What’s new in Android Support Library (Google I/O 2018)

Get to know AndroidX -- the new name and packaging for the Android Support Library -- the foundation for Android libraries in Jetpack, and learn about features available in the 1.0.0 release.

Load WebP from Internet and display in ListView

WebP is a modern image format that provides superior lossless and lossy compression for images on the web. Details refer Google Developers - WebP.

WebP is supported starting from Android 4.0+ (reference: Android Developers - Supported Media Formats). This example modify from the post "Async load image from internet to ListView" to load WebP from internet and display in ListView. Once item clicked, use "Simplest way to open browser using CustomTabsIntent.Builder".


To use CustomTabsIntent.Builder in our app, To use CustomTabsIntent.Builder, edit app/build.gradle to add dependencies of compile 'com.android.support:customtabs:23.0.0'.

The WebP images load from the page Google Developers - WebP Image Galleries.

MainActivity.java

package com.blogspot.android_er.androidimage;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.customtabs.CustomTabsIntent;
import android.support.v7.app.AppCompatActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Arrays;

public class MainActivity extends AppCompatActivity {

    final static String src[] = {
            "https://www.gstatic.com/webp/gallery3/1_webp_ll.webp",
            "https://www.gstatic.com/webp/gallery3/1_webp_a.webp",
            "https://www.gstatic.com/webp/gallery3/2_webp_ll.webp",
            "https://www.gstatic.com/webp/gallery3/2_webp_a.webp",
            "https://www.gstatic.com/webp/gallery3/3_webp_ll.webp",
            "https://www.gstatic.com/webp/gallery3/3_webp_a.webp",
            "https://www.gstatic.com/webp/gallery3/4_webp_ll.webp",
            "https://www.gstatic.com/webp/gallery3/4_webp_a.webp",
            "https://www.gstatic.com/webp/gallery3/5_webp_ll.webp",
            "https://www.gstatic.com/webp/gallery3/5_webp_a.webp" };

    ListView imageList;

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

        imageList = (ListView) findViewById(R.id.imagelist);
        ArrayList<String> srcList = new ArrayList<String>(Arrays.asList(src));
        imageList.setAdapter(new CustomListAdapter(this, srcList));

        imageList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                String imageSrc = src[position];
                Toast.makeText(MainActivity.this,
                        imageSrc,
                        Toast.LENGTH_LONG).show();

                Uri imageUri = Uri.parse(imageSrc);
                new CustomTabsIntent.Builder()
                        .build()
                        .launchUrl(MainActivity.this, imageUri);
            }
        });
    }

    // ----------------------------------------------------

    public class CustomListAdapter extends BaseAdapter {
        private ArrayList<String> listData;
        private LayoutInflater layoutInflater;

        public CustomListAdapter(Context context, ArrayList<String> listData) {
            this.listData = listData;
            layoutInflater = LayoutInflater.from(context);
        }

        @Override
        public int getCount() {
            return listData.size();
        }

        @Override
        public Object getItem(int position) {
            return listData.get(position);
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder holder;
            if (convertView == null) {
                convertView = layoutInflater.inflate(R.layout.row, null);
                holder = new ViewHolder();
                holder.icon = (ImageView)convertView.findViewById(R.id.icon);
                holder.text = (TextView)convertView.findViewById(R.id.text);
                convertView.setTag(holder);
            } else {
                holder = (ViewHolder) convertView.getTag();
            }

            holder.text.setText(
                    String.valueOf(position) + "\n" + src[position]);

            if (holder.icon != null) {
                new BitmapWorkerTask(holder.icon).execute(listData.get(position));
            }
            return convertView;
        }

        class ViewHolder {
            ImageView icon;
            TextView text;
        }
    }

