/* Java Applet source code for "RPN calculator on Java"
*
* This is an applet to realize "RPN caculator" on a Web browser.
* The author, T. Nakatsuka, does not insist any right on this program,
* i.e., free to re-distribute to any place with/without any modification.
* The author acknowledges Hewlett-Packard Corp. for their intelligent
* product of micro-calculators, which were borne in mind during designing.
*/
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
public class calcj extends Applet implements MouseListener,
KeyListener, ItemListener, FocusListener {
Image barea; Font font, fontb;
CheckboxGroup degrad; Checkbox degree, radian; int kdeg;
double y, z, t; Label regY, regZ, regT;
double x; TextField regX; StringBuffer xstr;
int key, kf, l, lce; double r, tmp;
/*
* key : Status for Register-X
* = 0 : Register-X shall be cleared by New-Value entry
* [after ENTER/CLR/CLX/STO operation]
* = 1 : CHS input after key=0
* = 2 : Register-X shall be pushed (on stack) by New-Value entry
* [after Arithmetic or SWAP/ROT operation,
* or definite value entry by RCL/'pi'/'e']
* = 3 : CHS input after key=2
* =4-7: on the way of New-Value entry
* [after Numeric input keys (0-9/./EEX)]
* =4 : neither . nor EEX input yet
* =5 : . already input but EEX not yet
* =6 : EEX already input but no exponent digit yet
* =7 : at least 1 exponent digit input already
* = 9 : error detected (use CLR/CLX to reset)
*/
String sz(String v) {
int len = v.length();
if ((v.charAt(--len) != '0') || (v.charAt(--len) != '.')) { return v; }
else { return v.substring(0,len); }
}
void showt() { regT.setText(sz(Double.toString(t))); }
void showz() { regZ.setText(sz(Double.toString(z))); }
void showy() { regY.setText(sz(Double.toString(y))); }
void showx() {
if (Double.isNaN(x) || Double.isInfinite(x)) error();
else {
String s = sz(Double.toString(x));
regX.setText(s); xstr.setLength(0); xstr.append(s);
l = s.length(); key=2;
}
}
void push(int k) { t = z; z = y; if (k==0) y = x; else y = -x;
showy(); showz(); showt(); }
void pop() { x = y; y = z; z = t; showz(); showy(); showx(); }
void rad0() { if (kdeg==1) x /= Math.PI/180.; }
void rad1() { if (kdeg==1) x *= Math.PI/180.; }
void num(int i) {
if (key<4) {
if (key==2) push(0); else if (key==3) push(1);
xstr.setLength(0); l=0;
if ((key==1) || (key==3)) { xstr.append("-"); l++; }
key=4;
}
xstr.append(Integer.toString(i)); l++;
if (key==6) key=7;
x = Double.valueOf(xstr.toString()).doubleValue();
regX.setText(xstr.toString());
}
void dot() {
if (key<4) {
if (key==2) push(0); else if (key==3) push(1);
xstr.setLength(0); x = 0.;
if ((key==1) || (key==3)) { xstr.append("-0"); l=2; }
else { xstr.append("0"); l=1; }
}
xstr.append("."); l++; key=5;
regX.setText(xstr.toString());
}
void eex() {
if (key<4) {
if (key==2) push(0); else if (key==3) push(1);
xstr.setLength(0);
if ((key==1) || (key==3)) { xstr.append("-1."); x = -1.; l=3; }
else { xstr.append("1."); x = 1.; l=2; }
}
xstr.append("E"); lce=l++; key=6;
regX.setText(xstr.toString());
}
void chs() {
if (key<6) {
if (key==0) key=1; else if (key==1) key=0;
if (key==2) key=3; else if (key==3) key=2;
if (xstr.charAt(0) == '-') {
String s = xstr.toString().substring(1);
--l; xstr.setLength(0); xstr.append(s);
}
else { xstr.insert(0, "-"); l++; }
x = -x;
}
else if (key==6) {
if (xstr.charAt(lce) == 'E') { lce++; xstr.append("-"); l++; }
