Android WebView example – tel, mailto, pdf and check internet connection

In this tutorial, we will develop an android application using Webview to load a web page. As a part of this tutorial, I will show you how you can detect telephone links “tel:”, email links “mailto”, load PDF files and also check for internet connection. I’ve also used a progress bar to determine whether web page is fully loaded.

Language: Java
Software: Android Studio 3.1
Testing
Classes: MainActivity.java, WebViewAndroid.java, activity_main.xml, activity_webview, strings.xml, AndroidManifest.xml

 

CODE:

 

MainActivity.java

 

package com.subzdesigns.webviewandroid;

/**
 * Created by Subz Designs.
 * Developed by Tansu Canturk
 */

import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.webkit.WebView;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    public MainActivity activity;

    boolean isConnected = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        this.activity = this;

        Button button1 = (Button) findViewById(R.id.btn1);

        button1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (isConnectingToInternet(getApplicationContext())) {
                    Intent intent = new Intent(MainActivity.this, WebViewAndroid.class);
                    intent.putExtra("Id", 1);
                    startActivity(intent);
                } else {
                    CheckCon();
                }
            }
        });
    }

    public  boolean isConnectingToInternet(Context context) {
        ConnectivityManager connectivity = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        if (connectivity != null) {
            NetworkInfo[] info = connectivity.getAllNetworkInfo();
            if (info != null)
                for (int i = 0; i < info.length; i++)
                    if (info[i].getState() == NetworkInfo.State.CONNECTED) {
                        return true;
                    }
        }
        return false;
    }

    public void CheckCon() {
        Toast.makeText(getApplicationContext(), "Check your network connection and try again.", Toast.LENGTH_SHORT).show();
    }

}


WebViewAndroid.Java

package com.subzdesigns.webviewandroid;

/**
 * Created by Subz Designs.
 * Developed by Tansu Canturk
 */

import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class WebViewAndroid extends AppCompatActivity
{
    Boolean isLoaded = false;
    int id;
    WebView webview;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_web);
        TextView titletextview = (TextView)findViewById(R.id.title);
        Button backbtn =(Button)findViewById(R.id.backBtn);

        Intent mIntent = getIntent();
        id = mIntent.getIntExtra("Id", 0);
        webview = (WebView) findViewById(R.id.webview);

        webview.getSettings().setJavaScriptEnabled(true);

        String website = getString(R.string.website);

        if(id==1)
        {
            setTitle("Webview");
            startWebView(website);
        }

        backbtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                AlertAction();

            }
        });
    }

    private void startWebView(String url) {

        webview.setWebViewClient(new WebViewClient() {
            ProgressDialog progressDialog;

            public boolean shouldOverrideUrlLoading(WebView view, String url) {

                if (url.contains("tel:")) {
                    Intent intent = new Intent(Intent.ACTION_DIAL, Uri.parse(url));
                    startActivity(intent);
                    return true;
                }

                else if (url.contains("mailto:")) {
                    view.getContext().startActivity(
                            new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
                    return true;

                }else if (url.contains(".pdf")) {
                    view.getContext().startActivity(
                            new Intent(Intent.ACTION_VIEW, Uri.parse("https://docs.google.com/gview?embedded=true&url=" + url)));
                    return true;

                }else {
                    view.loadUrl(url);
                    return true;
                }
            }

            public void onLoadResource (WebView view, String url) {
                if (isLoaded == false) {
                    isLoaded = true;
                    progressDialog = new ProgressDialog(WebViewAndroid.this);
                    progressDialog.setMessage("Loading...");
                    progressDialog.show();
                }
            }
            public void onPageFinished(WebView view, String url) {
                try{
                    progressDialog.dismiss();

                }catch(Exception exception){
                    exception.printStackTrace();
                }
            }

        });

        webview.getSettings().setJavaScriptEnabled(true);
        webview.loadUrl(url);

    }

    public void AlertAction () {
        AlertDialog alertDialog = new AlertDialog.Builder(WebViewAndroid.this).create();
        alertDialog.setMessage("Go back to main activity?");
        alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        finish();
                    }
                });
        alertDialog.setButton(AlertDialog.BUTTON1, "CANCEL",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });
        alertDialog.show();
    }
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (event.getAction() == KeyEvent.ACTION_DOWN) {
            switch (keyCode) {
                case KeyEvent.KEYCODE_BACK:
                    if (webview.canGoBack()) {
                        webview.goBack();
                    } else {
                        AlertAction();
                    }
                    return true;
            }

        }
        return super.onKeyDown(keyCode, event);
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
        <RelativeLayout
            xmlns:app="http://schemas.android.com/apk/res-auto"
            xmlns:tools="http://schemas.android.com/tools"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            tools:context="com.subzdesigns.webviewandroid.MainActivity">

            <Button
                android:id="@+id/btn1"
                android:layout_width="200dp"
                android:layout_height="60dp"
                android:layout_centerInParent="true"
                android:background="#d0272c"
                android:text="Click to load"
                android:textAllCaps="false"
                android:textColor="#fff"
                android:textSize="14sp" />

        </RelativeLayout>
</RelativeLayout>

activity_web.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.subzdesigns.webviewandroid.WebViewAndroid">

    <LinearLayout
        android:id="@+id/customToolbar"
        android:layout_width="match_parent"
        android:layout_height="45dp"
        android:gravity="center"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:background="#d0272c"
        android:orientation="horizontal">

        <Button
            android:id="@+id/backBtn"
            style="?android:attr/borderlessButtonStyle"
            android:layout_width="75dp"
            android:layout_height="35dp"
            android:background="#d0272c"
            android:text="Close"
            android:textAllCaps="false"
            android:textColor="#ffffff"
            android:textSize="15sp" />

    </LinearLayout>

    <WebView  xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@+id/customToolbar"
        />

</RelativeLayout>

 

strings.xml

<resources>
    <string name="app_name">Webview Android</string>
    <string name="website">https://subzdesigns.com/blog/android-webview-tel-mailto-pdf-check-internet-connection</string>
</resources>

 

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.subzdesigns.webviewandroid">

    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".WebViewAndroid">
        </activity>
    </application>

</manifest>

Screenshots:

 

 

 

 

 

 

 

 

Source code:

Click to download