scribble.java

java 绘图的代码,应用applet, awt, 可嵌入网页进行手写和绘图等

 {
    return (mousex != e.getX() || mousey != e.getY());
 }


 /*
   Method is a key segment in the operations where
   there are more than 2 variables deviating to
   makeup a graphical operation.
   This method calculates the new values for the
   global varibles drawX and drawY according to
   the new positions of the mouse cursor.
   This method eleviates the possibility that
   a negative width or height can occur.
 */
 public void setActualBoundry()
 {

       /*
         If the any of the current mouse coordinates
         are smaller than the origin coordinates, meaning
         if drag occured in a negative manner, where either
         the x-shift occured from right and/or y-shift occured
         from bottom to top.
       */
       if (mousex < Orx || mousey < Ory)
       {

          /*
            if the current mouse x coordinate is smaller
            than the origin x coordinate,
            equate the drawX to be the difference between
            the current width and the origin x coordinate.
          */
          if (mousex < Orx)
          {
             OrWidth = Orx - mousex;
             drawX   = Orx - OrWidth;
          }

          else
          {
             drawX    = Orx;
             OrWidth  = mousex - Orx;

          }

          /*
            if the current mouse y coordinate is smaller
            than the origin y coordinate,
            equate the drawY to be the difference between
            the current height and the origin y coordinate.
          */
          if (mousey < Ory)
          {
             OrHeight = Ory - mousey;
             drawY    = Ory - OrHeight;
          }

          else
          {
             drawY    = Ory;
             OrHeight = mousey - Ory;
          }

       }

       /*
         Else if drag was done in a positive manner meaning
         x-shift occured from left to right and or y-shift occured
         from top to bottom
       */
       else
       {
          drawX    = Orx;
          drawY    = Ory;
          OrWidth  = mousex - Orx;
          OrHeight = mousey - Ory;
       }

 }


 /*
   Method sets all the drawing varibles to the default
   state which is the current position of the mouse cursor
   Also the height and width varibles are zeroed off.
 */
 public void setGraphicalDefaults(MouseEvent e)
 {
    mousex   = e.getX();
    mousey   = e.getY();
    prevx    = e.getX();
    prevy    = e.getY();
    Orx      = e.getX();
    Ory      = e.getY();
    drawX    = e.getX();
    drawY    = e.getY();
    OrWidth  = 0;
    OrHeight = 0;
 }


 /*
   Method will be activated when mouse is being dragged.
   depending on what operation is the opstatus, the switch
   statement will call the relevent operation
 */
 public void mouseDragged(MouseEvent e)
 {
    updateMouseCoordinates(e);

    switch (opStatus)
    {
       /* If opStatus is PEN_OP  then call penOperation method */
       case PEN_OP   : penOperation(e);
                       break;

       /* If opStatus is LINE_OP then call lineOperation method */
       case LINE_OP  : lineOperation(e);
                       break;

       /* If opStatus is RECt_OP  then call rectOperation method */
       case RECT_OP  : rectOperation(e);
                       break;

       /* If opStatus is OVAL_OP then call ovalOperation method */
       case OVAL_OP  : ovalOperation(e);
                       break;

       /* If opStatus is FRECT_OP  then call frectOperation method */
       case FRECT_OP : frectOperation(e);
                       break;

       /* If opStatus is FOVAL_OP then call fovalOperation method */
       case FOVAL_OP : fovalOperation(e);
                       break;

       /* If opStatus is ERASER_OP then call eraserOperation method */
       case ERASER_OP: eraserOperation(e);
                       break;
    }

 }


 /*
    Method will be activated when mouse has been release from pressed \
    mode. At this stage the method will call the finalization routines
    for the current operation.
 */
 public void mouseReleased(MouseEvent e)
 {
    /* Update current mouse coordinates to screen */
    updateMouseCoordinates(e);

    switch (opStatus)
    {
       /* If opStatus is PEN_OP  then call releasedPen method */
       case PEN_OP    : releasedPen();
                        break;

       /* If opStatus is LINE_OP then call releasedLine method */
       case LINE_OP   : releasedLine();
                        break;

       /* If opStatus is RECT_OP  then call releasedRect method */
       case RECT_OP   : releasedRect();
                        break;

       /* If opStatus is OVAL_OP then call releasedOval method */
       case OVAL_OP   : releasedOval();
                        break;

       /* If opStatus is FRECT_OP  then call releasedFrect method */
       case FRECT_OP  : releasedFRect();
                        break;

       /* If opStatus is FOVAL_OP then call releasedFoval method */
       case FOVAL_OP  : releasedFOval();
                        break;

       /* If opStatus is ERASER_OP then call releasedEraser method */
       case ERASER_OP : releasedEraser();
                        break;
    }

 }


 /*
    Method will be activated when mouse enters the applet area.
    This method will then update the current mouse x and coordinates
    on the screen.
 */
 public void mouseEntered(MouseEvent e)
 {
    updateMouseCoordinates(e);
 }