else { xstr.setLength(--l); lce--; }
}
else if (key==7) {
if (xstr.charAt(lce) == 'E') { xstr.insert(++lce, "-"); l++; }
else {
String s = xstr.toString().substring(lce+1);
l--; xstr.setLength(lce); xstr.append(s); lce--;
}
x = Double.valueOf(xstr.toString()).doubleValue();
}
regX.setText(xstr.toString());
}
void error() { regX.setText(" E R R O R !!"); x = 0.; key=9; }
/***************************************************************************
* The Register-X field can be pasted by any value, which is evaluated *
* at the "focusGained" event when coming back from regX TextField. *
* Accordingly, the process of literal input to Register-X is finalized *
* by the temporal loss of focus, which may cause unexpected result. *
***************************************************************************/
public void focusGained(FocusEvent fe) {
kf = 1; repaint();
try {
String s = regX.getText();
if (s.length() == 0) x = 0.;
else x = Double.valueOf(s).doubleValue();
showx();
} catch (NumberFormatException nfe) { error(); }
}
public void focusLost(FocusEvent fe) { kf = 0; repaint(); }
public void itemStateChanged(ItemEvent ie) {
if (((Checkbox) ie.getItemSelectable()) == degree)
{ kdeg = 1; requestFocus(); }
else { kdeg = 0; requestFocus(); }
}
public void keyPressed(KeyEvent ke) {}
public void keyReleased(KeyEvent ke) {}
public void keyTyped(KeyEvent ke) {
char kc = ke.getKeyChar();
if (key < 9) {
switch (kc) { /* Only limited key inputs are supported */
case '0': num(0); break; /* '0'-'9' */
case '1': num(1); break;
case '2': num(2); break;
case '3': num(3); break;
case '4': num(4); break;
case '5': num(5); break;
case '6': num(6); break;
case '7': num(7); break;
case '8': num(8); break;
case '9': num(9); break;
case '^': chs(); break; /* ^ for ch +/- */
case 'E': /* E(e) for Eex */
case 'e': if (key<6) eex(); break;
case '.': if (key<5) dot(); break; /* decimal point */
case '*': y *= x; pop(); break; /* arithmetic *,/,+,- */
case '/': y /= x; pop(); break;
case '+': y += x; pop(); break;
case '-': if (key == 6) chs(); /* Only after Eex, '-' */
else { y -= x; pop(); } /* may be used to ch +/- */
break;
case KeyEvent.VK_ENTER: /* 'Enter' or 'ctrl-R' */
case '\r': showx(); break; /* finalizes regX input.*/
}
}
}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mousePressed(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public void mouseClicked(MouseEvent e) {
int fx, fy, m;
int px = e.getX() - 12; int py = 337 - e.getY();
if ((px<0) || (205<px) || (py<0) || (195<py)) m = 20;
else {
fx = px%42; fy = py%25; m = (px-fx)/42 + (py-fy)/5;
if (m == 20) m = 21;
else if ((37<fx) || (20<fy)) m = 20;
}
if (m == 20) {}
else if (m == 19) { x = 0.; showx(); key=0; } /* CLX */
else if (m == 24) { x = 0.; y = 0.; z = 0.; t = 0.; /* CLR */
showx(); showy(); showz(); showt();
r = 0.; key=0; }
else if (key < 9) {
switch (m) {
case 22: chs(); break; /* ch +/- */
case 23: if (key<6) eex(); break; /* Eex */
case 2: if (key<5) dot(); break; /* decimal point */
case 1: num(0); break; /* numerical digit 0-9 */
case 6: num(1); break;
case 7: num(2); break;
case 8: num(3); break;
case 11: num(4); break;
case 12: num(5); break;
case 13: num(6); break;
case 16: num(7); break;
case 17: num(8); break;
case 18: num(9); break;
case 3: if (key==3) push(1); else if (key>=2) push(0); /* 'PI' */
x = Math.PI; if ((key==1) || (key==3)) x = -x;