    // ----------------------------------------------------
    // Load bitmap in AsyncTask
    // ref:
    // http://developer.android.com/training/displaying-bitmaps/process-bitmap.html
    class BitmapWorkerTask extends AsyncTask<String, Void, Bitmap> {
        private final WeakReference<ImageView> imageViewReference;
        private String imageUrl;

        public BitmapWorkerTask(ImageView imageView) {
            // Use a WeakReference to ensure the ImageView can be garbage
            // collected
            imageViewReference = new WeakReference<ImageView>(imageView);
        }

        // Decode image in background.
        @Override
        protected Bitmap doInBackground(String... params) {
            imageUrl = params[0];
            return LoadImage(imageUrl);
        }

        // Once complete, see if ImageView is still around and set bitmap.
        @Override
        protected void onPostExecute(Bitmap bitmap) {
            if (imageViewReference != null && bitmap != null) {
                final ImageView imageView = imageViewReference.get();
                if (imageView != null) {
                    imageView.setImageBitmap(bitmap);
                }
            }
        }

        private Bitmap LoadImage(String URL) {
            Bitmap bitmap = null;
            InputStream in = null;
            try {
                in = OpenHttpConnection(URL);
                bitmap = BitmapFactory.decodeStream(in);
                in.close();
            } catch (IOException e1) {
            }
            return bitmap;
        }

        private InputStream OpenHttpConnection(String strURL)
                throws IOException {
            InputStream inputStream = null;
            URL url = new URL(strURL);
            URLConnection conn = url.openConnection();

            try {
                HttpURLConnection httpConn = (HttpURLConnection) conn;
                httpConn.setRequestMethod("GET");
                httpConn.connect();

                if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                    inputStream = httpConn.getInputStream();
                }
            } catch (Exception ex) {
            }
            return inputStream;
        }
    }
}

layout/row.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

layout/activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:padding="16dp"
    android:orientation="vertical"
    tools:context="com.blogspot.android_er.androidimage.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold" />

    <ListView
        android:id="@+id/imagelist"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />
</LinearLayout>

uses-permission of "android.permission.INTERNET" is needed in AndroidManifest.xml

Download the files .

Parse blogspot JSON feed: detect item clicked to open in browser using CustomTabsIntent

Last post show a example to "Download and parse blogspot JSON feed". In this post, OnItemClickListener is added to the ListView; for user clicking to open the url in browser, using "Simplest way to open browser using CustomTabsIntent.Builder".


To use CustomTabsIntent.Builder() in your project, you have to edit appbuild.gradle to add dependencies of compile 'com.android.support:customtabs:23.0.0'.

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.4.0'
    compile 'com.android.support:customtabs:23.0.0'
}

Edit MainActivity.java to add OnItemClickListener.

package com.blogspot.android_er.androidparsejson;

import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.customtabs.CustomTabsIntent;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    Button btnLoadFeed;
    TextView textViewFeedUrl;
    ListView listViewFeed;

    List<FeedItem> listFeedItems;
    ListAdapter adapterFeed;

    String myFeed = "http://android-er.blogspot.com/feeds/posts/default?alt=json";
    //String myFeed = "http://arduino-er.blogspot.com/feeds/posts/default?alt=json";
    //String myFeed = "http://helloraspberrypi.blogspot.com/feeds/posts/default?alt=json";
    //String myFeed = "http://photo-er.blogspot.com/feeds/posts/default?alt=json";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btnLoadFeed = (Button)findViewById(R.id.loadfeed);
        textViewFeedUrl = (TextView)findViewById(R.id.feedurl);
        listViewFeed = (ListView)findViewById(R.id.listviewfeed);

        listFeedItems = new ArrayList<>();
        adapterFeed = new ArrayAdapter<FeedItem>(
                this, android.R.layout.simple_list_item_1, listFeedItems);
        listViewFeed.setAdapter(adapterFeed);
        listViewFeed.setOnItemClickListener(listViewFeedOnItemClickListener);

        btnLoadFeed.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                textViewFeedUrl.setText(myFeed);
                new JsonTask(listFeedItems, listViewFeed).execute(myFeed);
            }
        });
    }

