Android - WebView click Error calling method on NPObject

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Android - WebView click Error calling method on NPObject

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I'm trying to try to perform an action in the Android application when I click on an html element in the webview. When clicking on the element, the event is activated but the following error occurs in alert(err) of javascript inside try catch:

Error: Error calling method on NPObject.

Android log error:

 android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
     at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:6433)
     at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:878)
     at android.view.View.requestLayout(View.java:16683)
     at android.view.View.requestLayout(View.java:16683)
     at android.view.View.requestLayout(View.java:16683)
     at android.view.View.requestLayout(View.java:16683)
     at android.view.View.requestLayout(View.java:16683)
     at android.view.View.requestLayout(View.java:16683)
     at android.widget.RelativeLayout.requestLayout(RelativeLayout.java:352)
     at android.view.View.requestLayout(View.java:16683)
     at android.view.View.requestLayout(View.java:16683)
     at android.widget.RelativeLayout.requestLayout(RelativeLayout.java:352)
     at android.view.View.requestLayout(View.java:16683)
     at android.view.View.setFlags(View.java:9055)
     at android.view.View.setVisibility(View.java:6127)
     at com.example.base.googlcloudvideointelligence.MainActivity$WebAppInterface.showMenu(MainActivity.java:131)
     at com.android.org.chromium.base.SystemMessageHandler.nativeDoRunLoopOnce(Native Method)
     at com.android.org.chromium.base.SystemMessageHandler.handleMessage(SystemMessageHandler.java:24)
     at android.os.Handler.dispatchMessage(Handler.java:102)
     at android.os.Looper.loop(Looper.java:136)
     at android.os.HandlerThread.run(HandlerThread.java:61)

I suppose it's a scope problem. Here is my code:

public class MainActivity extends AppCompatActivity {
    Button btnFinalizar;
    WebView webView;
    WebSettings webSettings;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        btnFinalizar = (Button) findViewById(R.id.btnFinalizar);
        webView = (WebView) findViewById(R.id.webView);

        webSettings = webView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setDomStorageEnabled(true);

        webView.addJavascriptInterface(new WebAppInterface(this), "Android");
        webSettings.setAllowUniversalAccessFromFileURLs(true);

        webView.setWebChromeClient(new WebChromeClient() {
            @Override
            public boolean onConsoleMessage(ConsoleMessage consoleMessage) {
                Log.d("MeuApp", consoleMessage.message() + " -- From line "
                    + consoleMessage.lineNumber() + " of "
                    + consoleMessage.sourceId());
                return super.onConsoleMessage(consoleMessage);
            }


        });
        webView.setWebViewClient(new WebViewClient ());
        webView.loadUrl("http://urlexemplo.com.br");
    }

    public class WebAppInterface {

        Context mContext;

        WebAppInterface(Context c) {
            mContext = c;
        }

        @JavascriptInterface
        public void showMenu() {
            Toast.makeText(mContext, "AQUI FUNCIONA", Toast.LENGTH_SHORT).show();
            btnFinalizar.setVisibility(View.VISIBLE);
        }
    }
}

The showMenu() function runs on Android. I put a Toast to test and it is called, LESS btnFinalizar.setVisibility(View.VISIBLE); And here is my JavaScript that is working.

$("body").on('click', '.step-question .go-step', function(event) {
    event.preventDefault();
    /* Act on the event */

    try {
        window.Android.showMenu();
        alert('foi');
    } catch(err) { alert(err); }
});

What do I need to do to btnFinalizar.setVisibility(View.VISIBLE); work? PS: this command is functional outside of this class WebAppInterface

java android webview

asked by anonymous 18.04.2017 / 17:23

1 answer

Fill null field with first non-null first field Dynamically displaying content from another page

score 0 · Answer 1

I have. The webview creates a thread that loses access to the MainActivity parent class. So I had to overwrite the parent thread and call it. I just modified the code for the showMenu()

    @JavascriptInterface
    public void showMenu() {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                btnFinalizar.setVisibility(View.VISIBLE);
            }
        });
    }