How to listen for a WebView finishing loading a URL

Question

I have a WebView that is loading a page from the Internet  I want to show a ProgressBar until the loading is complete    How do I listen for the completion of page loading of a WebView

User · Answer

You can trace the Progress Staus by the getProgress method in webview class.

Initialize the progress status

private int mProgressStatus = 0;

then the AsyncTask for loading like this:

private class Task_News_ArticleView extends AsyncTask<Void, Void, Void> {
    private final ProgressDialog dialog = new ProgressDialog(
            your_class.this);

    // can use UI thread here
    protected void onPreExecute() {
        this.dialog.setMessage("Loading...");
        this.dialog.setCancelable(false);
        this.dialog.show();
    }

    @Override
    protected Void doInBackground(Void... params) {
        try {
            while (mProgressStatus < 100) {
                mProgressStatus = webview.getProgress();

            }
        } catch (Exception e) {

        }
        return null;

    }

    protected void onPostExecute(Void result) {
        if (this.dialog.isShowing()) {
            this.dialog.dismiss();
        }
    }
}

User · Answer

ian this is not 100  accurate  If you have several iframes in a page you will have multiple onPageFinished  and onPageStarted   And if you have several redirects it may also fail  This approach solves  almost  all the problems   boolean loadingFinished   true  boolean redirect   false   mWebView setWebViewClient new WebViewClient           Override     public boolean shouldOverrideUrlLoading WebView view  String urlNewString            if   loadingFinished                redirect   true                     loadingFinished   false          webView loadUrl urlNewString           return true              Override     public void onPageStarted WebView view  String url            loadingFinished   false            SHOW LOADING IF IT ISNT ALREADY VISIBLE               Override     public void onPageFinished WebView view  String url            if   redirect               loadingFinished   true                HIDE LOADING IT HAS FINISHED           else               redirect   false                         UPDATE   According to the documentation  onPageStarted will NOT be called when the contents of an embedded frame changes  i e  clicking a link whose target is an iframe   I found a specific case like that on Twitter where only a pageFinished was called and messed the logic a bit  To solve that I added a scheduled task to remove loading after X seconds  This is not needed in all the other cases   UPDATE 2   Now with current Android WebView implementation   boolean loadingFinished   true  boolean redirect   false       mWebView setWebViewClient new WebViewClient               Override         public boolean shouldOverrideUrlLoading                  WebView view  WebResourceRequest request                if   loadingFinished                   redirect   true                             loadingFinished   false              webView loadUrl request getUrl   toString                 return true                      Override         public void onPageStarted                  WebView view  String url  Bitmap favicon                super onPageStarted view  url  favicon               loadingFinished   false                SHOW LOADING IF IT ISNT ALREADY VISIBLE                       Override         public void onPageFinished WebView view  String url                if   redirect                   loadingFinished   true                    HIDE LOADING IT HAS FINISHED               else                   redirect   false

User · Answer

for Kotlin users   webView webViewClient   object   WebViewClient                 override fun onPageFinished view  WebView   url  String                        do your logic                           there are a lot of methods that you can override though

User · Answer

Loading url with SwipeRefreshLayout and ProgressBar  UrlPageActivity java       WebView webView      SwipeRefreshLayout  swipe procesbar       Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout activity url page             String url    http   stackoverflow com              swipe procesbar    SwipeRefreshLayout findViewById R id url path swipe procesbar             swipe procesbar post new Runnable                                        Override                                   public void run                                            swipe procesbar setRefreshing true                                                                                           webView    WebView  findViewById R id url page web view           webView getSettings   setJavaScriptEnabled true            webView setWebViewClient new WebViewClient                 public void onPageFinished WebView view  String url                     swipe procesbar setRefreshing false                    swipe procesbar setEnabled false                                     webView loadUrl url           activity url page xml    lt android support v4 widget SwipeRefreshLayout xmlns android  http   schemas android com apk res android      android id    id url path swipe procesbar      android layout width  match parent      android layout height  wrap content  gt           lt RelativeLayout xmlns android  http   schemas android com apk res android              xmlns tools  http   schemas android com tools  android layout width  match parent              android layout height  match parent              tools context  com test test1 UrlPageActivity  gt                 lt WebView                 android layout width  fill parent                  android layout height  fill parent                  android id    id url page web view    gt           lt  RelativeLayout gt    lt  android support v4 widget SwipeRefreshLayout gt

