false
            if (event.action == KeyEvent.ACTION_DOWN &&
                keyCode ==  KeyEvent.KEYCODE_BACK) {
                (v as WebView).goBack()
                rv = true
            }
            rv
        }

Upvotes: 0

Daniel Nyamasyo
Daniel Nyamasyo

Reputation: 2312

You should the following libraries on your class handle the onBackKeyPressed. canGoBack() checks whether the webview can reference to the previous page. If it is possible then use the goBack() function to reference the previous page (go back).

@Override
public void onBackPressed() {
    if( mWebview.canGoBack()){
        mWebview.goBack(); 
    } else {
        //Do something else. like trigger pop up. Add rate app or see more app
    }
}

Upvotes: 1

Ammar Ahsan
Ammar Ahsan

Reputation: 123

I think I'm a little late but according to the android documentation, you can have custom back navigation inside fragments done by the following piece of code.

 requireActivity().onBackPressedDispatcher.addCallback(this) {
            // Handle the back button event
            if (binding.webView.canGoBack()){
                binding.webView.goBack()
            } else {
                findNavController().popBackStack()
            }
        }

you can customize what to do when you the webView cant go back as per your needs.

Upvotes: 4

Abubakar
Abubakar

Reputation: 141

 WebView mWebView;

 mWebView = findViewById(R.id.webView);

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

Upvotes: 5

Gyan
Gyan

Reputation: 12410

Why not use onBackPressed()?

@Override
public void onBackPressed() {
    // super.onBackPressed(); Do not call me!

    // Go to the previous web page.
}

Upvotes: 14

petrnohejl
petrnohejl

Reputation: 7759

This is my solution. It works also in Fragment.

webView.setOnKeyListener(new OnKeyListener() {
    @Override
    public boolean onKey(View v, int keyCode, KeyEvent event) {
        if (event.getAction() == KeyEvent.ACTION_DOWN) {
            WebView webView = (WebView) v;
            
            switch(keyCode) {
                case KeyEvent.KEYCODE_BACK:
                    if (webView.canGoBack()) {
                        webView.goBack();
                        return true;
                    }
                    break;
            }
        }
        
        return false;
    }
});

Upvotes: 140

Simbarashe Mupfururirwa
Simbarashe Mupfururirwa

Reputation: 375

You can try this for webview in a fragment:

private lateinit var webView: WebView

override fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
    val root = inflater.inflate(R.layout.fragment_name, container, false)
    webView = root!!.findViewById(R.id.home_web_view)
    var url: String = "http://yoururl.com"
    webView.settings.javaScriptEnabled = true
    webView.webViewClient = WebViewClient()
    webView.loadUrl(url)
    webView.canGoBack()
    webView.setOnKeyListener{ v, keyCode, event ->
        if(keyCode == KeyEvent.KEYCODE_BACK && event.action == MotionEvent.ACTION_UP
            && webView.canGoBack()){
            webView.goBack()
            return@setOnKeyListener true
        }
        false
    }
    return root
}

Upvotes: 2

vishnu benny
vishnu benny

Reputation: 1078

In kotlin:

override fun onBackPressed() {
    when {
        webView.canGoBack() -> webView.goBack()
        else -> super.onBackPressed()
    }
}

webView - id of the webview component in xml, if using synthetic reference.

Upvotes: 12

Faraz Ahmad
Faraz Ahmad

Reputation: 555

If someone wants to handle backPressed for a webView inside a fragment, then he can use below code.

  1. Copy below code into your Activity class (that contains a fragment YourFragmmentName)

    @Override
public void onBackPressed() {
List<Fragment> fragmentList = getSupportFragmentManager().getFragments();

boolean handled = false;
for(Object f: fragmentList) {
    if(f instanceof YourFragmentName) {
        handled = ((YourFragmentName)f).onBackPressed();
        if(handled) {
            break;
        }
    }
}

if(!handled) {
    super.onBackPressed();
}

    }

  2. Copy this code in the fragment YourFragmentName

    public boolean onBackPressed() {
   if (webView.canGoBack()) {
       webView.goBack();
       return true;
   } else {
       return false;
   }
}

Notes

  • Activity should be replaced with the actual Acitivity class you are using.
  • YourFragmentName should be replaced with the name of your Fragment.
  • Declare webView in YourFragmentName so that it can be accessed from within the function.

