Modification of Sound Player on android - audio

Question

i am trying to make a simple piano app. I found this tutorial ;http://www.martinhoeller.net/2012/01/13/developing-a-musical-instrument-app-for-android/ .
I downloaded the file on this link and import it. I run the app and there are 4 buttons on it which plays 4 different notes that are loaded in assets files.
And then i tried to modify this project to make a piano app.
At first i deleted these red buttons from xml.
I added a piano image to background.
And then i created buttons on each key.
The xml file is ;
<?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="fill_parent"
android:layout_gravity="fill_vertical"
android:background="#drawable/images"
android:orientation="vertical" >
<Button
android:id="#+id/buttonC4"
android:layout_width="294dp"
android:layout_height="60dp"
android:background="#android:color/transparent"
android:gravity="center_vertical|center_horizontal" />
<Button
android:id="#+id/buttonD4"
android:layout_width="294dp"
android:layout_height="60dp"
android:background="#android:color/transparent"
android:gravity="center_vertical|center_horizontal" />
<Button
android:id="#+id/buttonE4"
android:layout_width="294dp"
android:layout_height="60dp"
android:background="#android:color/transparent"
android:gravity="center_vertical|center_horizontal" />
<Button
android:id="#+id/buttonF4"
android:layout_width="294dp"
android:layout_height="58dp"
android:background="#android:color/transparent"
android:gravity="center_vertical|center_horizontal" />
<Button
android:id="#+id/buttonG4"
android:layout_width="294dp"
android:layout_height="58dp"
android:background="#android:color/transparent"
android:gravity="center_vertical|center_horizontal" />
<Button
android:id="#+id/buttonA4"
android:layout_width="294dp"
android:layout_height="60dp"
android:background="#android:color/transparent"
android:gravity="center_vertical|center_horizontal" />
<Button
android:id="#+id/buttonB4"
android:layout_width="294dp"
android:layout_height="58dp"
android:background="#android:color/transparent"
android:gravity="center_vertical|center_horizontal" />
<Button
android:id="#+id/buttonC5"
android:layout_width="294dp"
android:layout_height="58dp"
android:background="#android:color/transparent"
android:gravity="center_vertical|center_horizontal" />
<Button
android:id="#+id/buttonD5"
android:layout_width="294dp"
android:layout_height="58dp"
android:background="#android:color/transparent"
android:gravity="center_vertical|center_horizontal" />
<Button
android:id="#+id/buttonE5"
android:layout_width="294dp"
android:layout_height="58dp"
android:background="#android:color/transparent"
android:gravity="center_vertical|center_horizontal" />
</LinearLayout>
Then i found notes on internet and download them .
I upload these note files to assets folder.
Each of them is in the wav format.
Then i added these codes to PianoTest Activity ;
buttons = new ArrayList<View>();
buttons.add(findViewById(R.id.buttonC4));
buttons.add(findViewById(R.id.buttonD4));
buttons.add(findViewById(R.id.buttonF4));
buttons.add(findViewById(R.id.buttonG4));
buttons.add(findViewById(R.id.buttonA4));
buttons.add(findViewById(R.id.buttonB4));
buttons.add(findViewById(R.id.buttonC5));
buttons.add(findViewById(R.id.buttonD5));
buttons.add(findViewById(R.id.buttonE5));
And then i modified this function ;
private void toggleButtonSound(View button, boolean down)
{
String note = null;
switch (button.getId())
{
case R.id.buttonC4:
note = "C4";
break;
case R.id.buttonD4:
note = "D4";
break;
case R.id.buttonE4:
note = "E4";
break;
case R.id.buttonF4:
note = "F4";
break;
case R.id.buttonG4:
note = "G4";
break;
case R.id.buttonA4:
note = "A4";
break;
case R.id.buttonB4:
note = "B4";
break;
case R.id.buttonC5:
note = "C5";
break;
case R.id.buttonD5:
note = "D5";
break;
case R.id.buttonE5:
note = "E5";
break;
}
Then i changed AudioTrack class . I changed the format to wav file ;
public void run()
{
try
{
String path = note + ".wav";
Everything else is the same as in the original project.
But the app doesnt work properly.
When i run the app and click one the transparent buttons on a key , it plays a sound but it is not the same sound as it is.
It sounds something different.I can say that an elektronic version of a note.
And when i click some other keys the application crashes . It says the application stopped unexpectedly.
What is wrong ? What should i do to make it work ? The reason can be the files i dpwnloaded. What kind of notes do i need to find ? Is there any special format in terms of their bits or time durations for this project ?
This is very important for me , if you can download the file from the link and run , you can see how it works. You can suggest me the ways to modify it. I hope you can help me.
This is the logcat :
05-13 19:49:55.580: D/AndroidRuntime(485): Shutting down VM
05-13 19:49:55.580: W/dalvikvm(485): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
05-13 19:49:55.600: E/AndroidRuntime(485): FATAL EXCEPTION: main
