使用 Graphics2D，当我拖动形状时，我想移动形状

Question

当我拖动我绘制的形状时，我想移动。
但我不知道该怎么做。
我已经尝试过 GPanel 中的 make move 方法，但无法成功。
知识。

我已经为此工作了将近 1 周，并尝试了所有我能想到的解决方案。

这是我第一次发布关于堆栈溢出的代码问题。

我真的很想学习。 .爱你们。

我希望有一天我可以成为代码新手的救星

必须使用仿射变换

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这是绘图页

package frame;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.util.Vector;

import javax.swing.JPanel;

import main.GConstants.EAnchorLocation;
import main.GConstants.EDrawingStyle;
import shapeTool.GShapeTool;

public class GPanel extends JPanel {

private static final long serialVersionUID = 1L;

private GShapeTool shapeTool;
private GShapeTool selectedShape;
private Vector<GShapeTool> shapes;

public GPanel() {
    this.setBackground(Color.WHITE);

    this.shapes = new Vector<GShapeTool>();

    MouseHandler mouseHandler = new MouseHandler();
    this.addMouseListener(mouseHandler);
    this.addMouseMotionListener(mouseHandler);
    this.addMouseWheelListener(mouseHandler);
}

public void initialize() {}

public Vector<GShapeTool> getShapes() {
    return this.shapes;
}

public void setShapes(Vector<GShapeTool> shapes){
    this.shapes = shapes;
    this.updateUI();
}


public void paint(Graphics graphics) {
    super.paint(graphics);
    for(GShapeTool shape: this.shapes) {
        shape.draw((Graphics2D)graphics);
    }
}

public void setShapeTool(GShapeTool shapeTool) {
    this.shapeTool = shapeTool;
}

private boolean onShape(int x, int y) {
    boolean shapeCheck = false;
    for(GShapeTool shapeTool: this.shapes) {
        if(shapeTool.contains(x, y)) {
            this.selectedShape = shapeTool;
            shapeCheck = true;
        } else {
            shapeTool.setSelected(false, (Graphics2D)getGraphics());
        }
    }
    if(shapeCheck) {
        this.selectedShape.setSelected(true, (Graphics2D)getGraphics());
    }
    return shapeCheck;
}       


private void setInitialPoint(int x, int y) {
    this.selectedShape = this.shapeTool.clone();
    this.selectedShape.setInitialPoint(x, y);
}



private void setFinalPoint(int x, int y) {
    for(GShapeTool shapeTool: this.shapes) {
        shapeTool.setSelected(false, (Graphics2D)getGraphics());
    }

    //      Graphics2D graphics2D = (Graphics2D) this.getGraphics();
    //set xor mode;
    //      graphics2D.setXORMode(getBackground());
    this.selectedShape.setFinalPoint(x, y);
    this.selectedShape.setSelected(true, (Graphics2D)getGraphics());
    this.shapes.add(this.selectedShape);
}

private void setIntermediatePoint(int x, int y) {
    this.selectedShape.setIntermediatePoint(x, y);  
}

private void animate(int x, int y) {
    Graphics2D graphics2D = (Graphics2D) this.getGraphics();
    //set xor mode;
    graphics2D.setXORMode(getBackground());
    this.selectedShape.animate(graphics2D, x, y);
}




private class MouseHandler 
implements MouseListener, MouseMotionListener, MouseWheelListener {

    private boolean isDrawing;
    MouseHandler() {
        this.isDrawing = false;
    }

    @Override
    public void mouseClicked(MouseEvent e) {

        if(e.getButton() == MouseEvent.BUTTON1) {
            if(e.getClickCount() == 1) {
                this.mouseLButton1Clicked(e);
            } else if(e.getClickCount() == 2) {
                this.mouseLButton2Clicked(e);
            }   
        } else if(e.getButton() == MouseEvent.BUTTON2) {
            if(e.getClickCount() == 1) {
                this.mouseRButton1Clicked(e);
            }
        }
    }



