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Screen Shake like bug on 2D Grid JPanel

I am trying to create a 2d grid on a JPanel with Zoom functionality. The user will draw on the grid then if desired zoom in and out. Image of Grid
When I currently zoom in there is a screen shake like issue/bug when I move the mouse around, which I would like to remove.
The mouse wheel is used to zoom in and out.
Grid to be drawn at certain scale factor:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.RenderingHints;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseWheelEvent;
import java.awt.geom.AffineTransform;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
public class DrawExample extends JFrame {
/**
*
*/
private static final long serialVersionUID = 1L;
private double zoom = 1d;
private int tranx;
private int trany;
DrawPanel drawPanel;
int snapmousepositionx, snapmousepositiony;//current snap coords
int currentmousepositionx,currentmousepositiony;
public DrawExample() {
drawPanel = new DrawPanel();
JPanel containerPanel = new JPanel();
JFrame frame = new JFrame(); // Instance of a JFrame
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setSize(800, 800);
//drawPanel.setSize(800, 800);
containerPanel.setLayout(new GridBagLayout());
containerPanel.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(1, 0, 1)));
containerPanel.add(drawPanel);
frame.add(new JScrollPane(containerPanel));
drawPanel.addMouseWheelListener(new MouseAdapter() { //add wheel listener to drawPanel
#Override
public void mouseWheelMoved(MouseWheelEvent e) { //when wheel is moved
if (e.getPreciseWheelRotation() < 0) {
zoom += 0.1;
} else {
zoom -= 0.1;
}
if (zoom < 0.01) {
zoom = 0.01;
}
drawPanel.repaint();
}
});
drawPanel.addMouseMotionListener(new MouseAdapter() {
public void mouseMoved(MouseEvent me) {
super.mouseMoved(me);
drawPanel.createSnapGrid(me.getPoint().x, me.getPoint().y);
tranx=me.getPoint().x;
trany=me.getPoint().y;
drawPanel.repaint();
}
});
frame.setVisible(true);
}
public class DrawPanel extends JPanel {
#Override
public Dimension getPreferredSize() {
return new Dimension(800, 800);
}
#Override
protected void paintComponent(Graphics grphcs) {
super.paintComponent(grphcs);
Graphics2D g2d = (Graphics2D) grphcs;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
zoom=Math.round(zoom*10.0)/10.0;
AffineTransform at = g2d.getTransform();
at.translate(tranx, trany);
at.scale(zoom, zoom);
at.translate(-tranx, -trany);
g2d.setTransform(at);
g2d.setColor(Color.lightGray);
drawGrid(g2d);
}
public void createSnapGrid(int x, int y) {
currentmousepositionx = x;
currentmousepositiony = y;
int remainderx = currentmousepositionx % 10, remaindery = currentmousepositiony % 10;
if (remainderx<800/2) setSnapX(currentmousepositionx - remainderx) ;
else setSnapX(currentmousepositionx + (10-remainderx));
if (remaindery<800/2) setSnapY(currentmousepositiony - remaindery);
else setSnapY(currentmousepositiony + (10)-remaindery);
}
}
public void drawGrid(Graphics2D g) {
g.setColor(Color.lightGray);
g.clearRect(0, 0, 800, 800);
System.out.println(getHeight());
//grid vertical lines
for (int i= (10);i<800;i+=10) {
g.drawLine(i, 0, i, 800);
}
//grid horizontal lines
for (int j= (10);j<800;j+=10) {
g.drawLine(0, j, 800, j);
}
//show the snapped point
g.setColor(Color.BLACK);
if ( getSnapX()>=0 && getSnapY()>=0 && getSnapX()<=800 && getSnapY()<=800) {
// result =true;
g.drawOval((int) ( getSnapX())-4, (int) (getSnapY()-4), 8, 8);
}
}
public int getSnapX(){
return (this.snapmousepositionx);
}
public int getSnapY(){
return (this.snapmousepositiony);
}
public void setSnapX(int snap){
this.snapmousepositionx=(int) (snap);
}
public void setSnapY(int snap){
this.snapmousepositiony=(int) (snap);
}
public static void main(String args[]) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new DrawExample();
}
});
}
}

