Java swing如何对自定义绘画进行分层
背景 我目前正在从事一个项目，我希望能够在Java swing如何对自定义绘画进行分层,java,swing,layer,Java,Swing,Layer,背景 我目前正在从事一个项目，我希望能够在JPanel上画一个三角形、圆形和矩形，并将它们四处移动 当一个图形被移动时，它应该结束在“顶部”，以便它覆盖处于重叠位置的其他图形，当一个图形被移动时，选择“顶部”；如果多个图形覆盖鼠标指针的位置，则选择顶部的一个 我的问题 如果我将形状拖到同一个位置，我无法解决如何解决形状不会彼此重叠的问题。它们只是停留在同一层，如果我把它们都叠在一起，我仍然会首先选择矩形 如果我将形状拖到同一个位置，我无法解决如何解决形状不会彼此重叠的问题 面板上的组件是根据组件
JPanelZOrdermousespressedComponent child = e.getComponent();
child.getParent().setComponentZOrder(child, 0);
drawRec.paintComponent(g);
drawCirc.paintComponent(g);
drawTri.paintComponent(g);
drawTridrawRec…如果我把它们都叠在一起，我仍然会先拾取矩形 这是因为
ClickListenermousePressed我几乎可以肯定，对于这个问题，必须有比列表或数组更有效的数据结构（因为你必须在线性时间内迭代所有形状以找到单击的形状），但我不是碰撞检测方面的专家，因此，为了保持简单，我将坚持使用它。但我们还需要做另一个操作：更改绘制和单击形状的选择顺序。长话短说，我们可以使用
LinkedHashSetLinkedHashSetLinkedHashSetjava.awt.Shapecontainsimport java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Point;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.AffineTransform;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Objects;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class NonComponentMain {
public static Shape createRectangle(final double width,
final double height) {
return new Rectangle2D.Double(0, 0, width, height);
}
public static Shape createEllipse(final double width,
final double height) {
return new Ellipse2D.Double(0, 0, width, height);
}
public static Shape createCircle(final double radius) {
return createEllipse(radius + radius, radius + radius);
}
public static class MoveableShapeHolder {
private final Shape shape;
private final Paint paint;
private final Rectangle2D originalBounds;
private double offsetX, offsetY;
public MoveableShapeHolder(final Shape shape,
final Paint paint) {
this.shape = Objects.requireNonNull(shape);
this.paint = paint;
offsetX = offsetY = 0;
originalBounds = shape.getBounds2D();
}
public void paint(final Graphics2D g2d) {
final AffineTransform originalAffineTransform = g2d.getTransform();
final Paint originalPaint = g2d.getPaint();
g2d.translate(offsetX, offsetY);
if (paint != null)
g2d.setPaint(paint);
g2d.fill(shape);
g2d.setPaint(originalPaint);
g2d.setTransform(originalAffineTransform);
}
public void moveTo(final double newBoundsCenterX,
final double newBoundsCenterY) {
offsetX = newBoundsCenterX - originalBounds.getCenterX();
offsetY = newBoundsCenterY - originalBounds.getCenterY();
}
public void moveBy(final double dx,
final double dy) {
offsetX += dx;
offsetY += dy;
}
public boolean contains(final Point2D pt) {
return shape.contains(pt.getX() - offsetX, pt.getY() - offsetY);
}
public Point2D getTopLeft() {
return new Point2D.Double(offsetX + originalBounds.getX(), offsetY + originalBounds.getY());
}
public Point2D getCenter() {
return new Point2D.Double(offsetX + originalBounds.getCenterX(), offsetY + originalBounds.getCenterY()); //Like 'getTopLeft' but with adding half the size.
}
public Point2D getBottomRight() {
return new Point2D.Double(offsetX + originalBounds.getMaxX(), offsetY + originalBounds.getMaxY()); //Like 'getTopLeft' but with adding the size of the bounds.
}
}
public static class DrawPanel extends JPanel {
private class MouseDrag extends MouseAdapter {
private MoveableShapeHolder current;
private Point origin;
private Point2D center;
@Override
public void mousePressed(final MouseEvent e) {
current = null;
center = null;
final Point evtLoc = e.getPoint();
for (final MoveableShapeHolder moveable: moveables)
if (moveable.contains(evtLoc))
current = moveable; //Keep the last moveable found to contain the click point! It's important to be the last one, because the later the moveable appears in the collection, the closer to top its layer.
if (current != null) { //If a shape was clicked...