    @Override
    public void mouseMoved(MouseEvent e) {  
        if(isDrawing) {
            if(shapeTool.getDrawingStyle() == EDrawingStyle.eNPointDrawing) {
                animate(e.getX(), e.getY());
            }
        }
    }

    private void mouseLButton1Clicked(MouseEvent e) {
        if(!this.isDrawing) { 
            if(!onShape(e.getX(), e.getY())) {
                if(shapeTool.getDrawingStyle() == EDrawingStyle.eNPointDrawing) {
                    setInitialPoint(e.getX(), e.getY());
                    this.isDrawing = true;
                }
            }
            else if(onShape(e.getX(), e.getY())) {
                onShape(e.getX(), e.getY());
            }

        } else {
            if(shapeTool.getDrawingStyle() == EDrawingStyle.eNPointDrawing) {
                setIntermediatePoint(e.getX(),e.getY());
            }
        }   
    }

    private void mouseLButton2Clicked(MouseEvent e) {
        if(this.isDrawing) {
            if(shapeTool.getDrawingStyle() == EDrawingStyle.eNPointDrawing) {
                setFinalPoint(e.getX(), e.getY());
                this.isDrawing = false;
            }
        }
    }

    private void mouseRButton1Clicked(MouseEvent e) {

    }

    @Override
    public void mousePressed(MouseEvent e) {
        if(e.getButton() == MouseEvent.BUTTON1) {
            if(!this.isDrawing) {
                if(shapeTool.getDrawingStyle() == EDrawingStyle.e2PointDrawing) {
                    setInitialPoint(e.getX(), e.getY());
                    this.isDrawing = true;
                }
            }
        }
    }
    @Override
    public void mouseDragged(MouseEvent e) {
        if(this.isDrawing) {
            if(shapeTool.getDrawingStyle() == EDrawingStyle.e2PointDrawing) {
                animate(e.getX(), e.getY());
            }
        }
    }

    @Override
    public void mouseReleased(MouseEvent e) {
        if(this.isDrawing) {
            if(shapeTool.getDrawingStyle() == EDrawingStyle.e2PointDrawing) {
                setFinalPoint(e.getX(), e.getY());
                this.isDrawing = false;
            }
        }
    }

    @Override
    public void mouseEntered(MouseEvent e) {}
    @Override
    public void mouseExited(MouseEvent e) {}        
    @Override
    public void mouseWheelMoved(MouseWheelEvent e) {}

    }
}

---

这是形状的抽象类

package shapeTool;

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Ellipse2D.Double;
import java.awt.geom.Rectangle2D;
import java.io.Serializable;
import java.util.Vector;

import main.GConstants.EAnchorLocation;
import main.GConstants.EDrawingStyle;

public abstract class GShapeTool implements Serializable {

private static final long serialVersionUID = 1L;
public enum EAnchors {
    x0y0,
    x0y1,
    x0y2,
    x1y0,
    x1y2,
    x2y0,
    x2y1,
    x2y2,
    RR;
}

public final static int wAnchor = 10;
public final static int hAnchor = 10;

private EDrawingStyle eDrawingStyle;

protected boolean isSelected;

protected Shape shape;
private Ellipse2D[] anchors;

public GShapeTool(EDrawingStyle eDrawingStyle) {
    this.eDrawingStyle = eDrawingStyle;
    this.isSelected = false;
    this.anchors = new Ellipse2D.Double[EAnchors.values().length];
    for(EAnchors eAnchor: EAnchors.values()) {
        this.anchors[eAnchor.ordinal()] = new Ellipse2D.Double();
    }
}

public EDrawingStyle getDrawingStyle() {
    return this.eDrawingStyle;
}

public boolean contains(int x, int y) {
    return this.shape.contains(x , y);
}

private void drawAnchors(Graphics2D graphics2D) {
    // draw bounding rectangle
    Rectangle rectangle = this.shape.getBounds();
    int x0 = rectangle.x-wAnchor;
    int x1 = rectangle.x + rectangle.width/2;
    int x2 = rectangle.x + rectangle.width;
    int y0 = rectangle.y-hAnchor;
    int y1 = rectangle.y + rectangle.height/2;
    int y2 = rectangle.y + rectangle.height;