Mouse listener not working with JPanel

The paintcomponent works fine, the image shows up, no problems on that end or with the JFrame. I want to implement zooming and panning but not getting any luck as the added mouse listener isn't responding.
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseAdapter;
import javax.swing.JPanel;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
public class map extends JPanel {
public int moz = 100;
public void map()
{
addMouseListener(
new MouseAdapter()
{
#Override
public void mouseClicked(MouseEvent e)
{
moz = moz +100;
repaint();
}
}
);
}
public void paintComponent(Graphics g){
.....
g.drawLine( 0, moz, 100, 0 );
}
}

Your class doesn't have a real constructor but rather has a "pseudo" constructor since it has a return type -- yes void counts. So get rid of the void return type by changing:
// this is not a constructor
public void map()
to:
// this is a real constructor
public map()
Also as a side recommendation, change your variable and class names to conform with Java naming conventions: class names all start with an upper-case letter and method/variable names with a lower-case letter.
So in your case you'd name your class Map, and in playing with the code could have something like:
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Stroke;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.*;
public class Map extends JPanel {
private static final int PREF_W = 800;
private static final int PREF_H = 650;
private static final Color DRAW_RECT_COLOR = new Color(200, 200, 255);
public static final Stroke IMAGE_STROKE = new BasicStroke(3f);
public static final Color IMAGE_COLOR = Color.RED;
private BufferedImage image = new BufferedImage(PREF_W, PREF_H, BufferedImage.TYPE_INT_ARGB);
private Rectangle drawRectangle = null;
private List<Color> colors = new ArrayList<>();
private Random random = new Random();
public Map() {
MyMouse myMouse = new MyMouse();
addMouseListener(myMouse);
addMouseMotionListener(myMouse);
for (int r = 0; r < 4; r++) {
int r1 = (r * 255) / 3;
for (int g = 0; g < 4; g++) {
int g1 = (g * 255) / 3;
for (int b = 0; b < 4; b++) {
int b1 = (b * 255) / 3;
colors.add(new Color(r1, g1, b1));
}
}
}
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, this);
Graphics2D g2 = (Graphics2D) g;
if (drawRectangle != null) {
g.setColor(DRAW_RECT_COLOR);
g2.draw(drawRectangle);
}
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private class MyMouse extends MouseAdapter {
Point p1 = null;
#Override
public void mousePressed(MouseEvent e) {
p1 = e.getPoint();
}
#Override
public void mouseDragged(MouseEvent e) {
if (p1 == null) {
return;
}
Point p2 = e.getPoint();
drawRectangle = createDrawRect(p2);
repaint();
}
#Override
public void mouseReleased(MouseEvent e) {
Rectangle rectangle = createDrawRect(e.getPoint());
Graphics2D g2 = image.createGraphics();
g2.setStroke(IMAGE_STROKE);
Color c = colors.get(random.nextInt(colors.size()));
g2.setColor(c);
g2.draw(rectangle);
g2.dispose();
p1 = null;
drawRectangle = null;
repaint();
}
private Rectangle createDrawRect(Point p2) {
int x = Math.min(p1.x, p2.x);
int y = Math.min(p1.y, p2.y);
int w = Math.abs(p1.x - p2.x);
int h = Math.abs(p1.y - p2.y);
return new Rectangle(x, y, w, h);
}
}
private static void createAndShowGui() {
Map mainPanel = new Map();
JFrame frame = new JFrame("Map");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

Use MouseListener to draw circles?

I'm trying to write a program that allows user to specify a circle with 2 mouse presses, the first one on the center and the second on a point on the periphery, and the program I wrote is this.
import javax.swing.*;
import java.awt.geom.*;
import java.awt.event.*;
import java.awt.*;
public class CircleFrame extends JFrame
{
public CircleFrame()
{
circle = new Ellipse2D.Double();
hasCenter = false;
createComponent();
setSize(400, 400);
}
private void createComponent()
{
class CircleComponent extends JComponent
{
public void paintComponent(Graphics g)
{
Graphics2D g2 = (Graphics2D) g;
circle.setFrame(xTop, yTop, radius*2, radius*2);
g2.draw(circle);
}
}
class MousePressListener1 extends MouseAdapter
{
public void mousePressed(MouseEvent event)
{
if(!hasCenter)
{
xCenter = event.getX();
yCenter = event.getY();
hasCenter = true;
}
}
}
class MousePressListener2 extends MouseAdapter
{
public void mousePressed(MouseEvent event)
{
if (hasCenter)
{
xOut = event.getX();
yOut = event.getY();
xTop = xCenter - Math.abs(xOut - xCenter);
yTop = yCenter - Math.abs(yOut - yCenter);
radius =
Math.sqrt((xOut - xCenter)*(xOut - xCenter) + (yOut - yCenter)*(yOut - yCenter));
hasCenter = false;
}
}
}
addMouseListener(new MousePressListener1());
addMouseListener(new MousePressListener2());
CircleComponent component = new CircleComponent();
add(component);
}
private double xTop;
private double yTop;
private int xCenter;
private int yCenter;
private int xOut;
private int yOut;
private Ellipse2D.Double circle;
private double radius;
private boolean hasCenter;
}
And this is the main class
import javax.swing.JFrame;
public class CircleFrameViewer
{
public static void main(String[] args)
{
JFrame frame = new CircleFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
Somehow it only shows a blank frame, and no clicks make anything happen.
Anyone can help me?

