Develop Reference

Want to implement back button functionality to a basic Android WebView application

I created a basic WebView app, want to add a back button function which would take the user to the previous page rather than exiting the app. Have attached the MainActivity.java code with this question below.I am a newbie to stack overflow and android development.
package example.com;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class MainActivity extends AppCompatActivity {
private WebView webview;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
webview =(WebView)findViewById(R.id.webView);
webview.setWebViewClient(new WebViewClient());
webview.getSettings().setJavaScriptEnabled(true);
webview.getSettings().setDomStorageEnabled(true);
webview.setOverScrollMode(WebView.OVER_SCROLL_NEVER);
webview.loadUrl("https://www.example.com");
}
}

#Override onBackPress() inside your mainActivity and add your navigation logic inside it. Here is working snipped
public class MainActivity extends AppCompatActivity {
private WebView webView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
webView = findViewById(R.id.webView);
webView = new WebView(MainActivity.this);
webView.loadUrl(...);
}
#Override
public void onBackPressed() {
if (webView != null && webView.canGoBack()) {
webView.goBack();
}else{
//Your App exit logic here
}
}
}
I hope this will meet your requirements.

Try this, hope this helps
#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();
}
return true;
}
}
return super.onKeyDown(keyCode, event);
}

open all website URL within App and external URLs using external browser in WebView?

I have this code, but not because it works, it keeps opening in webview and what I want is that the links do not belong to my website open in your default browser. Any idea? thanks
here is my MainActivity.java
package club.moviestreet.www.webviewapp;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class MainActivity extends AppCompatActivity {
private WebView mywebView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mywebView = (WebView) findViewById(R.id.webview);
WebSettings webSettings= mywebView.getSettings();
webSettings.setJavaScriptEnabled(true);
mywebView.loadUrl("http://moviestreet.club/");
// Line of Code for opening links in app
mywebView.setWebViewClient(new WebViewClient());
}
//Code For Back Button
#Override
public void onBackPressed() {
if(mywebView.canGoBack())
{
mywebView.goBack();
}
else
{
super.onBackPressed();
}
}
}

What you need is shouldOverrideUrlLoading of WebViewClient
Give the host application a chance to take over the control when a new url is about to be loaded in the current WebView. If WebViewClient is not provided, by default WebView will ask Activity Manager to choose the proper handler for the url. If WebViewClient is provided, return true means the host application handles the url, while return false means the current WebView handles the url.
Replace
mywebView.setWebViewClient(new WebViewClient());
With this:
mywebView.setWebViewClient(new WebViewClient() {
#SuppressWarnings("deprecation")
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (!url.startsWith("http://moviestreet.club/")) {
Intent i = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
startActivity(i);
return true;
}
return false;
}
});

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

How can I open my links in one webview in android?

I have a ListView of some websites. What I want is that when a user clicks on listview, those websites are shown in same webview instead of starting a new activity. How can I do that?
Here is my webview java:
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.view.KeyEvent;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class Aftonbladet extends Activity {
private WebView myWebView;
/** Called when the activity is first created. */
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) { // Enables browsing to previous pages with the hardware back button
myWebView.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.webview);
final ProgressDialog pd = ProgressDialog.show(this, "", "Loading...",
true);
myWebView = (WebView) findViewById(R.id.mywebview);
myWebView.getSettings().setJavaScriptEnabled(true);
myWebView.getSettings().setSupportZoom(true);
myWebView.getSettings().setBuiltInZoomControls(true);
myWebView.setWebViewClient(new WebViewClient() {
#Override
public void onPageFinished(WebView view, String url) {
if(pd.isShowing() && pd!=null)
{
pd.dismiss();
}
}
});
myWebView.loadUrl("http://www.google.com");
}
}

For website loading in webview, you can use like this:
webview = (WebView) findViewById(R.id.webview);
webview.getSettings().setJavaScriptEnabled(true);
webview.loadUrl("http://www.linkedin.com");
webview.getSettings().setPluginState(PluginState.ON);
webview.getSettings().setAllowFileAccess(true);
webview.setWebViewClient(new MyWebViewClient());
and your MyWebViewClient class is:
private class MyWebViewClient extends WebViewClient {
#Override
//show the web page in webview but not in web browser
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl (url);
return true;
}
}
Hope it helps

EDIT: It looks like what you want is to pass the url from one activity to another. To achieve that you can use either SharedPreferences or putExtras to the intent like this in your ListView Activity:
Intent myIntent = new Intent(this, Aftonbladet.class);
Bundle b = new Bundle();
b.putString("url", theURL);
myIntent.putExtra(b);
startActivity(myIntent);
and then on your WebView Activity you can get that value:
Bundle b = this.getIntent().getExtras();
String url = b.getString("url");

Need assistance using phones back button to go back in Webview

This is my code:
package com.testappmobile;
import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Window;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class testappmobileActivity extends Activity
{
final Activity activity = this;
private WebView webview;
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// Check if the key event was the BACK key 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 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 boolean shouldOverrideUrlLoading(WebView view, String url)
{
view.loadUrl(url);
return true;
}
});
webView.loadUrl("http://developer.android.com/index.html");
}
}
Now im having trouble getting the hardware back button to work. The app loads fine as does page and everything else but as soon as i hit the phones back button it crashes then forces close.
I've searched google for the last 3 hours and have only found vague answers with very little info or broken links. Google's instructions sucked also as i am a beginner and they presume you know a certain amount.
Where should I place the code if it is in the wrong place?
Are there errors?
Cheers!

You have created a webView reference at class level but never initialized it thats why NullPointerException. I've made a small change in the onCreate method in your code, analyze it and make the necessary change(s);
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.getWindow().requestFeature(Window.FEATURE_PROGRESS);
setContentView(R.layout.main);
// Don't create another webview reference here,
// just use the one you declared at class level.
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);
}
});
// rest of code same
// ...
// ...
// ...
}
Hope you got it. :)

You have two different references to WebView. First local in onCreate, that is lost. Second webview member that you use in onKeyDown, but that is null all the time.