调整面板大小而无需重新验证 [英] Resize the panel without revalidation
本文介绍了调整面板大小而无需重新验证的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有一个JPanel，我在其中画线以创建铅笔的幻觉.该面板位于ScrollPane中.
I have aJPanel in which I draw lines to create an illusion of pencil. This panel is in aScrollPane.
当我调整面板大小时，将自动放置一个对revalidate()方法的调用，并且我在该面板中绘制的所有线条均消失了.有什么办法可以使我的画线以新的尺寸保留在面板中?
When I resize the panel one call to revalidate() method is automatically placed and all my drawn lines in this panel are gone. Is there any way to keep my drawn line in the panel with the new size ?
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
/**
*
* @author Sanjeev
*/
public class WorkArea extends JFrame implements ActionListener, MouseListener, MouseMotionListener
{
private final int PEN_OP = 1;
private final int ERASER_OP = 2;
private final int SCROLL_OP = 3;
private int mousex = 0;
private int mousey = 0;
private int prevx = 0;
private int prevy = 0;
private boolean initialPen = true;
private boolean initialEraser = true;
private int eraserLength = 5;
private int opStatus = PEN_OP;
private Color mainColor = new Color(0,0,0);
private int drawPanelHeight =1000;
public WorkArea()
{
initComponents();
setLocationRelativeTo(null);
pencilButton.addActionListener(this);
eraserButton.addActionListener(this);
drawPanel.addMouseMotionListener(this);
drawPanel.addMouseListener(this);
drawPanel.add(new TestPane());
this.addMouseListener(this);
this.addMouseMotionListener(this);
}
private void initComponents() {
headerPanel = new javax.swing.JPanel();
backButton = new javax.swing.JLabel();
headerImage = new javax.swing.JLabel();
controlPanel = new javax.swing.JPanel();
scrollButton = new javax.swing.JButton();
pencilButton = new javax.swing.JButton();
eraserButton = new javax.swing.JButton();
drawingPanel = new javax.swing.JPanel();
drawingScrollPane = new javax.swing.JScrollPane();
drawPanel = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("v0.1");
setBackground(new java.awt.Color(237, 254, 255));
setBounds(new java.awt.Rectangle(0, 0, 513, 693));
setResizable(false);
headerPanel.setBackground(new java.awt.Color(237, 254, 255));
headerPanel.setPreferredSize(new java.awt.Dimension(513, 25));
headerPanel.setLayout(null);
backButton.setBackground(new java.awt.Color(237, 254, 255));
backButton.setFont(new java.awt.Font("Tahoma", 0, 10)); // NOI18N
backButton.setForeground(new java.awt.Color(255, 255, 255));
backButton.setIcon(new javax.swing.ImageIcon(getClass().getResource("/images/back-arrow.png"))); // NOI18N
backButton.setText("Back");
backButton.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
backButton.setPreferredSize(new java.awt.Dimension(40, 20));
headerPanel.add(backButton);
backButton.setBounds(0, 3, 40, 20);
headerImage.setBackground(new java.awt.Color(237, 254, 255));
headerImage.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
headerImage.setForeground(new java.awt.Color(255, 255, 255));
headerImage.setIcon(new javax.swing.ImageIcon(getClass().getResource("/images/topbar_ipad_wide.png"))); // NOI18N
headerImage.setText("Work Area");
headerImage.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
headerImage.setPreferredSize(new java.awt.Dimension(513, 25));
headerPanel.add(headerImage);
headerImage.setBounds(0, 0, 513, 25);
controlPanel.setBackground(new java.awt.Color(237, 254, 255));
controlPanel.setPreferredSize(new java.awt.Dimension(90, 670));
controlPanel.setLayout(null);
scrollButton.setBackground(new java.awt.Color(237, 254, 255));
scrollButton.setIcon(new javax.swing.ImageIcon(getClass().getResource("/images/up_down_ipad.png"))); // NOI18N
scrollButton.setPreferredSize(new java.awt.Dimension(60, 60));
scrollButton.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
scrollButtonMouseClicked(evt);
}
});
controlPanel.add(scrollButton);
scrollButton.setBounds(20, 570, 60, 60);
pencilButton.setBackground(new java.awt.Color(237, 254, 255));
pencilButton.setIcon(new javax.swing.ImageIcon(getClass().getResource("/images/pencil_ipad.png"))); // NOI18N
pencilButton.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
pencilButtonMouseClicked(evt);
}
