We Keep Coding

My Zombie won't find itself.

That sounds extremely philosophical doesn't it?
Anyways, I have a rather complex problem.
My main_activity class gathers all of the Zombies like so:
//Testing Runnable (used to compare the first zombie with the player)
private Runnable updateLocations = new Runnable(){
#Override
public void run(){
try {
while(true) {
image_player.getLocationInWindow(pLoc);
Zombie zoms = zombieCollection.next();
if(!zoms.equals(null)){
zoms.getZombieImage().getLocationInWindow(zLoc);
}
System.out.println("Zombie: x = " + zLoc[0] + "; y = " + zLoc[1]);
System.out.println("Player: x = " + pLoc[0] + "; y = " + pLoc[1]);
Thread.sleep(500);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
My zombie class gathers information like so:
public class Zombie{
float X, Y;
int Width, Height;
Direction fdirc;
ImageView zImage;
Player player;
boolean dead;
int[] zLoc;
public Zombie(ImageView zImage, Player player){
zLoc = new int[2];
zImage.getLocationOnScreen(zLoc);
this.zImage = zImage;
this.X = zLoc[0];
this.Y = zLoc[1];
this.Width = zImage.getWidth();
this.Height = zImage.getHeight();
this.fdirc = Direction.EAST;
this.player = player;
this.dead = false;
Thread thread = new Thread(this.startZombieChase);
thread.start();
}
public ImageView getZombieImage(){
return zImage;
}
private Runnable startZombieChase = new Runnable() {
#Override
public void run() {
try {
while(!dead) {
moveTowardsPlayer();
Thread.sleep(10);
updateZombie.sendEmptyMessage(0);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
private Handler updateZombie = new Handler(Looper.getMainLooper()) {
public void handleMessage(android.os.Message msg) {
/** Because the zombie should always be on top! **/
zImage.getLocationOnScreen(zLoc);
zImage.bringToFront();
zImage.setX(X);
zImage.setY(Y);
}
};
private void moveTowardsPlayer(){
int player_x = player.getPosition()[0];
int player_y = player.getPosition()[1];
l("Where is it in zombie class : player - " + player_x + " " + player_y + "zombie - " + X + " " + Y);
float compareX = player_x - (int)X;
float compareY = player_y - (int)Y;
// Y is closer, so we're moving horizontally.
if(Math.abs(compareX) < Math.abs(compareY)){
//Moving North
if(player_y > Y){
Y+=1;
}
//Moving South
else if(player_y < Y){
Y-=1;
}
}
// X is closer, so we're moving vertically.
else{
//Moving East
if(player_x > X){
X+=1;
}
//Moving West
else if(player_x < X){
X-=1;
}
}
}
public void l(Object string){
System.out.println("Log - " + string);
}
}
The problem I'm having is that it will move relative to a number (So, it does move relative to something) but, not the correct thing.
logcat tells me this:
Where is it in zombie class: player - 750 451 zombie - 750 451
Where it is in main_activity: player - 750 451 zombie - 792 619
Could anyone help me understand what I'm doing wrong?
The entire project is located here.

Zombies that moves away from the Brainz, must be an ill Zombie. We can't have that, now can we?
To have a function that moves the Zombie towards the non-zombie, you use a function, but that function makes use of variables that are not arguments, and there fore hard to find out where they come from. I'd go with something like this: (this is a bit verbose, but clearly shows what is happening)
/*
* Function to update the position of the Zombie, aka walk to the Player.
* #player_pos - Where's the Brainz at?
* #zombie_pos - Where am I?
* Might want to build it overloaded with an option for the speed.
*
* #return - We return the new Zombie pos.
*/
private double [] moveTowardsPlayer(double [] player_pos, double [] zombie_pos) {
// To make sure we don't override the old position, we copy values. (Java stuff)
double [] player_pos_old = player_pos.clone();
double [] zombie_pos_old = zombie_pos.clone();
// Let's get the new X pos for the Zombie
double left_or_right = player_pos_old[0] - zombie_pos_old[0]; // pos number is right, neg is left
double zombie_pos_new_x;
if (left_or_right > 0) { // Right
zombie_pos_new_x = player_pos_old[0] + zombie_speed;
} else { // Left - this way we make sure we are always getting nearer to the Brainz.
zombie_pos_new_x = player_pos_old[0] - zombie_speed;
}
// TODO: do the same for the Y pos.
// Bring it together
double [] zombie_pos_new = {zombie_pos_new_x, zombie_pos_new_y};
// One step closer to the Brainz!
return zombie_pos_new;
}
And use like:
double [] zombie_pos = moveTowardsPlayer([2, 2], [5, 4]);
this.X = zombie_pos[0]; // I'd advice to keep these together as one var.
this.Y = zombie_pos[1]; // But it's your game.
And then figure out when the Zombie gets the Brainz (or the Bullet)

this here is not correct:
if(!zoms.equals(null)){
if you are trying to check that zoms is not pointing to a null reference then do
if(zoms != null ){

Where to declair the alarm manager for updating a watchface in ambient mode?

