// jsketch.java
// simple sketch:
//  "c" to clear, <space> for new color
//  "a" for anchored mode, "r" for rectangle mode.
//
//  This software comes with NO WARRANTY whatsoever.
//  It may be used as "free software" per the GNU GPL.
//  See http://www.gnu.org/copyleft/gpl.html for license information.
//  Copyright 1999 Demetri Patukas.   rev 99.06.19

import java.applet.*;
import java.awt.*;
import java.util.*; // for Random

public class jsketch extends Applet {

/// ----- instance variables

private int last_x = 0;
private int last_y = 0;
private boolean unanchored = true;
private boolean rectmode = false;
private Color current_color = Color.red;
private Random rnd;
private Graphics ggg; // cached GC/HDC

/// ------ applet control

public void init() {
    rnd = new Random();
    ggg = this.getGraphics();
    this.setBackground(Color.black);
}

/// ----- applet event handlers

public boolean mouseDown(Event e, int x, int y) {
    ggg.setColor(current_color);
    last_x = x;
    last_y = y;
    return true;
}

public boolean mouseDrag(Event e, int x, int y) {
    if (rectmode) {
	cornerRect(ggg, last_x, last_y, x, y);
    } else {
	ggg.drawLine(last_x, last_y, x, y);
    }
    if (unanchored) {
	last_x = x;
	last_y = y;
    }
    return true;
}

public boolean keyDown(Event e, int key) {
    switch (key) {
    case 'c': clearwindow(); break;
    case 'a': unanchored = !unanchored; break;
    case 'r': rectmode = !rectmode; break;
    case ' ': new_color(ggg); break;
    default: return false;
    }
    return true;
}

/// ----- private helpers

// make sure it's actually a different color.
void new_color(Graphics ggg) {
    Color oldcolor = current_color;
    new_color1(ggg);
    while (oldcolor == current_color) {
	new_color1(ggg);
    }
}

// random color, but skips black (uses white).
void new_color1(Graphics ggg) {
    switch (rnd.nextInt() & 7) {
    case 0: current_color = Color.white;
	break; //SB black
    case 1: current_color = Color.red;     break;
    case 2: current_color = Color.blue;    break;
    case 3: current_color = Color.magenta; break;
    case 4: current_color = Color.green;   break;
    case 5: current_color = Color.yellow;  break;
    case 6: current_color = Color.cyan;    break;
    case 7: current_color = Color.white;   break;
    }
    ggg.setColor(current_color);
}

void clearwindow() {
    ggg.clearRect(0, 0, 2000, 2000);
}

void cornerRect(Graphics ggg, int x1, int y1, int x2, int y2) {
    int t;
    if (x1 > x2) { t=x2; x2=x1; x1=t; }
    if (y1 > y2) { t=y2; y2=y1; y1=t; }
    ggg.fillRect(x1, y1, x2-x1, y2-y1);
}

} //end class jsketch