});
controlPanel.add(pencilButton);
pencilButton.setBounds(20, 450, 60, 60);
eraserButton.setBackground(new java.awt.Color(237, 254, 255));
eraserButton.setIcon(new javax.swing.ImageIcon(getClass().getResource("/images/eraser_ipad.png"))); // NOI18N
eraserButton.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
eraserButtonMouseClicked(evt);
}
});
controlPanel.add(eraserButton);
eraserButton.setBounds(20, 510, 60, 60);
drawingPanel.setBackground(new java.awt.Color(237, 254, 255));
drawingPanel.setPreferredSize(new java.awt.Dimension(420, 670));
drawingPanel.setLayout(null);
drawingScrollPane.setBorder(null);
drawingScrollPane.setPreferredSize(new java.awt.Dimension(423, 1000));
drawPanel.setBackground(new java.awt.Color(237, 254, 255));
drawPanel.setPreferredSize(new java.awt.Dimension(400, 1000));
drawPanel.setLayout(null);
drawingScrollPane.setViewportView(drawPanel);
drawingPanel.add(drawingScrollPane);
drawingScrollPane.setBounds(0, 0, 424, 670);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 513, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(headerPanel, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 513, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(controlPanel, javax.swing.GroupLayout.PREFERRED_SIZE, 90, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 423, Short.MAX_VALUE)))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(0, 93, Short.MAX_VALUE)
.addComponent(drawingPanel, javax.swing.GroupLayout.PREFERRED_SIZE, 420, javax.swing.GroupLayout.PREFERRED_SIZE)))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 693, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(headerPanel, javax.swing.GroupLayout.PREFERRED_SIZE, 25, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 668, Short.MAX_VALUE)))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(0, 23, Short.MAX_VALUE)
.addComponent(controlPanel, javax.swing.GroupLayout.PREFERRED_SIZE, 670, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(0, 23, Short.MAX_VALUE)
.addComponent(drawingPanel, javax.swing.GroupLayout.PREFERRED_SIZE, 670, javax.swing.GroupLayout.PREFERRED_SIZE)))
);
pack();
}
@Override
public void actionPerformed(ActionEvent e)
{
if (e.getActionCommand() == "Pen")
opStatus = PEN_OP;
if (e.getActionCommand() == "Eraser")
opStatus = ERASER_OP;
if(e.getActionCommand() == "Scroll")
opStatus = SCROLL_OP;
}
private void pencilButtonMouseClickedTest(java.awt.event.MouseEvent evt)
{
opStatus = PEN_OP;
Graphics g = drawPanel.getGraphics();
if (initialPen)
{
setGraphicalDefaults(evt);
initialPen = false;
g.drawLine(prevx,prevy,mousex,mousey);
}
if (mouseHasMoved(evt))
{
mousex = evt.getX();
mousey = evt.getY();
g.drawLine(prevx,prevy,mousex,mousey);
prevx = mousex;
prevy = mousey;
}
}
private void eraserButtonMouseClickedTest(java.awt.event.MouseEvent evt)
{
opStatus = ERASER_OP;
Graphics g = drawPanel.getGraphics();
if (initialEraser)
{
setGraphicalDefaults(evt);
initialEraser = false;
mousex = evt.getX();
mousey = evt.getY();
System.out.println("Initial Eraser ::::::::x's value is : "+prevx+" , "+mousey+" and y's value is : "+mousex+" , "+mousey);
g.setColor(new java.awt.Color(237,254,255));
g.fillRect(mousex-eraserLength, mousey-eraserLength,eraserLength*2,eraserLength*2);
//g.setColor(Color.black); //Eraser Border
g.drawRect(mousex-eraserLength,mousey-eraserLength,eraserLength*2,eraserLength*2);
prevx = mousex;
prevy = mousey;
}
if (mouseHasMoved(evt))
{
System.out.println("Eraser ::::::::x's value is : "+prevx+" , "+mousey+" and y's value is : "+mousex+" , "+mousey);
g.setColor(new java.awt.Color(237,254,255));
g.drawRect(prevx-eraserLength, prevy-eraserLength,eraserLength*2,eraserLength*2);
mousex = evt.getX();
mousey = evt.getY();
/* Draw eraser block to panel */
g.setColor(new java.awt.Color(237,254,255));
g.fillRect(mousex-eraserLength, mousey-eraserLength,eraserLength*2,eraserLength*2);
g.setColor(Color.black);//Eraser Border
g.drawRect(mousex-eraserLength,mousey-eraserLength,eraserLength*2,eraserLength*2);
prevx = mousex;
prevy = mousey;
}
}
private void scrollButtonMouseClicked(java.awt.event.MouseEvent evt) {