I'm trying to add an AlarmManager to update a watch face on half minute intervals.
This is for a ternary clock.
This is my first time programming with Java or android studio.
I'm following a guide at https://developer.android.com/training/wearables/apps/always-on.html
The guide says to "declare the alarm manager and the pending intent in the onCreate() method of your activity"
Should I use
#Override
public Engine onCreateEngine() {
return new Engine();
}
or
#Override
public Engine onCreateEngine() {
return new Engine();
}
or should I start a new method or declare it elsewhere?
Currently I'm using
private class Engine extends CanvasWatchFaceService.Engine {
final Handler mUpdateTimeHandler = new EngineHandler(this);
for most of my initialization.
This is my code without the alarm manager. The issue is that it must update during half minutes, because as balanced ternary the time should be to the nearest minute.
public class ternary extends CanvasWatchFaceService {
private static final Typeface NORMAL_TYPEFACE =
Typeface.create(Typeface.SANS_SERIF, Typeface.NORMAL);
private static final int MSG_UPDATE_TIME = 0;
#Override
public Engine onCreateEngine() {
return new Engine();
}
private static class EngineHandler extends Handler {
private final WeakReference<ternary.Engine> mWeakReference;
public EngineHandler(ternary.Engine reference) {
mWeakReference = new WeakReference<>(reference);
}
#Override
public void handleMessage(Message msg) {
ternary.Engine engine = mWeakReference.get();
if (engine != null) {
switch (msg.what) {
case MSG_UPDATE_TIME:
engine.handleUpdateTimeMessage();
break;
}
}
}
}
private class Engine extends CanvasWatchFaceService.Engine {
final Handler mUpdateTimeHandler = new EngineHandler(this);
boolean mRegisteredTimeZoneReceiver = false;
Paint mBackgroundPaint;
Paint mTextPaint;
boolean mAmbient;
Time mTime;
final BroadcastReceiver mTimeZoneReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
mTime.clear(intent.getStringExtra("time-zone"));
mTime.setToNow();
}
};
int mTapCount;
float mXOffset;
float mYOffset;
// adjust text size
float textRatio = (float)1; // 2/3;
// make adjusted offset for hours
float hrsIndent;
float hrsIndentAdjust = textRatio * 55;
// vertical offset for multiple lines
float ySpacer = textRatio * 65;
// first run.
boolean yesFirstRun = true;
// flag for seconds
boolean yesSecs;
// prior state of yesSecs
boolean wasSecs = true;
// flag for conservation mode (no seconds in ambient)
boolean yesConcerve = false;
// flag for allowing seconds
boolean allowSecs = true;
// for execution control
boolean openGate = false;
// counter for next draw
int c = 0;
// counter for time loops
int k;
boolean drawNow = true;
// strings for draw
String hrs = "";
String mns = "";
String sks = "";
// register for milliseconds
long millis = 0;
// float for calculating trits from time.
float tim = 0;
// ints for minute and hour offsets.
int minInt = 0;
int hourInt = 0;
// lists for time to trit for loop conversions.
int [] trits3 = {9, 3, 1};
int [] trits4 = {27, 9, 3, 1};
// absolute count for trouble shooting
// long x = 0;
/**
* Whether the display supports fewer bits for each color in ambient mode. When true, we
* disable anti-aliasing in ambient mode.
*/
boolean mLowBitAmbient;
#Override
public void onCreate(SurfaceHolder holder) {
super.onCreate(holder);
setWatchFaceStyle(new WatchFaceStyle.Builder(ternary.this)
.setCardPeekMode(WatchFaceStyle.PEEK_MODE_VARIABLE)
.setBackgroundVisibility(WatchFaceStyle.BACKGROUND_VISIBILITY_INTERRUPTIVE)
.setShowSystemUiTime(false)
.setAcceptsTapEvents(true)
.build());
Resources resources = ternary.this.getResources();
// shift y offset up
mYOffset = -30 + resources.getDimension(R.dimen.digital_y_offset);
mBackgroundPaint = new Paint();
mBackgroundPaint.setColor(resources.getColor(R.color.background));
mTextPaint = new Paint();
mTextPaint = createTextPaint(resources.getColor(R.color.digital_text));
mTime = new Time();
}
#Override
public void onDestroy() {
mUpdateTimeHandler.removeMessages(MSG_UPDATE_TIME);
super.onDestroy();
}
private Paint createTextPaint(int textColor) {
Paint paint = new Paint();
paint.setColor(textColor);
paint.setTypeface(NORMAL_TYPEFACE);
paint.setAntiAlias(true);
return paint;
}
#Override
public void onVisibilityChanged(boolean visible) {
super.onVisibilityChanged(visible);
if (visible) {
registerReceiver();
// Update time zone in case it changed while we weren't visible.
mTime.clear(TimeZone.getDefault().getID());
mTime.setToNow();
} else {
unregisterReceiver();
}
// Whether the timer should be running depends on whether we're visible (as well as
// whether we're in ambient mode), so we may need to start or stop the timer.
updateTimer();
}
private void registerReceiver() {
if (mRegisteredTimeZoneReceiver) {
return;
}
mRegisteredTimeZoneReceiver = true;
IntentFilter filter = new IntentFilter(Intent.ACTION_TIMEZONE_CHANGED);
ternary.this.registerReceiver(mTimeZoneReceiver, filter);
}
private void unregisterReceiver() {
if (!mRegisteredTimeZoneReceiver) {
return;
}
mRegisteredTimeZoneReceiver = false;
ternary.this.unregisterReceiver(mTimeZoneReceiver);
}
#Override
public void onApplyWindowInsets(WindowInsets insets) {
super.onApplyWindowInsets(insets);
// Load resources that have alternate values for round watches.
Resources resources = ternary.this.getResources();
boolean isRound = insets.isRound();
// shift offset 75 to the right
mXOffset = 75 + resources.getDimension(isRound
? R.dimen.digital_x_offset_round : R.dimen.digital_x_offset);
