Hamburger button in WebView of Android studio does not work - android

I have a problem in clicking on hamburger button, which was contained in website, website is also called by WebView, like webView.loadUrl(query)
but hamburger button contained in website does not work at all.
Thank you for your help and have a nice day.
as well as that, I also set
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(keyCode == KeyEvent.KEYCODE_BACK) {
if(webView.canGoBack()){
webView.goBack();
return false;
}
}
return super.onKeyDown(keyCode, event);
}
private class HybridWebViewClient extends WebViewClient{
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if(view != null) {
view.loadUrl(url);
}
return true;
}
}

Related

how to disable the back button in device by implement 1 function

i am trying to disable the back button in my device with the following code.
the code is working but i would like that the function that handle all the back button request in the fragments will derived from the Main Activity
this is the back button handler:
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
getView().setFocusableInTouchMode(true);
getView().requestFocus();
getView().setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
Toast.makeText(getActivity(), "Please navigate via the menu", Toast.LENGTH_SHORT).show();
return true;
}
}
return false;
}
});
}
It's easier to override onBackPressed function:
private boolean disabled = true;
#Override
public void onBackPressed() {
if (!disabled) {
super.onBackPressed();
}
}
With this you can easy change disable flag and enable back button when needed.
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// TODO Auto-generated method stub
if (keyCode == KeyEvent.KEYCODE_BACK) {
//leave it empty
}
return super.onKeyDown(keyCode, event);
}
It's generally not the best idea to disable the back button as the user expects that button to perform some sort of back navigation. Now that being said, if you have a specific reason you can disable the back button by overriding the onBackPressed at the activity level and not calling into super.
Put this code at your MainActivity:
#Override
public void onBackPressed() {
executeAtAndroidOnBackPressed();
}
#Override
public boolean onKeyDown(final int keyCode, final KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
executeAtAndroidOnBackPressed();
}
return false;
}
protected void executeAtAndroidOnBackPressed() {
// do nothing
}

How to disable back button pressed for webview in android?

How to disable back button pressed for webview in android ?
#Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if (wv1 != null && (keyCode == KeyEvent.KEYCODE_BACK)
&& wv1.canGoBack() )
{
wv1.goBack();
}
return true;
}
If you want to disable back button action when the WebView Visible and enable back button action if the WebView in not Visible try the below code in your Activity
#Override
public void onBackPressed() {
if(webview.getVisibility()==View.VISIBLE){
// dont pass back button action
if(webview.canGoBack()){
webview.goBack();
}
return;
}else{
// pass back button action
super.onBackPressed();
}
}
Simply override the onBackPressed() method.
#Override
public void onBackPressed() { }
Please try this
#Override
public void onBackPressed() {
if(webview.canGoBack()){
webview.goBack();
}
else{
super.onBackPressed();
}
}
There are many ways to make it,
Solution 1, overriding dispatchKeyEvent()
dispatchKeyEvent()(API Level 1, Android 1.0)
Refer to my answer use dispatchKeyEvent to disable back button
#Override
public boolean dispatchKeyEvent(KeyEvent event) {
// TODO Auto-generated method stub
if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
return true;
}
return super.dispatchKeyEvent(event);
}
Solution 2, overriding onBackPressed()
onBackPressed() (API Level 5, Android 2.0)
Refer to Use onBackPressed() to disable back button
#Override
public void onBackPressed() {
}
Solution 3, overriding onKeyDown()
onKeyDown() (API Level 1, Android 1.0)
Refer to Use onKeyDown() to disable back button
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
//preventing default implementation previous to android.os.Build.VERSION_CODES.ECLAIR
return true;
}
return super.onKeyDown(keyCode, event);
}
You have add below code in Activity for disable activity back pressed
#Override
public void onBackPressed() {
}
Add this below code in java file :
WebView mwebView;
Button backButton1;
backButton1 = findViewById(R.id.backButton1);
mwebView = findViewById(R.id.mwebView);
backButton1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
mWebView.destroy();
}
});

