I have an Android app which has a webview. When there's no internet connection, webview will display page not available. I want to make this look like an app as much as possible, so I don't want to display this page. I found some useful info online teaching you how to hide or load something else to cover it, but what I really want is to stay at the current page and a little pop up dialog says no connection. Basically, when user clicks on anything inside the webview, check for connection first. if no connection, stay at where it was and pop out a dialog box.
Thanks for the help!!
Edited:
Like I said, I already know how to check internet connection from the samples online. My problem is I don't know how to stop loading the next page. To be clear, when users try to go to the next page, check for internet connection. If no connection, the page will stay at where it was and would not go to the next page. I want users able to see their last loaded page and get informed while webpage content is still there. thanks!
This interface was deprecated in API level 12. This interface is now obsolete.
Add a close button and on its click set: webview. setVisibility(View. INVISIBLE); webview.
This example demonstrate about How to enable back button in android webview. Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project. Step 2 − Add the following code to res/layout/activity_main. xml.
I have used the following in my projects:
DetectConnection.Java
import android.content.Context;
import android.net.ConnectivityManager;
public class DetectConnection {
public static boolean checkInternetConnection(Context context) {
ConnectivityManager con_manager = (ConnectivityManager)
context.getSystemService(Context.CONNECTIVITY_SERVICE);
return (con_manager.getActiveNetworkInfo() != null
&& con_manager.getActiveNetworkInfo().isAvailable()
&& con_manager.getActiveNetworkInfo().isConnected());
}
}
Main code:
if (!DetectConnection.checkInternetConnection(this)) {
Toast.makeText(getApplicationContext(), "No Internet!", Toast.LENGTH_SHORT).show();
} else {
wv = (WebView) findViewById(R.id.donate_webView1);
c = new CustomWebViewClient();
wv.setWebViewClient(c);
wv.clearCache(true);
wv.clearHistory();
wv.getSettings().setJavaScriptEnabled(true);
wv.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
wv.getSettings().setBuiltInZoomControls(true);
wv.loadUrl("http://www.google.com");
}
// Function to load all URLs in same webview
private class CustomWebViewClient extends WebViewClient {
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (!DetectConnection.checkInternetConnection(this)) {
Toast.makeText(getApplicationContext(), "No Internet!", Toast.LENGTH_SHORT).show();
} else {
view.loadUrl(url);
}
return true;
}
}
Update the Manifest:
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
You can use my CustomWebViewClient
it -
All you need to do is attach it to your webView
webView.setWebViewClient(new CustomWebViewClient ());
CustomWebViewClient class
/**
* WebViewClient subclass loads all hyperlinks in the existing WebView
*/
public class CustomWebViewClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// When user clicks a hyperlink, load in the existing WebView
view.loadUrl(url);
return true;
}
Dialog loadingDialog = new Dialog(WebViewActivity.this);
@Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
super.onPageStarted(view, url, favicon);
webViewPreviousState = PAGE_STARTED;
if (loadingDialog == null || !loadingDialog.isShowing())
loadingDialog = ProgressDialog.show(WebViewActivity.this, "",
"Loading Please Wait", true, true,
new DialogInterface.OnCancelListener() {
@Override
public void onCancel(DialogInterface dialog) {
// do something
}
});
loadingDialog.setCancelable(false);
}
@RequiresApi(api = Build.VERSION_CODES.M)
@Override
public void onReceivedError(WebView view, WebResourceRequest request,
WebResourceError error) {
if (isConnected()) {
final Snackbar snackBar = Snackbar.make(rootView, "onReceivedError : " + error.getDescription(), Snackbar.LENGTH_INDEFINITE);
snackBar.setAction("Reload", new View.OnClickListener() {
@Override
public void onClick(View view) {
webView.loadUrl("javascript:window.location.reload( true )");
}
});
snackBar.show();
} else {
final Snackbar snackBar = Snackbar.make(rootView, "No Internet Connection ", Snackbar.LENGTH_INDEFINITE);
snackBar.setAction("Enable Data", new View.OnClickListener() {
@Override
public void onClick(View view) {
startActivityForResult(new Intent(Settings.ACTION_WIRELESS_SETTINGS), 0);
webView.loadUrl("javascript:window.location.reload( true )");
snackBar.dismiss();
}
});
snackBar.show();
}
super.onReceivedError(view, request, error);
}
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
@Override
public void onReceivedHttpError(WebView view,
WebResourceRequest request, WebResourceResponse errorResponse) {
if (isConnected()) {
final Snackbar snackBar = Snackbar.make(rootView, "HttpError : " + errorResponse.getReasonPhrase(), Snackbar.LENGTH_INDEFINITE);
snackBar.setAction("Reload", new View.OnClickListener() {
@Override
public void onClick(View view) {
webView.loadUrl("javascript:window.location.reload( true )");
}
});
snackBar.show();
} else {
final Snackbar snackBar = Snackbar.make(rootView, "No Internet Connection ", Snackbar.LENGTH_INDEFINITE);
snackBar.setAction("Enable Data", new View.OnClickListener() {
@Override
public void onClick(View view) {
startActivityForResult(new Intent(Settings.ACTION_WIRELESS_SETTINGS), 0);
webView.loadUrl("javascript:window.location.reload( true )");
snackBar.dismiss();
}
});
snackBar.show();
}
super.onReceivedHttpError(view, request, errorResponse);
}
@Override
public void onPageFinished(WebView view, String url) {
if (webViewPreviousState == PAGE_STARTED) {
if (null != loadingDialog) {
loadingDialog.dismiss();
loadingDialog = null;
}
}
}
}
Check Connectivity Method
/**
* Check if there is any connectivity
*
* @return is Device Connected
*/
public boolean isConnected() {
ConnectivityManager cm = (ConnectivityManager)
this.getSystemService(Context.CONNECTIVITY_SERVICE);
if (null != cm) {
NetworkInfo info = cm.getActiveNetworkInfo();
return (info != null && info.isConnected());
}
return false;
}
webView.setWebViewClient(new WebViewClient() {
int errorCode = 0;
@SuppressWarnings("deprecation")
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
return handleUri(view, url);
}
@TargetApi(Build.VERSION_CODES.N)
@Override
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
return handleUri(view, request.getUrl().toString());
}
private boolean handleUri(WebView view, final String url) {
view.loadUrl(url);
return true;
}
@Override
public void onPageFinished(WebView view, String url) {
if(errorCode == 0) {
//CHECK IS PAGE I NEED AND DO STUFF
} else {
errorCode = 0;
//delay and try again
}
}
@SuppressWarnings("deprecation")
@Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
handleError(errorCode);
}
@TargetApi(Build.VERSION_CODES.N)
@Override
public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
handleError(error.getErrorCode());
}
private void handleError(int errorCode) {
this.errorCode = errorCode;
}
});
You can check device is connect to internet through data or wifi by following code
ConnectivityManager manager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo i = manager.getActiveNetworkInfo();
boolean hasConnect = (i!= null && i.isConnected() && i.isAvailable());
if(hasConnect)
{
// show the webview
}
else
{
// do what ever you need when when no internet connection
}
After user go to webview , then if the connect is lost you can capture that event from following code
webView.setWebViewClient(new Callback());
public class Callback extends WebViewClient{
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl){
Toast.makeText(getApplicationContext(), "Failed loading app!, No Internet Connection found.", Toast.LENGTH_SHORT).show();
}
}
following permissions need to give
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
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