float textSize = resources.getDimension(isRound
? R.dimen.digital_text_size_round : R.dimen.digital_text_size);
// adjust hrs Indent to MXOffset
hrsIndent = hrsIndentAdjust + mXOffset;
// adjust size to textRatio
mTextPaint.setTextSize(textSize * textRatio );
}
#Override
public void onPropertiesChanged(Bundle properties) {
super.onPropertiesChanged(properties);
mLowBitAmbient = properties.getBoolean(PROPERTY_LOW_BIT_AMBIENT, false);
}
#Override
public void onTimeTick() {
super.onTimeTick();
invalidate();
}
#Override
public void onAmbientModeChanged(boolean inAmbientMode) {
super.onAmbientModeChanged(inAmbientMode);
if (mAmbient != inAmbientMode) {
mAmbient = inAmbientMode;
if (mLowBitAmbient) {
mTextPaint.setAntiAlias(!inAmbientMode);
}
invalidate();
}
// Whether the timer should be running depends on whether we're visible (as well as
// whether we're in ambient mode), so we may need to start or stop the timer.
updateTimer();
}
/**
* Captures tap event (and tap type) and toggles the background color if the user finishes
* a tap.
*/
#Override
public void onTapCommand(int tapType, int x, int y, long eventTime) {
Resources resources = ternary.this.getResources();
switch (tapType) {
case TAP_TYPE_TOUCH:
// The user has started touching the screen.
break;
case TAP_TYPE_TOUCH_CANCEL:
// The user has started a different gesture or otherwise cancelled the tap.
break;
case TAP_TYPE_TAP:
// The user has completed the tap gesture.
mTapCount++;
mBackgroundPaint.setColor(resources.getColor(mTapCount % 2 == 0 ?
R.color.background : R.color.background2));
break;
}
invalidate();
}
#Override
public void onDraw(Canvas canvas, Rect bounds) {
// Greebo counter
// x += 1;
// seconds handling
wasSecs = yesSecs;
yesSecs = allowSecs && !isInAmbientMode();
// for clearing seconds
if (!yesSecs && wasSecs) { sks = ""; }
// Draw at mid second
if (c == 0 && yesSecs) {
drawNow = true;
} else {
c = 0;
// mid minute
if (mTime.second == 30 || isInAmbientMode()) {
drawNow = true;
} else {
// mid hour
if (mTime.second == 0) {
if (mTime.minute == 30) {
drawNow = true;
} else {
// mid night
if (mTime.minute == 0) {
if (mTime.hour == 0) {
drawNow = true;
}
}
}
}
}
}
if (drawNow) {
drawNow = false;
mTime.setToNow();
millis = System.currentTimeMillis() % 1000;
// mid seconds
if (yesSecs) { if (millis > 499) { c = 1; } }
tim = (float)((mTime.minute * 60 + mTime.second) * 1000 + millis)/ 3600000;
// hours past noon
tim += mTime.hour - 12;
// find hrs 9s, 3s, 1s.
openGate = false;
if (yesFirstRun || mTime.minute == 30){ openGate = true; }
else { openGate = mTime.second == 0 && mTime.minute == 0 && mTime.hour == 0;}
if (openGate) {
hrs = "";
hourInt = 0;
// i is for item.
for (int i : trits3) {
if (tim > ((float) i / 2)) {
tim -= i;
hourInt -= i;
hrs = hrs + "1";
} else {
if (tim < ((float) i / -2)) {
tim += i;
hourInt += i;
hrs = hrs + "¬";
} else {
hrs = hrs + "0";
}
}
// add space
if (i > 1) {hrs += " "; }
}
} else { tim += hourInt; }
// minutes 27s, 9s, 3s, 1s
openGate = false;
if (yesFirstRun || mTime.second == 30 || isInAmbientMode()) {openGate = true; }
else { openGate = mTime.second == 0 && (mTime.minute == 30
|| (mTime.minute == 0 && mTime.hour == 0));}
if (openGate) {
mns = "";
tim *= 60;
minInt = 0;
// i is for item.
for (int i : trits4) {
if (tim > ((float) i / 2)) {
tim -= i;
if (yesSecs) {minInt -= i;}
mns = mns + "1";
} else {
if (tim < ((float) i / -2)) {
tim += i;
if (yesSecs) {minInt += i;}
mns = mns + "¬";
} else {
mns = mns + "0";
}
}
// add space
if (i > 1) {mns += " "; }
}
} else { if (yesSecs) { tim += minInt; tim *= 60; } }
// seconds 27s, 9s, 3s, 1s
if (yesSecs) {
sks = "";
tim *= 60;
for (int i : trits4) {
if (tim > ((float) i / 2)) {
tim -= i;
sks = sks + "1";
} else {
if (tim < ((float) i / -2)) {
tim += i;
sks = sks + "¬";
} else {
sks = sks + "0";
}
}
// add space
if (i > 1) {sks += " "; }
}
}
}
// Draw the background.
if (isInAmbientMode()) {
canvas.drawColor(Color.BLACK);
} else {
canvas.drawRect(0, 0, bounds.width(), bounds.height(), mBackgroundPaint);
}
// draw hours
canvas.drawText(hrs, hrsIndent, mYOffset - ySpacer, mTextPaint);
// draw minutes
canvas.drawText(mns, mXOffset, mYOffset, mTextPaint);
// draw or clear seconds
if (yesSecs || wasSecs) {canvas.drawText(sks, mXOffset, mYOffset + ySpacer , mTextPaint);}
// show count and millis for greebo reduction.
// canvas.drawText(String.format("%1$03d,%2$02d,%3$d", x % 1000, millis / 10, 0), mXOffset, mYOffset + 100, mTextPaint);
//canvas.drawText(String.format("%$02d:%2$02d:%3$02d", mTime.hour, mTime.minute,
// mTime.second), mXOffset, mYOffset + 100, mTextPaint);
}
/**
* Starts the {#link #mUpdateTimeHandler} timer if it should be running and isn't currently
* or stops it if it shouldn't be running but currently is.
*/
private void updateTimer() {
mUpdateTimeHandler.removeMessages(MSG_UPDATE_TIME);
if (shouldTimerBeRunning()) {
mUpdateTimeHandler.sendEmptyMessage(MSG_UPDATE_TIME);
}
}
/**
* Returns whether the {#link #mUpdateTimeHandler} timer should be running. The timer should
* only run when we're visible and in interactive mode.
*/
private boolean shouldTimerBeRunning() {
return isVisible() && !isInAmbientMode();
}
/**
* Handle updating the time periodically in interactive mode.
*/
private void handleUpdateTimeMessage() {
invalidate();
if (shouldTimerBeRunning()) {
long timeMs = System.currentTimeMillis();
long delayMs = INTERACTIVE_UPDATE_RATE_MS
- (timeMs % INTERACTIVE_UPDATE_RATE_MS);
mUpdateTimeHandler.sendEmptyMessageDelayed(MSG_UPDATE_TIME, delayMs);
}
}
}
}

