jsbasic/tty.js
2013-05-02 22:53:08 -04:00

925 lines
24 KiB
JavaScript

//
// Applesoft BASIC in Javascript
// TTY Emulation
//
// Copyright (C) 2009-2011 Joshua Bell
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Usage:
//
// tty = new TTY( screen_element, keyboard_element, bell );
// tty.clearScreen()
// tty.scrollScreen()
// tty.setTextStyle( textStyle )
// { width: w, height: h } = tty.getScreenSize()
// { x: x, y: y } = tty.getCursorPosition()
// tty.setFirmwareActive( bool )
// tty.setCursorPosition( x, y )
// tty.showCursor()
// tty.hideCursor()
// tty.focus()
//
// This just calls writeChar() in a loop; no need to hook it
// tty.writeString( string )
//
// The following can be hooked:
// tty.readLine( callback_function, prompt )
// tty.readChar( callback_function )
// tty.writeChar( c )
//
// tty.TEXT_STYLE_NORMAL = 0
// tty.TEXT_STYLE_INVERSE = 1
// tty.TEXT_STYLE_FLASH = 2
//
// Example:
//
// <script>
// tty = new TTY( document.getElementById( 'screen' ), document.getElementById( 'keyboard' ), 80, 24 );
// </script>
// <style>
// #screen { font-size: 10pt; font-family: monospace; font-weight: bold; background-color: black; color: #80ff80; }
// .normal { background-color: #000000; color: #80ff80; }
// .inverse { background-color: #80ff80; color: #000000; }
// </style>
// <div id="screen" tabindex="0"></div>
/*global getClassList*/ // from polyfill.js
/*global identifyKey */ // From keyboard.js
function TTY(screenElement, keyboardElement, bell) {
/*jslint browser: true, white: false, bitwise: false */
// Constants
this.TEXT_STYLE_NORMAL = 0;
this.TEXT_STYLE_INVERSE = 1;
this.TEXT_STYLE_FLASH = 2;
// Internal Fields
// For references to "this" within callbacks and closures
var self = this,
// Display
cursorX = 0,
cursorY = 0,
cursorVisible = false,
cursorElement = null,
styleElem,
screenGrid,
screenRow = [],
splitPos = 0,
screenWidth,
screenHeight,
curStyle = this.TEXT_STYLE_NORMAL,
cursorState = true,
cursorInterval,
firmwareActive = true, // 80-column firmware
mousetext = false,
// Input
lineCallback,
charCallback,
inputBuffer = [],
keyboardRegister = 0,
keyDown = false,
capsLock = true, // Caps lock state is tracked unique to the TTY
buttonState = [0, 0, 0, 0];
this.autoScroll = true;
//
// Display
//
function setCellByte(x, y, byte) {
var cell = screenGrid[x + screenWidth * y];
if (cell && cell.byte !== byte) {
cell.byte = byte;
cell.elem.className = 'a2c a2c' + String(byte);
}
}
// Apple II Character Generator (byte->character map)
// 0x00-0x1F = INVERSE @ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_
// 0x20-0x3F = INVERSE !"#$%&'()*+,-./0123456789:;<=>?
// 0x40-0x5F = FLASH @ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_ (80-col firmware active: mousetext symbols)
// 0x60-0x7F = FLASH !"#$%&'()*+,-./0123456789:;<=>? (80-col firmware active: inverse lowercase)
// 0x80-0x9F = NORMAL @ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_
// 0xA0-0xBF = NORMAL !"#$%&'()*+,-./0123456789:;<=>?