//Initialize MouseDrag's state:
origin = e.getPoint();
center = current.getCenter();
//Move to topmost layer:
moveables.remove(current); //Remove from its current position.
moveables.add(current); //Move to last (topmost layer).
//Rapaint panel:
repaint();
}
}
@Override
public void mouseDragged(final MouseEvent e) {
if (current != null) { //If we are dragging something (and not empty space), then:
current.moveTo(center.getX() + e.getX() - origin.x, center.getY() + e.getY() - origin.y);
repaint();
}
}
@Override
public void mouseReleased(final MouseEvent e) {
current = null;
origin = null;
center = null;
}
}
private final LinkedHashSet<MoveableShapeHolder> moveables;
public DrawPanel() {
moveables = new LinkedHashSet<>();
final MouseAdapter ma = new MouseDrag();
super.addMouseMotionListener(ma);
super.addMouseListener(ma);
}
/**
* Warning: all operations on the returned value must be made on the EDT.
* @return
*/
public Collection<MoveableShapeHolder> getMoveables() {
return moveables;
}
@Override
protected void paintComponent(final Graphics g) {
super.paintComponent(g);
moveables.forEach(moveable -> moveable.paint((Graphics2D) g)); //Topmost moveable is painted last.
}
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet())
return super.getPreferredSize();
final Dimension preferredSize = new Dimension();
moveables.forEach(moveable -> {
final Point2D max = moveable.getBottomRight();
preferredSize.width = Math.max(preferredSize.width, (int) Math.ceil(max.getX()));
preferredSize.height = Math.max(preferredSize.height, (int) Math.ceil(max.getY()));
});
return preferredSize;
}
}
private static void createAndShowGUI() {
final DrawPanel drawPanel = new DrawPanel();
final Collection<MoveableShapeHolder> moveables = drawPanel.getMoveables();
MoveableShapeHolder moveable = new MoveableShapeHolder(createRectangle(100, 50), Color.RED);
moveable.moveTo(100, 75);
moveables.add(moveable);
moveable = new MoveableShapeHolder(createCircle(40), Color.GREEN);
moveable.moveTo(125, 100);
moveables.add(moveable);
moveable = new MoveableShapeHolder(createRectangle(25, 75), Color.BLUE);
moveable.moveTo(125, 75);
moveables.add(moveable);
final JFrame frame = new JFrame("Click to drag");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(drawPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(final String[] args) {
SwingUtilities.invokeLater(NonComponentMain::createAndShowGUI);
}
}
导入java.awt.Color；
导入java.awt.Dimension；
导入java.awt.Graphics；
导入java.awt.Graphics2D；
导入java.awt.Paint；
导入java.awt.Point；
导入java.awt.Shape；
导入java.awt.event.MouseAdapter；
导入java.awt.event.MouseEvent；
导入java.awt.geom.AffineTransform；
导入java.awt.geom.Ellipse2D；
导入java.awt.geom.Point2D；
导入java.awt.geom.Rectangle2D；
导入java.util.Collection；
导入java.util.LinkedHashSet；
导入java.util.Objects；
导入javax.swing.JFrame；
导入javax.swing.JPanel；
导入javax.swing.SwingUtilities；
公共类非组件主{
P
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Point;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.AffineTransform;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Objects;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class NonComponentMain {
public static Shape createRectangle(final double width,
final double height) {
return new Rectangle2D.Double(0, 0, width, height);
}
public static Shape createEllipse(final double width,
final double height) {
return new Ellipse2D.Double(0, 0, width, height);
}
public static Shape createCircle(final double radius) {
return createEllipse(radius + radius, radius + radius);
}
public static class MoveableShapeHolder {
private final Shape shape;
private final Paint paint;
private final Rectangle2D originalBounds;
private double offsetX, offsetY;
public MoveableShapeHolder(final Shape shape,
final Paint paint) {
this.shape = Objects.requireNonNull(shape);
this.paint = paint;
offsetX = offsetY = 0;
originalBounds = shape.getBounds2D();
}
public void paint(final Graphics2D g2d) {
final AffineTransform originalAffineTransform = g2d.getTransform();
final Paint originalPaint = g2d.getPaint();
g2d.translate(offsetX, offsetY);
if (paint != null)
g2d.setPaint(paint);
g2d.fill(shape);
g2d.setPaint(originalPaint);
g2d.setTransform(originalAffineTransform);
}
public void moveTo(final double newBoundsCenterX,
final double newBoundsCenterY) {
offsetX = newBoundsCenterX - originalBounds.getCenterX();
offsetY = newBoundsCenterY - originalBounds.getCenterY();
}
public void moveBy(final double dx,
final double dy) {
offsetX += dx;
offsetY += dy;
}
public boolean contains(final Point2D pt) {
return shape.contains(pt.getX() - offsetX, pt.getY() - offsetY);
}
public Point2D getTopLeft() {
return new Point2D.Double(offsetX + originalBounds.getX(), offsetY + originalBounds.getY());
}
public Point2D getCenter() {
return new Point2D.Double(offsetX + originalBounds.getCenterX(), offsetY + originalBounds.getCenterY()); //Like 'getTopLeft' but with adding half the size.