The "onCreate()" method seems to correlate with:
public class ternary extends CanvasWatchFaceService
Your declaration should be as follows:
public class ternary extends CanvasWatchFaceService {
private AlarmManager mAmbientStateAlarmManager;
private PendingIntent mAmbientStatePendingIntent;
And be sure to import android.app.AlarmManager and android.app.PendingIntent
.

Edge Detection code for BufferedImage

I am trying to create an Object that given an Image and Point it will trace the inside edge of that Image.
For simplicity the edges will always be of RGB Color Black.
i Define enums of RIGHT DOWN LEFT UP (Clockwise)
I start at Point p.
I move through the Pixels in the Image based on the current Direction starting with RIGHT.
if this is not a border Pixel i move my Direction back one step anti Clockwise. e.g (Left->DOWN)
if i cannot move my chosen direction i move to next direction.
i add the Point to my border array.
i do this till we return to the first border Pixel.
Thats the Plan...
So far i hit a snag when i have to go from UP to RIGHT but back to RIGHT again immediately after in order to keep the direction focused on the edge rather than turn back into the Image.
Ive tried using a boolean flag if UP is used, Directing the Next direction for right to be UP and Not DOWN.
Any guidance would be much appreciated.
I have the full Code below.
CODE:
package edgedection;
import static edgedection.EdgeDection.testImage;
import java.awt.Color;
import java.awt.Point;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
/**
*
* #author Fionán
*/
public class EdgeDection {
/**
* #param args the command line arguments
*/
static BufferedImage testImage = null;
{
try {
testImage = ImageIO.read(this.getClass().getResourceAsStream("testImage2.png"));
} catch (IOException ex) {
Logger.getLogger(EdgeDection.class.getName()).log(Level.SEVERE, null, ex);
}
}
static enum DIRECTION {
RIGHT, DOWN, LEFT, UP, NOMOVE
}
BufferedImage bi;
int borderColor = Color.black.getRGB();
DIRECTION facing;
Point p;
ArrayList<Point> borders;
boolean upFlag = false;
int x = p.x;
int y = p.y;
public static void main(String[] args) {
int x = 150;
int y = 60;
//forcing instance for loading Images only.
EdgeDection test= new EdgeDection();
JFrame show = new JFrame();
show.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel picLabel = new JLabel(new ImageIcon(testImage));
show.add(picLabel);
show.pack();
show.setVisible(true);
EdgeDection dector = new EdgeDection(testImage, new Point(x, y));
dector.start();
dector.highLightEdge();
show.repaint();
}
boolean canMove(DIRECTION d, Point p) {
switch (d) {
case RIGHT:
return bi.getRGB(p.x + 1, p.y) != borderColor;
case DOWN:
return bi.getRGB(p.x, p.y + 1) != borderColor;
case LEFT:
return bi.getRGB(p.x - 1, p.y) != borderColor;
//Deafult is up
case UP:
return bi.getRGB(p.x, p.y - 1) != borderColor;
default:
return false;
}
}
public EdgeDection(BufferedImage bi, Point p) {
this.facing = DIRECTION.RIGHT;
this.bi = bi;
this.p = p;
this.borders = new ArrayList<>();
}
public EdgeDection() {
}
DIRECTION getDirection() {
return null;
}
void addBorder(Point p) {
if(borders.isEmpty()){
x = p.x;
y = p.y;
}
borders.add(p);
}
void start() {
do {
System.out.println("Checking " + p.x + " " + p.y + facing);
if (canMove(facing, p)) {
if (upFlag) {
facing = DIRECTION.UP;
// p =new Point(p.x+1,p.y);
}
p = NextPointByDirection();
if(!upFlag) stepBackDirection();
if(upFlag)upFlag=false;
} else {
addBorder(p);
setNextDirection();
System.out.println("going " + facing + " border array size = "+ borders.size());
System.out.println("Up Flag status "+upFlag);
}
} while (facing != DIRECTION.NOMOVE && (p.x != x || p.y != y));
}
private void stepBackDirection() {
switch (facing) {
case RIGHT:
if(upFlag) {facing = DIRECTION.UP;}else{
facing = DIRECTION.RIGHT;
}
break;
case DOWN:
facing = DIRECTION.RIGHT;
break;
case LEFT:
facing = DIRECTION.DOWN;
break;
case UP:
facing = DIRECTION.LEFT;
}
}
private void setNextDirection() {
switch (facing) {
case RIGHT:
facing = DIRECTION.DOWN;
if (upFlag) {
facing = DIRECTION.UP;
upFlag = false;
}
return;
case DOWN:
facing = DIRECTION.LEFT;
return;
case LEFT:
facing = DIRECTION.UP;
return;
case UP:
upFlag = true;
facing = DIRECTION.RIGHT;
// upFlag = true;
// if (canMove(facing, new Point(p.x + 1, p.y - 1))){
// p = new Point(p.x + 1, p.y - 1);
//
// } ;
//
// if (upFlag) {
// facing = DIRECTION.RIGHT;
// }
}
}
private Point NextPointByDirection() {
// if (upFlag) {
// facing = DIRECTION.UP;
// upFlag = !upFlag;
// }
switch (facing) {
case RIGHT:
return new Point(p.x + 1, p.y);
case DOWN:
return new Point(p.x, p.y + 1);
case LEFT:
return new Point(p.x - 1, p.y);
default:
return new Point(p.x, p.y - 1);
}
}
private void print() {
for (Point p : borders) {
System.out.print(p.x + " " + p.y + " ");
}
}
void highLightEdge() {
for (Point p : borders) {
bi.setRGB(p.x, p.y, Color.RED.getRGB());
}
}
}

For anyone interested , i solved this problem with the use of a Stack.
pre-populate the stack with the order of directions to take.
Start moving in a direction.
if it can move direction is popped from stack
else
Hit a border
push that direction to the stack
add The border to the Set of borders
if border is already in set break loop else
turn 90 degree relative to the direction