Don't use two listeners, use one, both listeners will be called whenever a mouse event occurs.
MouseEvents are contextual to the component which generated them. This means you should be adding your listener to the CircleComponent
Make sure you are calling repaint when you want the UI to be updated.
Something like...for example
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Rectangle2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test2 {
public static void main(String[] args) {
new Test2();
}
public Test2() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private Point centerPoint;
private Shape circle;
public TestPane() {
addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
if (centerPoint == null) {
centerPoint = e.getPoint();
repaint();
} else {
double xTop = Math.min(e.getPoint().x, centerPoint.x);
double yTop = Math.min(e.getPoint().y, centerPoint.y);
double xBottom = Math.max(e.getPoint().x, centerPoint.x);
double yBottom = Math.max(e.getPoint().y, centerPoint.y);
double radius = Math.max(xBottom - xTop, yBottom - yTop);
xTop = centerPoint.x - radius;
yTop = centerPoint.y - radius;
radius *= 2;
circle = new Ellipse2D.Double(xTop, yTop, radius, radius);
repaint();
}
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (circle != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.draw(circle);
g2d.dispose();
}
}
}
}

Sensing hover over outer edge of a Path2D circle in JPanel [duplicate]

This question already has an answer here:
Collision detection with complex shapes
(1 answer)
Closed 8 years ago.
So, I have a program that draws Path2D circles onto JPanel. What I am trying to do is resize the circle when the user clicks and drags the bottom right of the circle. So, what I want is to detect when they are on the bottom-right outer edge of the circle, not the bottom-right of the bounds around the circle. Basically, I need to figure out how to do something like this:
I know how to do this with rectangles using getBounds() but when you use getBounds() on a circle, it will return the square around the circle and not the bounds of the actual circle. Any ideas on how I can get this to work? Thanks!
Here is a shortened, runnable version of my program:
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Panel;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Path2D;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Editor {
public static void main(String[] args) {
JFrame frame = new UMLWindow();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(30, 30, 1000, 700);
frame.getContentPane().setBackground(Color.white);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
class UMLWindow extends JFrame {
Shapes shapeList = new Shapes();
Panel panel;
private static final long serialVersionUID = 1L;
public UMLWindow() {
addMenus();
panel = new Panel();
}
public void addMenus() {
getContentPane().add(shapeList);
setSize(300, 200);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
shapeList.addCircle(100, 100);
}
}
// Shapes class, used to draw the shapes on the panel
// as well as implements the MouseListener for dragging
class Shapes extends JPanel {
private static final long serialVersionUID = 1L;
private List<Path2D> shapes = new ArrayList<Path2D>();
int currentIndex;
public Shapes() {
MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
addMouseListener(myMouseAdapter);
addMouseMotionListener(myMouseAdapter);
}
public void addCircle(int width, int height) {
Path2D circ = new Path2D.Double();
circ.append(new Ellipse2D.Double(442, 269, width, height), true);
shapes.add(circ);
repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setStroke(new BasicStroke(2));
for (Path2D shape : shapes) {
g2.draw(shape);
}
}
class MyMouseAdapter extends MouseAdapter {
#Override
public void mousePressed(MouseEvent e) {
}
#Override
public void mouseDragged(MouseEvent e) {
}
#Override
public void mouseReleased(MouseEvent e) {
}
}
}