User · Answer

If you want show a progress bar you need to listen for a progress change event  not just for the completion of page   mWebView setWebChromeClient new WebChromeClient                  Override             public void onProgressChanged WebView view  int newProgress                       change your progress bar                               BTW if you want display just an Indeterminate ProgressBar overriding the method onPageFinished is enough

User · Answer

The renderer will not finish rendering when the OnPageFinshed method is called or the progress reaches 100  so both methods don t guarantee you that the view was completely rendered   But you can figure out from OnLoadResource method what has been already rendered and what is still rendering  And this method gets called several times            Override         public void onLoadResource WebView view  String url                super onLoadResource view  url                 Log and see all the urls and know exactly what is being rendered and visible  If you wanna know when the entire page is completely rendered  find the last url from log and check it with if clause and implement your logic there              if  url contains  assets loginpage img ui forms                          loginpage is rendered and visible now                    your logic here

User · Answer

Just to show progress bar   onPageStarted  and  onPageFinished  methods are enough  but if you want to have an  is loading  flag  along with page redirects        this methods may executed with non-sequencing  like  onPageStarted   onPageStarted   onPageFinished   onPageFinished  queue   But with my short test  test it yourself     onProgressChanged  method values queue is  0-100   0-100   0-100         private boolean is loading   false   webView setWebChromeClient new MyWebChromeClient context     private final class MyWebChromeClient extends WebChromeClient       Override     public void onProgressChanged WebView view  int newProgress            if  newProgress    0               is loading   true            else if  newProgress    100               is loading   false                    super onProgressChanged view  newProgress             Also set  is loading   false  on activity close  if it is a static variable because activity can be finished before page finish

User · Answer

Here s a novel method for detected when a URL has loaded by utilising Android s capability for JavaScript hooks  Using this pattern  we exploit JavaScript s knowledge of the document s state to generate a native method call within the Android runtime  These JavaScript-accessible calls can be made using the  JavaScriptInterface annotation   This implementation requires that we call setJavaScriptEnabled true  on the WebView s settings  so it might not be suitable depending on your application s requirements  e g  security concerns    src io github cawfree webviewcallback MainActivity java  Jelly Bean  API Level 16   package io github cawfree webviewcallback           Created by Alex Thomas   Cawfree   30 03 2017        import android net http SslError  import android support v7 app AppCompatActivity  import android os Bundle  import android webkit JavascriptInterface  import android webkit SslErrorHandler  import android webkit WebView  import android webkit WebViewClient  import android widget Toast       An Activity demonstrating how to introduce a callback mechanism into Android s WebView     public class MainActivity extends AppCompatActivity           Static Declarations         private static final String HOOK JS                Android       private static final String URL TEST               http   www zonal co uk        private static final String URL PREPARE WEBVIEW               Member Variables         private WebView mWebView   null           Create the Activity          Override protected final void onCreate final Bundle pSavedInstanceState               Initialize the parent definition          super onCreate pSavedInstanceState              Set the Content View          this setContentView R layout activity main              Fetch the WebView          this mWebView    WebView this findViewById R id webView              Enable JavaScript          this getWebView   getSettings   setJavaScriptEnabled true              Define the custom WebClient   Here I m just suppressing security errors  since older Android devices struggle with TLS           this getWebView   setWebViewClient new WebViewClient      Override     public final void onReceivedSslError final WebView pWebView  final SslErrorHandler pSslErrorHandler  final SslError pSslError    pSslErrorHandler proceed                     Define the WebView JavaScript hook          this getWebView   addJavascriptInterface this  MainActivity HOOK JS              Make this initial call to prepare JavaScript execution          this getWebView   loadUrl MainActivity URL PREPARE WEBVIEW                  When the Activity is Resumed          Override protected final void onPostResume                Handle as usual          super onPostResume               Load the URL as usual          this getWebView   loadUrl MainActivity URL TEST              Use JavaScript to embed a hook to Android s MainActivity   The onExportPageLoaded   function implements the callback  whilst we add some tests for the state of the WebPage so as to infer when to export the event           this getWebView   loadUrl  javascript      function onExportPageLoaded         MainActivity HOOK JS     onPageLoaded          if document readyState      complete     onExportPageLoaded      else   window addEventListener  onload   function      onExportPageLoaded       false                       Javascript-accessible callback for declaring when a page has loaded          JavascriptInterface  SuppressWarnings  unused   public final void onPageLoaded                Display the Message          Toast makeText this   Page has loaded    Toast LENGTH SHORT  show                  Getters         public final WebView getWebView             return this mWebView             res layout activity main xml   lt  xml version  1 0  encoding  utf-8   gt   lt WebView     xmlns android  http   schemas android com apk res android      android id    id webView      android layout width  wrap content      android layout height  wrap content    gt    Essentially  we re appending an additional JavaScript function that is used to test the state of the document  If it s loaded  we launch a custom onPageLoaded   event in Android s MainActivity  otherwise  we register an event listener that updates Android once the page is ready  using window addEventListener  onload           Since we re appending this script after the call to this getWebView   loadURL     has been made  it s probable that we don t need to  listen  for the events at all  since we only get a chance to append the JavaScript hook by making a successive call to loadURL  once the page has already been loaded

