I'm making an A* pathfinding application with a GUI. I have:
- an enum TileType
START(Color.GREEN),
WALL(Color.BLACK),
BLANK(new Color(240, 240, 240)),
END(Color.RED);
- a Grid class
public class Grid extends JPanel {
private final Color lineColour = new Color(200, 200, 200);
private Color defaultColour;
private final int pixelsPerTile;
private final int rows;
private final int columns;
private TileType[][] tiles;
public Grid(int rows, int columns, int pixelsPerTile) {
this.pixelsPerTile = pixelsPerTile;
this.rows = rows;
this.columns = columns;
this.tiles = new TileType[rows][columns];
this.setPreferredSize(new Dimension(rows * pixelsPerTile, columns * pixelsPerTile));
setTile(rows / 2 - 5, columns / 2, TileType.START);
setTile(rows / 2 + 5, columns / 2, TileType.END);
}
public void resetBoard() {
for (int i = 0; i < tiles.length; i++) {
for (int j = 0; j < tiles[0].length; j++) {
if (getTile(i, j) != TileType.START && getTile(i, j) != TileType.END) {
tiles[i][j] = null;
}
}
}
}
public void removeTile(int x, int y) {
tiles[x][y] = TileType.BLANK;
}
public TileType getTile(int x, int y) {
return tiles[x][y];
}
public Point getTile(boolean start) {
for (int x = 0; x < tiles.length; x++) {
for (int y = 0; y < tiles[0].length; y++) {
if (tiles[x][y] == (start ? TileType.START : TileType.END)) {
return new Point(x, y);
}
}
}
return null;
}
public void setTile(int x, int y, TileType tile) {
if (getTile(x, y) != TileType.START && getTile(x, y) != TileType.END) {
tiles[x][y] = tile;
}
}
#Override
public void paint(Graphics g1) {
Graphics2D g = (Graphics2D) g1;
for (int x = 0; x < columns; x++) {
for (int y = 0; y < columns; y++) {
if (getTile(x, y) != null) {
g.setColor(getTile(x, y).getColour());
g.fillRect(x * pixelsPerTile, y * pixelsPerTile, pixelsPerTile, pixelsPerTile);
}
}
}
// have the grid appear on top of blank tiles
g.setColor(lineColour);
for (int x = 0; x < columns; x++) {
for (int y = 0; y < rows; y++) {
g.drawLine(x * pixelsPerTile, 0, x * pixelsPerTile, getHeight());
g.drawLine(0, y * pixelsPerTile, getWidth(), y * pixelsPerTile);
}
}
}
public int getPixelsPerTile() {
return pixelsPerTile;
}
public int getRows() {
return rows;
}
public int getColumns() {
return columns;
}
}
- a Frame class
public class Frame extends JFrame {
private Grid grid;
public Frame() {
grid = new Grid(33, 33, 15); // odd so there is a definitive middle point
this.setAutoRequestFocus(true);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setTitle("A* Path finder");
this.setBounds(new Rectangle((grid.getRows()) * grid.getPixelsPerTile(),
(grid.getColumns() + 2) * grid.getPixelsPerTile()));
this.setResizable(true);
this.add(grid);
this.setVisible(true);
this.getContentPane().addMouseListener(new MouseLsntr()); // fixes alignment problems
ScheduledThreadPoolExecutor se = new ScheduledThreadPoolExecutor(5);
se.scheduleAtFixedRate(new RedrawGrid(), 0L, 20L, TimeUnit.MILLISECONDS);
}
private class RedrawGrid implements Runnable {
#Override
public void run() {
grid.repaint();
}
}
private class MouseLsntr implements MouseListener {
#Override
public void mouseClicked(MouseEvent me) {
int x = me.getX() / grid.getPixelsPerTile();
int y = me.getY() / grid.getPixelsPerTile();
switch (me.getButton()) {
case MouseEvent.BUTTON1:
if (grid.getTile(x, y) != TileType.WALL) {
grid.setTile(x, y, TileType.WALL);
System.out.println(String.format("(%d, %d) (%d, %d) wall", x, y, x, y));
} else {
grid.removeTile(x, y);
System.out.println(String.format("(%d, %d) (%d, %d) blank", x, y, x, y));
}
break;
}
}
#Override
public void mousePressed(MouseEvent me) {}
#Override
public void mouseReleased(MouseEvent me) {}
#Override
public void mouseEntered(MouseEvent me) {}
#Override
public void mouseExited(MouseEvent me) {}
}
}
and obviously a main class which calls Frame()
When the user left clicks on a grid, they make a WALL at that location. If it's already a WALL, it becomes BLANK. I want the user to be able to move the START and END tile by clicking on it and then dragging to the location they want to stop at, which I'm having trouble doing. Any help would be appreciated since I've been stumped about this for a while now.
You will need to implement the mousePressed and mouseReleased handlers in MouseListener interface, and the mouseDragged handler in MouseMotionListener.
