/*
* Copyright (C) 2013 Glyptodon LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
var Guacamole = Guacamole || {};
/**
* A reader which automatically handles the given input stream, returning
* strictly text data. Note that this object will overwrite any installed event
* handlers on the given Guacamole.InputStream.
*
* @constructor
* @param {Guacamole.InputStream} stream The stream that data will be read
* from.
*/
Guacamole.StringReader = function(stream) {
/**
* Reference to this Guacamole.InputStream.
* @private
*/
var guac_reader = this;
/**
* Wrapped Guacamole.ArrayBufferReader.
* @private
* @type {Guacamole.ArrayBufferReader}
*/
var array_reader = new Guacamole.ArrayBufferReader(stream);
/**
* The number of bytes remaining for the current codepoint.
*
* @private
* @type {Number}
*/
var bytes_remaining = 0;
/**
* The current codepoint value, as calculated from bytes read so far.
*
* @private
* @type {Number}
*/
var codepoint = 0;
/**
* Decodes the given UTF-8 data into a Unicode string. The data may end in
* the middle of a multibyte character.
*
* @private
* @param {ArrayBuffer} buffer Arbitrary UTF-8 data.
* @return {String} A decoded Unicode string.
*/
function __decode_utf8(buffer) {
var text = "";
var bytes = new Uint8Array(buffer);
for (var i=0; i<bytes.length; i++) {
// Get current byte
var value = bytes[i];
// Start new codepoint if nothing yet read
if (bytes_remaining === 0) {
// 1 byte (0xxxxxxx)
if ((value | 0x7F) === 0x7F)
text += String.fromCharCode(value);
// 2 byte (110xxxxx)
else if ((value | 0x1F) === 0xDF) {
codepoint = value & 0x1F;
bytes_remaining = 1;
}
// 3 byte (1110xxxx)
else if ((value | 0x0F )=== 0xEF) {
codepoint = value & 0x0F;
bytes_remaining = 2;
}
// 4 byte (11110xxx)
else if ((value | 0x07) === 0xF7) {
codepoint = value & 0x07;
bytes_remaining = 3;
}
// Invalid byte
else
text += "\uFFFD";
}
// Continue existing codepoint (10xxxxxx)
else if ((value | 0x3F) === 0xBF) {
codepoint = (codepoint << 6) | (value & 0x3F);
bytes_remaining--;
// Write codepoint if finished
if (bytes_remaining === 0)
text += String.fromCharCode(codepoint);
}
// Invalid byte
else {
bytes_remaining = 0;
text += "\uFFFD";
}
}
return text;
}
// Receive blobs as strings
array_reader.ondata = function(buffer) {
// Decode UTF-8
var text = __decode_utf8(buffer);
// Call handler, if present
if (guac_reader.ontext)
guac_reader.ontext(text);
};
// Simply call onend when end received
array_reader.onend = function() {
if (guac_reader.onend)
guac_reader.onend();
};
/**
* Fired once for every blob of text data received.
*
* @event
* @param {String} text The data packet received.
*/
this.ontext = null;
/**
* Fired once this stream is finished and no further data will be written.
* @event
*/
this.onend = null;
};