User · Answer

Here s a method which allows you to register a Runnable to be executed once a particular web address has finished loading  We associate each Runnable with a corresponding URL String in a Map  and we use the WebView s getOriginalUrl   method to choose the appropriate callback   package io github cawfree webviewcallback           Created by Alex Thomas   Cawfree   30 03 2017        import android net http SslError  import android os Bundle  import android support v7 app AppCompatActivity  import android webkit SslErrorHandler  import android webkit WebView  import android webkit WebViewClient   import java util HashMap  import java util Map       An Activity demonstrating how to introduce a callback mechanism into Android s WebView     public class MainActivity extends AppCompatActivity           Member Variables         private WebView               mWebView      private Map lt String  Runnable gt  mCallbackMap           Create the Activity          Override protected final void onCreate final Bundle pSavedInstanceState               Initialize the parent definition          super onCreate pSavedInstanceState              Set the Content View          this setContentView R layout activity main              Fetch the WebView          this mWebView        WebView this findViewById R id webView           this mCallbackMap   new HashMap lt  gt                Define the custom WebClient   Here I m just suppressing security errors  since older Android devices struggle with TLS           this getWebView   setWebViewClient new WebViewClient                     Handle when a request has been launched                  Override public final void onPageFinished final WebView pWebView  final String pUrl                       Determine whether we re allowed to process the Runnable  if the page hadn t been redirected  or if we ve finished redirection                  if pUrl equals pWebView getOriginalUrl                              Fetch the Runnable for the OriginalUrl                      final Runnable lRunnable   getCallbackMap   get pWebView getOriginalUrl                            Is it valid                      if lRunnable    null    lRunnable run                                           Handle as usual                  super onPageFinished pWebView  pUrl                                 Ensure we handle SSL state properly                  Override public final void onReceivedSslError final WebView pWebView  final SslErrorHandler pSslErrorHandler  final SslError pSslError    pSslErrorHandler proceed                             Assert that we wish to visit Zonal s website          this getWebView   loadUrl  http   www zonal co uk                Align a Callback for Zonal  this will be serviced once the page has loaded          this getCallbackMap   put  http   www zonal co uk    new Runnable          Override public void run        Do something                         Getters         public final WebView getWebView             return this mWebView             private final Map lt String  Runnable gt  getCallbackMap             return this mCallbackMap

User · Answer

Use setWebViewClient   and override onPageFinished

User · Answer

I am pretty partial to  NeTeInStEiN  and  polen  solution but would have implemented it with a counter instead of multiple booleans or state watchers  just another flavor but I thought might share     It does have a JS nuance about it but I feel the logic is a little easier to understand   private void setupWebViewClient         webView setWebViewClient new WebViewClient             private int running   0     Could be public if you want a timer to check            Override         public boolean shouldOverrideUrlLoading WebView webView  String urlNewString                running                webView loadUrl urlNewString               return true                      Override         public void onPageStarted WebView view  String url  Bitmap favicon                running   Math max running  1      First request move it to 1                      Override         public void onPageFinished WebView view  String url                if --running    0       just  running--   if you add a timer                     TODO  finished    if you want to fire a method

