/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
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;
};