    this.anchors[EAnchors.x0y0.ordinal()].setFrame(x0,y0,wAnchor,hAnchor);
    this.anchors[EAnchors.x0y1.ordinal()].setFrame(x0,y1,wAnchor,hAnchor);
    this.anchors[EAnchors.x0y2.ordinal()].setFrame(x0,y2,wAnchor,hAnchor);
    this.anchors[EAnchors.x1y0.ordinal()].setFrame(x1,y0,wAnchor,hAnchor);
    this.anchors[EAnchors.x1y2.ordinal()].setFrame(x1,y2,wAnchor,hAnchor);
    this.anchors[EAnchors.x2y0.ordinal()].setFrame(x2,y0,wAnchor,hAnchor);
    this.anchors[EAnchors.x2y1.ordinal()].setFrame(x2,y1,wAnchor,hAnchor);
    this.anchors[EAnchors.x2y2.ordinal()].setFrame(x2,y2,wAnchor,hAnchor);
    this.anchors[EAnchors.RR.ordinal()].setFrame(x1,y0-50,wAnchor,hAnchor);
    //draw anchors
    graphics2D.setColor(Color.BLACK);
    for(EAnchors eAnchor: EAnchors.values()) {
        graphics2D.draw(this.anchors[eAnchor.ordinal()]);
    }
}

private void eraseAnchors(Graphics2D graphics2D) {
    graphics2D.setColor(Color.WHITE);
    for(EAnchors eAnchor: EAnchors.values()) {
        graphics2D.draw(this.anchors[eAnchor.ordinal()]);
    }       
}

public void setSelected(boolean isSelected, Graphics2D graphics2D) {
    if(this.isSelected) {
        if(!isSelected) {
            //erase
            this.eraseAnchors(graphics2D);
        }

    } else {
        if(isSelected) {
            //draw
            this.drawAnchors(graphics2D);
        }

    }
    this.isSelected = isSelected;
}

public void draw(Graphics2D graphics) {
    graphics.draw(this.shape);  
}

public void animate(Graphics2D graphics2d, int x, int y) {
    //erase;
    this.draw(graphics2d);
    //      //move point
    this.movePoint(x,y);
    //      //draw;
    this.draw(graphics2d);
}

//interface
public abstract GShapeTool clone();

public abstract void setInitialPoint(int x, int y);

public abstract void setFinalPoint(int x, int y);

public abstract void setIntermediatePoint(int x, int y);

public abstract void movePoint(int x, int y);
}

---

这是扩展 GShapeTool 的形状类

package shapeTool;

import java.awt.Graphics2D;
import java.awt.Rectangle;

import main.GConstants.EDrawingStyle;

public class GRectangle extends GShapeTool {
//attributes
private static final long serialVersionUID = 1L;
//components
//constructor
public GRectangle() {
    super(EDrawingStyle.e2PointDrawing);
    this.shape = new Rectangle();
}

@Override
public GShapeTool clone() {
    GShapeTool cloned = new GRectangle();
    return cloned;
}
// methods
@Override
public void setInitialPoint(int x, int y) {
    Rectangle rectangle = (Rectangle) this.shape;
    rectangle.setLocation(x, y);
    rectangle.setSize(0, 0);
}

@Override
public void setIntermediatePoint(int x, int y) {
    // TODO Auto-generated method stub
    
}

@Override
public void setFinalPoint(int x, int y) {
}

@Override
public void movePoint(int x, int y) {
    Rectangle rectangle = (Rectangle) this.shape;
    rectangle.setSize(x-rectangle.x, y-rectangle.y);
    }
}

---

Answer 1

你应该得到一个 dragstart 事件。那是您保存鼠标位置和所选对象的时候。 当你得到一个 dragfinished 事件时，再次注意鼠标位置并相应地移动对象。移动可能只是发生在屏幕上，但例如万一掉落发生在垃圾桶上，您要删除它们。

现在，当拖动处于活动状态时，您可能会收到更多拖动事件，您应该使用它们来更新屏幕并向用户提供反馈。大多数情况下，这只是查看鼠标位置和选定的对象并相应地绘制它们。