match and delete elements in arraylists

I am making a robot maze where the robot reaches a target automatically without crashing into walls. I want the robot to do the maze once, learn the correct route and then the second time be able to get there straight away without going to any deadends. I thought I could do this by making three arraylists.
One for all the squares the robot visits.
Two for all the squares that lead to a deadend.
Three for all the directions the robot goes.
If the squares that lead to a dead end are found in the first arraylist then i can delete the same indexes in the third arraylist. That way, the second time, i can just iterate the third Arraylist.
My full code is below:
import java.util.ArrayList;
import java.util.*;
import java.util.Iterator;
import java.util.stream.IntStream;
public class Explorer {
private int pollRun = 0; // Incremented after each pass.
private RobotData robotData; // Data store for junctions.
private ArrayList<Integer> nonWallDirections;
private ArrayList<Integer> passageDirections;
private ArrayList<Integer> beenbeforeDirections;
private Random random = new Random();
int [] directions = {IRobot.AHEAD, IRobot.LEFT, IRobot.RIGHT, IRobot.BEHIND};
private ArrayList<Square> correctSquares;
private ArrayList<Square> wrongSquares;
private ArrayList<Integer> correctDirections;
public void controlRobot (IRobot robot) {
// On the first move of the first run of a new maze.
if ((robot.getRuns() == 0) && (pollRun ==0))
robotData = new RobotData();
pollRun++; /* Increment poll run so that the data is not reset
each time the robot moves. */
int exits = nonwallExits(robot);
int direction;
if ((robot.getRuns() != 0))
direction = grandfinale(robot);
nonWallDirections = new ArrayList<Integer>();
passageDirections = new ArrayList<Integer>();
beenbeforeDirections = new ArrayList<Integer>();
correctSquares = new ArrayList<Square>();
correctDirections = new ArrayList<Integer>();
// Adding each direction to the appropriate state ArrayList.
for(int item : directions) {
if(robot.look(item) != IRobot.WALL) {
nonWallDirections.add(item);
}
}
for(int item : directions) {
if(robot.look(item) == IRobot.PASSAGE) {
passageDirections.add(item);
}
}
for(int item : directions) {
if(robot.look(item) == IRobot.BEENBEFORE) {
beenbeforeDirections.add(item);
}
}
// Calling the appropriate method depending on the number of exits.
if (exits < 2) {
direction = deadEnd(robot);
} else if (exits == 2) {
direction = corridor(robot);
} else {
direction = junction(robot);
robotData.addJunction(robot);
robotData.printJunction(robot);
}
robot.face(direction);
addcorrectSquares(robot);
correctDirections.add(direction);
}
/* The specification advised to have to seperate controls: Explorer and Backtrack
and a variable explorerMode to switch between them.
Instead, whenever needed I shall call this backtrack method.
If at a junction, the robot will head back the junction as to when it first approached it.
When at a deadend or corridor, it will follow the beenbefore squares until it
reaches an unexplored path. */
public int backtrack (IRobot robot) {
if (nonwallExits(robot) > 2) {
addwrongSquares(robot);
return robotData.reverseHeading(robot);
} else {
do {
addwrongSquares(robot);
return nonWallDirections.get(0);
} while (nonwallExits(robot) == 1);
}
}
// Deadend method makes the robot follow the only nonwall exit.
public int deadEnd (IRobot robot) {
return backtrack(robot);
}
/* Corridor method will make the robot follow the one and only passage.
The exception is at the start. Sometimes, the robot will start with
two passages available to it in which case it will choose one randomly.
If there is no passage, it will follow the beenbefore squares
until it reaches an unexplored path.*/
public int corridor (IRobot robot) {
if (passageExits(robot) == 1) {
return passageDirections.get(0);
} else if (passageExits(robot) == 2) {
int randomPassage = random.nextInt(passageDirections.size());
return passageDirections.get(randomPassage);
} else {
return backtrack(robot);
}
}
/* Junction method states if there is more than one passage, it will randomly select one.
This applies to crossroads as well as essentially they are the same.
If there is no passage, it will follow the beenbefore squares until it reaches an unexplored
path. */
public int junction(IRobot robot) {
if (passageExits(robot) == 1) {
return passageDirections.get(0);
} else if (passageExits(robot) > 1) {
int randomPassage = random.nextInt(passageDirections.size());
return passageDirections.get(randomPassage);
} else {
return backtrack(robot);
}
}
// Calculates number of exits.
private int nonwallExits (IRobot robot) {
int nonwallExits = 0;
for(int item : directions) {
if(robot.look(item) != IRobot.WALL) {
nonwallExits++;
}
}
return nonwallExits;
}
// Calculates number of passages.
private int passageExits (IRobot robot) {
int passageExits = 0;
for(int item : directions) {
if(robot.look(item) == IRobot.PASSAGE) {
passageExits++;
}
}
return passageExits;
}
// Calculates number of beenbefores.
private int beenbeforeExits (IRobot robot) {
int beenbeforeExits = 0;
for(int item : directions) {
if(robot.look(item) == IRobot.PASSAGE) {
beenbeforeExits++;
}
}
return beenbeforeExits;
}
// Resets Junction Counter in RobotData class.
public int reset() {
return robotData.resetJunctionCounter();
}
public void addcorrectSquares(IRobot robot) {
Square newSquare = new Square(robot.getLocation().x, robot.getLocation().y);
correctSquares.add(newSquare);
}
public void addwrongSquares(IRobot robot) {
Square badSquare = new Square(robot.getLocation().x, robot.getLocation().y);
wrongSquares.add(badSquare);
}
public int grandfinale (IRobot robot) {
IntStream.range(0, correctSquares.size())
.map(index -> correctSquares.size() - index - 1)
.filter(index -> (((wrongSquares.x).contains(correctSquares.x)) && ((wrongSquares.y).contains(correctSquares.y))).get(index))
.forEach(index -> correctDirections.remove(index));
Iterator<Integer> routeIterator = correctDirections.iterator();
while (routeIterator.hasNext()) {
break;
}
return (routeIterator.next());
}
}
class RobotData {
/* It was advised in the specification to include the variable:
private static int maxJunctions = 10000;
However, as I am not using arrays, but ArrayLists, I do not
need this. */
private static int junctionCounter = 0;
private ArrayList<Junction> junctionList = new ArrayList<Junction>();
// Resets the Junction counter.
public int resetJunctionCounter() {
return junctionCounter = 0;
}
// Adds the current junction to the list of arrays.
public void addJunction(IRobot robot) {
Junction newJunction = new Junction(robot.getLocation().x, robot.getLocation().y, robot.getHeading());
junctionList.add(newJunction);
junctionCounter++;
}
// Gets the junction counter for Junction info method in Junction class.
public int getJunctionCounter (IRobot robot) {
return junctionCounter;
}
// Prints Junction info.
public void printJunction(IRobot robot) {
String course = "";
switch (robot.getHeading()) {
case IRobot.NORTH:
course = "NORTH";
break;
case IRobot.EAST:
course = "EAST";
break;
case IRobot.SOUTH:
course = "SOUTH";
break;
case IRobot.WEST:
course = "WEST";
break;
}
System.out.println("Junction " + junctionCounter + " (x=" + robot.getLocation().x + ", y=" + robot.getLocation().y +") heading " + course);
}
/* Iterates through the junction arrayList to find the
heading of the robot when it first approached the junction.
It does this by finding the first junction in the ArrayList
that has the same x and y coordinates as the robot.*/
public int searchJunction(IRobot robot) {
Junction currentJunction = null;
Iterator<Junction> junctionIterator = junctionList.iterator();
while (junctionIterator.hasNext()) {
currentJunction = junctionIterator.next();
if ((((currentJunction.x)==(robot.getLocation().x))) && ((currentJunction.y)==(robot.getLocation().y)))
break;
}
return currentJunction.arrived;
}
// Returns the reverse of the heading the robot had when first approaching the junction.
public int reverseHeading(IRobot robot) {
int firstHeading = searchJunction(robot);
int reverseHeading = 1; // Random integer to Iniitalise variable.
switch (firstHeading) {
case IRobot.NORTH:
if (robot.getHeading() == IRobot.NORTH)
reverseHeading = IRobot.BEHIND;
else if (robot.getHeading() == IRobot.EAST)
reverseHeading = IRobot.RIGHT;
else if (robot.getHeading() == IRobot.SOUTH)
reverseHeading = IRobot.AHEAD;
else
reverseHeading = IRobot.LEFT;
break;
case IRobot.EAST:
if (robot.getHeading() == IRobot.NORTH)
reverseHeading = IRobot.LEFT;
else if (robot.getHeading() == IRobot.EAST)
reverseHeading = IRobot.BEHIND;
else if (robot.getHeading() == IRobot.SOUTH)
reverseHeading = IRobot.RIGHT;
else
reverseHeading = IRobot.AHEAD;
break;
case IRobot.SOUTH:
if (robot.getHeading() == IRobot.NORTH)
reverseHeading = IRobot.AHEAD;
else if (robot.getHeading() == IRobot.EAST)
reverseHeading = IRobot.LEFT;
else if (robot.getHeading() == IRobot.SOUTH)
reverseHeading = IRobot.BEHIND;
else
reverseHeading = IRobot.RIGHT;
break;
case IRobot.WEST:
if (robot.getHeading() == IRobot.NORTH)
reverseHeading = IRobot.RIGHT;
else if (robot.getHeading() == IRobot.EAST)
reverseHeading = IRobot.AHEAD;
else if (robot.getHeading() == IRobot.SOUTH)
reverseHeading = IRobot.LEFT;
else
reverseHeading = IRobot.BEHIND;
break;
}
return reverseHeading;
}
}
class Junction {
int x;
int y;
int arrived;
public Junction(int xcoord, int ycoord, int course) {
x = xcoord;
y = ycoord;
arrived = course;
}
}
class Square {
int x;
int y;
public Square(int cordx, int cordy){
x = cordx;
y = cordy;
}
}