showx(); break;
case 4: if (key==3) push(1); else if (key>=2) push(0); /* 'e' */
x = Math.E; if ((key==1) || (key==3)) x = -x;
showx(); break;
case 14: r = x; showx(); key=0; break; /* STO */
case 9: if (key==3) push(1); else if (key>=2) push(0); /* RCL */
x = r; if ((key==1) || (key==3)) x = -x;
showx(); break;
case 0: y += x; pop(); break; /* arithmetic +,-,*,/ */
case 5: y -= x; pop(); break;
case 10: y *= x; pop(); break;
case 15: y /= x; pop(); break;
case 25: if (y <= 0.) error(); /* y**x */
else { y = Math.exp(Math.log(y)*x); pop(); }
break;
case 21: push(0); showx(); key=0; break; /* Enter */
case 29: tmp = x; pop(); t = tmp; showt(); break; /* rot */
case 28: tmp = x; x = y; y = tmp; /* swap */
showy(); showx(); break;
case 26: x = 1./x; showx(); break; /* 1./x */
case 27: x = Math.sqrt(x); showx(); break; /* sqrt */
case 30: x = Math.exp(x); showx(); break; /* exp */
case 31: x = Math.log(x); showx(); break; /* ln */
case 35: x = Math.pow(10., x); showx(); break; /* 10**x */
case 36: if (x <= 0.) error(); /* Log10 */
else { x = Math.log(x)/Math.log(10.); showx(); }
break;
case 32: rad1(); x = Math.sin(x); showx(); break; /* sin */
case 33: rad1(); x = Math.cos(x); showx(); break; /* cos */
case 34: rad1(); x = Math.tan(x); showx(); break; /* tan */
case 37: if ((x>1.) || (x<-1.)) error(); /* arcsin */
else { x = Math.asin(x); rad0(); showx(); }
break;
case 38: if ((x>1.) || (x<-1.)) error(); /* arccos */
else { x = Math.acos(x); rad0(); showx(); }
break;
case 39: x = Math.atan(x); rad0(); showx(); break; /* arctan */
}
}
}
public void paint(Graphics g) {
g.setColor(Color.lightGray);
g.fillRect(0, 0, 230, 30);
g.setColor(Color.black); g.setFont(font);
g.drawString("Angle:", 35, 22);
g.fillRect(0, 30, 230, 320);
g.setColor(Color.white); g.setFont(fontb);
g.drawString("T", 10, 53); g.drawString("Z", 10, 78);
g.drawString("Y", 10,103); g.drawString("X", 10,128);
g.drawImage(barea, 10,140, this);
if (kf == 0) {
g.setColor(Color.red); g.fillRect(0, 0, 90, 35);
g.setColor(Color.white); g.drawString("Focus", 3, 17);
g.drawString("Lost", 53, 17); g.drawString("click me!", 9, 32);
}
}
public void init() {
String courier = "Courier";
fontb = new Font(courier, Font.BOLD, 16);
font = new Font(courier, Font.PLAIN, 16);
barea = getImage(getDocumentBase(), "calc.gif");
setLayout(null);
regT = new Label("0", Label.LEFT);
regT.setSize(194,18);
regT.setLocation(26,36);
regT.setFont(font);
add(regT);
regZ = new Label("0", Label.LEFT);
regZ.setSize(194,18);
regZ.setLocation(26,61);
regZ.setFont(font);
add(regZ);
regY = new Label("0", Label.LEFT);
regY.setSize(194,18);
regY.setLocation(26,86);
regY.setFont(font);
add(regY);
regX = new TextField(30);
regX.setSize(195,22);
regX.setLocation(25,110);
regX.setFont(font);
regX.setText("0");
add(regX);
degrad = new CheckboxGroup();
degree = new Checkbox("Degree", true, degrad);
degree.setSize(58,14);
degree.setLocation(90,10);
add(degree); kdeg = 1;
degree.addItemListener(this);
radian = new Checkbox("Radian", false, degrad);
radian.setSize(58,14);
radian.setLocation(150,10);
add(radian);
radian.addItemListener(this);
addMouseListener(this);
addKeyListener(this); requestFocus();
addFocusListener(this); kf = 1;
xstr = new StringBuffer(32);
xstr.setLength(0); xstr.append("0"); l=1; lce=0;
x = 0.; y = 0.; z = 0.; t = 0.; r = 0.; key=0;
}
}