Upvotes: 2

Pradeep Kumar
Pradeep Kumar

Reputation: 2719

use this code to go back on page and when last page came then go out of activity

 @Override
    public void onBackPressed() {
        super.onBackPressed();
        Intent intent=new Intent(LiveImage.this,DashBoard.class);
        startActivity(intent);
    }

Upvotes: -4

SANAT
SANAT

Reputation: 9287

Official Kotlin Way:

override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {
    // Check if the key event was the Back button and if there's history
    if (keyCode == KeyEvent.KEYCODE_BACK && myWebView.canGoBack()) {
        myWebView.goBack()
        return true
    }
    // If it wasn't the Back key or there's no web page history, bubble up to the default
    // system behavior (probably exit the activity)
    return super.onKeyDown(keyCode, event)
}

https://developer.android.com/guide/webapps/webview.html#NavigatingHistory

Upvotes: 0

Gibolt
Gibolt

Reputation: 47297

Here is the Kotlin solution:

override fun onKeyUp(keyCode: Int, event: KeyEvent?): Boolean {
    if (event?.action != ACTION_UP || event.keyCode != KEYCODE_BACK) {
        return super.onKeyUp(keyCode, event)
    }

    if (mWebView.canGoBack()) {
        mWebView.goBack()
    } else {
        finish()
    }
    return true
}

Upvotes: 1

Ajowi
Ajowi

Reputation: 515

The first answer by FoamyGuy is correct but I have some additions; low reputations cannot allow me to do comments. If for some reasons your page fails to load, ensure that you set a flag to take note of the failure and then check it on the onBackPressed override. Otherwise your canGoBack() will be forever executed without heading to the actual back activity if it was there:

//flag with class wide access 
public boolean ploadFailFlag = false;

//your error handling override
@Override
public void onReceivedError(WebView view, WebResourceRequest req, WebResourceError rerr) {
    onReceivedError(view, rerr.getErrorCode(), rerr.getDescription().toString(), req.getUrl().toString());
    ploadFailFlag = true;       //note this change 
    .....
    .....
}

//finally to the answer to this question:
@Override
public void onBackPressed() {
    if(checkinWebView.canGoBack()){
        //if page load fails, go back for web view will not go back - no page to go to - yet overriding the super 
        if(ploadFailFlag){
            super.onBackPressed();
        }else {
            checkinWebView.goBack();
        }
    }else {
        Toast.makeText(getBaseContext(), "super:", Toast.LENGTH_LONG).show();
        super.onBackPressed();
    }
}

Upvotes: 3

Parsania Hardik
Parsania Hardik

Reputation: 4623

Full reference for next button and progress bar : put back and next button in webview

If you want to go to back page when click on phone's back button, use this:

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

You can also create custom back button like this:

btnback.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            if (wv.canGoBack()) {
                wv.goBack();
            }
        }
    });

Upvotes: 21

Zar E Ahmer
Zar E Ahmer

Reputation: 34390

Focusing should also be checked in onBackPressed

    @Override
    public void onBackPressed() {
        if (mWebview.isFocused() && mWebview.canGoBack()) {
            mWebview.goBack();       
        } else {
            super.onBackPressed();
            finish();
        }
    }

Upvotes: 17

FoamyGuy
FoamyGuy

Reputation: 46856

I use something like this in my activities with WebViews:

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (event.getAction() == KeyEvent.ACTION_DOWN) {
        switch (keyCode) {
            case KeyEvent.KEYCODE_BACK:
                if (mWebView.canGoBack()) {
                    mWebView.goBack();
                } else {
                    finish();
                }
                return true;
        }

    }
    return super.onKeyDown(keyCode, event);
}

Edit:

For this code to work, you need to add a field to the Activity containing the WebView:

private WebView mWebView;

Initialize it in the onCreate() method and you should be good to go.

mWebView = (WebView) findViewById(R.id.webView);

Upvotes: 593

Kevin Westwood
Kevin Westwood

Reputation: 7789

If using Android 2.2 and above (which is most devices now), the following code will get you what you want.

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

Upvotes: 350

Mohammed Ahmed
Mohammed Ahmed

Reputation: 441

here is a code with confirm exit:

@Override
    public void onBackPressed()
    {
        if(webView.canGoBack()){
            webView.goBack();
        }else{
            new AlertDialog.Builder(this)
            .setIcon(android.R.drawable.ic_dialog_alert)
            .setTitle("Exit!")
            .setMessage("Are you sure you want to close?")
            .setPositiveButton("Yes", new DialogInterface.OnClickListener()
            {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    finish();    
                }

            })
            .setNegativeButton("No", null)
            .show();    
        }   
    }

Upvotes: 12

Mahesh
Mahesh

Reputation: 2892

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    // Check if the key event was the Back button and if there's history
    if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) {
        myWebView.goBack();
        return true;
    }
    // If it wasn't the Back key or there's no web page history, bubble up to the default
    // system behavior (probably exit the activity)
    return super.onKeyDown(keyCode, event);
}

Upvotes: 6

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