First, make your MouseLsntr extend MouseAdapter class, which implements MouseListener and MouseMotionListener by default.
private class MouseLsntr extends MouseAdapter {
private int dragStartX, dragStartY;
private boolean dragging;
#Override
public void mouseClicked(MouseEvent me) {
int x = me.getX() / grid.getPixelsPerTile();
int y = me.getY() / grid.getPixelsPerTile();
switch (me.getButton()) {
case MouseEvent.BUTTON1:
if (grid.getTile(x, y) != TileType.WALL) {
grid.setTile(x, y, TileType.WALL);
System.out.println(String.format("(%d, %d) (%d, %d) wall", x, y, x, y));
} else {
grid.removeTile(x, y);
System.out.println(String.format("(%d, %d) (%d, %d) blank", x, y, x, y));
}
break;
}
}
#Override
public void mousePressed(MouseEvent me) {
switch (me.getButton()) {
case MouseEvent.BUTTON1:
// Save the drag starting position.
this.dragStartX = me.getX() / grid.getPixelsPerTile();
this.dragStartY = me.getY() / grid.getPixelsPerTile();
this.dragging = true;
break;
}
}
#Override
public void mouseReleased(MouseEvent me) {
switch (me.getButton()) {
case MouseEvent.BUTTON1:
if (this.dragging) {
moveTile(me);
}
this.dragging = false;
break;
}
}
#Override
public void mouseExited(MouseEvent me) {
this.dragging = false;
}
#Override
public void mouseDragged(MouseEvent me) {
if (this.dragging) {
moveTile(me);
}
}
private void moveTile(MouseEvent me) {
int dragEndX = me.getX() / grid.getPixelsPerTile();
int dragEndY = me.getY() / grid.getPixelsPerTile();
TileType dragStartType = grid.getTile(this.dragStartX, this.dragStartY);
TileType dragEndType = grid.getTile(dragEndX, dragEndY);
// If the starting tile was either START or END, move the tile to the destination.
if ((dragEndType == TileType.BLANK || dragEndType == null) &&
(dragStartType == TileType.START || dragStartType == TileType.END)) {
grid.removeTile(this.dragStartX, this.dragStartY);
grid.setTile(dragEndX, dragEndY, dragStartType);
// update the drag starting points
this.dragStartX = dragEndX;
this.dragStartY = dragEndY;
}
}
}
Next, add your MouseLsntr instance as a MouseMotionListener as well, so that mouseDragged handler is called when you are dragging. Note that you should not create two separate instances of MouseLsntr, because the member fields should be shared. You should do it like the following in the Frame() constructor.
MouseLsntr listener = new MouseLsntr();
this.getContentPane().addMouseListener(listener);
this.getContentPane().addMouseMotionListener(listener);
After doing this, the TileType.START / TileType.END tiles will follow the mouse when being dragged.
Related
As the title states, I am trying to detect a mouse hover over an object that is not a JComponent.
Right now I have a window with a green JPanel. When you left-click on this JPanel you create a point.
What I am trying to do is to have extra information displayed when I hover over these points. However, I have no idea how to even begin detecting if I am hovering my mouse over a point. I tried looking into the MouseListener interface but I could not find any examples of people using MouseListener with an object. I have only seen people use MouseListener with JComponents. I would preferably like to have this mouse hover detection code in my Point class if possible to keep my code clean.
JPanel Code
class Map extends JPanel implements MouseListener {
public static ArrayList<Point> points = new ArrayList<Point>(); //array for the points
public Map() {
this.setBackground(Color.green);
this.setPreferredSize(new Dimension(1280, 720));
this.addMouseListener(this);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D graphics = (Graphics2D) g;
drawPoints(graphics);
}
private void drawPoints(Graphics2D graphics) {
for(int i = 0; i < points.size(); i++) {
points.get(i).drawPoint(graphics);
}
}
#Override
public void mouseClicked(MouseEvent e) {
}
#Override
public void mousePressed(MouseEvent e) {
if(e.getButton() == MouseEvent.BUTTON1) { //Left Click
points.add(new Point(e.getX(), e.getY()));
repaint();
}
else if(e.getButton() == MouseEvent.BUTTON3) { //right click
for(int i = points.size() - 1; i >= 0; i--) { //loop backwards so if points overlap remove the one on top first
Point current = points.get(i);
if( Math.abs( e.getX() - current.x ) < current.size/2 && Math.abs( e.getY() - current.y ) < current.size/2 ) {
points.remove(i);
repaint();
break;
}
}
}
}
#Override
public void mouseReleased(MouseEvent e) {
}
#Override
public void mouseEntered(MouseEvent e) {
}
#Override
public void mouseExited(MouseEvent e) {
}
}
Point Code
public class Point {
public int x, y;
public int size = 10;
public Point(int x, int y) {
this.x = x;
this.y = y;
}
public Point() {
this.x = 0;
this.y = 0;
}
public void drawPoint(Graphics2D graphics) {
graphics.setPaint(Color.black);
graphics.setStroke(new BasicStroke(5));
graphics.drawOval(x - (size/2), y - (size/2), size, size);
graphics.setPaint(Color.red);
graphics.fillOval(x - (size/2), y - (size/2), size, size);
}
public void drawInfo(Graphics2D graphics) {
graphics.drawString("test", x, y);
}
}
I had the same issue with a Packet-Tracer-Like program, where I drew rects.
If they are just points, I would check if the mouse cords are the same as the point cords when the mouse is moved.
#Override
public void mouseMoved(MouseEvent e) {
entered = false;
if(point.x == e.getX() && point.y == e.getY()){
entered = true;
}
}
If although, like in my case, the drawn object has a width and a height, it gets messier.