// 0xC0-0xDF = NORMAL @ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_
// 0xE0-0xFF = NORMAL `abcdefghijklmnopqrstuvwxyz{|}~
function setCellChar(x, y, c) {
var byte;
if (c > 0xff) {
// Extension characters
byte = c;
} else {
// Lock to 7-bit; Control characters should be filtered already
c = (c >>> 0) & 0x7f;
if (firmwareActive) {
if (curStyle === self.TEXT_STYLE_INVERSE) {
if (0x20 <= c && c < 0x40) { byte = c; }
else if (0x40 <= c && c < 0x60) { byte = c - (mousetext ? 0 : 0x40); }
else if (0x60 <= c && c < 0x80) { byte = c; }
} else if (curStyle === self.TEXT_STYLE_FLASH) {
if (0x20 <= c && c < 0x40) { byte = c + 0x40; }
else if (0x40 <= c && c < 0x60) { byte = c - 0x40; }
else if (0x60 <= c && c < 0x80) { byte = c; }
} else {
if (0x20 <= c && c < 0x40) { byte = c + 0x80; }
else if (0x40 <= c && c < 0x60) { byte = c + 0x80; }
else if (0x60 <= c && c < 0x80) { byte = c + 0x80; }
}
} else {
if (curStyle === self.TEXT_STYLE_INVERSE) {
if (0x20 <= c && c < 0x40) { byte = c; }
else if (0x40 <= c && c < 0x60) { byte = c - 0x40; }
else if (0x60 <= c && c < 0x80) { byte = c - 0x40; } // no inverse lowercase
} else if (curStyle === self.TEXT_STYLE_FLASH) {
if (0x20 <= c && c < 0x40) { byte = c + 0x40; }
else if (0x40 <= c && c < 0x60) { byte = c; }
else if (0x60 <= c && c < 0x80) { byte = c; } // no lowercase flash
} else {
if (0x20 <= c && c < 0x40) { byte = c + 0x80; }
else if (0x40 <= c && c < 0x60) { byte = c + 0x80; }
else if (0x60 <= c && c < 0x80) { byte = c + 0x80; }
}
}
}
setCellByte(x, y, byte);
}
this.reset = function _reset() {
this.hideCursor();
lineCallback = undefined;
charCallback = undefined;
inputBuffer = [];
keyboardRegister = 0;
buttonState = [0, 0, 0, 0];
}; // reset
function init(active, rows, columns) {
firmwareActive = active;
screenWidth = columns;
screenHeight = rows;
// Reset parameters
self.textWindow = {};
self.textWindow.left = 0;
self.textWindow.top = 0;
self.textWindow.width = screenWidth;
self.textWindow.height = screenHeight;
self.setTextStyle(self.TEXT_STYLE_NORMAL);
// Build character cell grid
var x, y, table, tbody, tr, td;
screenGrid = [];
screenGrid.length = screenWidth * screenHeight;
table = document.createElement('table');
table.className = 'tty_table';
tbody = document.createElement('tbody');
styleElem = tbody;
getClassList(styleElem).add(screenWidth === 40 ? 'tty_40col' : 'tty_80col');
if (firmwareActive) { getClassList(styleElem).add('active'); }
for (y = 0; y < screenHeight; y += 1) {
tr = document.createElement('tr');
tr.className = 'tty_tr';
tr.style.visibility = (y < splitPos) ? "hidden" : "";
screenRow[y] = tr;
for (x = 0; x < screenWidth; x += 1) {
td = document.createElement('td');
screenGrid[screenWidth * y + x] = {
elem: td
};
tr.appendChild(td);
}
tbody.appendChild(tr);
}
table.appendChild(tbody);
screenElement.innerHTML = "";
screenElement.appendChild(table);
self.clearScreen();
// Create cursor
cursorElement = document.createElement('span');
cursorElement.className = 'a2c a2c-cursor a2c255';
self.setCursorPosition(0, 0);
}
this.clearScreen = function _clearScreen() {
var x, y;
cursorX = self.textWindow.left;
cursorY = self.textWindow.top;
for (y = self.textWindow.top; y < self.textWindow.top + self.textWindow.height; y += 1) {
