HFJ Music Box Page 392

[Davy Kelly]

Hey Guys,

been a while, still getting back into it, but on page 392 of the Head First Java, I was doing the Music Box program with GUI.

I get an error from the code, and I am not sure why.

the 1 error I get is this line of code

sequencer.addControllerEventListener(ml, new int[] {127});

i get this error:

MiniMusicPlayer3.java:33 addControllerEventListener(javax.sound.midi.ControllerEventListener,int[]) in javax.sound.midi.Sequencer cannot be applied to (MyDrawPanel,int[])
     sequencer.addControllerEventListener(ml, new int[] {127});
                 ^
1 error

I copied the code directly, i fixed other errors I done, but I have been looking at this for over an hour now, and cant get it.

here is the full program code:

import javax.sound.midi.*;
import java.io.*;
import javax.swing.*;
import java.awt.*;
 
public class MiniMusicPlayer3 
{
static JFrame f = new JFrame("My First Music Video");
static MyDrawPanel ml;
 
public static void main(String[] args)
{
MiniMusicPlayer3 mini = new MiniMusicPlayer3();
mini.go();
}//close main method

public void setUpGui()
{
ml = new MyDrawPanel();
f.setContentPane(ml);
f.setBounds(30, 30, 300, 300);
f.setVisible(true);
}//close setUpGui method
 
public void go()
{
setUpGui();
try
{
//make and open a sequencer
Sequencer sequencer = MidiSystem.getSequencer();
sequencer.open();
sequencer.addControllerEventListener(ml, new int[] {127});
 
//make a sequence and a track
Sequence seq = new Sequence(Sequence.PPQ, 4);
Track track = seq.createTrack();

int r = 0;
//make a bunch of events to make the notes keep going up
for (int i = 0; i < 60; i+= 4)
{
r = (int)((Math.random() * 50) +1);
//call a new makeEvent() method to make the message and event.
//then add the result to the track
track.add(makeEvent(144, 1, r, 100, i));
 
/*Here's how we pick up the beat - -
we insert our own ControllerEvent (176 says the event type is ControllerEvent)
with an argument for event #127. This will do NOTHING!
We put it in just so that we can get an event each time a note is played.
In other words, its sole purpose is so that something will fire that we can listen for
(we can listen for NOTE ON/OFF events).
Note that we're making this event happen at the same tick as the NOTE ON.
So when the NOTE ON event happens, we'll know about it because out event will fire at the same time.
*/
track.add(makeEvent(176, 1, 127, 0, i));
track.add(makeEvent(128, 1, r, 100, i + 2));
}//end for loop
 
//start the sequence runnning
sequencer.setSequence(seq);
sequencer.start();
sequencer.setTempoInBPM(220);
}//close try
catch (Exception ex)
{
ex.printStackTrace();
}//close catch
}//close go method

public MidiEvent makeEvent(int comd, int chan, int one, int two, int tick)
{
MidiEvent event = null;
try
{
ShortMessage a = new ShortMessage();
a.setMessage(comd, chan, one, two);
event = new MidiEvent(a, tick);
}//close try
catch (Exception e)
{
}//close catch
 
return event;
}//close makeEvent method
 
//inner class
class MyDrawPanel1 extends JPanel implements ControllerEventListener 
{
//set the flag to false, only set it to true when we get an event
boolean msg = false;
 
public void controlChange(ShortMessage event) 
{
//we got an event set the flag to true and repaint
msg = true;
repaint();
}
public void paintComponent(Graphics g)
{
if (msg)
{
//we have to use a flag because other things might trigger a repaint
//we only want to pain only there's a controllerEvent
Graphics2D g2 = (Graphics2D) g;
 
int r = (int)(Math.random()*250);
int gr = (int)(Math.random()*250);
int b = (int)(Math.random()*250);
 
g.setColor(new Color(r, gr, b));
 
int ht = (int)((Math.random()*120) + 10);
int width = (int)((Math.random()*120) + 10);
 
int x = (int)((Math.random()*40) + 10);
int y = (int)((Math.random()*40) + 10);
 
g.fillRect(x, y, ht, width);
msg = false;
}//close if
}//close paintComponent method
}//close inner class
}//close outer MiniMusicPlayer3 class

any help will be appreciated.

davy

[ November 18, 2006: Message edited by: Davy Kelly ]
[ November 18, 2006: Message edited by: Davy Kelly ]

[Davy Kelly]

Woo Hoo,

I figured it out, because I have another version of MyDrawPanel, I renamed the one in this program as MyDrawPanel1 and I forgot to fix the declerations of them, so some had MyDrawPanel and some had MyDrawPanel1, its all fixed now.

it took me a while, but I got there.

I think I need a break now.

davy