#Override
public void mouseMoved(MouseEvent e) {
entered = false;
if((e.getX() <= point.x+width) && (e.getX() >= point.x)){
if((e.getY() <= point.y+height) && (e.getY() >= point.y)){
entered = true;
}
}
}
Is there any way to get only the initial press from the drag, because right now it keeps toggling between black and white when dragged over the same square. Also, I am trying to get from the command line the width and height of the rectangles that will make the grid, if the user screws up or nothing is input then they are set to 50 by default. I tried creating a method because I didn't really know how to put them in the main an then use it in the JPanel.
public class Clicky extends JFrame {
private static class Board extends JPanel {
public int BRICK_WIDTH = 50;
public int BRICK_HEIGHT = 50;
public Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
public double width = screenSize.getWidth();
public double height = screenSize.getHeight();
public double bWidth;
public double bHeight;
private int COLS = (int) (width / bWidth);
private int ROWS = (int) (height / bHeight);
private Color CO = Color.BLACK;
private boolean[][] isWhite = new boolean[COLS + 1][ROWS + 1];
public Board() {
System.out.println("WIdth:" + COLS + "Height:" + ROWS);
setBackground(Color.BLACK);
addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
mx = e.getX();
my = e.getY();
System.out.printf("X: %d Y: %d ", mx, my);
isWhite[(int) (mx / bWidth)][(int) (my
/ bHeight)] = !isWhite[(int) (mx / bWidth)][(int) (my / bHeight)];
repaint();
}
});
addMouseMotionListener(new MouseMotionListener() {
#Override
public void mouseDragged(MouseEvent e) {
mx = e.getX();
my = e.getY();
isWhite[(int) (mx / bWidth)][(int) (my
/ bHeight)] = !isWhite[(int) (mx / bWidth)][(int) (my / bHeight)];
int gridx = e.getX();
int gridy = e.getY();
System.out.println(gridx);
}
#Override
public void mouseMoved(MouseEvent e) {
}
});
}
#Override
protected void paintComponent(Graphics g,String[] args ) {
super.paintComponent(g);
drawBricks(g);
getValues(args);
}
private double x;
private double y;
public void getValues(String[] args){
try
{
bWidth = Integer.valueOf(args[0]);
}
catch (IndexOutOfBoundsException | NumberFormatException ex)
{
// If the argument was bad then use the default.
bWidth = BRICK_WIDTH;
}
try
{
bHeight = Integer.valueOf(args[1]);
}
catch (IndexOutOfBoundsException | NumberFormatException ex)
{
// If the argument was bad then use the default.
bHeight = BRICK_HEIGHT;
}
}
private void drawBricks(Graphics g) {
Graphics2D brick = (Graphics2D) g.create();
x = 0;
y = 0;
for (int j = 0; j <= ROWS; j++) {
for (int a = 0; a <= COLS; a++) {
if (isWhite[a][j]) {
brick.setColor(Color.WHITE);
} else {
brick.setColor(Color.BLACK);
}
Rectangle2D.Double rect = new Rectangle2D.Double(x, y, bWidth, bHeight);
brick.fill(rect);
brick.setColor(Color.gray);
brick.draw(rect);
x += bWidth;
}
repaint();
x = 0;
y += bHeight;
}
}
public int mx = -100;
public int my = -100;
}
public Clicky() {
setDefaultCloseOperation(EXIT_ON_CLOSE); // mai bine cu exit on close
setSize(800, 820);
add(new Board());
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new Clicky().setVisible(true);
}
});
}
}
There isn't an event you can listen for that will tell you when the drag event starts. You can write one yourself. You'll need to some kind of stateful variable that can be toggled on the first receipt of a mouse dragged event then used as a guard for subsequent mouse dragged events. You can reset the stateful variable on a mouse release event. See MouseEvent and MouseEventListener.
As for your other question - I'm not really sure what you're asking. Are you wondering how to get user-supplied data from the command line or trying to figure out how to make use of them once they are supplied?
For the former it's dead simple with command line arguments. For the latter, all you have to do is write a setter method that validates the input and overrides the default if caller-supplied values are valid.
I am trying to get three different blocks to move back and forth from one side of the screen to the other. If the block on the far right reaches the game frame's width, it's velocity is reversed and it starts moving to the left side. However, my problem exists with the other two blocks. I put in my code a method that states once the second block reaches the (game width - 100), with 100 just being the width of each blocks, it's velocity should be reversed. The third block is suppose to work the same except once it reaches the x point (game width - 200). My attempt to change the velocity of the second and third blocks can be seen under the UpdateBlocks method in the PlayState class posted below.
Another thing I want to point out is that in update method in the block class, the x value is being reversed too. I tried at first to make it read the blocks from the PlayState then change the corresponding velocities but I got a thread error. That's why I am bringing my current predicament to you.
Here is the block class:
package com.jamescho.game.model;
import java.awt.Rectangle;
import com.jamescho.framework.util.RandomNumberGenerator;
import com.jamescho.game.main.GameMain;
import com.jamescho.game.state.PlayState;
public class Block {
private float x, y;
private int width, height, velX = 700;
private Rectangle rect;
private PlayState play;
private boolean visible;
private static final int UPPER_Y = 275;
private static final int LOWER_Y = 355;
public Block(float x, float y, int width, int height) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
rect = new Rectangle((int) x, (int) y, width, height);
visible = false;
}
// Note: Velocity value will be passed in from PlayState!
