screencanvas.java

基于java Swing的一款简单的2D图形绘制软件程序

import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Polygon;
import java.awt.Shape;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import javax.sound.sampled.Line;
import javax.swing.JPanel;
import javax.swing.event.MouseInputListener;

/**
 * 
 */

/**
 * @author squirrel
 *
 */
public class ScreenCanvas extends Canvas
 implements MouseListener,MouseMotionListener {

	private double beginX;
	
	private double beginY;
	
	private double endX;
	
	private double endY;
	
	private double atX;
	
	private double atY;
	
	private List shapeList;
	
	private int drawShapeType;
	
	private int drawToolType;
	
	private int resize;
	
	private Color drawColor;
	
	private Color paintColor;
	
	private Graphics g;
	
	private ShapeCreator shapeCreator;
	
	private JPanel screenPanel;
	
	public ScreenCanvas()
	{
		super();
		drawShapeType = -1;
		beginX = -1;
		beginY = -1;
		endX = -1;
		endY = -1;
		atX = -1;
		atY = -1;
		resize = 0;
		drawToolType = 0;
		shapeList = new ArrayList();
		drawColor = Color.BLACK;
		shapeCreator = new ShapeCreator();
		
		this.setBackground(Color.WHITE);
		
		this.addMouseListener(this);
		this.addMouseMotionListener(this);
		this.setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));
		
	}

	public double getBeginX() {
		return beginX;
	}

	public void setBeginX(double beginX) {
		this.beginX = beginX;
	}

	public double getBeginY() {
		return beginY;
	}

	public void setBeginY(double beginY) {
		this.beginY = beginY;
	}

	public int getDrawShapeType() {
		return drawShapeType;
	}

	public void setDrawShapeType(int drawShapeType) {
		this.drawShapeType = drawShapeType;
	}

	public double getEndX() {
		return endX;
	}

	public void setEndX(double endX) {
		this.endX = endX;
	}

	public double getEndY() {
		return endY;
	}

	public void setEndY(double endY) {
		this.endY = endY;
	}

	public double getAtX() {
		return atX;
	}

	public void setAtX(double atX) {
		this.atX = atX;
	}

	public double getAtY() {
		return atY;
	}

	public void setAtY(double atY) {
		this.atY = atY;
	}

	
	public int getResize() {
		return resize;
	}

	public void setResize(int resize) {
		this.resize = resize;
	}

	public Color getPaintColor() {
		return paintColor;
	}

	public void setPaintColor(Color paintColor) {
		this.paintColor = paintColor;
	}

	public int getDrawToolType() {
		return drawToolType;
	}

	public void setDrawToolType(int drawToolType) {
		this.drawToolType = drawToolType;
	}

	public Graphics getG() {
		return g;
	}

	public void setG(Graphics g) {
		this.g = g;
	}

	public Color getDrawColor() {
		return drawColor;
	}

	public void setDrawColor(Color drawColor) {
		this.drawColor = drawColor;
	}

	public List getShapeList() {
		return shapeList;
	}

	public void setShapeList(List shapeList) {
		this.shapeList = shapeList;
	}

	public void setScreenPanel(JPanel screenPanel) {
		this.screenPanel = screenPanel;
	}

	public void setDrawToolColor(Color color,int drawToolType)
	{
		if(drawToolType == 0)
			this.drawColor = color;
		else if(drawToolType == 1)
			this.paintColor = color;
	}
	
	public void paintShape(Graphics g)
	{
		Graphics2D g2D = (Graphics2D)g;
		
		if(drawShapeType == -1)
			return;
		
		Shape shape = this.getShape(drawShapeType,beginX,beginY,endX,endY);
		
		ShapeEntity entity = new ShapeEntity();
		entity.setShapeType(drawShapeType);
		entity.setBeginX(beginX);
		entity.setBeginY(beginY);
		entity.setEndX(endX);
		entity.setEndY(endY);
		entity.setDrawColor(drawColor);
		entity.setPaintColor(paintColor);
		shapeList.add(entity);
		g2D.setPaint(this.drawColor);
		if(entity.getShapeType() == 4)
		{
		  g2D.drawPolygon((Polygon) shape);	
		}
		else
		 g2D.draw(shape);
	}

	public void fillComponent(Graphics g)
	{
		Graphics2D g2D = (Graphics2D)g;
		
		if(atX == -1 && atY == -1)
			return;
		
		double distance = -1;
		
		int nearestShape = -1;
		
		if(shapeList == null || shapeList.size() == 0)
			return ;
		
		for(int i = 0; i < shapeList.size(); i++)
		{
			ShapeEntity entity = (ShapeEntity)shapeList.get(i);
			
			if(atX >= entity.getBeginX() && atX <= entity.getEndX()
					&& atY >= entity.getBeginY() && atY <= entity.getEndY())
			{
				//找出填充点与哪个图形的中心点最近
				double midX = entity.getBeginX() +((entity.getEndX() - entity.getBeginX()) /2);
				double midY = entity.getBeginY() +((entity.getEndY() - entity.getBeginY()) /2);
				
				double tempDistance = (Math.pow((midX - atX), 2) + Math.pow((midY - atY), 2));
				
				if(distance == -1)
				{
					distance = tempDistance;
					nearestShape = i;
				}
				else if(distance > 0 && distance > tempDistance)
				{
					distance = tempDistance;
					nearestShape = i;
				}
			}
		}
		
		if(distance == -1 || nearestShape == -1)
			return;
		