Android Back Button With Webview

I am having an issue with the back button in my android app. I am trying to have it go back through the previous pages and if unable then to exit. I pick through the code on the developer website and nothing is working. I would appreciate any help.
Below is my activity page:
WebView webView;
#SuppressLint("SetJavaScriptEnabled")
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
webView = (WebView)findViewById(R.id.webView);
WebSettings webSettings = webView.getSettings();
webSettings.setJavaScriptEnabled(true);
webView.setWebViewClient(new myWebView());
webView.loadUrl("http://google.com");
webView.setInitialScale(1);
webView.getSettings().setBuiltInZoomControls(true);
webView.getSettings().setUseWideViewPort(true);
}
#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) && webView.canGoBack()) {
webView.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);
}
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.diabetes_meal_planner, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
switch(item.getItemId())
{
case R.id.action_settings:
//exits app
finish();
break;
default:
break;
}
return true;
}
private class myWebView extends WebViewClient
{
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url)
{
if(url.startsWith("mailto:"))
{
String[] email = url.split(":");
Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
emailIntent.setType("plain/text");
emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL, new String[]{email[1]});
emailIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, "Send_Us_Your_Email");
Log.v("NOTICE", "Sending Email to" + email[1] + "with subject" + "Send Us Your Feedback");
startActivity(emailIntent);
}
view.loadUrl(url);
return true;
}
}
Dont do this onKeyDown. Override Activity.onBackPressed to do this..
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK) && webView!=null && webView.canGoBack()) {
webView.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
Try this at the end, works in my webview app

How to add "Go Back" function in WebView inside Fragment?