User · Answer

I found one elegant solution as well  have not tested it rigorously though   public void onPageFinished WebView view  String url                super onPageFinished view  url               if  m webView getProgress      100                    progressBar setVisibility View GONE                   m webView setVisibility View VISIBLE

User · Answer

Extend WebViewClient and call onPageFinished   as follows   mWebView setWebViewClient new WebViewClient         public void onPageFinished WebView view  String url               do your stuff here

User · Answer

Use this it should help  var currentUrl    google com  var partOfUrl   currentUrl substring 0  currentUrl length-2   webView setWebViewClient object  WebViewClient      override fun onLoadResource WebView view  String url           call loadUrl   method  here          also check if url contains partOfUrl  if not load it differently       if url contains partOfUrl  true                it should work if you reach inside this if scope         else if   currentUrl startWith  w   true               webView loadurl  www  currentUrl           else if   currentUrl startWith  h   true               webView loadurl  https    currentUrl           else              override fun onReceivedSslError view  WebView   handler  SslErrorHandler   error  SslError           you can call again loadUrl from here too if there is any error        You should also override other override method for error such as onReceiveError to see how all these methods are called one after another and how they behave while debugging with break point

User · Answer

I have simplified NeTeInStEiN s code to be like this   mWebView setWebViewClient new WebViewClient             private int       webViewPreviousState          private final int PAGE STARTED      0x1          private final int PAGE REDIRECTED   0x2            Override         public boolean shouldOverrideUrlLoading WebView view  String urlNewString                webViewPreviousState   PAGE REDIRECTED              mWebView loadUrl urlNewString               return true                      Override         public void onPageStarted WebView view  String url  Bitmap favicon                super onPageStarted view  url  favicon               webViewPreviousState   PAGE STARTED              if  dialog    null     dialog isShowing                    dialog   ProgressDialog show WebViewActivity this      getString R string loadingMessege   true  true                          new OnCancelListener                                   Override                             public void onCancel DialogInterface dialog                                       do something                                                                               Override         public void onPageFinished WebView view  String url                 if  webViewPreviousState    PAGE STARTED                    dialog dismiss                    dialog   null                                  It is easy to understand  OnPageFinished if the previous callback is on onPageStarted  so the page is completely loaded

User · Answer

this will been called before he start loading the page  and get the same parameters as onFinished     Override public void onPageCommitVisible WebView view  String url       super onPageCommitVisible view  url

User · Answer

thanks for the answers  It helped me  but I had to improve it a bit for my needs  I had several pagestarts and finishes so I added a timer which checks if atfer the pagefinish is started a new pagestart  Okay  bad explanation  See the code     myWebView setWebViewClient new WebViewClient             boolean loadingFinished   true          boolean redirect   false           long last page start          long now              Load the url         public boolean shouldOverrideUrlLoading WebView view  String url                if   loadingFinished                    redirect   true                             loadingFinished   false              view loadUrl url               return false                      Override         public void onPageStarted WebView view  String url  Bitmap favicon                Log i  p   pagestart                loadingFinished   false              last page start   System nanoTime                show splash                          When finish loading page         public void onPageFinished WebView view  String url                Log i  p   pagefinish                if  redirect                   loadingFinished   true                              call remove splash in 500 miSec             if loadingFinished  amp  amp   redirect                   now   System nanoTime                    new android os Handler   postDelayed                          new Runnable                                 public void run                                     remove splash                                                                                     500                 else                  redirect   false                                  private void show splash                 if myWebView getVisibility      View VISIBLE                    myWebView setVisibility View GONE                   myWebView splash setVisibility View VISIBLE                                     if a new  page start  was fired dont remove splash screen         private void remove splash                 if  last page start  lt  now                    myWebView setVisibility View VISIBLE                   myWebView splash setVisibility View GONE

[android] How to listen for a WebView finishing loading a URL?

Examples related to android

Examples related to android-webview