This is an app I am working on at the moment. I am making it for storymap.ie. It uses the new Google Maps API v2 and uses notification for playback controls. Stories can be streamed or downloaded beforehand. The app features rambles – Google Maps API is used to find optimal route between 2 points
VM Warfare is a multiplayer/singleplayer deathmatch game that won the Best Multiplayer Game award at GamesFleadh 2013. I created it together with Viktor Zolin, who made map editor and tile engine, while I mad emost of the game itself. You are a soldier defending the Earth against alien attack. To help you with this, helicopters
An android app for DIT students to view their timetables. It downloads timetable data from web timetables and saves a local copy on user’s device. It lets user filter lectures and labs by group. DIT Timetable in Google Play Store
A simple app for saving notes. It was designed for Android 4.0 and newer, but support to older versions was added using ActionbarSherlock. It is very simple, but has some useful features, it detects links, allows pasting contents of clipboard into a new link, sharing notes using intents and receiving intents from other aps. It
Project website: www.convoytrucking.net. Community forums: www.forum.convoytrucking.net This gamemode is my first and biggest project in Pawn. I started working on it in January 2010 and in two weeks created server called Convoy Trucking. To this day I continue working on it, and the community of players keeps growing. Some of the features included in
This tutorial shows how to make an audio playback service and how to control audio playback using buttons on a notification. I am going to assume that you have some knowledge of android app development, and know your way around Eclipse, or other SDK used for Android. This is my first tutorial, so please let me know in comments if anything needs to be explained in more depth, or point out any mistakes made.
First things first, we need to create the service that will play music. You can do that by creating a new class that extends Service. You will also need an instance of MediaPlayer. Your service should also implement OnPreparedListener and OnCompletionListener interfaces to receive callbacks from the MediaPlayer. Your code should look similar to this:
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public class AudioPlaybackService extends Service implements OnPreparedListener, OnCompletionListener { MediaPlayer mediaPlayer; @Override public int onStartCommand(Intent intent, int flags, int startId) { return START_STICKY; } @Override public void onCreate() { super.onCreate(); mediaPlayer = new MediaPlayer(); mediaPlayer.setOnPreparedListener(this); mediaPlayer.setOnCompletionListener(this); } @Override public void onCompletion(MediaPlayer mp) { // called when song has ended } @Override public void onPrepared(MediaPlayer mp) { // called by MediaPlayer when audio is ready to be played } @Override public IBinder onBind(Intent arg0) { // TODO Auto-generated method stub return null; } } |
onCreate() is called when your service is first started. We’ll use it to instantiate the MediaPlayer, and set listeners. onStartCommand() is called every time you launch your service from an activity – this could happen several times during service’s lifetime. Returning START_STICKY causes your service to stay alive after onStartCommand() finished executing.
You should also define your service in your project’s manifest. Put the following between the <application> tags:
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<service android:name="com.mick88.notificationexample.AudioPlaybackService"" android:enabled="true" android:label="Audio-playback service" /> |
Now that we have the service, let’s make it play the music. We will modify onStartCommand() to handle the incoming intent, and override onDestroy() to stop the music when service is stopped:
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public static final String EXTRA_AUDIO_URL = "audio_url"; String url; @Override public int onStartCommand(Intent intent, int flags, int startId) { this.url = intent.getStringExtra(EXTRA_AUDIO_URL); mediaPlayer.reset(); try { mediaPlayer.setDataSource(url); mediaPlayer.prepareAsync(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } return START_STICKY; } @Override public void onPrepared(MediaPlayer mp) { mediaPlayer.start(); } @Override public void onDestroy() // called when the service is stopped { mediaPlayer.stop(); super.onDestroy(); } |
This will get the url from intent and use it as a data source for media player. You can use this to stream media from the internet. the prepareAsync() method starts buffering the audio stream in a secondary thread, and will call onPrepared() when finished – that’s where you start playback by calling start() on the MediaPlayer.
If you want to stream music from the internet, don’t forget to request the INTERNET permission inside the <manifest> tags of your manifest:
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<uses-permission android:name="android.permission.INTERNET" /> |
Next we’ll create an Activity (you should know how to do this) that will start the service. Add 2 buttons the layout: first button will start the service and play music, while the other one will stop the service:
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@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); final Intent serviceIntent = new Intent(getApplicationContext(), AudioPlaybackService.class); findViewById(R.id.button1).setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { serviceIntent.putExtra(AudioPlaybackService.EXTRA_AUDIO_URL, "http://radionova128.media.vistatec.ie:80/"); startService(serviceIntent); } }); findViewById(R.id.button2).setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { stopService(serviceIntent); } }); } |
The code above will start the service with url link provided. It should start streaming Radio Nova. The app should work at this stage. Go on and try it!
