I'm working with java images for the first time and having a problem viewing them when the applet loads. If I resize the window they display fine. I feel like this is a common first-timer error. Has anyone else encountered this? Any idea what the fix could be? What I believe to be the pertinent parts of the code are listed below. Thanks for any and all help with this...
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
import java.util.*;
public class example extends JApplet implements Runnable
{
boolean updating;
Thread thread;
private int width, height;
Table aTable; //used to create and store values
private AudioClip[] sounds = new AudioClip[4]; //array to hold audio clips
private int counter = 0; //counter for audio clip array
private Image GameImage;
private Graphics GameGraphics;
public example() //set up applet gui
{
this.resize(new Dimension(600, 500));
//setup table
aTable = new Table(50, 50, 50, 50, 16, 16, getImage("images/FLY.gif", Color.white),
getImage("images/FlySwatter.gif", Color.white)); //Table must be square or flyswatter wont move straight
//add cordTxtFlds to bottom of screen
//this.add(cordTxtFlds, BorderLayout.SOUTH);
super.resize(800, 600);
repaint();
}
public void init()
{
width = getSize().width;
height = getSize().height;
GameImage = createImage(width, height);
GameGraphics = GameImage.getGraphics();
// Automatic in some systems, not in others
GameGraphics.setColor(Color.black);
repaint();
validate();
//show the greeting
ImageIcon icon = new ImageIcon("images/FLY.gif",
"a fly");
repaint();
validate();
}
/** Description of paint(Graphics g)
*
* Function draws table and sets the table color
* @param g graphics object used to draw table
* @return void
*/
public void paint(Graphics g)
{
GameGraphics.clearRect(0, 0, getWidth(), getHeight());
aTable.draw(GameGraphics);
g.drawImage(GameImage, 0, 0, this);
}
public void update(Graphics g)
{
paint(g);
validate();
}
public void start()
{
thread = new Thread(this);
thread.start();
}
public void stop()
{
updating = false;
}
public void run()
{
while(updating)
{
aTable.update();
}
}
//returns a transparent image.
//color is made transparent
private Image getImage(String imgPath, final Color color)
{
Image img = Toolkit.getDefaultToolkit().getImage(imgPath);
ImageFilter filter = new RGBImageFilter() {
// the color we are looking for... Alpha bits are set to opaque
public int markerRGB = color.getRGB() | 0xFFFFFF;
public final int filterRGB(int x, int y, int rgb) {
if ( ( rgb | 0xFF000000 ) == markerRGB ) {
// Mark the alpha bits as zero - transparent
return 0x00FFFFFF & rgb;
}
else {
// nothing to do
return rgb;
}
}
};
ImageProducer ip = new FilteredImageSource(img.getSource(), filter);
img = Toolkit.getDefaultToolkit().createImage(ip);
return img;
}
}
and the class which handles the drawing (in drawValues())
import java.awt.*;
import java.util.Random;
public class Table extends Panel
{
private char[][]values = new char[10][10]; //probably better to use array of integer values(0 or 1)
private Point[]coordLoc;// = new Point[100]; //stores the x & y coordinates of points on the grid
private boolean[]itemMarker; //stores the truth value of wether or not an item
// is located at the coresponding point in cordLoc array
private int [][]coords;// = new int [100][2];
Image itemImg; // stores the item image
private int Rows; // stores number of rows
private int Columns; // stores number of columns
private int BoxWidth ; // stores the width of a box
private int BoxHeight; // stores the height of a box
public Point Pos = new Point(); // creates a new point to draw from
private int tableHeight; // stores the height of the table
private int tableWidth; // stores the width of the table
private int numOfGridLocs;
/** Description of public Table( x, y, width, height, col, rows, X, O)
*
* Constructor function
* @param x contains an x-coordinate of the table
* @param y contains a y-coordinate of the table