 /*
   Method will set the main system color according to the
   current color status.
 */
 public void setMainColor()
 {

    switch (colorStatus)
    {
       case 1 : mainColor = Color.black;
                break;

       case 2:  mainColor = Color.blue;
                break;

       case 3:  mainColor = Color.green;
                break;

       case 4:  mainColor = Color.red;
                break;

       case 5:  mainColor = Color.magenta;
                break;

       case 6:  mainColor = Color.orange;
                break;

       case 7:  mainColor = Color.pink;
                break;

       case 8:  mainColor = Color.gray;
                break;

       case 9:  mainColor = Color.yellow;
                break;

       case 10: mainColor = userDefinedColor;
                break;

    }

 }


 /*
   Method is invoked when mouse has been released
   and current operation is Pen
 */
 public void releasedPen()
 {
    initialPen = true;
 }


 /*
   Method is invoked when mouse has been released
   and current operation is Line
 */
 public void releasedLine()
 {
    if ((Math.abs(Orx-mousex)+Math.abs(Ory-mousey)) != 0)
    {
       System.out.println("Line has been released....");
       initialLine = true;
       Graphics g  = drawPanel.getGraphics();
       g.setColor(mainColor);
       g.drawLine(Orx,Ory,mousex,mousey);
    }

 }


 /*
   Method is invoked when mouse has been released
   and current operation is Eraser
 */
 public void releasedEraser()
 {

    initialEraser = true;
    Graphics g  = drawPanel.getGraphics();
    g.setColor(mainColor.white);
    g.drawRect(mousex-eraserLength,mousey-eraserLength,eraserLength*2,eraserLength*2);

 }


 /*
   Method is invoked when mouse has been released
   and current operation is Rectangle
 */
 public void releasedRect()
 {

    initialRect = true;
    Graphics g  = drawPanel.getGraphics();
    g.setColor(mainColor);
    g.drawRect(drawX,drawY,OrWidth,OrHeight);

 }


 /*
   Method is invoked when mouse has been released
   and current operation is Oval
 */
 public void releasedOval()
 {

    initialOval = true;
    Graphics g  = drawPanel.getGraphics();
    g.setColor(mainColor);
    g.drawOval(drawX,drawY,OrWidth,OrHeight);

 }


 /*
   Method is invoked when mouse has been released
   and current operation is Fill-Rectangle
 */
 public void releasedFRect()
 {

    initialFRect = true;
    Graphics g  = drawPanel.getGraphics();
    g.setColor(mainColor);
    g.fillRect(drawX,drawY,OrWidth,OrHeight);

 }


 /*
   Method is invoked when mouse has been released
   and current operation is Fill-Oval
 */
 public void releasedFOval()
 {

    initialFOval = true;
    Graphics g  = drawPanel.getGraphics();
    g.setColor(mainColor);
    g.fillOval(drawX,drawY,OrWidth,OrHeight);

 }





 /*
   Method displays the mouse coordinates x and y values
   and updates the mouse status bar with the new values.
 */
 public void updateMouseCoordinates(MouseEvent e)
 {
    String xCoor ="";
    String yCoor ="";

    if (e.getX() < 0) xCoor = "0";
    else
    {
       xCoor = String.valueOf(e.getX());
    }

    if (e.getY() < 0) xCoor = "0";
    else
    {
       yCoor = String.valueOf(e.getY());
    }

    mouseStatusBar.setText("x:"+xCoor+"   y:"+yCoor);

 }


 /*
   Method updates user-defined values for udefRGB
 */
 public void updateRGBValues()
 {
    udefRedValue = redSlider.getValue();
    udefGreenValue = greenSlider.getValue();
    udefBlueValue = blueSlider.getValue();
    if (udefRedValue > 255)
       udefRedValue = 255;

    if (udefRedValue < 0 )
       udefRedValue =0;

    if (udefGreenValue > 255)
       udefGreenValue = 255;

    if (udefGreenValue < 0 )
       udefGreenValue =0;

    if (udefBlueValue > 255)
       udefBlueValue = 255;

    if (udefBlueValue < 0 )
       udefBlueValue =0;

    redValue.setText(String.valueOf(udefRedValue));
    greenValue.setText(String.valueOf(udefGreenValue));
    blueValue.setText(String.valueOf(udefBlueValue));

    userDefinedColor = new Color(udefRedValue,udefGreenValue,udefBlueValue);
    userDefButton.setBackground(userDefinedColor);

    Graphics g = udefdemcolPanel.getGraphics();
    g.setColor(userDefinedColor);
    g.fillRect(0,0,800,800);
 }


 /*
   Method updates mouse coordinates if mouse has been clicked
 */
 public void mouseClicked(MouseEvent e)
 {

    updateMouseCoordinates(e);
    switch (opStatus)
    {

       case 9  : splineOperation(e);
                 break;

       case 10 : polygonOperation(e);
                 break;

    }


}


 /*
   Method updates mouse coordinates if mouse has exited applet
 */
 public void mouseExited(MouseEvent e)
 {

    updateMouseCoordinates(e);

 }


 /*
   Method updates mouse coordinates if mouse has moved
 */
 public void mouseMoved(MouseEvent e)
 {
    updateMouseCoordinates(e);
 }


 /*
   Method updates mouse coordinates if mouse has been pressed
 */
 public void mousePressed(MouseEvent e)
 {

    updateMouseCoordinates(e);

 }



} // End of Scribble