IntStream.range(0, al1.length)
.filter(index -> al2.contains(al1.get(index)))
.forEach(index -> al3.remove(index));
Slightly more complex than this if removing elements from al3 shifts them left but in that case just reverse the stream before the .filter- then it will delete from the end. The easiest way to do that is:
.map(index -> al1.length - index - 1)
Without Streams the equivalent would be
for (int i = 0; i < al1.length; i++) {
if (al2.contains(al1.get(i))) {
al3.remove(i);
}
}
Similarly, if you need to delete from the right then the for loop would need to count down rather than up.
Without further details on arraylist structure it's hard to give any more hints.

Time delay and JInput

OK, I don't know how to word this question, but maybe my code will spell out the problem:
public class ControllerTest
{
public static void main(String [] args)
{
GamePadController rockbandDrum = new GamePadController();
DrumMachine drum = new DrumMachine();
while(true)
{
try{
rockbandDrum.poll();
if(rockbandDrum.isButtonPressed(1)) //BLUE PAD HhiHat)
{
drum.playSound("hiHat.wav");
Thread.sleep(50);
}
if(rockbandDrum.isButtonPressed(2)) //GREEN PAD (Crash)
{
//Todo: Change to Crash
drum.playSound("hiHat.wav");
Thread.sleep(50);
}
//Etc....
}
}
}
public class DrumMachine
{
InputStream soundPlayer = null;
AudioStream audio = null;
static boolean running = true;
public void playSound(String soundFile)
{
//Tak a sound file as a paramater and then
//play that sound file
try{
soundPlayer = new FileInputStream(soundFile);
audio = new AudioStream(soundPlayer);
}
catch(FileNotFoundException e){
e.printStackTrace();
}
catch(IOException e){
e.printStackTrace();
}
AudioPlayer.player.start(audio);
}
//Etc... Methods for multiple audio clip playing
}
Now the problem is, if I lower the delay in the
Thread.sleep(50)
then the sound plays multiple times a second, but if I keep at this level or any higher, I could miss sounds being played...
It's an odd problem, where if the delay is too low, the sound loops. But if it's too high it misses playing sounds. Is this just a problem where I would need to tweak the settings, or is there any other way to poll the controller without looping sound?
Edit: If I need to post the code for polling the controller I will...
import java.io.*;
import net.java.games.input.*;
import net.java.games.input.Component.POV;
public class GamePadController
{
public static final int NUM_BUTTONS = 13;
// public stick and hat compass positions
public static final int NUM_COMPASS_DIRS = 9;
public static final int NW = 0;
public static final int NORTH = 1;
public static final int NE = 2;
public static final int WEST = 3;
public static final int NONE = 4; // default value
public static final int EAST = 5;
public static final int SW = 6;
public static final int SOUTH = 7;
public static final int SE = 8;
private Controller controller;
private Component[] comps; // holds the components
// comps[] indices for specific components
private int xAxisIdx, yAxisIdx, zAxisIdx, rzAxisIdx;
// indices for the analog sticks axes
private int povIdx; // index for the POV hat
private int buttonsIdx[]; // indices for the buttons
private Rumbler[] rumblers;
private int rumblerIdx; // index for the rumbler being used
private boolean rumblerOn = false; // whether rumbler is on or off
public GamePadController()
{
// get the controllers
ControllerEnvironment ce =
ControllerEnvironment.getDefaultEnvironment();
Controller[] cs = ce.getControllers();
if (cs.length == 0) {
System.out.println("No controllers found");
System.exit(0);
}
else
System.out.println("Num. controllers: " + cs.length);
// get the game pad controller
controller = findGamePad(cs);
System.out.println("Game controller: " +
controller.getName() + ", " +
controller.getType());
// collect indices for the required game pad components
findCompIndices(controller);
findRumblers(controller);
} // end of GamePadController()
private Controller findGamePad(Controller[] cs)
/* Search the array of controllers until a suitable game pad
controller is found (eith of type GAMEPAD or STICK).
*/
{
Controller.Type type;
int i = 0;
while(i < cs.length) {
type = cs[i].getType();
if ((type == Controller.Type.GAMEPAD) ||
(type == Controller.Type.STICK))
break;
i++;
}
if (i == cs.length) {
System.out.println("No game pad found");
System.exit(0);
}
else
System.out.println("Game pad index: " + i);
return cs[i];
} // end of findGamePad()
private void findCompIndices(Controller controller)
/* Store the indices for the analog sticks axes
(x,y) and (z,rz), POV hat, and
button components of the controller.
*/
{
comps = controller.getComponents();
if (comps.length == 0) {
System.out.println("No Components found");
System.exit(0);
}
else
System.out.println("Num. Components: " + comps.length);
// get the indices for the axes of the analog sticks: (x,y) and (z,rz)
xAxisIdx = findCompIndex(comps, Component.Identifier.Axis.X, "x-axis");
yAxisIdx = findCompIndex(comps, Component.Identifier.Axis.Y, "y-axis");
zAxisIdx = findCompIndex(comps, Component.Identifier.Axis.Z, "z-axis");
rzAxisIdx = findCompIndex(comps, Component.Identifier.Axis.RZ, "rz-axis");
// get POV hat index
povIdx = findCompIndex(comps, Component.Identifier.Axis.POV, "POV hat");
findButtons(comps);
} // end of findCompIndices()
private int findCompIndex(Component[] comps,
Component.Identifier id, String nm)
/* Search through comps[] for id, returning the corresponding
array index, or -1 */
{
Component c;
for(int i=0; i < comps.length; i++) {
c = comps[i];
if ((c.getIdentifier() == id) && !c.isRelative()) {
System.out.println("Found " + c.getName() + "; index: " + i);
return i;
}
}
System.out.println("No " + nm + " component found");