for (x = self.textWindow.left; x < self.textWindow.left + self.textWindow.width; x += 1) {
setCellChar(x, y, 0x20);
}
}
};
this.clearEOL = function _clearEOL() {
var x;
for (x = cursorX; x < self.textWindow.left + self.textWindow.width; x += 1) {
setCellChar(x, cursorY, 0x20);
}
};
this.setFirmwareActive = function _setFirmwareActive(active) {
init(active, 24, active ? 80 : 40);
};
function scrollUp() {
var x, y, cell;
for (y = self.textWindow.top; y < self.textWindow.top + self.textWindow.height - 1; y += 1) {
for (x = self.textWindow.left; x < self.textWindow.left + self.textWindow.width; x += 1) {
cell = screenGrid[x + screenWidth * (y + 1)];
setCellByte(x, y, cell.byte);
}
}
y = self.textWindow.top + (self.textWindow.height - 1);
for (x = self.textWindow.left; x < self.textWindow.left + self.textWindow.width; x += 1) {
setCellChar(x, y, 0x20);
}
}
function scrollDown() {
var x, y, cell;
for (y = self.textWindow.top + self.textWindow.height - 1; y > self.textWindow.top; y -= 1) {
for (x = self.textWindow.left; x < self.textWindow.left + self.textWindow.width; x += 1) {
cell = screenGrid[x + screenWidth * (y - 1)];
setCellByte(x, y, cell.byte);
}
}
y = self.textWindow.top;
for (x = self.textWindow.left; x < self.textWindow.left + self.textWindow.width; x += 1) {
setCellChar(x, y, 0x20);
}
}
this.scrollScreen = function _scrollScreen() {
scrollUp();
};
this.setTextStyle = function _setTextStyle(style) {
curStyle = style;
};
// Internal
function updateCursor() {
if (cursorVisible && cursorState) {
var elem = screenGrid[cursorY * screenWidth + cursorX].elem;
if (elem !== cursorElement.parentNode) {
elem.appendChild(cursorElement);
}
} else if (cursorElement.parentNode) {
cursorElement.parentNode.removeChild(cursorElement);
}
}
// Internal
function lineFeed() {
cursorY += 1;
if (cursorY >= self.textWindow.top + self.textWindow.height) {
cursorY = self.textWindow.top + self.textWindow.height - 1;
if (self.autoScroll) {
self.scrollScreen();
}
}
updateCursor();
}
// Internal
function advanceCursor() {
// Advance the cursor
cursorX += 1;
if (cursorX >= self.textWindow.left + self.textWindow.width) {
cursorX = self.textWindow.left;
lineFeed();
}
updateCursor();
}
// Hookable
this.writeChar = function _writeChar(c) {
var code = c.charCodeAt(0),
x, y;
switch (code) {
case 0:
case 1:
case 2:
case 3:
case 4: // DOS hook takes care of CHR$(4)
case 5:
case 6:
// no-op
break;
case 7: // (BEL) bell
if (bell) {
bell();
}
break;
case 8: // (BS) backspace
cursorX -= 1;
if (cursorX < self.textWindow.left) {
cursorX += self.textWindow.width;
cursorY -= 1;
if (cursorY < self.textWindow.top) {
cursorY = self.textWindow.top;
}
}
break;
case 9:
break;
case 10: // (LF) line feed
lineFeed();
break;
case 11: // (VT) clear EOS
if (firmwareActive) {
// Clears from the cursor position to the end of the window
for (x = cursorX; x < self.textWindow.left + self.textWindow.width; x += 1) {
setCellChar(x, cursorY, 0x20);
}
for (y = cursorY + 1; y < self.textWindow.top + self.textWindow.height; y += 1) {
for (x = self.textWindow.left; x < self.textWindow.left + self.textWindow.width; x += 1) {
setCellChar(x, y, 0x20);
}
}
}
break;
case 12: // (FF) clear
if (firmwareActive) {
// move cursor to upper left and clear window
self.clearScreen();
}
break;
case 13: // (CR) return
cursorX = self.textWindow.left;
lineFeed();