public void update(float delta) {
x += velX * delta;
if (x <= 0 || x >= GameMain.GAME_WIDTH - 100) {
velX = -velX;
}
updateRect();
}
public void updateRect() {
rect.setBounds((int) x, (int) y, width, height);
}
public void invisible() {
visible = false;
}
public void visible() {
visible = true;
}
public void stop() {
velX = 0;
}
public void reverse() {
velX = -velX;
}
public float getX() {
return x;
}
public float getY() {
return y;
}
public boolean isVisible() {
return visible;
}
public Rectangle getRect() {
return rect;
}
}
Here is the PlayState where everything is going on:
package com.jamescho.game.state;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import com.jamescho.game.main.GameMain;
import com.jamescho.game.main.Resources;
import com.jamescho.game.model.Block;
public class PlayState extends State {
private ArrayList<Block> row1;
private ArrayList<Block> row2;
private ArrayList<Block> row3;
private Block block;
private Font scoreFont;
private int playerScore = 0;
private static final int BLOCK_HEIGHT = 100;
private static final int BLOCK_WIDTH = 100;
private int blockSpeed = -200;
private static final int PLAYER_WIDTH = 66;
private static final int PLAYER_HEIGHT = 92;
#Override
public void init() {
row1 = new ArrayList<Block>();
row2 = new ArrayList<Block>();
scoreFont = new Font("SansSerif", Font.BOLD, 25);
for (int i = 0; i < 3; i++) {
Block b = new Block(i * 105, GameMain.GAME_HEIGHT - 101,
BLOCK_WIDTH, BLOCK_HEIGHT);
row1.add(b);
b.visible();
for (int h = 0; h < 3; h++) {
Block b2 = new Block(h * 105, b.getY() - 208,
BLOCK_WIDTH, BLOCK_HEIGHT);
row2.add(b2);
b2.invisible();
}
}
}
#Override
public void update(float delta) {
playerScore += 1;
if (playerScore % 500 == 0 && blockSpeed > -280) {
blockSpeed -= 10;
}
Resources.runAnim.update(delta);// starts iterating through its frames
updateBlocks(delta);
}
private void updateBlocks(float delta) { // time from last update
for (Block b : row1) { //foreach statement; for each iteration of "b" the code is executed, one "b" at a time
if(row1.get(1).getX() == GameMain.GAME_WIDTH - BLOCK_WIDTH - 5) {
row1.get(1).reverse();
}
else if(row1.get(2).getX() == GameMain.GAME_WIDTH - 2 * BLOCK_WIDTH - 5) {
row1.get(2).reverse();
}
b.update(delta);
}
for (Block c : row2) { //foreach statement; for each iteration of "b" the code is executed, one "b" at a time
// used with objects; can't use primitive
c.update(delta);
if (c.isVisible()) {
}
}
}
#Override
public void render(Graphics g) {
g.setColor(Color.BLACK);
g.fillRect(0, 0, GameMain.GAME_WIDTH, GameMain.GAME_HEIGHT);
renderPlayer(g);
renderBlocks(g);
renderScore(g);
}
private void renderScore(Graphics g) {
g.setFont(scoreFont);
g.setColor(Color.GRAY);
g.drawString("" + playerScore / 100, 20, 30);
}
private void renderPlayer(Graphics g) {
}
private void renderBlocks(Graphics g) {
for (Block b : row1) {
if (b.isVisible()) {
g.drawImage(Resources.blue_panel, (int) b.getX(), (int) b.getY(),
BLOCK_WIDTH, BLOCK_HEIGHT, null); // change null if you want the object to know about object
}
}
for (Block c : row2) {
if (c.isVisible()) {
g.drawImage(Resources.blue_panel, (int) c.getX(), (int) c.getY()+105,
BLOCK_WIDTH, BLOCK_HEIGHT, null); // change null if you want the object to know about object
}
}
}
#Override
public void onClick(MouseEvent e) {
}
#Override
public void onKeyPress(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_SPACE) {
for (Block b : row1) {
b.stop();
for (Block c : row2) {
if (c.isVisible() == true) {
c.stop();
}
}
}
}
else if (e.getKeyCode() == KeyEvent.VK_DOWN) {
}
}
#Override
public void onKeyRelease(KeyEvent e) {
if(e.getKeyCode() == KeyEvent.VK_SPACE) {
for (Block c: row2) {
c.visible();
}
}
}
public float getb1X() {
return row1.get(1).getX();
}
}
Sorry I haven't gone through your entire code. But this is how I would do it:
int x , int y -- are the coordinates of each block on the screen.
a block can move on the screen in 4 ways / directions / quadrants:
1) x = x + deltaX, y = y + deltaY
2) x = x - deltaX, y = y + deltaY
3) x = x + deltaX, y = y - deltaY
4) x = x - deltaX, y = y - deltaY
Thus in order to change the direction when a block hits any side you should multiply deltaX with -1 if it hits left or right side and deltaY with -1 if it hits the bottom or top. this will reverse its direction.
I am writing a program that allows a user to paint rectangles onto a JLabel, and show the intersection and union of these rectangles. I have setup the GUI for the class but am struggling to find a way to integrate the intersection and union methods from the rectangle class. I know these methods work when used separately from the GUI.
When I try to run the program I keep getting an IndexOutOfBoundsException and the drawn rectangles are cleared from the gui. The intersections of each rectangle should show up in a different color on the JLabel. I tried to debug the program and for some reason when I create two rectangles and store them in my array list many many rectangle objects of the same characteristics are being created.
For the union method, a new rectangle should be create that contains all of the rectangles on the inside.
