Develop Reference

WebView is exiting instead of going back

As an example, here used google as the website. When we click on any link and try to go back by hitting back button, it not calling goBack() but exiting. Back button in websites also not working.
public class MainActivity extends Activity {
public WebView mWebView;
#SuppressLint({"setJavaScriptEnabled"})
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mWebView = findViewById(R.id.WebView);
mWebView.clearCache(true);
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.setWebViewClient(new WebViewClient(){
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
});
mWebView.loadUrl("http://google.com");
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && mWebView.canGoBack()) {
mWebView.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
}
I'm using this code for months without any error, suddenly i got issue this few days back without any modifications. I also tried by calling goBack() in onBackPressed() with if statement but still shows same issue. Any help will be appreciated!!

because its chrome bug : https://bugs.chromium.org/p/chromium/issues/detail?id=794020
This has been fixed in M64. You can find a public release calendar here [1]. This is just an approximate schedule, but we aim to be close to the public schedule.
According to the schedule, M64 will go to stable January 23rd.
While M64 is currently in beta, we have not yet made a beta release with the fix. I do not have information for when such a beta release will go out (but it will be sooner than Jan 23rd).
[1] https://www.chromium.org/developers/calendar

Denied starting an intent without a user gesture Webview Android

Trying to redirect local html page in android webview using Javascript redirect, gets denied starting an intent in Logcat:
Testing on android 5.1.1
document.location = "index.html";
Denied starting an intent without a user gesture, URI:
file:///android_asset/index.html

I read the documentation in 1,000 attempts Android.developer and this was my solution
I do not know if you understand, I speak Spanish
webView.setWebViewClient(new WebViewClient() {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
return false;
}
});

This worked for me:
webView.setWebViewClient(new WebViewClient());

There are few issues here.
From newest androids, the WebView and Chrome Client is separated application which can be automatically updated without user intention.
From Chrome x >= 25 version, they changed how loading url is working in android application which is using webview component. https://developer.chrome.com/multidevice/android/intents Looks like they are blocking changing url without user gesture and launched from JavaScript timers
Solution here is to force user to activate URL change, for example on button click.
Also, you can override method mentioned above "shouldOverrideUrlLoading" in WebView client.

As alternate, i figured out was to add addJavascriptInterface each button click event fire action to JavascriptInterface
webView.addJavascriptInterface(new java2JSAgent(), "java2JSAgentVar"); //webView webview object
public class java2JSAgent
{
#JavascriptInterface
public String getContacts()
{
String jsonResponse = "{result:'redirected'}";
runOnUiThread(new Runnable() {
#Override
public void run() {
webView.loadUrl("file:///android_asset/index.html");
}
});
return jsonResponse;
}
}
might not be a good approach but atleast its working :-)
Thanks

Android Webview Video not working

I build a little Android library in Eclipse, that open new Activity, put inside it WebView and load into WebView html page with video. I'm using WebView like:
webView.setWebChromeClient(new WebChromeClient() {
#Override
public void onProgressChanged(WebView view, int newProgress) {
if (newProgress == 100) {
showContentOrLoadingIndicator(true);
}
}
});
webView.setWebViewClient(new WebViewClient() {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
view.loadUrl(url);
return true;
}
});
and
webView.loadUrl("http://www.example.com/mobile/player/" + VeediUtils.GAME_ID + "/" + ((JSONObject)VeediUtils.LEVELS.get(gameLevel - 1)).getInt("unique_id") + ".html" + ((debugState == 0) ? ("") : ("?debug=veedi")));
Next step, I had built new project, added my first project like a Android dependency, and all works ok, how it should. But when I gave my library to other developer (I don't have access to his code) and he added it like Android dependency to his project, he found an issue: there is he hear sound but instead of video he see black screen. So here the question: what it can be in his application, that break my video in WebView? Thanks.

The webview does not properly support HTML5 video.
See here for a library for proper video support.
If the video is in flash format, it will not work on android 4.4 and up. Otherwise, the user needs to have flashplayer installed, and you need to enable plugins in your webview.

WebView back history without redirects

I implemented android webview and onKeyDown method for back key. (It implements webview.goBack();)
My problem is exactly similar to the question in this post below (no answers there)
How to control the Android WebView history/back stack?
PROBLEM - When I press back button, webview selects the previous URL, but if that URL was actually a redirect, it goes into this vicious cycle/loop. If you look at chrome or stock browser it correctly handles the back without going back to the redirects.
How can this be solved?
Example: go to gap.com. Then select "My Gap Credit Card". This opens a redirect link and then the final page. Now when I click back, it never goes to Gap.com home page.
Any suggestions...
Additional Information: I did implement the shouldOverrideUrlLoading. If I remove that method, it seems to work fine but with this method it does not...