break;
case 14: // (SO) normal
if (firmwareActive) {
curStyle = self.TEXT_STYLE_NORMAL;
}
break;
case 15: // (SI) inverse
if (firmwareActive) {
curStyle = self.TEXT_STYLE_INVERSE;
}
break;
case 16:
break;
case 17: // (DC1) 40-column
if (firmwareActive) {
// set display to 40 columns
init(true, 24, 40);
}
break;
case 18: // (DC2) 80-column
if (firmwareActive) {
// set display to 80 columns
init(true, 24, 80);
}
break;
case 19: // (DC3) stop list
case 20:
break;
case 21: // (NAK) quit
if (firmwareActive) {
// deactivate, home, clear screen
init(false, 24, 40);
}
break;
case 22: // (SYN) scroll down
if (firmwareActive) {
// scroll display down, leaving cursor
scrollDown();
}
break;
case 23: // (ETB) scroll up
if (firmwareActive) {
// scroll display up, leaving cursor
scrollUp();
}
break;
case 24: // (CAN) disable mousetext
if (firmwareActive) {
// http://www.umich.edu/~archive/apple2/technotes/tn/mous/TN.MOUS.006
mousetext = false;
}
break;
case 25: // (EM) home
if (firmwareActive) {
// Moves cursor to upper-left corner of window (but doesn't clear)
cursorX = self.textWindow.left;
cursorY = self.textWindow.top;
}
break;
case 26: // (SUB) clear line
if (firmwareActive) {
// Clears the line the cursor position is on
for (x = 0; x < self.textWindow.width; x += 1) {
setCellChar(self.textWindow.left + x, cursorY, 0x20);
}
}
break;
case 27: // (ESC) enable mousetext
if (firmwareActive) {
// http://www.umich.edu/~archive/apple2/technotes/tn/mous/TN.MOUS.006
mousetext = true;
}
break;
case 28: // (FS) fwd. space
if (firmwareActive) {
// Moves cursor position one space to the right; from right edge
// of window, moves it to left end of line below
cursorX += 1;
if (cursorX > (self.textWindow.left + self.textWindow.width)) {
cursorX -= self.textWindow.width;
cursorY += 1;
if (cursorY > self.textWindow.top + self.textWindow.height) {
cursorY = self.textWindow.top + self.textWindow.height;
}
}
}
break;
case 29: // (GS) clear EOL
if (firmwareActive) {
// Clear line rom cursor position to the right edge of the window
self.clearEOL();
}
break;
case 30: // RS - gotoXY (not supported from BASIC)
case 31:
break;
default:
setCellChar(cursorX, cursorY, code);
advanceCursor();
break;
}
};
// Hookable
this.writeString = function _writeString(s) {
var i;
for (i = 0; i < s.length; i += 1) {
this.writeChar(s.charAt(i));
}
};
this.getScreenSize = function _getScreenSize() {
return { width: screenWidth, height: screenHeight };
};
this.getCursorPosition = function _getCursorPosition() {
return { x: cursorX, y: cursorY };
};
this.setCursorPosition = function _setCursorPosition(x, y) {
if (x !== undefined) {
x = Math.min(Math.max(Math.floor(x), 0), screenWidth - 1);
} else {
x = cursorX;
}
if (y !== undefined) {
y = Math.min(Math.max(Math.floor(y), 0), screenHeight - 1);
} else {
y = cursorY;
}
if (x === cursorX && y === cursorY) {
// no-op
return;
}
cursorX = x;
cursorY = y;
updateCursor();
};
this.showCursor = function _showCursor() {
cursorVisible = true;
cursorInterval = setInterval(function() {
cursorState = !cursorState;
updateCursor();
}, 500);
};
this.hideCursor = function _hideCursor() {
clearInterval(cursorInterval);
cursorVisible = false;
updateCursor();
};
this.splitScreen = function _splitScreen(splitAt) {
splitPos = splitAt;
var y;