opStatus = SCROLL_OP;
drawingScrollPane.getVerticalScrollBar().addAdjustmentListener(new AdjustmentListener() {
@Override
public void adjustmentValueChanged(AdjustmentEvent e)
{
int extent,curValue;
extent = drawingScrollPane.getVerticalScrollBar().getModel().getExtent();
curValue = drawingScrollPane.getVerticalScrollBar().getValue()+extent;
if(curValue==drawPanel.getHeight())
{
System.out.println("value of scroll equals to Max value....");
drawPanel.setPreferredSize(new Dimension(423,drawPanelHeight*4));
}
System.out.println("Value: " + curValue + " Max: " + drawingScrollPane.getVerticalScrollBar().getMaximum());
}
});
}
private void eraserButtonMouseClicked(java.awt.event.MouseEvent evt) {
eraserButtonMouseClickedTest(evt);
updateMouseCoordinates(evt);
}
private void pencilButtonMouseClicked(java.awt.event.MouseEvent evt) {
opStatus = PEN_OP;
}
public boolean mouseHasMoved(MouseEvent e)
{
return (mousex != e.getX() || mousey != e.getY());
}
public void setGraphicalDefaults(MouseEvent e)
{
mousex = e.getX();
mousey = e.getY();
prevx = e.getX();
prevy = e.getY();
}
@Override
public void mouseDragged(MouseEvent e)
{
updateMouseCoordinates(e);
switch (opStatus)
{
case PEN_OP : pencilButtonMouseClickedTest(e);
break;
case ERASER_OP: eraserButtonMouseClicked(e);
break;
case SCROLL_OP: scrollButtonMouseClicked(e);
break;
}
}
public void mouseReleased(MouseEvent e)
{
updateMouseCoordinates(e);
switch (opStatus)
{
case PEN_OP : releasedPen();
break;
case ERASER_OP : releasedEraser();
break;
}
}
public void mouseEntered(MouseEvent e)
{
updateMouseCoordinates(e);
}
public void releasedPen()
{
initialPen = true;
}
public void releasedEraser()
{
initialEraser = true;
Graphics g = drawPanel.getGraphics();
g.setColor(mainColor.white);
g.drawRect(mousex-eraserLength,mousey-eraserLength,eraserLength*2,eraserLength*2);
}
public void updateMouseCoordinates(MouseEvent e)
{
String xCoor ="";
String yCoor ="";
if (e.getX() < 0) xCoor = "0";
else
{
xCoor = String.valueOf(e.getX());
}
if (e.getY() < 0) xCoor = "0";
else
{
yCoor = String.valueOf(e.getY());
}
}
public static void main(String args[]) {
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(WorkArea.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(WorkArea.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(WorkArea.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(WorkArea.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new WorkArea().setVisible(true);
}
});
}
private javax.swing.JLabel backButton;
private javax.swing.JPanel controlPanel;
private javax.swing.JPanel drawPanel;
private javax.swing.JPanel drawingPanel;
private javax.swing.JScrollPane drawingScrollPane;
private javax.swing.JButton eraserButton;
private javax.swing.JLabel headerImage;
private javax.swing.JPanel headerPanel;
private javax.swing.JButton pencilButton;
private javax.swing.JButton scrollButton;
@Override
public void mouseClicked(MouseEvent e) {
}
@Override
public void mouseExited(MouseEvent e) {
updateMouseCoordinates(e);
}
@Override
public void mouseMoved(MouseEvent e) {
updateMouseCoordinates(e);
}
@Override
public void mousePressed(MouseEvent e) {
updateMouseCoordinates(e);
}
}
推荐答案
我假设您正在通过使用getGraphics()并将其输出呈现到JPanel上.
I assume you are drawing to the JPanel by using getGraphics() and rendering your out put to it.
您现在已经知道了为什么不应该这样做.重新涂装组件时，以前涂过的所有东西都会被擦拭干净，您应该重新涂装内容.
You have now seen why you shouldn't do this. When the component is repainted, anything previously painted to is wiped cleaned and you are expected to repaint the contents.
首先要覆盖paintComponent并更新此方法中的所有行(请不要忘记调用super.paintComponent
Start by overriding paintComponent and updating all the lines within this method (don't forget to call super.paintComponent
请参见执行自定义绘画和
See Performing Custom Painting and Painting in AWT and Swing for more details
例如.
- Drawing a rectangle that won't disappear in next paint
- MouseEvent is not registering a release when I release the mouse button
已更新示例
This is a modified version of the answer to MouseEvent is not registering a release when I release the mouse button which includes a scroll pane...