I've just tested this on jellybean and it seems to work.
Essentially, whenever a new URL is loaded in the WebView keep a copy of the url.
On the next URL request, double check they we aren't already on this page, if they are, then go back in the webview history another step.
Essentially this is relying on the url passed into the override step being the redirected url, rather than the final redirected url.
public class MainActivity extends Activity {
private Button mRefreshButton;
private WebView mWebView;
private String mCurrentUrl;
public void onCreate(Bundle savedInstance) {
super.onCreate(savedInstance);
setContentView(R.layout.main);
mWebView = (WebView) findViewById(R.id.webview);
mRefreshButton = (Button) findViewById(R.id.refresh);
mRefreshButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mWebView.reload();
}
});
WebSettings webSettings = mWebView.getSettings();
webSettings.setJavaScriptEnabled(true);
mWebView.setWebViewClient(new WebViewClient() {
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if(mCurrentUrl != null && url != null && url.equals(mCurrentUrl)) {
mWebView.goBack();
return true;
}
view.loadUrl(url);
mCurrentUrl = url;
return true;
}
});
mWebView.loadUrl("http://www.gap.com/");
}
#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;
}
break;
}
}
return super.onKeyDown(keyCode, event);
}
}

I hope this answer if anyone is still looking for it.I had been hunting to fix similar issues in my project and had tried multiple approaches like using
- WebView.HitTestResult
- Pushing the urls into the list
- onKeyDown and so on...
I think most of it would work if your app consists of just webview. But my project had a combination of native and webview and handles some native schema.
Essentially found that the key is how you override the method shouldOverrideUrlLoading. Since i wanted my app to handles some of the urls and the webview to handle some of the other ones especially the back handling.I used a flag for back presses something like ..
#Override
public void onBackPressed() {
if (mWebView.canGoBack()) {
mClient.setIsBackPressed(true);
//mClient is an instance of the MyWebviewClient
mWebView.goBack();
} else {
super.onBackPressed();
}
}
public class MyWebviewClient extends WebViewClient {
private Boolean isBackPressed = false;
public void setIsBackPressed(Boolean isBackPressed) {
this.isBackPressed = isBackPressed;
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (isBackPressed){
return false;
}
else {
// handle the url by implementing your logic
return true;
}
}
#Override
public void onPageFinished(WebView view, String url) {
isBackPressed = false;
super.onPageFinished(view, url);
}
}
In this way, whenever there is a redirect when you click back, then it return false and hence mocks the behaviour of the webview. At the same time, you make sure that the isBackPressed is set to false after the page finishes loading.
Hope this helps !!

Android : click link in a page within web view

I have included a web application within android web view , and there is a link in the webpage which opens some other site , when the link is clicked it works fine for the first click, however when clicked for the second time the website is not found ,
the code is :
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (url.contains("some site ")) {
Intent i = new
Intent(Intent.ACTION_VIEW, Uri.parse(url));
startActivity(i);
return true;
} else {
view.loadUrl(url);
return false;
}
}
#THelper and #mikegr, thanks for the reply,
Actually in my case i have a modal panel (JSF) in my web application which contains some buttons, on clicking the button i am opening some other site using javascript window.open() method which works fine in desktop browser, however, when i wrap this web application within android webview, everything works fine except when i first click this button i'm able to open the other site using the external browser, however on second click the webview tries to open this othersite within the webview instead of the external browser and i get website not found with the entire URL of the other site, this happens even when i logout and login again as the application launched is still running.
also in my case after sometime when the application is idle i get the black screen.
i surfed through the net and found simillar issue but that didn't help either , here is the link:
http://groups.google.com/group/android-for-beginners/browse_thread/thread/42431dd1ca4a9d98
handling links in a webview ,
any help and ideas would be very helpful for me, this is taking too long for me,
since i'm trying to display my web application in the web view, i have only one activity, which contains code like this
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState != null) {
// so that when launcher is clicked while the application is
// running , the application doesn't start from the begnining
} else {
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);
// Show the ProgressDialog on this thread
this.progressDialog = ProgressDialog.show(this, "Pleas Wait..", "Loading", true);
browser = (WebView) findViewById(R.id.webview);
browser.getSettings().setJavaScriptEnabled(true);
browser.setWebViewClient(new WebViewClient() {
public void onPageFinished(WebView view, String url) {
Log.i(TAG, "Finished loading URL: " +url);
if (progressDialog.isShowing()) {
progressDialog .dismiss();
}
}
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (url.contains("some site")) {
Intent i = new
Intent(Intent.ACTION_VIEW, Uri.parse(url));
startActivity(i);
return true;
} else {
view.loadUrl(url);
return true;
}
}
});
browser.loadUrl("mysite");
}
}

I had the experience that shouldOverrideUrlLoading() is not called in certain circumstances.
There are a few bugs about this topic on
http://code.google.com/p/android/issues
like bug number 15827, 9122, 812, 2887
As a workaround try to add the method onPageStarted() and check if you get this call. For me this method is always called even if shouldOverrideUrlLoading() was not called before.

onPageStarted worked for me. Had to tweak it a bit, as that method is called when the webview is first rendered too, and I wanted to only execute it on the onClick of the banner's javascript.
I was simulating a banner with a custom page, so when the ad.html was being rendered, I avoided the startActivity. Otherwise, it launches the new browser window.
WebViewClient newWebClient = new WebViewClient() {
#Override
public void onPageStarted(WebView view, String url, Bitmap favicon) {
// TODO Auto-generated method stub
super.onPageStarted(view, url, favicon);
if(!url.equals("http://xxxx.ad.html"))
view.getContext().startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
}
};

Try to append the System parameter pattern in url before you load that, something like.
String url = "http://xxxx.ad.html?t="+System.nanoTime();
and in your shouldOverrideUrlLoading() method remove the query part (in a very first line).
int idx;
if ((idx = url.indexOf("?")) != -1) {
url = url.substring(0, idx);
}