DoraCMS/node_modules/gm/lib/getters.js

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2015-09-25 10:55:13 +08:00
/**
* Extend proto.
*/
module.exports = function (gm) {
var proto = gm.prototype;
/**
* `identify` states
*/
const IDENTIFYING = 1;
const IDENTIFIED = 2;
/**
* Map getter functions to output names.
*
* - format: specifying the -format argument (see man gm)
* - verbose: use -verbose instead of -format (only if necessary b/c its slow)
* - helper: use the conversion helper
*/
var map = {
'format': { key: 'format', format: '%m ', helper: 'Format' }
, 'depth': { key: 'depth', format: '%q' }
, 'filesize': { key: 'Filesize', format: '%b' }
, 'size': { key: 'size', format: '%wx%h ', helper: 'Geometry' }
, 'color': { key: 'color', format: '%k', helper: 'Colors' }
, 'orientation': { key: 'Orientation', verbose: true }
, 'res': { key: 'Resolution', verbose: true }
}
/**
* Getter functions
*/
Object.keys(map).forEach(function (getter) {
proto[getter] = function (opts, callback) {
if (!callback) callback = opts, opts = {};
if (!callback) return this;
var val = map[getter]
, key = val.key
, self = this;
if (self.data[key]) {
callback.call(self, null, self.data[key]);
return self;
}
self.on(getter, callback);
self.bufferStream = !!opts.bufferStream;
if (val.verbose) {
self.identify(opts, function (err, stdout, stderr, cmd) {
if (err) {
self.emit(getter, err, self.data[key], stdout, stderr, cmd);
} else {
self.emit(getter, err, self.data[key]);
}
});
return self;
}
var args = makeArgs(self, val);
self._exec(args, function (err, stdout, stderr, cmd) {
if (err) {
self.emit(getter, err, self.data[key], stdout, stderr, cmd);
return;
}
var result = (stdout||'').trim();
if (val.helper in helper) {
helper[val.helper](self.data, result);
} else {
self.data[key] = result;
}
self.emit(getter, err, self.data[key]);
});
return self;
}
});
/**
* identify command
*
* Overwrites all internal data with the parsed output
* which is more accurate than the fast shortcut
* getters.
*/
proto.identify = function identify (opts, callback) {
// identify with pattern
if (typeof(opts) === 'string') {
opts = {
format: opts
}
}
if (!callback) callback = opts, opts = {};
if (!callback) return this;
if (opts && opts.format) return identifyPattern.call(this, opts, callback);
var self = this;
if (IDENTIFIED === self._identifyState) {
callback.call(self, null, self.data);
return self;
}
self.on('identify', callback);
if (IDENTIFYING === self._identifyState) {
return self;
}
self._identifyState = IDENTIFYING;
self.bufferStream = !!opts.bufferStream;
var args = makeArgs(self, { verbose: true });
self._exec(args, function (err, stdout, stderr, cmd) {
if (err) {
self.emit('identify', err, self.data, stdout, stderr, cmd);
return;
}
err = parse(stdout, self);
if (err) {
self.emit('identify', err, self.data, stdout, stderr, cmd);
return;
}
self.data.path = self.source;
self.emit('identify', null, self.data);
self._identifyState = IDENTIFIED;
});
return self;
}
/**
* identify with pattern
*
* Execute `identify -format` with custom pattern
*/
function identifyPattern (opts, callback) {
var self = this;
self.bufferStream = !!opts.bufferStream;
var args = makeArgs(self, opts);
self._exec(args, function (err, stdout, stderr, cmd) {
if (err) {
return callback.call(self, err, undefined, stdout, stderr, cmd);
}
callback.call(self, err, (stdout||'').trim());
});
return self;
}
/**
* Parses `identify` responses.
*
* @param {String} stdout
* @param {Gm} self
* @return {Error} [optionally]
*/
function parse (stdout, self) {
// normalize
var parts = (stdout||"").trim().replace(/\r\n|\r/g, "\n").split("\n");
// skip the first line (its just the filename)
parts.shift();
try {
var len = parts.length
, rgx1 = /^( *)(.+?): (.*)$/ // key: val
, rgx2 = /^( *)(.+?):$/ // key: begin nested object
, out = { indent: {} }
, level = null
, lastkey
, i = 0
, res
, o
for (; i < len; ++i) {
res = rgx1.exec(parts[i]) || rgx2.exec(parts[i]);
if (!res) continue;
var indent = res[1].length
, key = res[2] ? res[2].trim() : '';
if ('Image' == key || 'Warning' == key) continue;
var val = res[3] ? res[3].trim() : null;
// first iteration?
if (null === level) {
level = indent;
o = out.root = out.indent[level] = self.data;
} else if (indent < level) {
// outdent
if (!(indent in out.indent)) {
continue;
}
o = out.indent[indent];
} else if (indent > level) {
// dropping into a nested object
out.indent[level] = o;
// wierd format, key/val pair with nested children. discard the val
o = o[lastkey] = {};
}
level = indent;
if (val) {
o[key] = val;
if (key in helper) {
helper[key](o, val);
}
}
lastkey = key;
}
} catch (err) {
err.message = err.message + "\n\n Identify stdout:\n " + stdout;
return err;
}
}
/**
* Create an argument array for the identify command.
*
* @param {gm} self
* @param {Object} val
* @return {Array}
*/
function makeArgs (self, val) {
var args = [
'identify'
, '-ping'
];
if (val.format) {
args.push('-format', val.format);
}
if (val.verbose) {
args.push('-verbose');
}
args = args.concat(self.src());
return args;
}
/**
* identify -verbose helpers
*/
var helper = gm.identifyHelpers = {};
helper.Geometry = function Geometry (o, val) {
// We only want the size of the first frame.
// Each frame is separated by a space.
var split = val.split(" ").shift().split("x");
o.size = {
width: parseInt(split[0], 10)
, height: parseInt(split[1], 10)
}
};
helper.Format = function Format (o, val) {
o.format = val.split(" ")[0];
};
helper.Depth = function Depth (o, val) {
o.depth = parseInt(val, 10);
};
helper.Colors = function Colors (o, val) {
o.color = parseInt(val, 10);
};
}