UPDATE: Solved! Problem was related to my Viewpager not WebView.
I'm trying to add a "Go Back" function to my WebView which is inside a Fragment. But I can't figure out how to:
public final class TestFragment extends Fragment {
static WebView mWeb;
private View mContentView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
mContentView = inflater.inflate(R.layout.webview, null);
mWeb = (WebView)mContentView.findViewById(R.id.webview);
WebSettings settings = mWeb.getSettings();
settings.setJavaScriptEnabled(true);
settings.setSupportZoom(false);
mWeb.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
mWeb.getSettings().setBuiltInZoomControls(false);
mWeb.loadUrl("myurl...");
mWeb.setOnKeyListener(new OnKeyListener(){
public boolean onKey(View v, int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK) && mWeb.canGoBack()) {
mWeb.goBack();
return true;
}
return false;
}
});
}
}
I also tried something like:
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK) && mWeb.canGoBack()) {
mWeb.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
Another solution but same problem:
#Override
public void onBackPressed()
{
if(webView.canGoBack())
webView.goBack();
else
super.onBackPressed();
}
Any ideas how to get this working?
Perhaps its android restriction. Try to do this using handler.
public final class TestFragment extends Fragment {
static WebView mWeb;
private View mContentView;
private Handler handler = new Handler(){
#Override
public void handleMessage(Message message) {
switch (message.what) {
case 1:{
webViewGoBack();
}break;
}
}
};
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
mContentView = inflater.inflate(R.layout.webview, null);
mWeb = (WebView)mContentView.findViewById(R.id.webview);
WebSettings settings = mWeb.getSettings();
settings.setJavaScriptEnabled(true);
settings.setSupportZoom(false);
mWeb.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
mWeb.getSettings().setBuiltInZoomControls(false);
mWeb.loadUrl("myurl...");
mWeb.setOnKeyListener(new OnKeyListener(){
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK
&& event.getAction() == MotionEvent.ACTION_UP
&& mWeb.canGoBack()) {
handler.sendEmptyMessage(1);
return true;
}
return false;
}
});
}
private void webViewGoBack(){
mWeb.goBack();
}
}
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;
}
});
Actually you can not do directly inside the fragment. The onBackPressed can be overridden in the FragmentActivity. What you can do is:
Override the onBackPressed inside the activity.
When the onBackPressed is called, check if the instance of the current fragment is the instance showing the webview.
If it is, ask the fragment if the webview can go back.
if it is not, call the super or whatever you need
Edit:
#Override
public void onBackPressed() {
Fragment webview = getSupportFragmentManager().findFragmentByTag("webview");
if (webview instanceof MyWebViewFragment) {
boolean goback = ((MyWebViewFragment)webview).canGoBack();
if (!goback)
super.onBackPressed();
}
}
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;
}
}
}
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();
}
#RomanBlack's answer gave me the right idea, but since we use kotlin I had to adapt the answer a little bit.
webView.setOnKeyListener { _, _, keyEvent ->
if (keyEvent.keyCode == KeyEvent.KEYCODE_BACK && !webView.canGoBack()) {
false
} else if (keyEvent.keyCode == KeyEvent.KEYCODE_BACK && keyEvent.action == MotionEvent.ACTION_UP) {
webView.goBack()
true
} else true
}
if you want to do it with returns you have to add something like:
return#setOnKeyListener true
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.
my solution was in fragment I added to public methods
public static boolean canGoBack(){
return mWebView.canGoBack();
}
public static void goBack(){
mWebView.goBack();
}
then from activity I call
#Override
public void onBackPressed() {
if(webFragment.canGoBack()){
webFragment.goBack();
}else{
super.onBackPressed();
}
}
note The mwebview is static
you can do this by :
in the Activity put :
// Set WebView
public void setWebView(WebView web) {
this.web = web;
}
in the web fragment after ActivityCreated() put:
((Your_Activity) getActivity()).setWebView(webView);
Don't forget to set webView from the onCreateView() like these:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
webView = (WebView) inflater.inflate(R.layout.your_web_fragment, container,
false);
return web;
}
#OmidAmnivia answer is correct your app the solution to the crash is
#Override
public void onBackPressed() {
if(webFragment.isInitialized && webFragment.canGoBack()){
webFragment.goBack();
}else{
super.onBackPressed();
}
}
You have to check whether your class has been initialised or not.
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
})
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.
This worked in my case
public class FantasyFragment extends Fragment implements SwipeRefreshLayout.OnRefreshListener {
WebView webview;
SwipeRefreshLayout swipeLayout;
String currentUrl="https://www.stackoverflow.com/";
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View root = inflater.inflate(R.layout.fragment_stadium, container, false);
swipeLayout = (SwipeRefreshLayout) root.findViewById(R.id.swipescreen);
swipeLayout.setOnRefreshListener(this);
return root;
}
#Override
public void onStart() {
super.onStart();
LoadWeb();
}
public void LoadWeb() {
webview = (WebView) getActivity().findViewById(R.id.webview786);
swipeLayout.setRefreshing(true);
webview.getSettings().setRenderPriority(WebSettings.RenderPriority.HIGH);
webview.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);
webview.getSettings().setAppCacheEnabled(true);
WebSettings webSettings = webview.getSettings();
webSettings.setJavaScriptEnabled(true);
webSettings.setDatabaseEnabled(true);
webSettings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.NARROW_COLUMNS);
webSettings.setUseWideViewPort(true);
webSettings.setSavePassword(true);
webSettings.setSaveFormData(true);
webSettings.setEnableSmoothTransition(true);
webview.loadUrl(currentUrl);
webview.setWebViewClient(new WebViewClient() {
#Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
Snackbar.make(view, "Connection Error", Snackbar.LENGTH_LONG)
.setAction("Retry", new View.OnClickListener() {
#Override
public void onClick(View v) {
LoadWeb();
}
}).show();
}
#Override
public void onPageFinished(WebView view, String url) {
swipeLayout.setRefreshing(false);
currentUrl = url;
super.onPageFinished(view, url);
}
});
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;
}
});
}
#Override
public void onRefresh() {
LoadWeb();
}
}
The simplest answer is jut to setOnKeyListeneron into webView itself:
webView.setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey( View v, int keyCode, KeyEvent event ) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
if( keyCode == KeyEvent.KEYCODE_BACK && webView.canGoBack()){
webView.goBack();
return true;
}
}
return false;
}
});

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);
}
});
}
}
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);
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();
}
}
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;
}
});
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();
}
}
});
Focusing should also be checked in onBackPressed
#Override
public void onBackPressed() {
if (mWebview.isFocused() && mWebview.canGoBack()) {
mWebview.goBack();
} else {
super.onBackPressed();
finish();
}
}
Why not use onBackPressed()?
#Override
public void onBackPressed() {
// super.onBackPressed(); Do not call me!
// Go to the previous web page.
}
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();
}
}
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.
#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);
}
WebView mWebView;
mWebView = findViewById(R.id.webView);
#Override
public void onBackPressed() {
if (webView.canGoBack()) {
webView.goBack();
} else {
super.onBackPressed();
}
}
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();
}
}
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
}
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
}
}
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
}
If someone wants to handle backPressed for a webView inside a fragment, then he can use below code.
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();
}
}
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.
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.
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
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);
}

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