RectangleFrame1:
public class RectangleFrame1 extends JFrame implements ActionListener
{
JPanel buttonPanel;
JButton saveImage;
JButton clearImage;
JCheckBox intersections;
JCheckBox union;
RectangleLabel drawingArea;
boolean intersect = false;
boolean uni = false;
public RectangleFrame1()
{
super();
setTitle("Rectangles");
setSize(600,600);
setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
buttonPanel = new JPanel();
buttonPanel.setBorder(BorderFactory.createLineBorder(Color.black));
this.add(buttonPanel, BorderLayout.SOUTH);
intersections = new JCheckBox("Draw Intersections");
buttonPanel.add(intersections);
intersections.addActionListener(this);
intersections.setActionCommand("Intersections");
union = new JCheckBox("Draw Union");
buttonPanel.add(union);
union.addActionListener(this);
union.setActionCommand("Union");
saveImage = new JButton("Save Image");
saveImage.setMargin(new Insets(0,0,0,0));
buttonPanel.add(saveImage);
saveImage.addActionListener(this);
saveImage.setActionCommand("Save Image");
clearImage = new JButton("Clear Image");
clearImage.setMargin(new Insets(0,0,0,0));
buttonPanel.add(clearImage);
clearImage.addActionListener(this);
clearImage.setActionCommand("Clear Image");
drawingArea = new RectangleLabel();
drawingArea.setBorder(BorderFactory.createLineBorder(Color.blue));
this.add(drawingArea, BorderLayout.CENTER);
drawingArea.addMouseListener((MouseListener) drawingArea);
drawingArea.addMouseMotionListener((MouseMotionListener) drawingArea);
}
#Override
public void actionPerformed(ActionEvent arg0)
{
switch(arg0.getActionCommand())
{
case "Intersections":
if(intersections.isSelected())
{
intersect = true;
}
else
{
intersect = false;
}
case "Union":
if(union.isSelected())
{
uni = true;
}
else
{
uni = false;
}
case "Clear Image": drawingArea.clearImage();
case "Save Image": drawingArea.saveImage();
}
}
class RectangleLabel extends JLabel implements MouseListener, MouseMotionListener
{
Rectangle rectangle = null;
int x, y, x2, y2;
ArrayList<Rectangle> a = new ArrayList();
int counter;
public RectangleLabel()
{
super();
}
#Override
public void mousePressed(MouseEvent arg0)
{
x = arg0.getX();
y = arg0.getY();
rectangle = new Rectangle(x, y, 0, 0);
}
#Override
public void mouseDragged(MouseEvent arg0)
{
// TODO Auto-generated method stub
x2 = arg0.getX();
y2 = arg0.getY();
if(rectangle.getX() > x2)
{
rectangle.setWidth(x-x2);
}
if(x2 > rectangle.getX())
{
rectangle.setWidth(x2-x);
}
if(y > y2)
{
rectangle.setHeight(y-y2);
}
if(y2 > y)
{
rectangle.setHeight(y2-y);
}
a.add(rectangle);
counter++;
repaint();
}
#Override
public void mouseReleased(MouseEvent arg0)
{
repaint();
}
#Override
public void mouseMoved(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseClicked(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
if(rectangle != null)
{
for(int i = 0; i < a.size(); i++)
{
float thickness = 2;
((Graphics2D) g).setStroke(new BasicStroke(thickness));
g.setColor(Color.BLUE);
g.drawRect(a.get(i).getX(), a.get(i).getY(), a.get(i).getWidth(), a.get(i).getHeight());
g.setColor(Color.gray);
g.fillRect(a.get(i).getX(), a.get(i).getY(), a.get(i).getWidth(), a.get(i).getHeight());
}
}
if(intersect == true && counter > 0)
{
for(int h = 0; h < counter-1; h++)
{
for(int j = 1; j < counter; j++)
{ if(a.get(h).overlaps(a.get(j)))
{
Rectangle rect = a.get(h).intersect(a.get(j));
g.setColor(Color.RED);
g.fillRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
}
}
}
}
if(uni == true && counter > 0)
{
for(int h = 0; h < counter - 1; h++)
{
for(int j = 1; j < counter; j++)
{
Rectangle rect = a.get(h).union(a.get(j));
g.setColor(Color.WHITE);
g.drawRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
}
}
}
}
public void saveImage()
{
BufferedImage image = new BufferedImage(this.getWidth(), this.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D aaaaa = image.createGraphics();
aaaaa.setBackground(Color.WHITE);
aaaaa.clearRect(0, 0, this.getWidth(), this.getHeight());
this.paintAll(aaaaa);
try
{
File output = new File("rectangle.png");
ImageIO.write(image, "Rectangles", output);
}
catch(IOException ie)
{
}
}
public void clearImage()
{
a.clear();
repaint();
}
}
}
Rectangle:
public class Rectangle
{
private int x,y,width,height;
public Rectangle(int x,int y,int width,int height)
{
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
public Rectangle(Rectangle a)
{
this.x = a.x;
this.y = a.y;
this.width = a.width;
this.height = a.height;
}
public String toString()
{
return "Start: ("+x+","+y+"), Width: "+width+", Height: "+height+"\n";
}
public int getX()
{
return x;
}
public int getY()
{
return y;
}
public int getWidth()
{
return width;
}
public int getHeight()
{
return height;
}
public void setX(int x)
{
this.x = x;
}
public void setY(int y)
{
this.y = y;
}
public void setWidth(int width)
{
this.width = width;
}
public void setHeight(int height)
{
this.height = height;
}
public int area()
{
return width*height;
}
public boolean overlaps(Rectangle a)
{
if ((x>a.x+a.width) || (a.x>x+width) || (y>a.y+a.height) || (a.y>y+height))
{
return false;
}
return true;
}
public Rectangle intersect(Rectangle a)
{
if (!overlaps(a))
return null;
int left,right,top,bottom;
if (x<a.x)
left = a.x;
else
left = x;
if (y<a.y)
bottom = a.y;
else
bottom = y;
if ((x+width)<(a.x+a.width))
right = x+width;
else
right = a.x+a.width;
if ((y+height)<(a.y+a.height))
top = y+height;
else
top = a.y+a.height;
return new Rectangle(left,bottom,right-left,top-bottom);
}
public Rectangle union(Rectangle a)
{
int left,right,top,bottom;
if (x<a.x)
left = x;
else
left = a.x;
if (y<a.y)
bottom = y;
else
bottom = a.y;
if ((x+width)<(a.x+a.width))
right = a.x+a.width;
else
right = x+width;
if ((y+height)<(a.y+a.height))
top = a.y+a.height;
else
top = y+height;
return new Rectangle(left,bottom,right-left,top-bottom);
}
}
There are a number of problems...