}
public Point2D getBottomRight() {
return new Point2D.Double(offsetX + originalBounds.getMaxX(), offsetY + originalBounds.getMaxY()); //Like 'getTopLeft' but with adding the size of the bounds.
}
}
public static class DrawPanel extends JPanel {
private class MouseDrag extends MouseAdapter {
private MoveableShapeHolder current;
private Point origin;
private Point2D center;
@Override
public void mousePressed(final MouseEvent e) {
current = null;
center = null;
final Point evtLoc = e.getPoint();
for (final MoveableShapeHolder moveable: moveables)
if (moveable.contains(evtLoc))
current = moveable; //Keep the last moveable found to contain the click point! It's important to be the last one, because the later the moveable appears in the collection, the closer to top its layer.
if (current != null) { //If a shape was clicked...
//Initialize MouseDrag's state:
origin = e.getPoint();
center = current.getCenter();
//Move to topmost layer:
moveables.remove(current); //Remove from its current position.
moveables.add(current); //Move to last (topmost layer).
//Rapaint panel:
repaint();
}
}
@Override
public void mouseDragged(final MouseEvent e) {
if (current != null) { //If we are dragging something (and not empty space), then:
current.moveTo(center.getX() + e.getX() - origin.x, center.getY() + e.getY() - origin.y);
repaint();
}
}
@Override
public void mouseReleased(final MouseEvent e) {
current = null;
origin = null;
center = null;
}
}
private final LinkedHashSet<MoveableShapeHolder> moveables;
public DrawPanel() {
moveables = new LinkedHashSet<>();
final MouseAdapter ma = new MouseDrag();
super.addMouseMotionListener(ma);
super.addMouseListener(ma);
}
/**
* Warning: all operations on the returned value must be made on the EDT.
* @return
*/
public Collection<MoveableShapeHolder> getMoveables() {
return moveables;
}
@Override
protected void paintComponent(final Graphics g) {
super.paintComponent(g);
moveables.forEach(moveable -> moveable.paint((Graphics2D) g)); //Topmost moveable is painted last.