The final part of this tutorial is creating the notification that will show when service is running and present user with playback control buttons. Let’s create a showNotification() method inside our Service. The notification will have Stop and Pause Buttons. You can add buttons by addAction(). We should also define the broadcasts for those buttons.
We will use NotificationCompat class from the support library for building the notification so it’s backwards compatible. If you want you can use the Notification class, however it’s not recommended.
To make my life easier, I made the createPendingIntent() method to create broadcast pending intents easy:
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final int NOTIFICATION_ID = 1; public static final String BROADCAST_PLAYBACK_STOP = "stop", BROADCAST_PLAYBACK_PAUSE = "pause"; private PendingIntent makePendingIntent(String broadcast) { Intent intent = new Intent(broadcast); return PendingIntent.getBroadcast(getApplicationContext(), 0, intent, 0); } private void showNotification() { // Create notification NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this) .setSmallIcon(R.drawable.ic_launcher) .setContentTitle(getString(R.string.app_name)) .setContentText(this.url) // audio url will show in notification .setContentIntent(PendingIntent.getActivity(getApplicationContext(), 0, new Intent(getApplicationContext(), MainActivity.class), 0)) .addAction(R.drawable.stop_light, "Stop", makePendingIntent(BROADCAST_PLAYBACK_STOP)) .addAction(R.drawable.pause_light, "Pause", makePendingIntent(BROADCAST_PLAYBACK_PAUSE)); // Show notification startForeground(NOTIFICATION_ID, notificationBuilder.build()); } |
startForeground() method will bring your service to the foreground by showing the notification.
Notification should be shown whenever new stream is played:
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@Override public int onStartCommand(Intent intent, int flags, int startId) { this.url = intent.getStringExtra(EXTRA_AUDIO_URL); Log.d("URL", url); mediaPlayer.reset(); try { mediaPlayer.setDataSource(url); mediaPlayer.prepareAsync(); showNotification(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } return START_STICKY; } |
Now all that’s left is handling the button presses. To do that, we need to create a BroadcastReceiver, register it inside onCreate() method, and unregister when service is destroyed:
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final BroadcastReceiver broadcastReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if (action.equals(BROADCAST_PLAYBACK_STOP)) stopSelf(); else if (action.equals(BROADCAST_PLAYBACK_PAUSE)) { if (mediaPlayer.isPlaying()) mediaPlayer.pause(); else mediaPlayer.start(); } } }; @Override public void onCreate() { super.onCreate(); mediaPlayer = new MediaPlayer(); mediaPlayer.setOnPreparedListener(this); mediaPlayer.setOnCompletionListener(this); IntentFilter intentFilter = new IntentFilter(); intentFilter.addAction(BROADCAST_PLAYBACK_STOP); intentFilter.addAction(BROADCAST_PLAYBACK_PAUSE); registerReceiver(broadcastReceiver, intentFilter); } @Override public void onDestroy() // called when the service is stopped { mediaPlayer.stop(); stopForeground(true); unregisterReceiver(broadcastReceiver); super.onDestroy(); } |
At last, we should implement the onCompletion() method. It is called when song finished playing. In my implementation it simply stops the service:
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@Override public void onCompletion(MediaPlayer mp) { stopSelf(); } |
That’s it! You can now test the app. When you start the audio, you should be able to see this in your notification shade:
Of course, the app is a bit rough around the edges; the “pause” button doesn’t turn into “play” when you press it, but I will leave this as an exercise for the reader.
