111 lines
2.5 KiB
JavaScript

'use strict';
var util = require('util');
var zlib = require('zlib');
var ChunkStream = require('./chunkstream');
var FilterAsync = require('./filter-parse-async');
var Parser = require('./parser');
var bitmapper = require('./bitmapper');
var formatNormaliser = require('./format-normaliser');
var ParserAsync = module.exports = function(options) {
ChunkStream.call(this);
this._parser = new Parser(options, {
read: this.read.bind(this),
error: this._handleError.bind(this),
metadata: this._handleMetaData.bind(this),
gamma: this.emit.bind(this, 'gamma'),
palette: this._handlePalette.bind(this),
transColor: this._handleTransColor.bind(this),
finished: this._finished.bind(this),
inflateData: this._inflateData.bind(this)
});
this._options = options;
this.writable = true;
this._parser.start();
};
util.inherits(ParserAsync, ChunkStream);
ParserAsync.prototype._handleError = function(err) {
this.emit('error', err);
this.writable = false;
this.destroy();
if (this._inflate && this._inflate.destroy) {
this._inflate.destroy();
}
this.errord = true;
};
ParserAsync.prototype._inflateData = function(data) {
if (!this._inflate) {
this._inflate = zlib.createInflate();
this._inflate.on('error', this.emit.bind(this, 'error'));
this._filter.on('complete', this._complete.bind(this));
this._inflate.pipe(this._filter);
}
this._inflate.write(data);
};
ParserAsync.prototype._handleMetaData = function(metaData) {
this.emit('metadata', metaData);
this._bitmapInfo = Object.create(metaData);
this._filter = new FilterAsync(this._bitmapInfo);
};
ParserAsync.prototype._handleTransColor = function(transColor) {
this._bitmapInfo.transColor = transColor;
};
ParserAsync.prototype._handlePalette = function(palette) {
this._bitmapInfo.palette = palette;
};
ParserAsync.prototype._finished = function() {
if (this.errord) {
return;
}
if (!this._inflate) {
this.emit('error', 'No Inflate block');
}
else {
// no more data to inflate
this._inflate.end();
}
this.destroySoon();
};
ParserAsync.prototype._complete = function(filteredData) {
if (this.errord) {
return;
}
try {
var bitmapData = bitmapper.dataToBitMap(filteredData, this._bitmapInfo);
var normalisedBitmapData = formatNormaliser(bitmapData, this._bitmapInfo);
bitmapData = null;
}
catch (ex) {
this._handleError(ex);
return;
}
this.emit('parsed', normalisedBitmapData);
};