So, if I try to move the shape, it actually moves, but there is no motion animation. In order for the moved shape to be drawn, the application window must be minimized or maximized.
Here is the PentaminoShape class:
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.List;
public class PentominoShape extends JFrame implements MouseListener, MouseMotionListener {
JPanel shapePane;
Container contentPane;
private Polygon currPolygon;
private int x, y;
ArrayList<Polygon> polygons = new ArrayList<Polygon>();
JFrame frame;
public PentominoShape(JFrame frame){
this.frame = frame;
initShape();
}
private void initShape() {
Polygon fig1 = new Polygon(new int[]{10, 50, 50, 10}, new int[]{10, 10, 200, 200}, 4);
Polygon fig2 = new Polygon(new int[]{130, 210, 210, 170, 170, 130, 130, 90, 90, 130}, new int[]{80, 80, 120, 120, 200, 200, 160, 160, 120, 120}, 10);
Polygon fig3 = new Polygon(new int[]{290, 330, 330, 250, 250, 290}, new int[]{50, 50, 200, 200, 160, 160}, 6);
Polygon fig4 = new Polygon(new int[]{10, 90, 90, 50, 50, 10}, new int[]{280, 280, 400, 400, 360, 360}, 6);
Polygon fig5 = new Polygon(new int[]{170, 210, 210, 170, 170, 130, 130, 170}, new int[]{240, 240, 360, 360, 400, 400, 320, 320}, 8);
Polygon fig6 = new Polygon(new int[]{250, 370, 370, 330, 330, 290, 290, 250}, new int[]{280, 280, 320, 320, 400, 400, 320, 320}, 8);
Polygon fig7 = new Polygon(new int[]{10, 50, 50, 90, 90, 130, 130, 10}, new int[]{480, 480, 520, 520, 480, 480, 560, 560}, 8);
Polygon fig8 = new Polygon(new int[]{170, 250, 250, 290, 290, 170}, new int[]{520, 520, 440, 440, 560, 560}, 6);
Polygon fig9 = new Polygon(new int[]{330, 370, 370, 410, 410, 450, 450, 410, 410, 330}, new int[]{520, 520, 480, 480, 440, 440, 520, 520, 560, 560}, 10);
Polygon fig10 = new Polygon(new int[]{10, 50, 50, 90, 90, 130, 130, 90, 90, 50, 50, 10}, new int[]{680, 680, 640, 640, 680, 680, 720, 720, 760, 760, 720, 720}, 12);
Polygon fig11 = new Polygon(new int[]{170, 210, 210, 250, 250, 210, 210, 170}, new int[]{640, 640, 600, 600, 760, 760, 680, 680}, 8);
Polygon fig12 = new Polygon(new int[]{330, 410, 410, 370, 370, 290, 290, 330}, new int[]{640, 640, 680, 680, 760, 760, 720, 720}, 8);
polygons.add(fig1);
polygons.add(fig2);
polygons.add(fig3);
polygons.add(fig4);
polygons.add(fig5);
polygons.add(fig6);
polygons.add(fig7);
polygons.add(fig8);
polygons.add(fig9);
polygons.add(fig10);
polygons.add(fig11);
polygons.add(fig12);
Color[] c = new Color[12];
c[0] = new Color(25, 165, 25);
c[1] = new Color(255, 165, 25);
c[2] = new Color(255, 50, 50);
c[3] = new Color(150, 45, 90);
c[4] = new Color(25, 165, 150);
c[5] = new Color(25, 165, 255);
c[6] = new Color(255, 40, 190);
c[7] = new Color(180, 90, 60);
c[8] = new Color(90, 80, 70);
c[9] = new Color(70, 80, 90);
c[10] = new Color(150, 30, 20);
c[11] = new Color(80, 80, 80);
shapePane = new JPanel(){
public void paintComponent(Graphics g){
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setColor(c[0]); g2.fill(fig1);
g2.setColor(c[1]); g2.fill(fig2);
g2.setColor(c[2]); g2.fill(fig3);
g2.setColor(c[3]); g2.fill(fig4);
g2.setColor(c[4]); g2.fill(fig5);
g2.setColor(c[5]); g2.fill(fig6);
g2.setColor(c[6]); g2.fill(fig7);
g2.setColor(c[7]); g2.fill(fig8);
g2.setColor(c[8]); g2.fill(fig9);
g2.setColor(c[9]); g2.fill(fig10);
g2.setColor(c[10]); g2.fill(fig11);
g2.setColor(c[11]); g2.fill(fig12);
}
};
/*contentPane = this.getContentPane();
contentPane.add(shapePane);
this.pack();*/