		ShapeEntity object = (ShapeEntity)shapeList.get(nearestShape);
		object.setPaintColor(paintColor);
		
		for(int i = 0; i < shapeList.size(); i++)
		{
			ShapeEntity entity = (ShapeEntity)shapeList.get(i);
			
			double x1 = entity.getBeginX();
			double y1 = entity.getBeginY();
			double x2 = entity.getEndX();
			double y2 = entity.getEndY();
			
			double x3 = 0;
			double y3 = 0;
			
			Shape shape = this.getShape(entity.getShapeType(),x1,y1,x2,y2);
			g2D.setPaint(entity.getDrawColor());
			g2D.draw(shape);
			if(entity.getPaintColor() != null)
			{
				g2D.setPaint(entity.getPaintColor());
				g2D.fill(shape);
			}
		}
	}
	
	public void paintShapes()
	{
        if(g == null)
        	g = this.getGraphics();
        
		Graphics2D g2D = (Graphics2D)g;

		if(shapeList == null || shapeList.size() == 0)
			return ;
		
		for(int i = 0; i < shapeList.size(); i++)
		{
			ShapeEntity entity = (ShapeEntity)shapeList.get(i);
			
			double x1 = entity.getBeginX();
			double y1 = entity.getBeginY();
			double x2 = entity.getEndX();
			double y2 = entity.getEndY();

			Shape shape = this.getShape(entity.getShapeType(),x1,y1,x2,y2);
			g2D.setPaint(entity.getDrawColor());
			g2D.draw(shape);
			
			if(entity.getPaintColor() != null)
			{
				g2D.setPaint(entity.getPaintColor());
				g2D.fill(shape);
			}
		}
	}
	
	public void addShape(ShapeEntity shapeEntity)
	{
		if(shapeList == null)
			shapeList = new ArrayList();
		
		shapeList.add(shapeEntity);
	}
	
	public void paint(Graphics g)
	{
		super.paint(g);
		this.paintShapes();
	}
	
	private Shape getShape(int shapeType,double x1,double y1,double x2,double y2)
	{
		Shape shape = null;
		switch(shapeType)
		{
			case 0:  //曲线
			case 1:  //直线
				shape = shapeCreator.createLine2D(x1, y1, x2, y2);	
				break;
			case 2:  //椭圆
				shape = shapeCreator.createEllipse2D(x1, y1, x2, y2);
				break;
			case 3:   //方形
				shape = shapeCreator.createRectangle(x1, y1, x2, y2);
				break;
		    default:
		    	;
		    	break;
		}
		
		return shape;
	}
	
	public void mouseDragged(MouseEvent e) {
		
		if(this.drawToolType == 0)
		{
			if(g == null)
			    g = this.getGraphics();
		
			Point p = e.getPoint();
		    
			
		    endX = p.getX();
		    endY = p.getY();
			
			if(drawShapeType == 0)
			{
				this.paintShape(g);
				beginX = endX;
				beginY = endY;
			}
		}
	}

	public void mouseMoved(MouseEvent e) {
		
		if(this.drawToolType == 0 || this.drawShapeType == 4)
		{
			Point p = e.getPoint();
		
			beginX = p.getX();
			beginY = p.getY();
		}
		
	}

	public void mouseReleased(MouseEvent arg0) {
		
		if(this.drawToolType == 0)
		{
			if(g == null)
				g = this.getGraphics();
			
			if(drawShapeType == 1 || drawShapeType == 2 || drawShapeType == 3)
				this.paintShape(g);
		}
		
	}
	
	public void mouseClicked(MouseEvent e) {
		
		if(g == null)
			g = this.getGraphics();
		
		if(this.drawToolType == 1)
		{
			Point p = e.getPoint();
		
			atX = p.getX();
			atY = p.getY();
			this.fillComponent(g);
		}
	}
	
	public void mouseEntered(MouseEvent e) {
		
	}


	public void mouseExited(MouseEvent arg0) {
		// TODO Auto-generated method stub
		
	}

	public void mousePressed(MouseEvent arg0) {
		// TODO Auto-generated method stub
		
	}

}