Develop Reference

can webview start an activity onReceivedError?

I am trying to start an activity (Errorpage) when webview failed to load content.But there is no error during the build, but the app closes, while inernet is off. It was supposed to launh the Errorpage activity.
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.view.WindowManager;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ProgressBar;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import androidx.appcompat.app.AppCompatActivity;
public class smwebview extends AppCompatActivity {
private WebView webview;
private ProgressBar spinner;
String ShowOrHideWebViewInitialUse = "show";
private WebView mWebView; //added for back buton override
public boolean mShouldPause = false;
String fullurl;
private ProgressBar spinner;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_smwebview);
getIntent();
fullurl= getIntent().getStringExtra("full_url");
webview = (WebView) findViewById(R.id.webView_Latest);
webview.setWebViewClient(new CustomWebViewClient());
spinner = (ProgressBar)findViewById(R.id.progressBar2);
webview.getSettings().setJavaScriptEnabled(true);
webview.getSettings().setDomStorageEnabled(true);
webview.getSettings().setAppCacheEnabled(true);
webview.getSettings().setCacheMode(WebSettings.LOAD_DEFAULT);
webview.setOverScrollMode(WebView.OVER_SCROLL_NEVER);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);// keep screen on
webview.loadUrl(fullurl);
private class CustomWebViewClient extends WebViewClient {
#Override
public void onPageStarted(WebView webview, String url, Bitmap favicon) {
if (ShowOrHideWebViewInitialUse.equals("show")) {
webview.setVisibility(webview.INVISIBLE);
}
}
#Override
public void onLoadResource(WebView webview, String url) {
super.onLoadResource(webview, url);
if (url.contains("youtube.com")) mShouldPause = true;
}
public void onReceivedError(WebView webview, int errorCode, String description, String failingUrl) {
Intent intent7 = new Intent(smwebview.this,Errorpage.class);
startActivity(intent7);
}
#Override
public void onPageFinished(WebView view, String url) {
ShowOrHideWebViewInitialUse = "hide";
spinner.setVisibility(View.GONE);
view.setVisibility(webview.VISIBLE);
super.onPageFinished(view, url);
}
}
public class WebViewClient extends android.webkit.WebViewClient {
#Override
public void onPageStarted(WebView webview, String url, Bitmap favicon) {
if (ShowOrHideWebViewInitialUse.equals("show")) {
webview.setVisibility(webview.INVISIBLE);
}
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
#Override
public void onPageFinished(WebView view, String url) {
ShowOrHideWebViewInitialUse = "hide";
spinner.setVisibility(View.GONE);
view.setVisibility(webview.VISIBLE);
super.onPageFinished(view, url);
}
}
#Override
public void onResume()
{
super.onResume();
webview.onResume();
}
#Override
public void onPause() {
super.onPause();
if(mShouldPause){
webview.onPause();
}
mShouldPause = false;
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (keyCode) {
case KeyEvent.KEYCODE_BACK:
if (webview.canGoBack()) {
webview.goBack();
} else {
super.onBackPressed();
}
return true;
}
}
return super.onKeyDown(keyCode, event);
}
}
If anybody have any idea Please help me. Also please comment your suggestions on the code/logic. (I am very new to android programming)

Internet if off. Its different scenario you must add check internet connection before load.
Or onRwleceiveError is different case. When you load wrong url or utl you entered is not working

Making a News reading app in Android Studio (WebView). but when ever i click a video in a selected article it does not play

