Hi! There is such problem: on mouse click on the certain picture, it is necessary to distinguish in what area of a picture have got ( transparent or color ). Whether there is a ready decision of this problem? Clearly, what it is necessary to receive bitmap a picture and to address to parameter an alpha but how it to make?
From the java documentation:
public class PixelGrabber
extends Object
implements ImageConsumer
The PixelGrabber class implements an ImageConsumer which can be attached to an Image or ImageProducer object to retrieve a subset of the pixels in that image. Here is an example:
public void handlesinglepixel(int x, int y, int pixel) {
int alpha = (pixel >> 24) & 0xff;
int red= (pixel >> 16) & 0xff;
int green = (pixel >> 8) & 0xff;
int blue = (pixel) & 0xff;
// Deal with the pixel as necessary...
}
public void handlepixels(Image img, int x, int y, int w, int h) {
int[] pixels = new int[w * h];
PixelGrabber pg = new PixelGrabber(img, x, y, w, h, pixels, 0, w);
try {
pg.grabPixels();
} catch (InterruptedException e) {
System.err.println("interrupted waiting for pixels!");
return;
}
if ((pg.getStatus() & ImageObserver.ABORT) != 0) {
System.err.println("image fetch aborted or errored");
return;
}
for (int j = 0; j < h; j++) {
for (int i = 0; i < w; i++) {
handlesinglepixel(x+i, y+j, pixels[j * w + i]);
}
}
}
import java.awt.*;
import java.awt.event.*;
import java.math.*;
public class CalculatorApplet extends Frame
{
Frame CalFrame;
private LCD_Screen out;
private Keypad in;
private Math operations;
private Color b;
public CalculatorApplet()
{
b=Color.black;
setLayout(new BorderLayout());
setBackground(b);
out = new LCD_Screen();
operations = new Math(out);
in = new Keypad(out);
super( "Calculator");
add("North",out);
add("Center",in);
add("East",operations);
this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
});
}
public static void main(String[] args)
{
Frame f=new CalculatorApplet();
f.setSize(180,180);
f.show();
}
}
class LCD_Screen extends Panel
{
private TextField show;
public LCD_Screen ()
{
show = new TextField(20);
Panel p=new Panel();
p.add(show);
add("Center",p);
}
public void write(String s)
{
show.setText(s);
}
public String read()
{
return show.getText();
}
}