Android WebView application example

This example can be used to open any Web SDK example page like in a bowser. To open the page, the URL should be set

MCU Client example opened in Android Webview in audio only conference mode looks as follows

Analyzing the code

To analyze the code take MainActivity.java and WebViewActivity.java classes of the webview-example application, which is available in build 1.1.0.26.

1. Launch WebViewActivity with URL entered

code

        button = (Button) findViewById(R.id.btnUrl);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                EditText et = (EditText) findViewById(R.id.textUrl);
                String url = et.getText().toString();
                if (url.isEmpty()) {
                    showDialog();
                } else {
                    Intent intent = new Intent(context, WebViewActivity.class);
                    intent.putExtra("url", url);
                    startActivity(intent);
                }
            }
        });

2. WebView settings configuration

code

        WebSettings settings = webView.getSettings();

        // Enable Javascript
        settings.setJavaScriptEnabled(true);

        // Use WideViewport and Zoom out if there is no viewport defined
        settings.setUseWideViewPort(true);
        settings.setLoadWithOverviewMode(true);

        // Enable pinch to zoom without the zoom buttons
        settings.setBuiltInZoomControls(true);

        // Allow use of Local Storage
        settings.setDomStorageEnabled(true);

        if(Build.VERSION.SDK_INT > Build.VERSION_CODES.HONEYCOMB) {
            // Hide the zoom controls for HONEYCOMB+
            settings.setDisplayZoomControls(false);
        }

        // Enable remote debugging via chrome://inspect
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            WebView.setWebContentsDebuggingEnabled(true);
        }

3. SSL certificates error handler configuration

code

        webView.setWebViewClient(new WebViewClient() {
            @Override
            public void onReceivedSslError(WebView view, final SslErrorHandler handler, SslError error) {

                final AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
                String message = "SSL Certificate error.";
                switch (error.getPrimaryError()) {
                    case SslError.SSL_UNTRUSTED:
                        message = "The certificate authority is not trusted";
                        break;
                    case SslError.SSL_EXPIRED:
                        message = "The certificate has expired";
                        break;
                    case SslError.SSL_NOTYETVALID:
                        message = "The certificate is not yet valid.";
                        break;
                    case SslError.SSL_IDMISMATCH:
                        message = "The cerificate ID is mismatch";
                        break;
                    case SslError.SSL_DATE_INVALID:
                        message = "The certificate date is invalid";
                        break;
                    case SslError.SSL_INVALID:
                        message = "The certificate is invalid";
                        break;
                }
                builder.setTitle("SSL Cerificate Error");
                builder.setMessage(message);
                builder.setPositiveButton("Continue", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        handler.proceed();
                    }
                });
                builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        handler.cancel();
                    }
                });
                Log.d(TAG, "onReceivedSslError " + message);
                final AlertDialog dialog = builder.create();
                dialog.show();
            }
        });
    }

4. Camera and microphone access requesting handler configuration

code

        webView.setWebChromeClient(new WebChromeClient() {
            @Override
            public void onPermissionRequest(final PermissionRequest request) {
                Log.d(TAG, "Request permissions: ");
                for (String res : request.getResources()) {
                    Log.d(TAG, res);
                }
                WebViewActivity.this.runOnUiThread(new Runnable() {
                    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
                    @Override
                    public void run() {
                        request.grant(request.getResources());
                    }
                });
            }

            @Override
            public void onPermissionRequestCanceled(PermissionRequest request) {
                Log.d(TAG, "onPermissionRequestCanceled");
            }

        });

5. Requesting camera and microphone access on activity start

code

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            int hasCameraPermission = checkSelfPermission(Manifest.permission.CAMERA);
            int hasRecordPermission = checkSelfPermission(Manifest.permission.RECORD_AUDIO);
            List<String> permissions = new ArrayList<>();
            if (hasCameraPermission != PackageManager.PERMISSION_GRANTED) {
                permissions.add(Manifest.permission.CAMERA);
            }
            if (hasRecordPermission != PackageManager.PERMISSION_GRANTED) {
                permissions.add(Manifest.permission.RECORD_AUDIO);
            }
            if (!permissions.isEmpty()) {
                requestPermissions(permissions.toArray(new String[permissions.size()]), 111);
            }
        }

6. URL opening

code

        webView.loadUrl(url);

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Android WebView application example

Analyzing the code