You're mouseDragged event handler is adding the same Rectangle to the a ArrayList, over and over again, increasing the counter value along with it.
This is not required. All you need to do is add the Rectangle on the mousePressed event. When mouseReleased is called, you could evaluate the Rectangle to check if the size is greater than 0x0 and remove it if it's not (ie remove any Rectangle whose size is 0x0)
Don't rely on the counter variable, it's too easy for the value to become misaligned with the size of the a List. Instead, rely on a.size instead.
The switch statement in your ActionListener is evaluating the matching case, but also all the following cases below it. This is a feature of switch. If you don't want to evaluate the following cases, you need to add a break at the end of each case (or where ever you want to "break" the processing).
For example, when you click Draw Intersections, it is also evaluating Union, Clear Image and Save Image cases...
You could try using something like...
switch (arg0.getActionCommand()) {
case "Intersections":
intersect = intersections.isSelected();
break;
case "Union":
uni = union.isSelected();
break;
case "Clear Image":
drawingArea.clearImage();
break;
case "Save Image":
drawingArea.saveImage();
break;
}
instead...
Logic Errors in Painting Code...
There's also a logic area with your intersect paint code, where it is comparing a rectangle with itself, which ends up painting the whole rectangle.
Instead of
if (a.get(h).overlaps(a.get(j))) {
You might consider using
if (!a.get(h).equals(a.get(j)) && a.get(h).overlaps(a.get(j))) {
This is possibly occurring in you union painting logic as well, but I didn't really check that
Works fine for me...
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class RectangleFrame1 extends JFrame implements ActionListener {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
RectangleFrame1 frame = new RectangleFrame1();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
JPanel buttonPanel;
JButton saveImage;
JButton clearImage;
JCheckBox intersections;
JCheckBox union;
RectangleLabel drawingArea;
boolean intersect = false;
boolean uni = false;
public RectangleFrame1() {
super();
setTitle("Rectangles");
setSize(600, 600);
// setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
buttonPanel = new JPanel();
buttonPanel.setBorder(BorderFactory.createLineBorder(Color.black));
this.add(buttonPanel, BorderLayout.SOUTH);
intersections = new JCheckBox("Draw Intersections");
buttonPanel.add(intersections);
intersections.addActionListener(this);
intersections.setActionCommand("Intersections");
union = new JCheckBox("Draw Union");
buttonPanel.add(union);
union.addActionListener(this);
union.setActionCommand("Union");
saveImage = new JButton("Save Image");
saveImage.setMargin(new Insets(0, 0, 0, 0));
buttonPanel.add(saveImage);
saveImage.addActionListener(this);
saveImage.setActionCommand("Save Image");
clearImage = new JButton("Clear Image");
clearImage.setMargin(new Insets(0, 0, 0, 0));
buttonPanel.add(clearImage);
clearImage.addActionListener(this);
clearImage.setActionCommand("Clear Image");
drawingArea = new RectangleLabel();
drawingArea.setBorder(BorderFactory.createLineBorder(Color.blue));
this.add(drawingArea, BorderLayout.CENTER);
drawingArea.addMouseListener((MouseListener) drawingArea);
drawingArea.addMouseMotionListener((MouseMotionListener) drawingArea);
}
#Override
public void actionPerformed(ActionEvent arg0) {
switch (arg0.getActionCommand()) {
case "Intersections":
intersect = intersections.isSelected();
break;
case "Union":
uni = union.isSelected();
break;
case "Clear Image":
drawingArea.clearImage();
break;
case "Save Image":
drawingArea.saveImage();
break;
}
repaint();
}
class RectangleLabel extends JLabel implements MouseListener, MouseMotionListener {
Rectangle rectangle = null;
int x, y, x2, y2;
ArrayList<Rectangle> a = new ArrayList();
public RectangleLabel() {
super();
}
#Override
public void mousePressed(MouseEvent arg0) {
x = arg0.getX();
y = arg0.getY();
rectangle = new Rectangle(x, y, 0, 0);
a.add(rectangle);
}
#Override
public void mouseDragged(MouseEvent arg0) {
// TODO Auto-generated method stub
x2 = arg0.getX();
y2 = arg0.getY();
if (rectangle.getX() > x2) {
rectangle.setWidth(x - x2);
}
if (x2 > rectangle.getX()) {
rectangle.setWidth(x2 - x);
}
if (y > y2) {
rectangle.setHeight(y - y2);
}
if (y2 > y) {
rectangle.setHeight(y2 - y);
}
repaint();
}
#Override
public void mouseReleased(MouseEvent arg0) {
rectangle = null;
repaint();
}
#Override
public void mouseMoved(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseClicked(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
for (Rectangle rect : a) {
float thickness = 2;
((Graphics2D) g).setStroke(new BasicStroke(thickness));
g.setColor(Color.BLUE);
g.drawRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
g.setColor(Color.gray);
g.fillRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
}
if (intersect) {
for (int h = 0; h < a.size() - 1; h++) {
for (int j = 1; j < a.size(); j++) {
if (!a.get(h).equals(a.get(j)) && a.get(h).overlaps(a.get(j))) {
Rectangle rect = a.get(h).intersect(a.get(j));
g.setColor(Color.RED);
g.fillRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
}
}
}
}
if (uni) {
for (int h = 0; h < a.size() - 1; h++) {
for (int j = 1; j < a.size(); j++) {
if (!a.get(h).equals(a.get(j)) && a.get(h).overlaps(a.get(j))) {
Rectangle rect = a.get(h).union(a.get(j));
g.setColor(Color.WHITE);
g.drawRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