Is their something i'm doing wrong? Do i have to include some lib?
I've tried adding the Youtube Api but that didn't help.
Edit#1: This is the WebView code
On some instance the Audio Playback works but instead of video it's just a rotating circle animation trying to load the video.
package com.PAKGN.Mizzy;
import android.app.Activity;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.Toolbar;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
import android.webkit.WebSettings;
private WebView webView1;
private Toolbar toolbar;
private String title;
private String url;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_webview);
// this.getWindow().requestFeature(Window.FEATURE_PROGRESS);
WebView myWebView = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = myWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
title = getIntent().getExtras().getString("title");
url = getIntent().getExtras().getString("url");
getSupportActionBar().setTitle(title);
if (savedInstanceState != null) {
((WebView) findViewById(R.id.webView1)).restoreState(savedInstanceState);
} else {
webView1 = (WebView) findViewById(R.id.webView1);
webView1.getSettings().setJavaScriptEnabled(true);
webView1.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
final Activity activity = this;
webView1.setWebViewClient(new WebViewClient()
{
#Override
public boolean shouldOverrideUrlLoading(WebView view,
String url) {
// TODO Auto-generated method stub
view.loadUrl(url);
return true;
}
});
webView1.setWebChromeClient(new WebChromeClient() {
public void onProgressChanged(WebView view, int progress) {
// Activities and WebViews measure progress with different scales.
// The progress meter will automatically disappear when we reach 100%
activity.setProgress(progress * 1000);
}
});
webView1.setWebViewClient(new WebViewClient() {
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
Toast.makeText(activity, "Oh no! " + description, Toast.LENGTH_SHORT).show();
}
});
runOnUiThread(new Runnable() {
#Override
public void run() {
// Code for WebView goes here
webView1.loadUrl(url);
}
});
}
}
#Override
protected void onSaveInstanceState(Bundle outState ){
((WebView) findViewById(R.id.webView1)).saveState(outState);
}
#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) && webView1.canGoBack()) {
webView1.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 onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// Respond to the action bar's Up/Home button
case android.R.id.home:
NavUtils.navigateUpFromSameTask(this);
return true;
}
return super.onOptionsItemSelected(item);
}
.

You need to enable javaScript.WebView myWebView = (WebView) findViewById(R.id.webview);
WebSettings webSettings = myWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
EDIT:
You are setting the WebClient for webview twice.
`webView1.setWebViewClient(new WebViewClient()
{
#Override
public boolean shouldOverrideUrlLoading(WebView view,
String url) {
// TODO Auto-generated method stub
view.loadUrl(url);
return true;
}
});`
You aren't really doing anything here thats different from the original implementation and this code isn't even running because you replace the webview with another webclient so delete this.
` runOnUiThread(new Runnable() {
#Override
public void run() {
// Code for WebView goes here
webView1.loadUrl(url);
}
});
`
Delete this too, just type webview1.loadUrl(url) no need for a runOnUiThread.
` webView1.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
Delete this too, its this line that is causing your issue. `

progress dialog in webview,qr code scanner

package net.sourceforge.zbar.android.CameraTest;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.KeyEvent;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class WebViewActivity extends Activity {
private WebView webView;
#SuppressLint("SetJavaScriptEnabled")
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.webview);
String mUrl = getIntent().getStringExtra("mUrl");
webView = (WebView) findViewById(R.id.web_engine);
webView.setWebViewClient(new MyWebClient());
webView.getSettings().setJavaScriptEnabled(true);
webView.loadUrl(mUrl);
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(event.getAction() == KeyEvent.ACTION_DOWN){
switch(keyCode)
{
case KeyEvent.KEYCODE_BACK:
if(webView.canGoBack()){
webView.goBack();
}else{
finish();
}
return true;
}
}
return super.onKeyDown(keyCode, event);
}
}
class MyWebClient extends WebViewClient {
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
// TODO Auto-generated method stub
super.onPageStarted(view, url, favicon);
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
// TODO Auto-generated method stub
return false;
}
}
I tried putting a progress dialog in this code but the app stops. I put it in the webclient class but after i ran the app the progress dialog appeared but the app stops. I already deleted that part so you can see the working code. How can I do it?

You have to add a ProgressBar object in your layout, but hidden. Then, when a page starts loading, you show the progress bar:
ProgressBar progress = (ProgressBar) findViewById(R.id.progress);
progress.setVisibility(View.VISIBLE);
You can even override the progress change
#Override
public void onProgressChanged(WebView view, int percentage) {
ProgressBar progress = (ProgressBar) findViewById(R.id.progress);
progress.setProgress(percentage);
}
For this last method, you have to extend WebChromeClient.

backbutton on my android webview

I tried to add a back button to my android webview but i've got this error:
The method onBackPressed() of type new WebViewClient(){} must override or implement a supertype method
This is my Java file:
package sherdle.donald.duck.app;
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class WebPageLoader extends Activity
{
WebView webview;
final Activity activity = this;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
this.getWindow().requestFeature(Window.FEATURE_PROGRESS);
setContentView(R.layout.main);
WebView webView = (WebView) findViewById(R.id.webview);
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebChromeClient(new WebChromeClient() {
public void onProgressChanged(WebView view, int progress)
{
activity.setTitle("Loading...");
activity.setProgress(progress * 100);
if(progress == 100)
activity.setTitle(R.string.app_name);
}
});
webView.setWebViewClient(new WebViewClient() {
#Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl)
{
// Handle the error
}
#Override
public void onBackPressed() {
// do something on back.
return;
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url)
{
view.loadUrl(url);
return true;
}
});
webView.loadUrl("http://example.com");
}
}
Thanks for your help.

