使用 Graphics2D，当我拖动形状时，我想移动形状 [英] Using Graphics2D, when I drag the shapes, I want to move the shapes

问题描述

当我拖动我绘制的形状时，我想移动.
但我不知道该怎么做.
我在 GPanel 中尝试了 make move 方法，但无法成功.
知识.

When I drag the shapes that I drew, I want to move.
but I do not know how to do it.
I have tried the make move method in GPanel but could not make it.
knowledge.

我已经为此工作了将近 1 周，并尝试了我能想到的所有解决方案.

I have been working on this for almost 1 week and tried all the solutions that I could think of.

这是我第一次发布关于堆栈溢出的代码问题.

This is my first time posting a code question on stack overflow.

我真的很想学习..并爱你们.

I do really want to learn. . And love you all.

希望有一天我能成为代码新手的救星

I hope one day I could be a savior for code newbies

必须使用仿射变换

这是绘图页面

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);
    }
}

---

推荐答案

你应该得到一个 dragstart 事件.那是当您保存鼠标位置和所选对象时.当您收到 dragfinished 事件时，再次注意鼠标位置并相应地移动对象.移动可能只发生在屏幕上，但例如如果您想删除垃圾桶上的垃圾桶.

You should get a dragstart event. That is when you save the mouse position and the selected object(s). When you get a dragfinished event, again note the mouse positon and move the objects accordingly. The move might just happen on the screen, but e.g. in case the drop occurred on the trashcan you want to delete them.

现在，当拖动处于活动状态时，您可能会收到更多拖动事件，您应该使用这些事件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所选对象并相应地绘制它们.

Now while the drag is active you might get a number of more dragging events, which you should use to update the screen and give feedback to the user. This would most of the time just be to look at the mouse positon and the selected objects and draw them accordingly.

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