* @param width contains the width of a box in the table
* @param height contains the height of a box in the table
* @param col contains the number of columns in the table
* @param rows contains the number of rows in the table
* @param itemImg contains the "target" image ie: ant, fly, ... unicorn
* @return none
*/
public Table(int x, int y, int width, int height, int col, int rows, Image itemImg, Image swatterImg)
{
/*set values*/
numOfGridLocs = (col - 1) * (rows - 1);
//initialize arrays
coordLoc = new Point[numOfGridLocs];
for(int i = 0; i < numOfGridLocs; i++)
coordLoc[i] = new Point();
Rows = rows;
Columns = col;
BoxWidth = width;
BoxHeight = height;
Pos.x = x;
Pos.y = y;
this.itemImg = itemImg;
tableHeight = Rows*BoxHeight;
tableWidth = Columns*BoxWidth;
itemMarker = new boolean[numOfGridLocs];
coords = new int [numOfGridLocs][2];
this.setValues();
mapGrid();
}
/** Description of draw(Graphics g)
*
* Function draws the lines used in the table
* @param g object used to draw the table
* @return none
*/
public void draw(Graphics g)
{
Graphics2D g2=(Graphics2D)g;
//draw flyswatter
drawValues(g2); //draw values
//draw vertical table lines
for (int i = 0 ; i <= Columns ; i++)
{
//make center line thicker
if(i == Rows/2)
g2.setStroke(new BasicStroke(2));
else
g2.setStroke(new BasicStroke(1));
g2.drawLine(i*BoxWidth + Pos.x, Pos.y, i*BoxWidth + Pos.x, tableHeight+Pos.y);
}
//draw horizontal table line
for(int i = 0 ; i <= Rows ; i++)
{
//make center line thicker
if(i == Rows/2)
g2.setStroke(new BasicStroke(2));
else
g2.setStroke(new BasicStroke(1));
g2.drawLine(Pos.x, i*BoxHeight + Pos.y, tableWidth+Pos.x, i*BoxHeight + Pos.y);
}
drawLables(g);
}
/** Description of drawLables(Graphics g)
*
* Function draws the Lables of the Table
* @param g object used to draw the table
* @return none
*/
private void drawLables(Graphics g)
{
String Lable;
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
Font font = new Font("Serif", Font.PLAIN, 10);
g2.setFont(font);
int xLabel = this.Columns/2 * -1;
int yLabel = this.Rows/2;
//draw Row lables
for (int i = 0 ; i <= Rows ; i++)
{
Lable = "" + yLabel;
g2.drawString(Lable, Pos.x - 25, Pos.y + BoxHeight*i);
yLabel--;
}
//draw Column lables
for (int i = 0 ; i <= Columns ; i++)
{
Lable = "" + xLabel;
g2.drawString(Lable, Pos.x + BoxWidth*i - 5, Pos.y - 20 );
xLabel++;
}
}
/** Description of randomChangeFunc()
*
* Function randomly determines which table value to change
* @param none
* @return void
*/
public int getX(int XCordinate)
{
int x = XCordinate+Columns/2;
if(x < 0) x *= -1; //x must be positive
x *= BoxWidth;
x += Pos.x;
return x-BoxWidth/2;
}
//returns Position of Y-cordinate
public int getY(int YCordinate)
{
int y = YCordinate -Rows/2;
if (y < 0) y *= -1; //y must be positive
y *= BoxHeight;
y += Pos.y;
return y-BoxHeight/2;
}
/** Description of getValue( col, row )
*
* Function draws the lines used in the table
* @param col contains a column coordinate
* @param row contains a row coordinate
* @return returns table coordinates
*/
public char getValue(int col, int row)
{
return values[row][col];
}
/** Description of isDrawable( x, y )
*
* Function returns true if (x,y) is a point in the table
* @param x contains a table column
* @param y contains a table row
* @return boolean if (x,y) is a point in the table
*/
public boolean isDrawable(int x, int y)
{
if((this.getRow(y)!=-1)||(this.getColumn(x)!=-1))
return true;
else
return false;
}
private void drawValues(Graphics g)
{
for(int i = 0; i < numOfGridLocs; i++)
if(itemMarker[i])
g.drawImage(itemImg,coordLoc[i].x+1, coordLoc[i].y+1, BoxWidth-1, BoxHeight-1, null);
g.setColor(Color.black); // set color of table to black
}
//sets the randomized boolean values in itemMarker array
private void setValues()
{
double probOfItem = .25;
for(int count = 0; count < numOfGridLocs; count++){
itemMarker[count] = randomBool(probOfItem);
if(itemMarker[count])
System.out.println("true");
else