According to the doc, there is no onBackPressed method in the WebViewClient class. Did you want to Override it on your activity ?
try smthing like this:
package sherdle.donald.duck.app;
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class WebPageLoader extends Activity
{
WebView webView;
final Activity activity = this;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
this.getWindow().requestFeature(Window.FEATURE_PROGRESS);
setContentView(R.layout.main);
webView = (WebView) findViewById(R.id.webview);
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebChromeClient(new WebChromeClient() {
public void onProgressChanged(WebView view, int progress)
{
activity.setTitle("Loading...");
activity.setProgress(progress * 100);
if(progress == 100)
activity.setTitle(R.string.app_name);
}
});
webView.setWebViewClient(new WebViewClient() {
#Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl)
{
// Handle the error
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url)
{
view.loadUrl(url);
return true;
}
});
webView.loadUrl("http://example.com");
}
#Override
public void onBackPressed (){
if(webView.canGoBack()) webView.goBack();
else super.onBackPressed();
}
}

You have to override the onkeyDown() method in your Activity.
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if(event.getAction() == KeyEvent.ACTION_DOWN){
switch(keyCode)
{
case KeyEvent.KEYCODE_BACK:
if(mWebView.canGoBack() == true){
mWebView.goBack();
}else{
finish();
}
return true;
}
}
return super.onKeyDown(keyCode, event);
}

Try this
package sherdle.donald.duck.app;
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class WebPageLoader extends Activity
{
WebView webview;
final Activity activity = this;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
this.getWindow().requestFeature(Window.FEATURE_PROGRESS);
setContentView(R.layout.main);
webView = (WebView) findViewById(R.id.webview);
webView.getSettings().setJavaScriptEnabled(true);
webView.loadUrl("http://example.com");
webView.setWebChromeClient(new WebChromeClient() {
public void onProgressChanged(WebView view, int progress)
{
activity.setTitle("Loading...");
activity.setProgress(progress * 100);
if(progress == 100)
activity.setTitle(R.string.app_name);
}
});
webView.setWebViewClient(new WebViewClient() {
#Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl)
{
// Handle the error
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url)
{
view.loadUrl(url);
return true;
}
});
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
switch (keyCode) {
case KeyEvent.KEYCODE_BACK:
if(mWebView.canGoBack() == true)
webview.goBack();
else finish();
break;
default:
break;
}
return super.onKeyDown(keyCode, event);
}
}
And this method should be override in Activty.

WebView webView = (WebView) findViewById(R.id.webview);
Change it to:
webView = (WebView) findViewById(R.id.webview);
and then use the second answer - works like a charm!

How to add back button to Android Web App

I'm trying to sort out a web app but cannot find a possible way to include the use of a back button via the phone's soft keys. How can I go about doing this?
i.e I want to use the back button on my phone to return to the previous viewed web page.
Thank you
Jordan
package com.wear2gym;
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
public class Wear2gym extends Activity
{
final Activity activity = this;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
this.getWindow().requestFeature(Window.FEATURE_PROGRESS);
setContentView(R.layout.main);
WebView webView = (WebView) findViewById(R.id.WebView);
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebChromeClient(new WebChromeClient() {
public void onProgressChanged(WebView view, int progress)
{
activity.setTitle("Pumping some iron...");
activity.setProgress(progress * 100);
if(progress == 100)
activity.setTitle(R.string.app_name);
}
});
webView.setWebViewClient(new WebViewClient() {
#Override
public void onReceivedError(WebView view, int errorCode, String description, String failingUrl)
{
Toast.makeText(activity, "Sorry but there is no internet connection! " , Toast.LENGTH_LONG).show();
view.loadUrl("file:///android_asset/nointernet.html");
// Handle the error
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url)
{
view.loadUrl(url);
return true;
}
});
webView.loadUrl("http://wear2gym.co.uk");
webView.canGoBack();
}
}

I wouldn't recommand onBackPressed() as thatś only available since API level 5
You will find great info here: http://developer.android.com/guide/webapps/webview.html
#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);
}

override the onBackPressed() method:
#Override
public void onBackPressed() {
if(mWebView.canGoBack()) {
mWebView.goBack();
}
else {
super.onBackPressed();
}
}
This will go back on the WebView until it can't go back, in which case it will exit the Activity