for (y = 0; y < screenHeight; y += 1) {
screenRow[y].style.visibility = (y < splitPos) ? "hidden" : "";
}
};
//
// Input
//
// Internal
function onKey(code) {
var cb, c, s;
keyboardRegister = code | 0x80;
if (charCallback) {
keyboardRegister = keyboardRegister & 0x7f;
cb = charCallback;
charCallback = undefined;
self.hideCursor();
cb(String.fromCharCode(code));
} else if (lineCallback) {
keyboardRegister = keyboardRegister & 0x7f;
if (code >= 32 && code <= 127) {
c = String.fromCharCode(code);
inputBuffer.push(c);
self.writeChar(c); // echo
} else {
switch (code) {
case 8: // Left Arrow
if (inputBuffer.length > 0) {
inputBuffer.pop();
self.setCursorPosition(Math.max(self.getCursorPosition().x - 1, 0), self.getCursorPosition().y);
}
break;
case 13: // Enter
// Respond to INPUT callback, if defined
s = inputBuffer.join("");
inputBuffer = [];
self.writeString("\r");
cb = lineCallback;
lineCallback = undefined;
self.hideCursor();
cb(s);
break;
}
}
}
// else: nothing - key stays in the keyboard register
} // onKey
function toAppleKey(e) {
function ord(c) { return c.charCodeAt(0); }
switch (e.code) {
// Non-Printables
case 'Backspace': return 127;
case 'Tab': return 9; // NOTE: Blocked elsewhere, for web page accessibility
case 'Enter': return 13;
case 'Esc': return 27;
case 'ArrowLeft': return 8;
case 'ArrowUp': return 11;
case 'ArrowRight': return 21;
case 'ArrowDown': return 10;
case 'Delete': return 127;
case 'Clear': return 24; // ctrl-X - used on the IIgs
// Numeric
case 'Numpad0': return 0x30;
case 'Numpad1': return 0x31;
case 'Numpad2': return 0x32;
case 'Numpad3': return 0x33;
case 'Numpad4': return 0x34;
case 'Numpad5': return 0x35;
case 'Numpad6': return 0x36;
case 'Numpad7': return 0x37;
case 'Numpad8': return 0x38;
case 'Numpad9': return 0x39;
case 'Digit0':
case 'Digit1':
case 'Digit2':
case 'Digit3':
case 'Digit4':
case 'Digit5':
case 'Digit6':
case 'Digit7':
case 'Digit8':
case 'Digit9':
var digit = e.code.substring(5);
if (e.ctrlKey) {
if (e.shiftKey) {
switch (digit) {
case '2': return 0; // ctrl-@
case '6': return 30; // ctrl-^
}
}
return (void 0);
} else if (e.shiftKey) {
return ')!@#$%^&*('.charCodeAt(ord(digit) - ord('0'));
} else {
return ord(digit);
}
// Alphabetic
case 'KeyA':
case 'KeyB':
case 'KeyC':
case 'KeyD':
case 'KeyE':
case 'KeyF':
case 'KeyG':
case 'KeyH':
case 'KeyI':
case 'KeyJ':
case 'KeyK':
case 'KeyL':
case 'KeyM':
case 'KeyN':
case 'KeyO':
case 'KeyP':
case 'KeyQ':
case 'KeyR':
case 'KeyS':
case 'KeyT':
case 'KeyU':
case 'KeyV':
case 'KeyW':
case 'KeyX':
case 'KeyY':
case 'KeyZ':
var letter = e.code.substring(3);
if (e.ctrlKey) {
return ord(letter) - 0x40; // Control keys, Apple II-style
} else if (capsLock || e.shiftKey) {
return ord(letter); // Upper case
} else {
return ord(letter) + 0x20; // Lower case
}
// Symbol and Punctuation
case 'Space': return ord(' ');
case 'Semicolon': return e.shiftKey ? ord(':') : ord(';');
case 'Equal': return e.shiftKey ? ord('+') : ord('=');
case 'Comma': return e.shiftKey ? ord('<') : ord(',');
case 'Minus': return e.ctrlKey ? 31 : e.shiftKey ? ord('_') : ord('-');
case 'Period': return e.shiftKey ? ord('>') : ord('.');
case 'Slash': return e.shiftKey ? ord('?') : ord('/');
case 'BackQuote': return e.shiftKey ? ord('~') : ord('`');
case 'BracketLeft': return e.ctrlKey ? 27 : e.shiftKey ? ord('{') : ord('[');