    AdapterView.OnItemClickListener listViewFeedOnItemClickListener =
            new AdapterView.OnItemClickListener(){
                @Override
                public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                    FeedItem clickedFeedItem = (FeedItem) parent.getItemAtPosition(position);
                    String url = clickedFeedItem.getUrl();
                    Uri uri = Uri.parse(url);
                    new CustomTabsIntent.Builder()
                            .build()
                            .launchUrl(MainActivity.this, uri);
                }
            };

    /*
    JsonTask:
    AsyncTask to download and parse JSON Feed of blogspot in background
     */
    private class JsonTask extends AsyncTask<String, FeedItem, String> {

        List<FeedItem> jsonTaskList;
        ListView jsonTaskListView;

        public JsonTask(List<FeedItem> targetList, ListView targetListView) {
            super();
            jsonTaskList = targetList;
            jsonTaskListView = targetListView;
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            jsonTaskList.clear();
            jsonTaskListView.invalidateViews();
        }

        @Override
        protected String doInBackground(String... params) {

            try {
                final String queryResult = sendQuery(params[0]);
                parseQueryResult(queryResult);
            } catch (IOException e) {
                e.printStackTrace();

                final String eString = e.toString();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(MainActivity.this,
                                eString,
                                Toast.LENGTH_LONG).show();
                    }
                });

            } catch (JSONException e) {
                e.printStackTrace();

                final String eString = e.toString();
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(MainActivity.this,
                                eString,
                                Toast.LENGTH_LONG).show();
                    }
                });
            }
            return null;
        }

        @Override
        protected void onProgressUpdate(FeedItem... values) {
            FeedItem newItem = values[0];
            jsonTaskList.add(newItem);
            jsonTaskListView.invalidateViews();
        }

        private String sendQuery(String query) throws IOException {
            String queryReturn = "";
            URL queryURL = new URL(query);

            HttpURLConnection httpURLConnection = (HttpURLConnection)queryURL.openConnection();

            if(httpURLConnection.getResponseCode() == HttpURLConnection.HTTP_OK){
                InputStreamReader inputStreamReader =
                        new InputStreamReader(httpURLConnection.getInputStream());
                BufferedReader bufferedReader = new BufferedReader(
                        inputStreamReader, 8192);
                String line = null;
                while((line = bufferedReader.readLine()) != null){
                    queryReturn += line;
                }

                bufferedReader.close();
            }


            return queryReturn;
        }

        private void parseQueryResult(String json) throws JSONException {
            JSONObject jsonObject = new JSONObject(json);
            final JSONObject jsonObject_feed = jsonObject.getJSONObject("feed");
            final JSONArray jsonArray_entry = jsonObject_feed.getJSONArray("entry");

            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    if(jsonArray_entry == null){
                        Toast.makeText(MainActivity.this,
                                "jsonArray_entry == null",
                                Toast.LENGTH_LONG).show();
                    }else{
                        Toast.makeText(MainActivity.this,
                                String.valueOf(jsonArray_entry.length()),
                                Toast.LENGTH_LONG).show();
                        for(int i=0; i<jsonArray_entry.length(); i++){
                            try {
                                JSONObject thisEntry = (JSONObject) jsonArray_entry.get(i);
                                JSONObject thisEntryTitle = thisEntry.getJSONObject("title");
                                String thisEntryTitleString = thisEntryTitle.getString("$t");

                                JSONArray jsonArray_EntryLink = thisEntry.getJSONArray("link");

                                //search for the link element with rel="alternate"
                                //I assume it's one and only one element with rel="alternate",
                                //and its href hold the link to the page
                                for(int j=0; j<jsonArray_EntryLink.length(); j++){
                                    JSONObject thisLink = (JSONObject) jsonArray_EntryLink.get(j);
                                    try{
                                        String thisLinkRel = thisLink.getString("rel");
                                        if(thisLinkRel.equals("alternate")){
                                            try{
                                                String thisLinkHref = thisLink.getString("href");
                                                FeedItem thisElement = new FeedItem(
                                                        thisEntryTitleString.toString(),
                                                        thisLinkHref);
                                                publishProgress(thisElement);
                                                break;
                                            }catch (JSONException e){
                                                //no such mapping exists
                                            }
                                        }
                                    }catch (JSONException e){
                                        //no such mapping exists
                                    }

