This is an example of how to create a Customized ListView on on Android. The normal ListView component of Android is very useful. But we have the ability to further customize it which makes it more flexible.
In order to create your own, customized ListView, follow these steps:
- Create a new XML file that describes the layout of each row
- Create a custom
ArrayAdapter. by Creating a new class that extendsArrayAdapter<T> - Override the
getViewmethod, inflate the XML layout file and retrieve reference of the described View - Take reference of each of the views widgets using the
findViewByIdmethod, and customize them as you wish - In your activity class extend
ListActivity - use
setListAdaptermethod to set your customAdapteras theArrayAdapterfor theListView.
Let’s see how the code looks like:
package com.javacodegeeks.android.apps.moviesearchapp.ui;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import com.javacodegeeks.android.apps.moviesearchapp.R;
import com.javacodegeeks.android.apps.moviesearchapp.io.FlushedInputStream;
import com.javacodegeeks.android.apps.moviesearchapp.model.Movie;
import com.javacodegeeks.android.apps.moviesearchapp.services.HttpRetriever;
public class MoviesAdapter extends ArrayAdapter<Movie> {
private HttpRetriever httpRetriever = new HttpRetriever();
private ArrayList<Movie> movieDataItems;
private Activity context;
public MoviesAdapter(Activity context, int textViewResourceId, ArrayList<Movie> movieDataItems) {
super(context, textViewResourceId, movieDataItems);
this.context = context;
this.movieDataItems = movieDataItems;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View view = convertView;
if (view == null) {
LayoutInflater vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = vi.inflate(R.layout.movie_data_row, null);
}
Movie movie = movieDataItems.get(position);
if (movie != null) {
// name
TextView nameTextView = (TextView) view.findViewById(R.id.name_text_view);
nameTextView.setText(movie.name);
// rating
TextView ratingTextView = (TextView) view.findViewById(R.id.rating_text_view);
ratingTextView.setText("Rating: " + movie.rating);
// released
TextView releasedTextView = (TextView) view.findViewById(R.id.released_text_view);
releasedTextView.setText("Release Date: " + movie.released);
// certification
TextView certificationTextView = (TextView) view.findViewById(R.id.certification_text_view);
certificationTextView.setText("Certification: " + movie.certification);
// language
TextView languageTextView = (TextView) view.findViewById(R.id.language_text_view);
languageTextView.setText("Language: " + movie.language);
// thumb image
ImageView imageView = (ImageView) view.findViewById(R.id.movie_thumb_icon);
String url = movie.retrieveThumbnail();
if (url != null) {
Bitmap bitmap = fetchBitmapFromCache(url);
if (bitmap == null) {
new BitmapDownloaderTask(imageView).execute(url);
} else {
imageView.setImageBitmap(bitmap);
}
} else {
imageView.setImageBitmap(null);
}
}
return view;
}
private LinkedHashMap<String, Bitmap> bitmapCache = new LinkedHashMap<String, Bitmap>();
private void addBitmapToCache(String url, Bitmap bitmap) {
if (bitmap != null) {
synchronized (bitmapCache) {
bitmapCache.put(url, bitmap);
}
}
}
private Bitmap fetchBitmapFromCache(String url) {
synchronized (bitmapCache) {
final Bitmap bitmap = bitmapCache.get(url);
if (bitmap != null) {
// Bitmap found in cache
// Move element to first position, so that it is removed last
bitmapCache.remove(url);
bitmapCache.put(url, bitmap);
return bitmap;
}
}
return null;
}
private class BitmapDownloaderTask extends AsyncTask<String, Void, Bitmap> {
private String url;
private final WeakReference<ImageView> imageViewReference;
public BitmapDownloaderTask(ImageView imageView) {
imageViewReference = new WeakReference<ImageView>(imageView);
}
@Override
protected Bitmap doInBackground(String... params) {
url = params[0];
InputStream is = httpRetriever.retrieveStream(url);
if (is == null) {
return null;
}
return BitmapFactory.decodeStream(new FlushedInputStream(is));
}
@Override
protected void onPostExecute(Bitmap bitmap) {
if (isCancelled()) {
bitmap = null;
}
addBitmapToCache(url, bitmap);
if (imageViewReference != null) {
ImageView imageView = imageViewReference.get();
if (imageView != null) {
imageView.setImageBitmap(bitmap);
}
}
}
}
}package com.javacodegeeks.android.apps.moviesearchapp;
import java.util.ArrayList;
import android.app.ListActivity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.ListView;
import android.widget.Toast;
import com.javacodegeeks.android.apps.moviesearchapp.model.Movie;
import com.javacodegeeks.android.apps.moviesearchapp.ui.MoviesAdapter;
public class MoviesListActivity extends ListActivity {
private static final String IMDB_BASE_URL = "http://m.imdb.com/title/";
private ArrayList<Movie> moviesList = new ArrayList<Movie>();
private MoviesAdapter moviesAdapter;
@SuppressWarnings("unchecked")
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.movies_layout);
moviesAdapter = new MoviesAdapter(this, R.layout.movie_data_row, moviesList);
moviesList = (ArrayList<Movie>) getIntent().getSerializableExtra("movies");
setListAdapter(moviesAdapter);
if (moviesList != null && !moviesList.isEmpty()) {
moviesAdapter.notifyDataSetChanged();
moviesAdapter.clear();
for (int i = 0; i < moviesList.size(); i++) {
moviesAdapter.add(moviesList.get(i));
}
}
moviesAdapter.notifyDataSetChanged();
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
Movie movie = moviesAdapter.getItem(position);
String imdbId = movie.imdbId;
if (imdbId == null || imdbId.length() == 0) {
longToast(getString(R.string.no_imdb_id_found));
return;
}
String imdbUrl = IMDB_BASE_URL + movie.imdbId;
Intent imdbIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(imdbUrl));
startActivity(imdbIntent);
}
public void longToast(CharSequence message) {
Toast.makeText(this, message, Toast.LENGTH_LONG).show();
}
}<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="?android:attr/listPreferredItemHeight"
android:padding="6dip">
<ImageView
android:id="@+id/movie_thumb_icon"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_marginRight="6dip"/>
<LinearLayout
android:orientation="vertical"
android:layout_width="0dip"
android:layout_weight="1"
android:layout_height="fill_parent">
<TextView
android:id="@+id/name_text_view"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:singleLine="true"
android:ellipsize="marquee"
android:textStyle="bold"
/>
<TextView
android:id="@+id/rating_text_view"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:singleLine="true"
android:ellipsize="marquee"
/>
<TextView
android:id="@+id/released_text_view"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:singleLine="true"
android:ellipsize="marquee"
/>
<TextView
android:id="@+id/certification_text_view"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:singleLine="true"
android:ellipsize="marquee"
/>
<TextView
android:id="@+id/language_text_view"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:singleLine="true"
android:ellipsize="marquee"
/>
<TextView
android:id="@+id/adult_text_view"
android:layout_width="fill_parent"
android:layout_height="0dip"
android:layout_weight="1"
android:singleLine="true"
android:ellipsize="marquee"
/>
</LinearLayout>
</LinearLayout>
This was an example of how to create a Customized ListView in Android.
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