myapplet.java

使用Swing完成基本流程图的绘制

                        itemList[i].pressCount = 0;
                        itemList[i].R = 0;
                        itemList[i].G = 0;
                        itemList[i].B = 0;
                        itemList[i].isSelected = false;
                        repaint();
                        break;
                    }
                }// */
            }
            else if(currentChoice == STATUS_ARROW)
            {
                CPoint point = new CPoint(e.getPoint());
                int i;
                for (i = 0; i < index; i++)
                {
                    if (point.pointInArea(itemList[i]))
                    {
                        if (itemList[i].type == 5)
                        {
                            itemList[index].x2 = itemList[i].x1;
                            itemList[index].y2 = (itemList[i].y1 + itemList[i].y2)/2;
                        }
                        repaint();
                        index++;
                        createNewItem();
                        break;
                    }
                }// */
                if (i == index)
                {
                    itemList[index].x2 = e.getX();
                    itemList[index].y2 = e.getY();
                    repaint();
                    index++;
                    createNewItem();
                }
            }
            else
            {
                itemList[index].x2 = e.getX();
                itemList[index].y2 = e.getY();
                repaint();
                index++;
                createNewItem();
            }
        }

        public void mouseEntered(MouseEvent e)
        {
            statusBar.setText("     Mouse Entered @:[" + e.getX() + ", "
                    + e.getY() + "]");
        }

        public void mouseExited(MouseEvent e)
        {
            statusBar.setText("     Mouse Entered @:[" + e.getX() + ", "
                    + e.getY() + "]");
        }
    }

    // 鼠标事件mouseB类继承了MouseMotionAdapter，用来完成鼠标拖动和鼠标移动时的相应操作
    class mouseB extends MouseMotionAdapter
    {
        public void mouseDragged(MouseEvent e)
        {
            statusBar.setText("     Mouse Dragged @:[" + e.getX() + ", "
                    + e.getY() + "]");

            if (currentChoice == STATUS_MOUSE)
            {
                CPoint point = new CPoint(e.getPoint());
                for (int i = 0; i < index; i++)
                {
                    if (point.pointInArea(itemList[i]) && itemList[i].pressCount > 1)
                    {
                        int moveX = e.getX() - x_old;
                        int moveY = e.getY() - y_old;

                        itemList[i].x1 += moveX;
                        itemList[i].y1 += moveY;
                        itemList[i].x2 += moveX;
                        itemList[i].y2 += moveY;
                        
                        itemList[i].isDraging = true;
                        itemList[i].R = 255;
                        itemList[i].G = 0;
                        itemList[i].B = 0;
                        break;
                    }
                }// */
            }
            else
            {
                itemList[index].x2 = e.getX();
                itemList[index].y2 = e.getY();
            }
            
            x_old = e.getX();
            y_old = e.getY();
            repaint();
        }

        public void mouseMoved(MouseEvent e)
        {
            statusBar.setText("     Mouse Dragged @:[" + e.getX() + ", "
                    + e.getY() + "]");
        }
    }

    // 新建一个画图基本单元对象的程序段
    void createNewItem()
    {
        if (currentChoice == STATUS_COLOR)// 进行相应的游标设置
            myDraw.setCursor(Cursor.getPredefinedCursor(Cursor.TEXT_CURSOR));
        else
            myDraw.setCursor(Cursor
                    .getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));

        switch (currentChoice)
        {
            case STATUS_MOUSE:
                return;
            case STATUS_LINE:
                itemList[index] = new Line();
                break;
            case STATUS_RECT:
                itemList[index] = new Rect();
                break;
            case STATUS_FRECT:
                 itemList[index]=new fillRect();
                break;
            case STATUS_OVAL:
                // itemList[index]=new Oval();
                break;
            case STATUS_FOVAL:
                // itemList[index]=new fillOval();
                break;
            case STATUS_CIRCLE:
                // itemList[index]=new Circle();
                break;
            case STATUS_FCIRCLE:
                // itemList[index]=new fillCircle();
                break;
            case STATUS_ROUNDRECT:
                // itemList[index]=new RoundRect();
                break;
            case STATUS_FROUNDRECT:
                // itemList[index]=new fillRoundRect();
                break;
            case STATUS_ARROW:
                itemList[index] = new Arrow();
                break;
            case STATUS_COLOR:
                // itemList[index]=new Word();
                break;
        }
        itemList[index].type = currentChoice;
        itemList[index].R = R;
        itemList[index].G = G;
        itemList[index].B = B;
        itemList[index].stroke = stroke;
        itemList[index].isSelected = false;
        itemList[index].isDraging = false;
        itemList[index].pressCount = 0;
    }
}

class FlowItems implements Serializable
{
    int x1, y1, x2, y2; // 定义坐标属性

    int R, G, B; // 定义色彩属性

    float stroke; // 定义线条粗细属性

    int type; // 定义字体属性

    String s1;