Full source code:
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package com.mick88.notificationexample; import android.app.PendingIntent; import android.app.Service; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.media.MediaPlayer; import android.media.MediaPlayer.OnCompletionListener; import android.media.MediaPlayer.OnPreparedListener; import android.os.IBinder; import android.support.v4.app.NotificationCompat; import android.util.Log; public class AudioPlaybackService extends Service implements OnPreparedListener, OnCompletionListener { final int NOTIFICATION_ID = 1; public static final String EXTRA_AUDIO_URL = "audio_url"; public static final String BROADCAST_PLAYBACK_STOP = "stop", BROADCAST_PLAYBACK_PAUSE = "pause"; MediaPlayer mediaPlayer; String url; final BroadcastReceiver broadcastReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if (action.equals(BROADCAST_PLAYBACK_STOP)) stopSelf(); else if (action.equals(BROADCAST_PLAYBACK_PAUSE)) { if (mediaPlayer.isPlaying()) mediaPlayer.pause(); else mediaPlayer.start(); } } }; @Override public int onStartCommand(Intent intent, int flags, int startId) { this.url = intent.getStringExtra(EXTRA_AUDIO_URL); Log.d("URL", url); mediaPlayer.reset(); try { mediaPlayer.setDataSource(url); mediaPlayer.prepareAsync(); showNotification(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } return START_STICKY; } @Override public void onCreate() { super.onCreate(); mediaPlayer = new MediaPlayer(); mediaPlayer.setOnPreparedListener(this); mediaPlayer.setOnCompletionListener(this); IntentFilter intentFilter = new IntentFilter(); intentFilter.addAction(BROADCAST_PLAYBACK_STOP); intentFilter.addAction(BROADCAST_PLAYBACK_PAUSE); registerReceiver(broadcastReceiver, intentFilter); } @Override public void onCompletion(MediaPlayer mp) { stopSelf(); } @Override public void onPrepared(MediaPlayer mp) { Log.d("Service", "MediaPlayer prepared. Music will play now."); mediaPlayer.start(); } @Override public IBinder onBind(Intent arg0) { // TODO Auto-generated method stub return null; } private PendingIntent makePendingIntent(String broadcast) { Intent intent = new Intent(broadcast); return PendingIntent.getBroadcast(getApplicationContext(), 0, intent, 0); } private void showNotification() { // Create notification NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this) .setSmallIcon(R.drawable.ic_launcher) .setContentTitle(getString(R.string.app_name)) .setContentText(this.url) // audio url will show in notification .setContentIntent(PendingIntent.getActivity(getApplicationContext(), 0, new Intent(getApplicationContext(), MainActivity.class), 0)) .addAction(R.drawable.stop_light, "Stop", makePendingIntent(BROADCAST_PLAYBACK_STOP)) .addAction(R.drawable.pause_light, "Pause", makePendingIntent(BROADCAST_PLAYBACK_PAUSE)); // Show notification startForeground(NOTIFICATION_ID, notificationBuilder.build()); } @Override public void onDestroy() // called when the service is stopped { mediaPlayer.stop(); stopForeground(true); unregisterReceiver(broadcastReceiver); super.onDestroy(); } } |
This little algorithm is one of the coolest things I learned from the programming lectures with Dr Bryan Duggan. Essentially this algorithm shows how much one word needs to be edited to change into another word. It is very useful for writing a spellchecker, or a music recognition app. Below is a C# implementation of the algorithm:
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static int getEditDistance(string word1, string word2) { int cols = word1.Length+1, rows = word2.Length+1; int [,] matrix = new int [rows,cols]; // fill top and left side of the matrix with 1 for (int i = 0; i < cols; i++) matrix[0, i] = i; for (int i = 0; i < rows; i++) matrix[i, 0] = i; // fill the matrix for (int row = 1; row < rows; row++) { for (int col = 1; col < cols; col++) { int value; if (word1[col - 1] == word2[row - 1]) { value = matrix[row - 1, col - 1]; } else { value = getMin(matrix[row - 1, col - 1], matrix[row - 1, col], matrix[row, col - 1]) + 1; } matrix[row, col] = value; } } // result is the number on the bottom-right of the matrix return matrix[rows-1, cols-1]; } static int getMin(int n1, int n2, int n3) { return Math.Min(Math.Min(n1, n2), n3); } |
the getEditDistance() method returns 0 if both words are equal, 1 of one letter needs to be changed, etc.
This is an app I am working on at the moment. I am making it for storymap.ie. It uses the new Google Maps API v2 and uses notification for playback controls. Stories can be streamed or downloaded beforehand. The app features rambles – Google Maps API is used to find optimal route between 2 points with stories in-between. The rambles are automatically downloaded from server, but user can create their own ramble by specifying the start and end point. It also handles storymap.ie links, so they open in the app instead of web browser. It’s designed to look clean and be easy to use.
Notification is shown while story is being played back.
Notification shows download progress
I made this little program to test my sudoku-solving algorithm around the christmas time. I used XNA to draw the puzzle, and solving algorithm works in a separate thread (included below). This is not the best algorithm since it can’t solve “hard” puzzles. But it can logically deduct numbers (no guessing) and put them in the right place.
