anandgeorge · March 12, 2012 14:57 · Mar 12, 2012 · Mar 12, 2012
diff --git a/mouse.js b/mouse.js
@@ -2,7 +2,7 @@
  * Read Linux mouse(s) in node.js
  * Author: Marc Loehe ([email protected])
  *
- * Adapted from Tim Caswells nice solution to read a linux joystick
+ * Adapted from Tim Caswell's nice solution to read a linux joystick
  * http://nodebits.org/linux-joystick
  * https://github.com/nodebits/linux-joystick
  */

diff --git a/mouse.js b/mouse.js
@@ -0,0 +1,93 @@
+/**
+ * Read Linux mouse(s) in node.js
+ * Author: Marc Loehe ([email protected])
+ *
+ * Adapted from Tim Caswells nice solution to read a linux joystick
+ * http://nodebits.org/linux-joystick
+ * https://github.com/nodebits/linux-joystick
+ */
+
+var fs = require('fs'),
+    EventEmitter = require('events').EventEmitter;
+
+/**
+ * Parse PS/2 mouse protocol
+ * According to http://www.computer-engineering.org/ps2mouse/
+ */
+function parse(mouse, buffer) {
+  var event = {
+    leftBtn:    (buffer[0] & 1  ) > 0, // Bit 0
+    rightBtn:   (buffer[0] & 2  ) > 0, // Bit 1
+    middleBtn:  (buffer[0] & 4  ) > 0, // Bit 2
+    xSign:      (buffer[0] & 16 ) > 0, // Bit 4
+    ySign:      (buffer[0] & 32 ) > 0, // Bit 5
+    xOverflow:  (buffer[0] & 64 ) > 0, // Bit 6
+    yOverflow:  (buffer[0] & 128) > 0, // Bit 7
+    xDelta:      buffer.readInt8(1),   // Byte 2 as signed int
+    yDelta:      buffer.readInt8(2)    // Byte 3 as signed int
+  };
+  if (event.leftBtn || event.rightBtn || event.middleBtn) {
+    event.type = 'button';
+  } else {
+    event.type = 'moved';
+  }
+  return event;
+}
+
+function Mouse(mouseid) {
+  this.wrap('onOpen');
+  this.wrap('onRead');
+  this.dev = typeof(mouseid) === 'number' ? 'mouse' + mouseid : 'mice';
+  this.buf = new Buffer(3);
+  fs.open('/dev/input/' + this.dev, 'r', this.onOpen);
+}
+
+Mouse.prototype = Object.create(EventEmitter.prototype, {
+  constructor: {value: Mouse}
+});
+
+Mouse.prototype.wrap = function(name) {
+  var self = this;
+  var fn = this[name];
+  this[name] = function (err) {
+    if (err) return self.emit('error', err);
+    return fn.apply(self, Array.prototype.slice.call(arguments, 1));
+  };
+};
+
+Mouse.prototype.onOpen = function(fd) {
+  this.fd = fd;
+  this.startRead();
+};
+
+Mouse.prototype.startRead = function() {
+  fs.read(this.fd, this.buf, 0, 3, null, this.onRead);
+};
+
+Mouse.prototype.onRead = function(bytesRead) {
+  var event = parse(this, this.buf);
+  event.dev = this.dev;
+  this.emit(event.type, event);
+  if (this.fd) this.startRead();
+};
+
+Mouse.prototype.close = function(callback) {
+  fs.close(this.fd, (function(){console.log(this);}));
+  this.fd = undefined;
+}
+
+/****************
+ * Sample Usage *
+ ****************/
+
+// read all mouse events from /dev/input/mice
+var mouse = new Mouse();
+mouse.on('button', console.log);
+mouse.on('moved', console.log);
+
+// to read only a specific mouse by id (e.g. /dev/input/mouse0) use
+// var mouse0 = newMouse(0);
+
+// to close mouse
+// mouse.close();
+// mouse = undefined;