return -1;
} // end of findCompIndex()
private void findButtons(Component[] comps)
/* Search through comps[] for NUM_BUTTONS buttons, storing
their indices in buttonsIdx[]. Ignore excessive buttons.
If there aren't enough buttons, then fill the empty spots in
buttonsIdx[] with -1's. */
{
buttonsIdx = new int[NUM_BUTTONS];
int numButtons = 0;
Component c;
for(int i=0; i < comps.length; i++) {
c = comps[i];
if (isButton(c)) { // deal with a button
if (numButtons == NUM_BUTTONS) // already enough buttons
System.out.println("Found an extra button; index: " + i + ". Ignoring it");
else {
buttonsIdx[numButtons] = i; // store button index
System.out.println("Found " + c.getName() + "; index: " + i);
numButtons++;
}
}
}
// fill empty spots in buttonsIdx[] with -1's
if (numButtons < NUM_BUTTONS) {
System.out.println("Too few buttons (" + numButtons +
"); expecting " + NUM_BUTTONS);
while (numButtons < NUM_BUTTONS) {
buttonsIdx[numButtons] = -1;
numButtons++;
}
}
} // end of findButtons()
private boolean isButton(Component c)
/* Return true if the component is a digital/absolute button, and
its identifier name ends with "Button" (i.e. the
identifier class is Component.Identifier.Button).
*/
{
if (!c.isAnalog() && !c.isRelative()) { // digital and absolute
String className = c.getIdentifier().getClass().getName();
// System.out.println(c.getName() + " identifier: " + className);
if (className.endsWith("Button"))
return true;
}
return false;
} // end of isButton()
private void findRumblers(Controller controller)
/* Find the rumblers. Use the last rumbler for making vibrations,
an arbitrary decision. */
{
// get the game pad's rumblers
rumblers = controller.getRumblers();
if (rumblers.length == 0) {
System.out.println("No Rumblers found");
rumblerIdx = -1;
}
else {
System.out.println("Rumblers found: " + rumblers.length);
rumblerIdx = rumblers.length-1; // use last rumbler
}
} // end of findRumblers()
// ----------------- polling and getting data ------------------
public void poll()
// update the component values in the controller
{
controller.poll();
}
public int getXYStickDir()
// return the (x,y) analog stick compass direction
{
if ((xAxisIdx == -1) || (yAxisIdx == -1)) {
System.out.println("(x,y) axis data unavailable");
return NONE;
}
else
return getCompassDir(xAxisIdx, yAxisIdx);
} // end of getXYStickDir()
public int getZRZStickDir()
// return the (z,rz) analog stick compass direction
{
if ((zAxisIdx == -1) || (rzAxisIdx == -1)) {
System.out.println("(z,rz) axis data unavailable");
return NONE;
}
else
return getCompassDir(zAxisIdx, rzAxisIdx);
} // end of getXYStickDir()
private int getCompassDir(int xA, int yA)
// Return the axes as a single compass value
{
float xCoord = comps[ xA ].getPollData();
float yCoord = comps[ yA ].getPollData();
// System.out.println("(x,y): (" + xCoord + "," + yCoord + ")");
int xc = Math.round(xCoord);
int yc = Math.round(yCoord);
// System.out.println("Rounded (x,y): (" + xc + "," + yc + ")");
if ((yc == -1) && (xc == -1)) // (y,x)
return NW;
else if ((yc == -1) && (xc == 0))
return NORTH;
else if ((yc == -1) && (xc == 1))
return NE;
else if ((yc == 0) && (xc == -1))
return WEST;
else if ((yc == 0) && (xc == 0))
return NONE;
else if ((yc == 0) && (xc == 1))
return EAST;
else if ((yc == 1) && (xc == -1))
return SW;
else if ((yc == 1) && (xc == 0))
return SOUTH;
else if ((yc == 1) && (xc == 1))
return SE;
else {
System.out.println("Unknown (x,y): (" + xc + "," + yc + ")");
return NONE;
}
} // end of getCompassDir()
public int getHatDir()
// Return the POV hat's direction as a compass direction
{
if (povIdx == -1) {
System.out.println("POV hat data unavailable");
return NONE;
}
else {
float povDir = comps[povIdx].getPollData();
if (povDir == POV.CENTER) // 0.0f
return NONE;
else if (povDir == POV.DOWN) // 0.75f
return SOUTH;
else if (povDir == POV.DOWN_LEFT) // 0.875f
return SW;
else if (povDir == POV.DOWN_RIGHT) // 0.625f
return SE;
else if (povDir == POV.LEFT) // 1.0f
return WEST;
else if (povDir == POV.RIGHT) // 0.5f
return EAST;
else if (povDir == POV.UP) // 0.25f
return NORTH;
else if (povDir == POV.UP_LEFT) // 0.125f
return NW;
else if (povDir == POV.UP_RIGHT) // 0.375f
return NE;
else { // assume center
System.out.println("POV hat value out of range: " + povDir);
return NONE;
}
}
} // end of getHatDir()
public boolean[] getButtons()
/* Return all the buttons in a single array. Each button value is
a boolean. */
{
boolean[] buttons = new boolean[NUM_BUTTONS];
float value;
for(int i=0; i < NUM_BUTTONS; i++) {
value = comps[ buttonsIdx[i] ].getPollData();
buttons[i] = ((value == 0.0f) ? false : true);
}
return buttons;
} // end of getButtons()
public boolean isButtonPressed(int pos)
/* Return the button value (a boolean) for button number 'pos'.
pos is in the range 1-NUM_BUTTONS to match the game pad
button labels.
*/
{
if ((pos < 1) || (pos > NUM_BUTTONS)) {
System.out.println("Button position out of range (1-" +
NUM_BUTTONS + "): " + pos);
return false;
}
if (buttonsIdx[pos-1] == -1) // no button found at that pos
return false;
float value = comps[ buttonsIdx[pos-1] ].getPollData();
// array range is 0-NUM_BUTTONS-1
return ((value == 0.0f) ? false : true);
} // end of isButtonPressed()
// ------------------- Trigger a rumbler -------------------
public void setRumbler(boolean switchOn)
// turn the rumbler on or off
{
if (rumblerIdx != -1) {
if (switchOn)
rumblers[rumblerIdx].rumble(0.8f); // almost full on for last rumbler
else // switch off
rumblers[rumblerIdx].rumble(0.0f);
rumblerOn = switchOn; // record rumbler's new status
}
} // end of setRumbler()
public boolean isRumblerOn()
{ return rumblerOn; }
} // end of GamePadController class