System.out.println("false");
}
}
//returns random boolean value, p is prob of 'true'
private boolean randomBool(double p)
{
return (Math.random() < p);
}
public int getColumn(int x)
{
x += (BoxWidth/2); //aTable.getX/Y returns in the middle of squares not at upper left point
int offsetx=0;
for (int i = 0 ; i < Columns*2 ; i++)
{
offsetx = i*BoxWidth;
if((x>=Pos.x+offsetx)&& (x<Pos.x+offsetx+BoxWidth))
return i-Columns;
}
return -100;
}
public int getRow(int y)
{
int offsety=0;
y += (BoxHeight/2); //aTable.getX/Y returns in the middle of squares not at upper left point
for (int i = 0 ; i < Rows*2 ; i++) {
offsety = i * BoxHeight;
if((y >= (offsety+Pos.y))&& (y < (offsety+BoxHeight+Pos.y)))
{
return ((i)*-1)+Rows;
}
}
return -100;
}
public boolean isValidGuess(int x, int y)
{
if ((x > Columns/2) || (x < Columns/2*-1) || (y > Rows/2) || (y < Rows/2*-1))
return false;
return true;
}
/** Description of randomChangeFunc()
*
* Function randomly determines which table value to change
* @param none
* @return void
*/
public void randomChangeFunc()
{
//get random row and column
Random rand=new Random();
int randRow = rand.nextInt(Rows); // gets and holds a random column
int randCol = rand.nextInt(Columns); // gets and holds a random column
System.out.println("randRow = " + randRow + " randCol = " + randCol);
if(values[randRow][randCol] == 'X')
values[randRow][randCol] = 'O';
else if(values[randRow][randCol] == 'O')
values[randRow][randCol] = 'X';
else
System.out.println("ERROR SWAPPING SQUARE VALUE"); // error message
}
private void mapGrid() //set values for coordLoc array
{
//set counter variables
int count = 0;
int index = 0;
//loop through all points, assigning them to the coordLoc array
for (int r=0; r < Rows-1; r++)
for (int c=0; c < Columns-1; c++) {
//the width/height / 2 places the points on grid line intersections, not the boxes they create
coordLoc[count].x = Pos.x + (BoxWidth) * c + (BoxWidth/2); // record x-point
coordLoc[count].y = Pos.y + (BoxHeight) * r + (BoxHeight/2); // record y-point
System.out.println(coordLoc[count].getX() + ", " + coordLoc[count].getY());
count++;
} //end inner for
//set positive x coord values for coords array
int y_axisBeginingIndex = (Rows - 2)/2;
for(int greaterIndex = 0; greaterIndex < ((Rows) / 2); greaterIndex++){
for(int minorIndex = 0; minorIndex < (Rows - 1); minorIndex++){
index = y_axisBeginingIndex + greaterIndex + ((Rows - 1) * minorIndex);
coords[index][0] = greaterIndex;
}
}
//set negative x coord values for coords array
for(int greaterIndex = -1; greaterIndex > (0-((Rows) / 2)); greaterIndex--){
for(int minorIndex = 0; minorIndex < (Rows - 1); minorIndex++){
index = y_axisBeginingIndex + greaterIndex + ((Rows - 1) * minorIndex);
coords[index][0] = greaterIndex;
}
}
//set positive y values for coords array
int x_axisBeginingIndex = (Rows - 1) * ((Rows / 2) - 1);
for(int greaterIndex = 0; greaterIndex < ((Rows) / 2); greaterIndex++){
for(int minorIndex = 0; minorIndex < (Rows - 1); minorIndex++){
index = x_axisBeginingIndex + minorIndex;
coords[index][1] = greaterIndex;
}
x_axisBeginingIndex -= (Rows - 1);
}
//set negative y values for coords array
x_axisBeginingIndex = (Rows - 1) * ((Rows / 2) - 1) + (Rows - 1);
for(int greaterIndex = -1; greaterIndex > (0-((Rows) / 2)); greaterIndex--){
for(int minorIndex = 0; minorIndex < (Rows - 1); minorIndex++){
index = x_axisBeginingIndex + minorIndex;
coords[index][1] = greaterIndex;
}
x_axisBeginingIndex += (Rows - 1);
}
//print out the x and y coords
for(int i = 0; i < numOfGridLocs; i++){
System.out.println("[" + i + "] -> x = " + coords[i][0] + " y = " + coords[i][1]);
}
}
public boolean thereIsAnItemAt(int index){
return itemMarker[index];
}
public boolean bugsLeft(){
boolean thereAreBugsLeft = false;
for(int i = 0; i < numOfGridLocs; i++)
if(itemMarker[i])
thereAreBugsLeft = true;
return thereAreBugsLeft;
}
void update()
{
this.repaint();
}
}
Been stumped on this for weeks. Thanks again...