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
public class MouseDraggedTest {
public static void main(String[] args) {
new MouseDraggedTest();
}
public MouseDraggedTest() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new JScrollPane(new TestPane()));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private Map<Point, List<Point>> mapPoints;
private Point currentPoint;
public TestPane() {
mapPoints = new HashMap<>(25);
MouseAdapter mouseListener = new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
currentPoint = e.getPoint();
mapPoints.put(currentPoint, new ArrayList<Point>(25));
}
@Override
public void mouseReleased(MouseEvent e) {
List<Point> points = mapPoints.get(currentPoint);
if (points.isEmpty()) {
mapPoints.remove(currentPoint);
}
currentPoint = null;
}
@Override
public void mouseDragged(MouseEvent me) {
List<Point> points = mapPoints.get(currentPoint);
points.add(me.getPoint());
repaint();
}
};
addMouseListener(mouseListener);
addMouseMotionListener(mouseListener);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(200, 800);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (Point startPoint : mapPoints.keySet()) {
List<Point> points = mapPoints.get(startPoint);
for (Point p : points) {
if (startPoint != null) {
g.drawLine(startPoint.x, startPoint.y, p.x, p.y);
}
startPoint = p;
}
}
}
}
}
使用BufferedImage示例进行了更新
由于您需要提供的不仅仅是绘图操作，您可能会发现将BufferedImage用作主要绘图表面并将其渲染到DrawingPanel
Because you need to supply more operations than just drawing, you may find it easier to use BufferedImage as your primary drawing surface and render this to your DrawingPanel
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Point;
import java.awt.Shape;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.image.BufferedImage;
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JToggleButton;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class MyPicture {
public static void main(String[] args) {
new MyPicture();
}
public MyPicture() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public enum DrawOperation {
Draw,
Erase
}
public class TestPane extends JPanel {
private DrawOperation op;
private JToggleButton pencil;
private JToggleButton eraser;
private DrawPane drawPane;
public TestPane() {
setLayout(new BorderLayout());
drawPane = new DrawPane();
MouseAdapter adapter = new MouseAdapter() {
private Point startPoint;
@Override
public void mouseEntered(MouseEvent e) {
drawPane.updateDrawCursor(e.getPoint(), op);
}
@Override
public void mouseExited(MouseEvent e) {
drawPane.removeDrawCursor();
}
@Override
public void mousePressed(MouseEvent e) {
startPoint = e.getPoint();
}
@Override
public void mouseReleased(MouseEvent e) {
startPoint = null;
}
@Override
public void mouseDragged(MouseEvent e) {
drawPane.applyOperation(startPoint, e.getPoint(), op);
drawPane.updateDrawCursor(e.getPoint(), op);
startPoint = e.getPoint();
}
@Override
public void mouseMoved(MouseEvent e) {
drawPane.updateDrawCursor(e.getPoint(), op);
}
};
drawPane.addMouseListener(adapter);
drawPane.addMouseMotionListener(adapter);
JPanel operations = new JPanel(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = GridBagConstraints.REMAINDER;
pencil = new JToggleButton("Draw");
eraser = new JToggleButton("Erase");
ButtonGroup bgOps = new ButtonGroup();
bgOps.add(pencil);
bgOps.add(eraser);
operations.add(pencil, gbc);
operations.add(eraser, gbc);
pencil.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
op = DrawOperation.Draw;
}
});
eraser.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
op = DrawOperation.Erase;
}
});
add(operations, BorderLayout.WEST);
add(new JScrollPane(drawPane));
}
}
public class DrawPane extends JPanel {
private BufferedImage image;
private Shape drawCursor;
private Point cursorPoint;
private int eraseSize = 20;
public DrawPane() {
image = new BufferedImage(400, 400, BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = image.createGraphics();
g2d.setBackground(Color.WHITE);
g2d.fillRect(0, 0, 400, 400);
g2d.dispose();
}
@Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
if (image != null) {
g2d.drawImage(image, 0, 0, this);
}
if (drawCursor != null && cursorPoint != null) {
int x = (cursorPoint.x - (drawCursor.getBounds().width) / 2);
int y = (cursorPoint.y - (drawCursor.getBounds().height) / 2);
g2d.translate(x, y);
g2d.draw(drawCursor);
g2d.translate(-x, -y);
}
g2d.dispose();
}
public void updateDrawCursor(Point point, DrawOperation op) {
cursorPoint = point;
if (op != null) {
switch (op) {
case Draw:
drawCursor = new Ellipse2D.Float(0, 0, 4, 4);
break;
case Erase:
drawCursor = new Ellipse2D.Float(0, 0, eraseSize, eraseSize);
break;
}
} else {
drawCursor = null;
}
repaint();
}
protected void removeDrawCursor() {
drawCursor = null;
repaint();
}
protected void applyOperation(Point fromPoint, Point toPoint, DrawOperation op) {
if (image != null) {
if (op != null) {
Graphics2D g2d = image.createGraphics();
switch (op) {
case Draw:
g2d.setColor(Color.BLACK);
g2d.draw(new Line2D.Float(fromPoint, toPoint));
break;
case Erase:
g2d.setColor(Color.WHITE);
g2d.setStroke(new BasicStroke(eraseSize));
g2d.draw(new Line2D.Float(fromPoint, toPoint));
break;
}
g2d.dispose();
}
}
repaint();
}
}
}
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