}
@Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet())
return super.getPreferredSize();
final Dimension preferredSize = new Dimension();
moveables.forEach(moveable -> {
final Point2D max = moveable.getBottomRight();
preferredSize.width = Math.max(preferredSize.width, (int) Math.ceil(max.getX()));
preferredSize.height = Math.max(preferredSize.height, (int) Math.ceil(max.getY()));
});
return preferredSize;
}
}
private static void createAndShowGUI() {
final DrawPanel drawPanel = new DrawPanel();
final Collection<MoveableShapeHolder> moveables = drawPanel.getMoveables();
MoveableShapeHolder moveable = new MoveableShapeHolder(createRectangle(100, 50), Color.RED);
moveable.moveTo(100, 75);
moveables.add(moveable);
moveable = new MoveableShapeHolder(createCircle(40), Color.GREEN);
moveable.moveTo(125, 100);
moveables.add(moveable);
moveable = new MoveableShapeHolder(createRectangle(25, 75), Color.BLUE);
moveable.moveTo(125, 75);
moveables.add(moveable);
final JFrame frame = new JFrame("Click to drag");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(drawPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(final String[] args) {
SwingUtilities.invokeLater(NonComponentMain::createAndShowGUI);
}
}
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Polygon;
import java.awt.RenderingHints;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class MoveShapes implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new MoveShapes());
}
private final DrawingPanel drawingPanel;
private final ShapeModel shapeModel;
public MoveShapes() {
this.shapeModel = new ShapeModel();
this.drawingPanel = new DrawingPanel();
}
@Override
public void run() {
JFrame frame = new JFrame("Move Shapes");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(drawingPanel, BorderLayout.CENTER);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public void repaint() {
drawingPanel.repaint();
}
public class DrawingPanel extends JPanel {
private static final long serialVersionUID = 1L;
public DrawingPanel() {
this.setBackground(Color.WHITE);
this.setPreferredSize(new Dimension(600, 500));
MoveListener listener = new MoveListener();
this.addMouseListener(listener);
this.addMouseMotionListener(listener);
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
for (Shape shape : shapeModel.getShapes()) {
g2d.setColor(shape.getColor());
g2d.fillPolygon(shape.getShape());
}
}
}
public class MoveListener extends MouseAdapter {
private Point pressedPoint;
private Shape selectedShape;
@Override
public void mousePressed(MouseEvent event) {
this.pressedPoint = event.getPoint();
this.selectedShape = null;
List<Shape> shapes = shapeModel.getShapes();
for (int i = shapes.size() - 1; i >= 0; i--) {
Shape shape = shapes.get(i);
if (shape.getShape().contains(pressedPoint)) {
selectedShape = shape;
break;
}
}
if (selectedShape != null) {
shapes.remove(selectedShape);
shapes.add(selectedShape);
}
}
@Override
public void mouseReleased(MouseEvent event) {
moveShape(event.getPoint());
}
@Override
public void mouseDragged(MouseEvent event) {
moveShape(event.getPoint());
}
private void moveShape(Point point) {
if (selectedShape != null) {
int x = point.x - pressedPoint.x;
int y = point.y - pressedPoint.y;
selectedShape.incrementCenterPoint(x, y);
drawingPanel.repaint();
pressedPoint = point;
}
}
}
public class ShapeModel {
private final List<Shape> shapes;
public ShapeModel() {
this.shapes = new ArrayList<>();
this.shapes.add(new Shape(100, 250, Color.BLUE, ShapeType.TRIANGLE));
this.shapes.add(new Shape(300, 250, Color.RED, ShapeType.RECTANGLE));
this.shapes.add(new Shape(500, 250, Color.BLACK, ShapeType.CIRCLE));
}
public List<Shape> getShapes() {
return shapes;
}
}
public class Shape {
private final Color color;
private Point centerPoint;
private Polygon shape;
private final ShapeType shapeType;
public Shape(int x, int y, Color color, ShapeType shapeType) {
this.centerPoint = new Point(x, y);
this.color = color;
this.shapeType = shapeType;
createPolygon(shapeType);
}
public void incrementCenterPoint(int x, int y) {
centerPoint.x += x;
centerPoint.y += y;
createPolygon(shapeType);
}
private void createPolygon(ShapeType shapeType) {
this.shape = new Polygon();
switch (shapeType) {
case TRIANGLE:
int angle = 30;
int radius = 100;
for (int i = 0; i < 3; i++) {
Point point = toCartesianCoordinates(angle, radius);
shape.addPoint(point.x, point.y);
angle += 120;
}
break;
case RECTANGLE:
angle = 45;
radius = 100;
for (int i = 0; i < 4; i++) {
Point point = toCartesianCoordinates(angle, radius);
shape.addPoint(point.x, point.y);
angle += 90;
}
break;
case CIRCLE:
radius = 75;
for (angle = 0; angle < 360; angle++) {
Point point = toCartesianCoordinates(angle, radius);
shape.addPoint(point.x, point.y);
}
break;
}
}
private Point toCartesianCoordinates(int angle, int radius) {
double theta = Math.toRadians(angle);
int x = (int) Math.round(Math.cos(theta) * radius) + centerPoint.x;
int y = (int) Math.round(Math.sin(theta) * radius) + centerPoint.y;
return new Point(x, y);
}
public Color getColor() {
return color;
}
public Point getCenterPoint() {
return centerPoint;
}
public Polygon getShape() {
return shape;
}
}
public enum ShapeType {
TRIANGLE, RECTANGLE, CIRCLE
}
}