Dissapearing Image
I am having trouble with the following code, which reads in a set of .png images that are named 1 -26 respectively, and outputs 25 of them in a grid. I draw each image to an offscreen image, back, which I then draw to the JFrame.
When I run the program, I see the image for a second (actually much less time) and then it dissapears.
import javax.swing.*;
import java.awt.*;
import java.awt.image.*;
publicclass wordtestextends JFrame{
ImageIcon lett;
ImageIcon [] letters;
ImageIcon correct;
ImageIcon incorrect;
ImageIcon outOfPlace;
public wordtest(){
letters =new ImageIcon [26];
BufferedImage back =new BufferedImage(230,230,BufferedImage.TYPE_INT_ARGB_PRE);// image to which i draw the 25 sepatate images
outOfPlace =new ImageIcon("outofplace.png");
try{// loading the 26 images
for(int i = 0; i < 26; i++){
System.out.println("Image pre-Loaded");
lett =new ImageIcon((i +1) +".png");
letters[i] = lett;
}
}
catch(Exception e){
System.out.println("File loading Exception");
System.out.println(e);
}
setSize(500,500);//set size of JFrame
//validate();
Graphics2D g = back.createGraphics();//get the graphics context for off screen image
int curr = 0;//counter for drawing each image from the array
try{
for(int j = 0; j < 5; j++){
for (int k = 0; k < 5; k++){
System.out.println("Image pre drawn");
g.drawImage(letters[curr].getImage(), j*46,k*46,null);
System.out.println("Image drawn");
curr++;
}
}
}
catch(Exception e ){
System.out.println("printing exception");
System.out.println(e);
}
g.dispose();
setVisible(true);
Graphics f = getGraphics();
f.drawImage(back,10,10,null);//draw offscreen image
f.dispose();
//validate();
}
publicstaticvoid main(String[] args){
wordtest larry =new wordtest();
}
}
# 1
import java.awt.*;
import java.awt.font.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;
public class WT extends JFrame{
ImageIcon[] letters;
ImageIcon outOfPlace;
ImageComponent imageComponent;
public WT() {
generateImagesToLoad();
ImageIcon[] icons = loadImages();
BufferedImage image = makeImage(icons);
imageComponent = new ImageComponent(image);
getContentPane().add(imageComponent);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setSize(500,500);//set size of JFrame
setVisible(true);
}
private ImageIcon[] loadImages() {
ImageIcon[] letters = new ImageIcon [26];
outOfPlace = new ImageIcon("outofplace.png");
for(int j = 0; j < 26; j++){
letters[j] = new ImageIcon("wtImages/" + (j+1) + ".png");
int loadStatus = letters[j].getImageLoadStatus();
// ImageIcon doesn't throw exceptions so you have to
// check on the loading status/success on your own.
if(loadStatus != MediaTracker.COMPLETE) {
String errorStr = "letters["+j+"] loadStatus = ";
switch(loadStatus) {
case MediaTracker.ABORTED:
errorStr += "ABORTED";
break;
case MediaTracker.ERRORED:
errorStr += "ERRORED";
}
System.out.println(errorStr);
}
}
return letters;
}
private BufferedImage makeImage(ImageIcon[] letters) {
// image to which i draw the 25 sepatate images
BufferedImage back = new BufferedImage(230,230,BufferedImage.TYPE_INT_ARGB_PRE);
// get the graphics context for off screen image
Graphics2D g = back.createGraphics();
int curr = 0;//counter for drawing each image from the array
try{
for(int j = 0; j < 5; j++){
for (int k = 0; k < 5; k++){
g.drawImage(letters[curr].getImage(), j*46,k*46,null);
curr++;
}
}
} catch(Exception e ){
System.out.println("printing exception");
System.out.println(e);
}
g.dispose();
return back;
}
private void generateImagesToLoad() {
// Make up some images to save for loading above.
int w = 46;
int h = 46;
BufferedImage[] toSave = new BufferedImage[26];
for(int j = 0; j < toSave.length; j++) {
int type = BufferedImage.TYPE_INT_ARGB_PRE;
toSave[j] = new BufferedImage(w, h, type);
Graphics2D g2 = toSave[j].createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setPaint(Color.blue);
g2.drawRect(0,0,w-1,h-1);
g2.setPaint(Color.red);
g2.setFont(g2.getFont().deriveFont(16f));
FontRenderContext frc = g2.getFontRenderContext();
String s = String.valueOf(j+1);
float sw = (float)g2.getFont().getStringBounds(s, frc).getWidth();
float sh = g2.getFont().getLineMetrics(s, frc).getAscent();
float x = (w - sw)/2;
float y = (h + sh)/2;
g2.drawString(s, x, y);
}
// Save the images to file.
File folder = new File("wtImages");
if(!folder.exists()) {
folder.mkdir();
for(int j = 0; j < toSave.length; j++) {
File file = new File(folder, (j+1)+".png");
try {
ImageIO.write(toSave[j], "png", file);
} catch(IOException e) {
System.out.println("IO Error for " + file.getPath());
}
}
}
}
public static void main(String[] args){
WT larry = new WT();
}
}
class ImageComponent extends JPanel {
BufferedImage image;
public ImageComponent(BufferedImage image) {
this.image = image;
setPreferredSize(new Dimension(image.getWidth(), image.getHeight()));
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
int x = (getWidth() - image.getWidth())/2;
int y = (getHeight() - image.getHeight())/2;
g.drawImage(image, x, y, this);
}
}