You'll want to brush up your trig (or google search like I did ;)). The basic concept is "relatively" easy, but I created a nice method to all the work for me...
This method...
public Point2D getPointOnEdge(float angel, Rectangle bounds) {
float radius = Math.max(bounds.width, bounds.height) / 2;
float x = radius;
float y = radius;
double rads = Math.toRadians((angel + 90));
// Calculate the outter point of the line
float xPosy = (float) (x + Math.cos(rads) * radius);
float yPosy = (float) (y + Math.sin(rads) * radius);
return new Point2D.Float(xPosy + bounds.x, yPosy + bounds.y);
}
Will calculate the x/y point that a given angle will appear on a circle, remember, this will ONLY work for circles!
I then use another method...
public Rectangle2D getActiveBounds(float angel, Rectangle bounds) {
Point2D p = getPointOnEdge(angel, bounds);
return new Rectangle2D.Double(p.getX() - 4, p.getY() - 4, 8, 8);
}
To calculate the "mouse zone" in which I would consider to be the bottom/right area, cause a single pixel is hard to find and simply use Rectangle#contains, passing it the current mouse location...
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Panel;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import static javax.swing.JFrame.EXIT_ON_CLOSE;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Editor {
public static void main(String[] args) {
new Editor();
}
public Editor() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new UMLWindow();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(30, 30, 1000, 700);
frame.getContentPane().setBackground(Color.white);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public static class UMLWindow extends JFrame {
Shapes shapeList = new Shapes();
Panel panel;
private static final long serialVersionUID = 1L;
public UMLWindow() {
addMenus();
panel = new Panel();
}
public void addMenus() {
getContentPane().add(shapeList);
setSize(300, 200);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
shapeList.addCircle(100, 100);
}
}
// Shapes class, used to draw the shapes on the panel
// as well as implements the MouseListener for dragging
public static class Shapes extends JPanel {
private static final long serialVersionUID = 1L;
private List<Path2D> shapes = new ArrayList<Path2D>();
int currentIndex;
private Point mousePoint;
public Shapes() {
MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
addMouseListener(myMouseAdapter);
addMouseMotionListener(myMouseAdapter);
}
public void addCircle(int width, int height) {
Path2D circ = new Path2D.Double();
circ.append(new Ellipse2D.Double(442, 269, width, height), true);
shapes.add(circ);
repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setStroke(new BasicStroke(2));
for (Path2D shape : shapes) {
g2.setColor(Color.BLACK);
g2.draw(shape);
g2.setColor(Color.RED);
Rectangle2D bottomRight = getActiveBounds(-45, shape.getBounds());
g2.draw(bottomRight);
if (mousePoint != null) {
if (bottomRight.contains(mousePoint)) {
g2.fill(bottomRight);
}
}
}
}
public Rectangle2D getActiveBounds(float angel, Rectangle bounds) {
Point2D p = getPointOnEdge(angel, bounds);
return new Rectangle2D.Double(p.getX() - 4, p.getY() - 4, 8, 8);
}
public Point2D getPointOnEdge(float angel, Rectangle bounds) {
float radius = Math.max(bounds.width, bounds.height) / 2;
float x = radius;
float y = radius;
double rads = Math.toRadians((angel + 90));
// Calculate the outter point of the line
float xPosy = (float) (x + Math.cos(rads) * radius);
float yPosy = (float) (y + Math.sin(rads) * radius);
return new Point2D.Float(xPosy + bounds.x, yPosy + bounds.y);
}
class MyMouseAdapter extends MouseAdapter {
#Override
public void mouseMoved(MouseEvent e) {
mousePoint = e.getPoint();
repaint();
}
}
}
}
This example does all the work within the paint method, because I wanted to see the "area of effect", you can easily use the same logic to change the mouse cursor within the MouseMoitionListener

Not sure if this will work but you can try something like:
Create a Shape circle that is a couple of pixels smaller than your original Shape
Create a Shape circle that is a couple of pixels larger than your original Shape
Create an Area object using the larger Shape
Create an Area object using the smaller Shape and subtract this Area from the larger Area
Use the contains(...) method to determine if the mouse point is within this Area.