frame.add(shapePane);
shapePane.addMouseListener(this);
shapePane.addMouseMotionListener(this);
/*shapePane.addMouseListener(this);
shapePane.addMouseMotionListener(this);*/
}
public void mousePressed(MouseEvent e) {
for(Polygon polygon: polygons) {
if (polygon.contains(e.getPoint())) {
System.out.println("Pressed");
currPolygon = polygon;
x = e.getX();
y = e.getY();
}
}
}
public void mouseDragged(MouseEvent e) {
try {
if (currPolygon.contains(x, y)) {
System.out.println("Dragged");
int dx = e.getX() - x;
int dy = e.getY() - y;
currPolygon.translate(dx, dy);
x = dx;
y = dy;
repaint();
}
}catch (NullPointerException ex){
}
}
public void mouseReleased(MouseEvent e){
currPolygon = null;
}
public void mouseClicked(MouseEvent e){}
public void mouseEntered(MouseEvent e){}
public void mouseExited(MouseEvent e){}
public void mouseMoved(MouseEvent e){}
}
And the main Pentamino class:
import javax.swing.*;
public class Pentomino extends JFrame {
JFrame frame;
PentominoShape shape;
PentominoPanel panel;
public Pentomino(){
initUI();
}
private void initUI(){
frame = new JFrame("Пентамино");
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.setSize(1500, 900);
setResizable(false);
shape = new PentominoShape(frame);
panel = new PentominoPanel(frame);
/*frame.add(shape);
frame.add(panel);*/
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
Pentomino game = new Pentomino();
}
}
I'm new to Java and I don't understand how to solve this problem. Tried searching the internet for a similar problem but couldn't find anything.
CodePudding user response：
Your bug is here:
public void mouseDragged(MouseEvent e) {
try {
if (currPolygon.contains(x, y)) {
System.out.println("Dragged");
int dx = e.getX() - x;
int dy = e.getY() - y;
currPolygon.translate(dx, dy);
x = dx;
y = dy;
repaint(); // ***** here ****
}
}catch (NullPointerException ex){
}
}
You're calling repaint() on the enclosing class, a JFrame, one that is never displayed, and this will have not have the effect desired.
In fact, ask yourself, why this...
public class PentominoShape extends JFrame // ...
Why is PentominoShape extending JFrame at all, when it isn't behaving as a JFrame, when it shouldn't be behaving as a JFrame?
Instead, call repaint on the JPanel that holds the shapes, the shapePane JPanel, and yes, get rid of catching the NullPointerException. That should never be in your code:
public void mouseDragged(MouseEvent e) {
if (currPolygon == null) {
return;
}
if (currPolygon.contains(x, y)) {
System.out.println("Dragged");
int dx = e.getX() - x;
int dy = e.getY() - y;
currPolygon.translate(dx, dy);
x = dx;
y = dy;
shapePane.repaint(); // now we're repainting the correct JPanel!
}
}
Side note: I'd clean things up a bit including
- Not having any class extend JFrame if possible
- Create my own polygon type of class:
public class PentominoShape2 {
private Polygon polygon;
private Color color;
public PentominoShape2(Polygon polygon, Color color) {
this.polygon = polygon;
this.color = color;
}
public void draw(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.setColor(color);
g2.fill(polygon);
}
public Polygon getPolygon() {
return polygon;
}
public Color getColor() {
return color;
}
public boolean contains(Point p) {
return polygon.contains(p);
}
}
and then in the drawing JPanel
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (PentominoShape2 poly : polys) {
poly.draw(g);
}
}
same for the mouse listener