case 'Backslash': return e.ctrlKey ? 28 : e.shiftKey ? ord('|') : ord('\\');
case 'BracketRight': return e.ctrlKey ? 29 : e.shiftKey ? ord('}') : ord(']');
case 'Quote': return e.shiftKey ? ord('"') : ord('\'');
// Apple IIgs Keyboard
case 'NumpadClear': return 24;
case 'NumpadAdd': return ord('+');
case 'NumpadSubtract': return ord('-');
case 'NumpadMultiply': return ord('*');
case 'NumpadDivide': return ord('/');
case 'NumpadDecimal': return ord('.');
case 'NumpadEnter': return 13;
default:
break;
}
return -1;
}
function isBrowserKey(e) {
return e.code === 'Tab' || e.code === 'F5' || e.metaKey;
}
// Internal
function handleKeyDown(e) {
identifyKey(e);
if (!e.code || isBrowserKey(e)) {
return true;
}
var handled = false, code;
switch (e.code) {
case 'CapsLock':
capsLock = !capsLock;
handled = true;
break;
// Used as paddle buttons (0=Open Apple, 1=Solid Apple)
case 'Home': buttonState[0] = 255; handled = true; break;
case 'End': buttonState[1] = 255; handled = true; break;
case 'PageUp': buttonState[2] = 255; handled = true; break;
case 'Shift':
case 'ShiftLeft':
case 'ShiftRight':
buttonState[2] = 255; handled = true; break;
case 'PageDown': buttonState[3] = 255; handled = true; break;
default:
code = toAppleKey(e);
if (code !== -1) {
keyDown = true;
onKey(code);
handled = true;
}
break;
}
if (handled) {
e.stopPropagation();
e.preventDefault();
}
return !handled;
}
// Internal
function handleKeyUp(e) {
identifyKey(e);
if (!e.code || isBrowserKey(e)) {
return true;
}
var handled = false,
code;
switch (e.code) {
case 'CapsLock':
handled = true;
break;
// Used as paddle buttons (0=Open Apple, 1=Solid Apple)
case 'Home': buttonState[0] = 0; handled = true; break;
case 'End': buttonState[1] = 0; handled = true; break;
case 'PageUp': buttonState[2] = 0; handled = true; break;
case 'Shift': buttonState[2] = 0; handled = true; break;
case 'PageDown': buttonState[3] = 0; handled = true; break;
default:
code = toAppleKey(e);
if (code !== -1) {
keyDown = false;
handled = true;
}
break;
}
if (handled) {
e.stopPropagation();
e.preventDefault();
}
return !handled;
}
this.getButtonState = function _getButtonState(btn) {
return buttonState[btn];
};
this.focus = function _focus() {
keyboardElement.focus();
};
// Hookable
this.readLine = function _readLine(callback, prompt) {
self.writeString(prompt);
lineCallback = callback;
self.showCursor();
self.focus();
};
// Hookable
this.readChar = function _readChar(callback) {
// If there is a key ready, deliver it immediately
if (keyboardRegister & 0x80) {
keyboardRegister = keyboardRegister & 0x7f;
// Non-blocking return
setTimeout(function() { callback(String.fromCharCode(keyboardRegister)); }, 0);
} else {
charCallback = callback;
self.showCursor();
self.focus();
}
};
this.getKeyboardRegister = function _getKeyboardRegister() {
return keyboardRegister;
};
this.clearKeyboardStrobe = function _clearKeyboardStrobe() {
keyboardRegister = keyboardRegister & 0x7f;
return keyboardRegister | (keyDown ? 0x80 : 0x00);
};
//
// Constructor Logic
//
init(false, 24, 40);
window.addEvent(keyboardElement, 'keydown', handleKeyDown);
window.addEvent(keyboardElement, 'keyup', handleKeyUp);
setInterval(function _blinkFlash() {
window.getClassList(styleElem).toggle('flash');
}, 250);
}