Java Swing - How to create custom components with auto size adjustment to the parent

I'm trying to build a custom triangle component that has the same features as a JComponent (like a JButton per say).
The porpoise of the program will be to add triangle on a mouse click exactly where the mouse is and to handle a mouseover event by highlighting the bg of the shape.
I let the default layouts(or null), because while using others, the applications just doesn't place the triangles where I want...
Right now my major issue is how to adjust the size of the triangles with direct proportionality relative to the form size? So that if I reduce the frame size 50% all the components are down that value as well.
One other issue is that the JComponent requires a rectangular area to handle events, for what I've seen there's no way countering this, so if I try to click on the affected area it will just ignore it instead of creating a new triangle there.
And yet another problem is that sometimes while moving out of the triangle from the bottom it is still green.
Thanks!
Here is the SSCCE:
// TriangleCustom.java
package TriangleCustom;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.GeneralPath;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import javax.swing.BorderFactory;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class TriangleCustom {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowGUI();
}
});
}
private static void createAndShowGUI() {
JFrame f = new JFrame("Triangle");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(1200, 800);
Panel p = new Panel();
f.add(p);
f.setVisible(true);
}
}
class Panel extends JPanel {
// the offsets are the area (rect border) to contain the triangle shape
private final int xOFFSET = 25;
private final int yOFFSET = 50;
ArrayList<TriangleShape> triangleAL = new ArrayList<TriangleShape>();
public Panel() {
setBounds(0, 0, 800, 400);
// setBorder(BorderFactory.createLineBorder(Color.black,2));
addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
addTriangle(new Point(e.getX(), e.getY()), new Point(e.getX()
- xOFFSET, e.getY() + yOFFSET), new Point(e.getX()
+ xOFFSET, e.getY() + yOFFSET));
}
});
}
private void addTriangle(Point topCorner, Point leftCorner,
Point rightCorner) {
final TriangleDTO tdto = new TriangleDTO(new Point(25, 0), new Point(0,
50), new Point(50, 50));
TriangleShape ts = new TriangleShape(tdto);
ts.setBorderColor(Color.BLACK);
ts.setFillColor(Color.RED);
ts.setBounds((int) (topCorner.getX() - 25), (int) topCorner.getY(), 51,
51);
triangleAL.add(ts);
this.add(ts);
repaint();
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.draw(new Rectangle2D.Double(0, 0, 799, 399));
}
}
// the custom component in a shape of a triangle
class TriangleShape extends JComponent {
private GeneralPath triangle = new GeneralPath();
private TriangleDTO tdto = new TriangleDTO();
private Color borderColor = new Color(0);
private Color fillColor = new Color(0);
// Constructor
public TriangleShape(TriangleDTO tdto) {
this.tdto = tdto;
triangle.moveTo(tdto.getTopCorner().getX(), tdto.getTopCorner().getY());
triangle.lineTo(tdto.getLeftCorner().getX(), tdto.getLeftCorner()
.getY());
triangle.lineTo(tdto.getRightCorner().getX(), tdto.getRightCorner()
.getY());
triangle.closePath();
addMouseMotionListener(new MouseAdapter() {
public void mouseMoved(MouseEvent e) {
// there are some issues when going out of the triangle from
// bottom
if (triangle.contains((Point2D) e.getPoint())) {
setFillColor(Color.GREEN);
repaint();
} else {
setFillColor(Color.RED);
repaint();
}
}
});
}
public void setBorderColor(Color borderColor) {
this.borderColor = borderColor;
}
public void setFillColor(Color fillColor) {
this.fillColor = fillColor;
}
#Override
public void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
g2d.setPaint(fillColor);
g2d.fill(triangle);
g2d.setPaint(borderColor);
g2d.draw(triangle);
}
}
// just a plain DTO for the triangle points
class TriangleDTO {
private Point topCorner = new Point();
private Point leftCorner = new Point();
private Point rightCorner = new Point();
// Constructors
public TriangleDTO() {
}
public TriangleDTO(Point topCorner, Point leftCorner, Point rightCorner) {
super();
this.topCorner = topCorner;
this.leftCorner = leftCorner;
this.rightCorner = rightCorner;
}
// Getters and Setters
public Point getTopCorner() {
return topCorner;
}
public void setTopCorner(Point topCorner) {
this.topCorner = topCorner;
}
public Point getLeftCorner() {
return leftCorner;
}
public void setLeftCorner(Point leftCorner) {
this.leftCorner = leftCorner;
}
public Point getRightCorner() {
return rightCorner;
}
public void setRightCorner(Point rightCorner) {
this.rightCorner = rightCorner;
}
}