SudokuSolver.cs:
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using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading; namespace Sudoku { class SudokuSolver { volatile PuzzleState puzzleState; bool aborting=false; volatile bool solving = false; Thread solvingThread; public PuzzleState PuzzleState { get { return puzzleState; } } public bool Solving { get { return solving; } } public SudokuSolver(PuzzleState puzzleState) { this.puzzleState = puzzleState; } public void solvePuzzle(bool threaded) { if (solving == true) return; aborting = false; if (threaded == true) { solvingThread = new Thread(new ThreadStart(solve)); solvingThread.Start(); } else solve(); } void solve() { solving = true; while (iterate() == true && aborting == false) { } solving = false; puzzleState.onPuzzleSolved(true); Thread.CurrentThread.Abort(); } public void abort() { aborting = true; if (solvingThread != null) solvingThread.Abort(); } /// <summary> /// Single iteration /// </summary> /// <returns>True if any progress was made, false if puzzle was solved</returns> public bool iterate() { bool progressed=false; const int delay = 200; /*Eliminate possiblilities*/ foreach(Cell cell in PuzzleState.AllCells) { /*test other cells within square*/ foreach (Cell otherCell in cell.Square.Cells) { if (otherCell != cell) { bool changed = cell.removePossibility(otherCell.Value); if (changed) { progressed = true; //Thread.Sleep(delay); } } } /*Row*/ int rowNum = cell.Row; for (int x = 0; x < PuzzleState.cellsInRow; x++) { Cell otherCell = puzzleState.getCell(x, rowNum); if (cell != otherCell) { bool changed = cell.removePossibility(otherCell.Value); if (changed) { progressed = true; //Thread.Sleep(delay); } } } /*Column*/ int colNum = cell.Column; for (int y = 0; y < PuzzleState.cellsInCol; y++) { Cell otherCell = puzzleState.getCell(colNum, y); if (cell != otherCell) { bool changed = cell.removePossibility(otherCell.Value); if (changed) { progressed = true; //Thread.Sleep(delay); } } } } if (progressed) Thread.Sleep(delay); if (progressed == false) { /*look for suitable numbers within square*/ foreach (BigSquare square in puzzleState.Squares) { for (int n = 1; n <= 9; n++) { bool numberPresent = false; foreach (Cell cell in square.Cells) if (cell.Value == n) numberPresent = true; if (numberPresent == true) continue; int candidates = 0; Cell candidate = null; foreach (Cell cell in square.Cells) { if (cell.Value == 0 && cell.PossibleValues.IndexOf(n) > -1) { candidate = cell; candidates++; if (candidates > 1) { break; } } } if (candidates == 1) { candidate.Value = n; progressed = true; Thread.Sleep(delay); } } } } if (progressed == false) { /*look for suitable numbers within a row*/ for (int row = 0; row < PuzzleState.cellsInRow; row++) { for (int n = 1; n <= 9; n++) { bool numberPresent = false; for (int col = 0; col < PuzzleState.cellsInCol; col++) { Cell cell = puzzleState.getCell(col, row); if (cell.Value == n) numberPresent = true; } if (numberPresent) continue; int candidates = 0; Cell candidate = null; for (int col = 0; col < PuzzleState.cellsInCol; col++) { Cell cell = puzzleState.getCell(col, row); if (cell.Value==0 && cell.PossibleValues.IndexOf(n) > -1) { candidate = cell; candidates++; if (candidates > 1) { break; } } } if (candidates == 1) { candidate.Value = n; progressed = true; Thread.Sleep(delay); } } } } if (progressed == false) { /*look for suitable numbers within a column*/ for (int col = 0; col < PuzzleState.cellsInCol; col++) { for (int n = 1; n <= 9; n++) { bool numberPresent = false; for (int row = 0; row < PuzzleState.cellsInRow; row++) { Cell cell = puzzleState.getCell(col, row); if (cell.Value == n) numberPresent = true; } if (numberPresent) continue; int candidates = 0; Cell candidate = null; for (int row = 0; row < PuzzleState.cellsInRow; row++) { Cell cell = puzzleState.getCell(col, row); if (cell.Value == 0 && cell.PossibleValues.IndexOf(n) > -1) { candidate = cell; candidates++; if (candidates > 1) { break; } } } if (candidates == 1) { candidate.Value = n; progressed = true; Thread.Sleep(delay); } } } } return progressed; } } } |
I remember making this program back in 2004. Still, I was very surprised today when I started it and noticed how developed it is. It has an awful lot of features for something that I knew I would not use anyway. Obviously it doesn’t offer syntax highlighting but has other useful features for novice web designers, like html templates. It allows to easily add html tags and has color pickers. Unfortunately no source code.
The readme.txt file reads:
Aplikacja do edycji stron HTML. Nie obsluguje
kolorowania skladni, ale posiada wbudowane
szablony znaczników. w kazdym razie jest
nieco lepszy od standardowago notepada :)
Which basically explains that it’s a simple program, but still better than windows notepad.