}
}
}
}
}
public void saveImage() {
BufferedImage image = new BufferedImage(this.getWidth(), this.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D aaaaa = image.createGraphics();
aaaaa.setBackground(Color.WHITE);
aaaaa.clearRect(0, 0, this.getWidth(), this.getHeight());
this.paintAll(aaaaa);
try {
File output = new File("rectangle.png");
ImageIO.write(image, "Rectangles", output);
} catch (IOException ie) {
}
}
public void clearImage() {
a.clear();
repaint();
}
}
public class Rectangle {
private int x, y, width, height;
public Rectangle(int x, int y, int width, int height) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
public Rectangle(Rectangle a) {
this.x = a.x;
this.y = a.y;
this.width = a.width;
this.height = a.height;
}
public String toString() {
return "Start: (" + x + "," + y + "), Width: " + width + ", Height: " + height + "\n";
}
public int getX() {
return x;
}
public int getY() {
return y;
}
public int getWidth() {
return width;
}
public int getHeight() {
return height;
}
public void setX(int x) {
this.x = x;
}
public void setY(int y) {
this.y = y;
}
public void setWidth(int width) {
this.width = width;
}
public void setHeight(int height) {
this.height = height;
}
public int area() {
return width * height;
}
public boolean overlaps(Rectangle a) {
if ((x > a.x + a.width) || (a.x > x + width) || (y > a.y + a.height) || (a.y > y + height)) {
return false;
}
return true;
}
public Rectangle intersect(Rectangle a) {
if (!overlaps(a)) {
return null;
}
int left, right, top, bottom;
if (x < a.x) {
left = a.x;
} else {
left = x;
}
if (y < a.y) {
bottom = a.y;
} else {
bottom = y;
}
if ((x + width) < (a.x + a.width)) {
right = x + width;
} else {
right = a.x + a.width;
}
if ((y + height) < (a.y + a.height)) {
top = y + height;
} else {
top = a.y + a.height;
}
return new Rectangle(left, bottom, right - left, top - bottom);
}
public Rectangle union(Rectangle a) {
int left, right, top, bottom;
if (x < a.x) {
left = x;
} else {
left = a.x;
}
if (y < a.y) {
bottom = y;
} else {
bottom = a.y;
}
if ((x + width) < (a.x + a.width)) {
right = a.x + a.width;
} else {
right = x + width;
}
if ((y + height) < (a.y + a.height)) {
top = a.y + a.height;
} else {
top = y + height;
}
return new Rectangle(left, bottom, right - left, top - bottom);
}
}
}
I am trying to develop a checkerboard given a template of classes and some code for school. I got the board to appear but the right amount of checkers are not being drawn. There are supposed to be 7 red and 9 black checkers but each time I run the program a different amount of each is drawn.
import java.applet.Applet;
import java.awt.*;
import java.util.Random;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
public class Checkers extends JApplet
{
private final int MAX_SIZE = 8;
private final int APP_WIDTH = 400;
private final int APP_HEIGHT = 400;
private final int MAXSIZE = 8;
Square[][] sq;
public void paint(Graphics page)
{
setBackground(Color.white);
fillBoard(page); // draws the method that will draw the checkers
placeCheckers(page, 7, Color.red); //method to place the red checkers
placeCheckers(page, 9, Color.black); //method to draw black checkers
CheckJumps(page); //check if checkers can jump
setSize (APP_WIDTH,APP_HEIGHT);
}
public void fillBoard(Graphics page)
{
sq = new Square[8][8];
int x,y;
Color rb;
for (int row = 0; row < MAXSIZE; row++)
for (int col = 0; col < MAXSIZE; col++)
{
x = row * (APP_WIDTH/MAXSIZE);
y = col * (APP_HEIGHT/MAXSIZE);
if ( (row % 2) == (col % 2) )
rb = Color.red;
else
rb = Color.black;
sq[row][col] = new Square (x, y, rb);
}
for (int row = 0; row < 8; row++)
for (int col = 0; col < 8; col++)
sq[row][col].draw(page);
}
public void placeCheckers (Graphics page, int num_checkers, Color ncolor)
{
int count, row, col;
int x, y;
Circle c;
Random rand = new Random();
for (count = 0; count < num_checkers; count++)
{
do
{
row = rand.nextInt(8);
col = rand.nextInt(8);
} while (sq[row][col].getOccupy() || ncolor == sq[row][col].getColor());
x = row * (APP_WIDTH/MAXSIZE);
y = col * (APP_HEIGHT/MAXSIZE);
c = new Circle (x, y, 50, ncolor);
c.draw(page);
sq[row][col].setOccupy(true);
}
}
class Square
{
private int x, y = 0;
private Color c;
private boolean occupied;
public Square (int x, int y, Color c)
{
this.x = x;
this.y = y;
this.c = c;
}
public void setX (int x)
{
x = this.x;
}
public int getX ()
{
return x;
}
public void setY (int y)
{
y= this.y;
}
public int getY ()
{
return y;
}
public void setColor (Color c)
{
c = this.c;
}
public Color getColor ()
{
return c;
}
public void setOccupy (boolean occupied)
{
occupied = this.occupied;
}
public boolean getOccupy ()
{
return occupied;
}
public String toString()
{
return ("X coordinate: " + x + "\nY coordinate:" + y + "\nSquare color: " + c);
}
public void draw (Graphics page)
{
page.setColor(c);
page.fillRect(x, y, 50, 50);
}
}
class Circle
{
private int x,y;
private int diameter;
private Color c;
public Circle (int x, int y, int diameter, Color c)
{
this.x = x;
this.y = y;
this.diameter = diameter;
this.c = c;
}
public void setX (int x)
{
x = this.x;
}
public int getX ()
{
return x;
}
public void setY (int y)
{
y= this.y;
}
public int getY ()
{
return y;
}
public void setColor (Color c)
{
c = this.c;
}
public Color getColor ()
{
return c;
}
public void setDiameter (int x)
{
diameter = x;
}
public void draw (Graphics page)
{
page.setColor(c);
page.fillOval(x, y, diameter, diameter);
}
}
If, you have followed some of the advice from your previous question you may have avoided this issue.