    String s2; // 定义字体风格属性

    boolean isSelected; // 定义图元状态 0 未选中 1 选中
    
    boolean isDraging; // 是否处于拖放状态
    
    int pressCount; // 鼠标按下的次数
    
    void draw(Graphics2D g2d)
    {
    };// 定义绘图函数
}

/*******************************************************************************
 * 下面是各种基本图形单元的子类，都继承自父类FlowItems
 ******************************************************************************/

class Line extends FlowItems // 直线类
{
    void draw(Graphics2D g2d)
    {
        g2d.setPaint(new Color(R, G, B));
        g2d.setStroke(new BasicStroke(stroke, BasicStroke.CAP_ROUND,
                BasicStroke.JOIN_BEVEL));
        g2d.drawLine(x1, y1, x2, y2);
    }
}

class Rect extends FlowItems // 矩形类
{
    void draw(Graphics2D g2d)
    {
        g2d.setPaint(new Color(R, G, B));
        g2d.setStroke(new BasicStroke(stroke, BasicStroke.CAP_ROUND,
                BasicStroke.JOIN_BEVEL));
        g2d.drawRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2),
                Math.abs(y1 - y2));
    }
}

class fillRect extends FlowItems // 实矩形
{
    void draw(Graphics2D g2d)
    {
        g2d.setPaint(new Color(R, G, B));
        g2d.setStroke(new BasicStroke(stroke, BasicStroke.CAP_ROUND,
                BasicStroke.JOIN_BEVEL));
        g2d.fillRect(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2),
                Math.abs(y1 - y2));
    }
}


class Arrow extends FlowItems // 箭头类
{
    void draw(Graphics2D g2d)
    {
        g2d.setPaint(new Color(R, G, B));
        g2d.setStroke(new BasicStroke(stroke, BasicStroke.CAP_ROUND,
                BasicStroke.JOIN_BEVEL));
        // 利用向量来进行计算
        int len = 10; // 箭头的边长
        int x0 = 0, y0 = 0;      
        double dx = x2 - x0, dy = y2 - y0;
        
        //共线 模长为len
        //0 = (x2 -x1)*dy  - dx*(y2 -y1); dx*dx + dy*dy = len*len
        double mAB = (x2 - x1)*(x2 - x1) + (y2 - y1)*(y2 - y1);
        dx = (x2 -x1)*len / java.lang.Math.sqrt(mAB) ;
        dy = (y2 -y1)*len / java.lang.Math.sqrt(mAB) ;
        x0 = (int) (x2 - dx);
        y0 = (int) (y2 - dy);
        
        int x3 = 0, y3 = 0, x4, y4; 
        dx = x3 - x0;
        dy = y3 - y0;
        double mCB = (x2 - x0)*(x2 - x0) + (y2 - y0)*(y2 - y0);
        dx = -(y2 -y0)*len / java.lang.Math.sqrt(mCB) ;
        dy = (x2 -x0)*len / java.lang.Math.sqrt(mCB) ;
        x3 = (int) (dx + x0);
        y3 = (int) (dy + y0);
        x4 = 2*x0 - x3;
        y4 = 2*y0 - y3;
        
        g2d.drawLine(x1, y1, x0, y0);
        g2d.setPaint(new Color(255, 0, 0));
        Polygon p = new Polygon();
        p.addPoint(x2, y2);
        p.addPoint(x3, y3);
        p.addPoint(x4, y4);
        g2d.drawPolygon(p);
        g2d.fillPolygon(p);
    }
}


class CPoint extends Point
{
    public CPoint(Point point)
    {
       this.x = point.x;
       this.y = point.y;
    }

    public boolean pointInArea(FlowItems item)
    {
        if (item != null)
        {
            if ((x > item.x1 && x < item.x2) || (x > item.x2 && x < item.x1))
            {
                if ((y > item.y1 && y < item.y2) || (y > item.y2 && y < item.y1))
                {
                    return true;
                }
            }
        }
        
        return false;
    }
}