view
Customized list view
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
getView
method, inflate the XML layout file and retrieve reference of the described View - Take reference of each of the views widgets using the
findViewById
method, and customize them as you wish - In your activity class extend
ListActivity
- use
setListAdapter
method to set your customAdapter
as theArrayAdapter
for 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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