As near as I can tell, your problem is you're not calling super.paint, which is responsible for (amongst a lot of other things) preparing the Graphics context for painting. It does this, by clearing what ever was painted on it previously.
Instead of overriding paint of JApplet, which will cause flicker when the applet is updated, you should start with something like a JPanel and override it's paintComponent method. JPanel is double buffered, which will prevent any flicker from occuring. Don't forget to call super.paintComponent.
You shouldn't be calling fillBorder every time paint is called, this is wasteful on a number of levels, instead, you should only call it when you need to. With a little bit more clever design, you could actually get away with calling it from the constructor, but I don't have the time to re-code your entire program.
The size the applet is defined by the HTML page which contains it, not the applet itself, relying on magic numbers (like APP_WIDTH and APP_HEIGHT) is a bad idea. You should, instead, rely on known values, like getWidth and getHeight. This of course assumes you'd like to be able to resize the playable area and avoid possible issues with people deploying your applet with the wrong size ;)
While, I'm guessing that placeCheckers is a test method, you should know, paint can be called any number of times for any number of reasons, many of which you don't control, this means that the checkers will be randomized each time paint is called.
Instead, you should consider creating a virtual board which contains the information about the state of the game and update this as required. You would then simply use the painting process to reflect this model.
An example of how I might "start"...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.util.Random;
import javax.swing.JApplet;
import javax.swing.JPanel;
public class Checkers extends JApplet {
#Override
public void init() {
add(new Board());
}
public class Board extends JPanel {
private final int APP_WIDTH = 400;
private final int APP_HEIGHT = 400;
private final int MAXSIZE = 8;
Square[][] sq;
#Override
public void invalidate() {
fillBoard();
super.invalidate();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g); //To change body of generated methods, choose Tools | Templates.
for (int row = 0; row < 8; row++) {
for (int col = 0; col < 8; col++) {
sq[row][col].draw(g);
}
}
setBackground(Color.white);
placeCheckers(g, 7, Color.red); //method to place the red checkers
placeCheckers(g, 9, Color.black); //method to draw black checkers
}
#Override
public Dimension getPreferredSize() {
return new Dimension(APP_WIDTH, APP_HEIGHT);
}
public void fillBoard() {
sq = new Square[8][8];
int x, y;
Color rb;
int gridSize = Math.min(getWidth(), getHeight());
int size = gridSize / MAXSIZE;
for (int row = 0; row < MAXSIZE; row++) {
for (int col = 0; col < MAXSIZE; col++) {
x = row * (gridSize / MAXSIZE);
y = col * (gridSize / MAXSIZE);
if ((row % 2) == (col % 2)) {
rb = Color.red;
} else {
rb = Color.black;
}
sq[row][col] = new Square(x, y, rb, size);
}
}
}
public void placeCheckers(Graphics page, int num_checkers, Color ncolor) {
int count, row, col;
int x, y;
Circle c;
int gridSize = Math.min(getWidth(), getHeight());
int size = gridSize / MAXSIZE;
Random rand = new Random();
for (count = 0; count < num_checkers; count++) {
do {
row = rand.nextInt(8);
col = rand.nextInt(8);
} while (sq[row][col].getOccupy() || ncolor == sq[row][col].getColor());
x = row * (gridSize / MAXSIZE);
y = col * (gridSize / MAXSIZE);
c = new Circle(x, y, size, ncolor);
c.draw(page);
sq[row][col].setOccupy(true);
}
}
}
class Square {
private int x, y = 0;
private Color c;
private boolean occupied;
private int size;
public Square(int x, int y, Color c, int size) {
this.x = x;
this.y = y;
this.c = c;
this.size = size;
}
public void setX(int x) {
x = this.x;
}
public int getX() {
return x;
}
public void setY(int y) {
y = this.y;
}
public int getY() {
return y;
}
public void setColor(Color c) {
c = this.c;
}
public Color getColor() {
return c;
}
public void setOccupy(boolean occupied) {
occupied = this.occupied;
}
public boolean getOccupy() {
return occupied;
}
public String toString() {
return ("X coordinate: " + x + "\nY coordinate:" + y + "\nSquare color: " + c);
}
public void draw(Graphics page) {
page.setColor(c);
page.fillRect(x, y, size, size);
}
}
class Circle {
private int x, y;
private int diameter;
private Color c;
public Circle(int x, int y, int diameter, Color c) {
this.x = x;
this.y = y;
this.diameter = diameter;
this.c = c;
}
public void setX(int x) {
x = this.x;
}
public int getX() {
return x;
}
public void setY(int y) {
y = this.y;
}
public int getY() {
return y;
}
public void setColor(Color c) {
c = this.c;
}
public Color getColor() {
return c;
}
public void setDiameter(int x) {
diameter = x;
}
public void draw(Graphics page) {
page.setColor(c);
page.fillOval(x, y, diameter, diameter);
}
}
}
Updated
This ones had me scratching me head for a while. Basically, after some additional checking I discovered that the checkers where being allowed to occupy space that was suppose to be already taken. After bashing me head against the do-while loop, I check the setOccupy method and found...
public void setOccupy(boolean occupied) {
occupied = this.occupied;
}
You're assiging the Square's occupied state back to the value you are passing, which has no effect on anything
Instead, it should look more like...
public void setOccupy(boolean occupied) {
this.occupied = occupied;
}
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