                                }

                            } catch (JSONException e) {
                                e.printStackTrace();
                            }

                        }
                    }

                }
            });
        }
    }
}

Other files, FeedItem.java, activity_main.xml and AndroidManifest.xml, refer last post.

Simplest way to open browser using CustomTabsIntent.Builder

This post show the simplest way to open browser using CustomTabsIntent.Builder.


To use CustomTabsIntent.Builder, edit app/build.gradle to add dependencies of compile 'com.android.support:customtabs:23.0.0'.

MainActivity.java

package com.blogspot.android_er.androidcustomtabsintent;

import android.net.Uri;
import android.os.Bundle;
import android.support.customtabs.CustomTabsIntent;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    Button btnLaunch;
    Uri uriMyBlog = Uri.parse("http://android-er.blogspot.com");

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btnLaunch = (Button)findViewById(R.id.launch);
        btnLaunch.setOnClickListener(btnLaunchOnClickListener);
    }

    View.OnClickListener btnLaunchOnClickListener = new View.OnClickListener(){

        @Override
        public void onClick(View v) {
            new CustomTabsIntent.Builder()
                    .build()
                    .launchUrl(MainActivity.this, uriMyBlog);

        }
    };
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:padding="16dp"
    android:orientation="vertical"
    tools:context="com.blogspot.android_er.androidcustomtabsintent.MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:autoLink="web"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold" />

    <Button
        android:id="@+id/launch"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Launch"/>
</LinearLayout>

Android Support Library 23.2

The Android Support Library 23.2 brings brand new libraries in the form of support-vector-drawable and animated-vector-drawable as well as important updates to existing libraries such as extended support for VectorDrawableCompat throughout AppCompat, a new Theme.AppCompat.DayNight, a bottom sheet behavior in the Design Library, MediaBrowserServiceCompat and MediaBrowserCompat for media apps using Support v4, and improvements to the GuidedStepFragment in the Android TV Leanback library. Not to mention important updates to RecyclerView and new features to Custom Tabs - read the blog post for all the details: http://goo.gl/HVyTAf

Add Support Library, com.android.support:support-v4, to Android Studio project

This video show how to add dependency of Support Library of "com.android.support:support-v4" to Android Studio project.

Add Support Libraries of RecyclerView, CardView to Android Studio Project

If you want to use android.support.v7.widget.RecyclerView and/or android.support.v7.widget.CardView in your Android Studio project, you have to add these libraries as dependencies.

To add the libraries to Android Studio as dependencies, follow the steps here shown in the video:
- In Android Studio > File > Project Structure
- Select App -> Dependencies
- Click on the '+' symbol to add the libraries
- OK

---

More Examples:
- RecyclerView example
- CardView example

Example of using ActionBarCompat with android-support-v7-appcompat

This exercise show the steps to modify the auto-generated "Hello World" by Android ADT/Eclipse, to implement ActionBarCompat, with backward-compatible Action Bar back to Android 2.1.

ActionBarCompat on Nexus One running Android 2.3.6

- Before start our new project, you have to "Create library project with the appcompat v7 support library".

- New a Android Application Project as normal.

- Right click on the project, select Properties, select Android tab on the left box, scroll down on the right to make sure the check box of "is Library" is un-checked, and click the Add button to add library of "android-support-v7-appcompat". then click OK.

add library of android-support-v7-appcompat

- Modify AndroidManifest.xml, change android:theme inside to "@style/Theme.AppCompat". And make sure android:minSdkVersion is equal or higher than 7, Android 2.1.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.testactionbarcompat"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/Theme.AppCompat" >
        <activity
            android:name="com.example.testactionbarcompat.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

- Modify menu resources file, /res/menu/main.xml.
Add a new xmlns, xmlns:myapp="http://schemas.android.com/apk/res-auto". You can choice any name (myapp in my example) you want. But it has to be matched with the name space in .
 Modify to define myapp:showAsAction="always".