I think you are using the wrong design pattern here. You should use the observer pattern for this type of thing.
A polling loop not very efficient, and as you've noticed doesn't really yield the desired results.
I'm not sure what you are using inside your objects to detect if a key is pressed, but if it's a GUI architecture such as Swing or AWT it will be based on the observer pattern via the use of EventListeners, etc.

Here is a (slightly simplified) Observer-pattern
applied to your situation.
The advantage of this design is that when a button
is pressed and hold, method 'buttonChanged' will
still only be called once, instead of start
'repeating' every 50 ms.
public static final int BUTTON_01 = 0x00000001;
public static final int BUTTON_02 = 0x00000002;
public static final int BUTTON_03 = 0x00000004;
public static final int BUTTON_04 = 0x00000008; // hex 8 == dec 8
public static final int BUTTON_05 = 0x00000010; // hex 10 == dec 16
public static final int BUTTON_06 = 0x00000020; // hex 20 == dec 32
public static final int BUTTON_07 = 0x00000040; // hex 40 == dec 64
public static final int BUTTON_08 = 0x00000080; // etc.
public static final int BUTTON_09 = 0x00000100;
public static final int BUTTON_10 = 0x00000200;
public static final int BUTTON_11 = 0x00000400;
public static final int BUTTON_12 = 0x00000800;
private int previousButtons = 0;
void poll()
{
rockbandDrum.poll();
handleButtons();
}
private void handleButtons()
{
boolean[] buttons = getButtons();
int pressedButtons = getPressedButtons(buttons);
if (pressedButtons != previousButtons)
{
buttonChanged(pressedButtons); // Notify 'listener'.
previousButtons = pressedButtons;
}
}
public boolean[] getButtons()
{
// Return all the buttons in a single array. Each button-value is a boolean.
boolean[] buttons = new boolean[MAX_NUMBER_OF_BUTTONS];
float value;
for (int i = 0; i < MAX_NUMBER_OF_BUTTONS-1; i++)
{
int index = buttonsIndex[i];
if (index < 0) { continue; }
value = comps[index].getPollData();
buttons[i] = ((value == 0.0f) ? false : true);
}
return buttons;
}
private int getPressedButtons(boolean[] array)
{
// Mold all pressed buttons into a single number by OR-ing their values.
int pressedButtons = 0;
int i = 1;
for (boolean isBbuttonPressed : array)
{
if (isBbuttonPressed) { pressedButtons |= getOrValue(i); }
i++;
}
return pressedButtons;
}
private int getOrValue(int btnNumber) // Get a value to 'OR' with.
{
int btnValue = 0;
switch (btnNumber)
{
case 1 : btnValue = BUTTON_01; break;
case 2 : btnValue = BUTTON_02; break;
case 3 : btnValue = BUTTON_03; break;
case 4 : btnValue = BUTTON_04; break;
case 5 : btnValue = BUTTON_05; break;
case 6 : btnValue = BUTTON_06; break;
case 7 : btnValue = BUTTON_07; break;
case 8 : btnValue = BUTTON_08; break;
case 9 : btnValue = BUTTON_09; break;
case 10 : btnValue = BUTTON_10; break;
case 11 : btnValue = BUTTON_11; break;
case 12 : btnValue = BUTTON_12; break;
default : assert false : "Invalid button-number";
}
return btnValue;
}
public static boolean checkButton(int pressedButtons, int buttonToCheckFor)
{
return (pressedButtons & buttonToCheckFor) == buttonToCheckFor;
}
public void buttonChanged(int buttons)
{
if (checkButton(buttons, BUTTON_01)
{
drum.playSound("hiHat.wav");
}
if (checkButton(buttons, BUTTON_02)
{
drum.playSound("crash.wav");
}
}

Please post more information about the GamePadController class that you are using.
More than likely, that same library will offer an "event" API, where a "callback" that you register with a game pad object will be called as soon as the user presses a button. With this kind of setup, the "polling" loop is in the framework, not your application, and it can be much more efficient, because it uses signals from the hardware rather than a busy-wait polling loop.
Okay, I looked at the JInput API, and it is not really event-driven; you have to poll it as you are doing. Does the sound stop looping when you release the button? If so, is your goal to have the sound play just once, and not again until the button is release and pressed again? In that case, you'll need to track the previous button state each time through the loop.
Human response time is about 250 ms (for an old guy like me, anyway). If you are polling every 50 ms, I'd expect the controller to report the button depressed for several iterations of the loop. Can you try something like this:
boolean played = false;
while (true) {
String sound = null;
if (controller.isButtonPressed(1))
sound = "hiHat.wav";
if (controller.isButtonPressed(2))
sound = "crash.wav";
if (sound != null) {
if (!played) {
drum.playSound(sound);
played = true;
}
} else {
played = false;
}
Thread.sleep(50);
}