05-13 19:49:55.600: E/AndroidRuntime(485): java.lang.RuntimeException: Unable to start activity ComponentInfo{net.martinhoeller/net.martinhoeller.PianoTestActivity}: android.view.InflateException: Binary XML file line #9: Error inflating class ButtonView
05-13 19:49:55.600: E/AndroidRuntime(485): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.app.ActivityThread.access$2300(ActivityThread.java:125)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.os.Handler.dispatchMessage(Handler.java:99)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.os.Looper.loop(Looper.java:123)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.app.ActivityThread.main(ActivityThread.java:4627)
05-13 19:49:55.600: E/AndroidRuntime(485): at java.lang.reflect.Method.invokeNative(Native Method)
05-13 19:49:55.600: E/AndroidRuntime(485): at java.lang.reflect.Method.invoke(Method.java:521)
05-13 19:49:55.600: E/AndroidRuntime(485): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-13 19:49:55.600: E/AndroidRuntime(485): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-13 19:49:55.600: E/AndroidRuntime(485): at dalvik.system.NativeStart.main(Native Method)
05-13 19:49:55.600: E/AndroidRuntime(485): Caused by: android.view.InflateException: Binary XML file line #9: Error inflating class ButtonView
05-13 19:49:55.600: E/AndroidRuntime(485): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:576)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.view.LayoutInflater.rInflate(LayoutInflater.java:618)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.view.LayoutInflater.inflate(LayoutInflater.java:407)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
05-13 19:49:55.600: E/AndroidRuntime(485): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:198)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.app.Activity.setContentView(Activity.java:1647)
05-13 19:49:55.600: E/AndroidRuntime(485): at net.martinhoeller.PianoTestActivity.onCreate(PianoTestActivity.java:23)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
05-13 19:49:55.600: E/AndroidRuntime(485): ... 11 more
05-13 19:49:55.600: E/AndroidRuntime(485): Caused by: java.lang.ClassNotFoundException: android.view.ButtonView in loader dalvik.system.PathClassLoader[/data/app/net.martinhoeller-1.apk]
05-13 19:49:55.600: E/AndroidRuntime(485): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243)
05-13 19:49:55.600: E/AndroidRuntime(485): at java.lang.ClassLoader.loadClass(ClassLoader.java:573)
05-13 19:49:55.600: E/AndroidRuntime(485): at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.view.LayoutInflater.createView(LayoutInflater.java:466)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.view.LayoutInflater.onCreateView(LayoutInflater.java:544)
05-13 19:49:55.600: E/AndroidRuntime(485): at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
05-13 19:49:55.600: E/AndroidRuntime(485): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:563)
05-13 19:49:55.600: E/AndroidRuntime(485): ... 20 more
05-13 19:52:22.293: D/AndroidRuntime(513): Shutting down VM
05-13 19:52:22.293: W/dalvikvm(513): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
05-13 19:52:22.309: E/AndroidRuntime(513): FATAL EXCEPTION: main
05-13 19:52:22.309: E/AndroidRuntime(513): java.lang.ArrayIndexOutOfBoundsException
05-13 19:52:22.309: E/AndroidRuntime(513): at net.martinhoeller.PianoTestActivity.onTouchEvent(PianoTestActivity.java:66)
05-13 19:52:22.309: E/AndroidRuntime(513): at android.app.Activity.dispatchTouchEvent(Activity.java:2089)
05-13 19:52:22.309: E/AndroidRuntime(513): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1655)
05-13 19:52:22.309: E/AndroidRuntime(513): at android.view.ViewRoot.handleMessage(ViewRoot.java:1785)
05-13 19:52:22.309: E/AndroidRuntime(513): at android.os.Handler.dispatchMessage(Handler.java:99)
05-13 19:52:22.309: E/AndroidRuntime(513): at android.os.Looper.loop(Looper.java:123)
05-13 19:52:22.309: E/AndroidRuntime(513): at android.app.ActivityThread.main(ActivityThread.java:4627)
05-13 19:52:22.309: E/AndroidRuntime(513): at java.lang.reflect.Method.invokeNative(Native Method)
05-13 19:52:22.309: E/AndroidRuntime(513): at java.lang.reflect.Method.invoke(Method.java:521)
05-13 19:52:22.309: E/AndroidRuntime(513): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
05-13 19:52:22.309: E/AndroidRuntime(513): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
05-13 19:52:22.309: E/AndroidRuntime(513): at dalvik.system.NativeStart.main(Native Method)

Answer 1

You seem to have a number of issues. Let's try and fix the layout inflate crash first.
List<Button> buttons;
...
buttons = new ArrayList<Button>();
buttons.add((Button)findViewById(R.id.buttonC4));
buttons.add((Button)findViewById(R.id.buttonD4));
...
for (Button button : buttons) {
button.setOnClickListener(this);
}
That will properly cast your layout's Button Views and set an OnClickListener for each.
Your Activity will need to implement View.OnClickListener to use setOnClickListener(this). Replace with the appropriate class if you have your click handling separated, that class will implement OnClickListener instead of your Activity in that case.