//############################################################################

//# FILE Emulation.java

//# VERSION 0.94

//# DATE: 4/27/96

//# AUTHOR:  Bret Dahlgren (bret@lm.com)

//#

//# Ver. 0.94  4/27/96 Change to the scrollup and scrolldown calls

//#                  Had a need for scrolls within the screen for

//#                  VT100 compatability.  Scrolls now are not specific

//#                  for which rows to scroll.

//# Ver. 0.90  2/29/96 Initial release.

//#

//# Copyright (c) 1996 Bret G. Dahlgren, All Rights Reserved.

//############################################################################

import java.awt.*;

import java.awt.image.*;



//############################################################################

//# CLASS: Emulation

//#   The Emulation class is used as a base class for other classes that will

//#   manipulate the incoming data to display.  This class takes care of the

//#   actual displaying of the data according to coordinate position and colors

//#

//# USAGE NOTE:  This class is abstract.  Create subclasses from it.

//#

//# DESIGN NOTE:  I know some of the public methods and variables should not be

//#   for good OO code.  If I have time I'll try to change this.

//# 

//############################################################################

//# 

//# STATIC VARIABLE: owner

//#   Used to provide this class an easy way to retrieve TelnetClient values for

//#   images.  Probably could be better designed.

//# 

//# STATIC VARIABLES: width, height, char_w, char_h

//#   Canvas area to work with and character sizes.

//# 

//# STATIC METHOD: initClass

//#   method used to initialize this classes static variables

//#   *** Call this before Using this Class Type ***

//# 

//# CONSTRUCTOR:

//#   method to set default colors and coordinate position.

//# 

//# METHOD: clearcoord

//#   method to clear out a section of the canvas graphically.

//#

//# METHOD: scrolldown

//#   method to move the graphic image down a row between ScrollTop

//#   and ScrollBottom.

//#

//# METHOD: scrollup

//#   method to move the graphic image up a row between ScrollTop

//#   and ScrollBottom.

//#

//# METHOD: clearscreen

//#   method to clear the graphic canvas with the background color.

//#

//# METHOD: displaych

//#   method to draw a character on the canvas.

//#

//# METHOD: displaybytes

//#   method to be used in the subclass.  Nothing done here.

//#

//# METHOD: transmitch

//#   method to transmit char over the pipe.  Overridden to

//#   map to emulation characters.

//#

//############################################################################



public abstract class Emulation {





  protected static TelnetClient owner = null;

  protected static int width = 0;

  protected static int height = 0;

  protected static int char_w = 0;

  protected static int char_h = 0;







  static public void initClass (TelnetClient parent) {



    owner = parent;

    width = owner.width;

    height = owner.height;

    char_w = owner.w;

    char_h = owner.h;

    }





  public int column;

  public int row;

  public Color foreground;

  public Color background;



  public Emulation() {

  

    foreground = Color.white;

    background = Color.black;

    row = 0;

    column = 0;

    }



  public void clearcoord(int row1, int col1, int row2, int col2) {

  

    owner.bgr.setColor(background);



    if ( row1 == row2) {

   

      owner.bgr.fillRect(col1 * owner.chw, ( row1 )*owner.chh, (col2 - col1 + 1)*owner.chw, owner.chh);

      return;

      }



    owner.bgr.fillRect(col1 * owner.chw, ( row1 )*owner.chh, (char_w - col1)*owner.chw, owner.chh);



    if ( (row2-row1) > 1) {

      for (int i = row1+1; i < row2; i++){

          

        owner.bgr.fillRect(0, ( i )*owner.chh, char_w*owner.chw, owner.chh);

        }

      }



    owner.bgr.fillRect(0, ( row2 )*owner.chh, ( col2 + 1 )*owner.chw, owner.chh);

    }







  public void scrolldown(int ScrollTop, int ScrollBottom) {



    owner.bgr.copyArea(0, (ScrollTop) * owner.chh, char_w*owner.chw,

                          (ScrollBottom - ScrollTop)*owner.chh, 0, owner.chh);



    owner.bgr.setColor(background);



    owner.bgr.fillRect(0, (ScrollTop) * owner.chh, char_w*owner.chw, owner.chh);

    }



  public void scrollup(int ScrollTop, int ScrollBottom ) {



    owner.bgr.copyArea(0, (ScrollTop+1) * owner.chh,

                 char_w*owner.chw, (ScrollBottom - ScrollTop)*owner.chh, 0, -owner.chh);

    owner.bgr.setColor(background);



    owner.bgr.fillRect(0, (ScrollBottom)*owner.chh, char_w*owner.chw, owner.chh);



    }



  public void clearscreen() {



    owner.bgr.setColor(background);

    owner.bgr.fillRect(0,0,width,height);

    }



  public void displaych(char c) {



    owner.bgr.setColor(background);

    owner.bgr.fillRect(column*owner.chw, row*owner.chh, owner.chw, owner.chh);

    owner.bgr.setColor(foreground);

    owner.bgr.drawString(String.valueOf(c), column*owner.chw, (row+1)*owner.chh-owner.chd);



    }



  public void displaybytes(byte b[], int len) {

    }



  public void transmitch(char ch)

    {

    owner.transmitch(ch);

    }





  }