<menu 
    xmlns:myapp="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android" >

    <item
        android:id="@+id/action_settings"
        android:orderInCategory="100"
        myapp:showAsAction="always"
        android:title="@string/action_settings"/>

</menu>

- Modify MainActivity to extend ActionBarActivity with android.support.v7.app.ActionBarActivity imported.

package com.example.testactionbarcompat;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;

public class MainActivity extends ActionBarActivity {

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


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
}

- Now it can be re-build to generate app with Action Bar running on devices of Android 2.1 or higher.


Next:
- Add MenuItem to ActionBarCompat using Java

---

Visit: ActionBarCompat Step-by-step

Create library project with the appcompat v7 support library

It's outdate post:

Make sure "Android Support Repository" is checked to install in SDK Manager. In current Android Studio, 'com.android.support:appcompat-v7:23.+' will be added by default if you create project using Android Studio Wizard.

---

To use the ActionBar APIs in the support library. So before you can add the action bar, you must set up your project with the appcompat v7 support library by following the instructions in the Support Library Setup.

1. Make sure you have downloaded the Android Support Library using the SDK Manager.
2. Create a library project and ensure the required JAR files are included in the project's build path:
   1. Select File > Import.
   2. Select Existing Android Code Into Workspace and click Next.
   3. Browse to the SDK installation directory and then to the Support Library folder. For example, if you are adding theappcompat project, browse to /extras/android/support/v7/appcompat/.
   4. Click Finish to import the project. For the v7 appcompat project, you should now see a new project titled android-support-v7-appcompat.
   5. In the new library project, expand the libs/ folder, right-click each .jar file and select Build Path > Add to Build Path. For example, when creating the the v7 appcompat project, add both the android-support-v4.jar andandroid-support-v7-appcompat.jar files to the build path.
   6. Right-click the library project folder and select Build Path > Configure Build Path.
   7. In the Order and Export tab, check the .jar files you just added to the build path, so they are available to projects that depend on this library project. For example, the appcompat project requires you to export both the android-support-v4.jar and android-support-v7-appcompat.jar files.
   8. Uncheck Android Dependencies.
   9. Click OK to complete the changes.

next:
- Example of using ActionBarCompat with android-support-v7-appcompat

---

ActionBarCompat Step-by-step

Intro to ActionBarCompat Support Library

DevBytes: Intro to ActionBarCompat Support Library

An introduction to this new support library, which allows you to add a compatible Action Bar to your application, targeting Android v2.1 or newer. This DevByte covers integrating the library, from adding it as a dependency to modifying your resources and code. For more information you can visit - http://developer.android.com/guide/topics/ui/actionbar.html

Tips to add Support Library

In case you need to add Android Support Library, such as android-support-v4.jar; Google documents suggested to:
- In Eclipse Select Project > Properties, select Java Build Path, and navigate to Libraries.
- Select Add External Jars, include the following jar files, and click OK: <android-sdk-folder>/extras/android/compatibility/v4/android-support-v4.jar

But...I found that it is not always work, even always NOT work!

No error when you compile your code, but fail with error "Caused by: java.lang.NoClassDefFoundError: youractivity" at runtime.

My alternatively, Right click your project, select Android Tools > Add Support Library...

----------

Here is another solution advised by Stefan de Bruijn in comments:
- create a folder called "libs", NOT "lib".
- copy the required jar in "libs" folder.
- Update Java Build Path by selecting "Add JARs..." (NOT "Add External JARs...") to add the jar in libs.
- like this: java.lang.NoClassDefFoundError: com.google.ads.AdView.