Initial commit

node_modules/canvas/lib/pngstream.js

@@ -0,0 +1,46 @@
+'use strict';
+
+/*!
+ * Canvas - PNGStream
+ * Copyright (c) 2010 LearnBoost <tj@learnboost.com>
+ * MIT Licensed
+ */
+
+var Readable = require('stream').Readable;
+var util = require('util');
+
+var PNGStream = module.exports = function PNGStream(canvas, options) {
+  if (!(this instanceof PNGStream)) {
+    throw new TypeError("Class constructors cannot be invoked without 'new'");
+  }
+
+  Readable.call(this);
+
+  if (options &&
+    options.palette instanceof Uint8ClampedArray &&
+    options.palette.length % 4 !== 0) {
+    throw new Error("Palette length must be a multiple of 4.");
+  }
+  this.canvas = canvas;
+  this.options = options || {};
+};
+
+util.inherits(PNGStream, Readable);
+
+function noop() {}
+
+PNGStream.prototype._read = function _read() {
+  // For now we're not controlling the c++ code's data emission, so we only
+  // call canvas.streamPNGSync once and let it emit data at will.
+  this._read = noop;
+  var self = this;
+  self.canvas.streamPNGSync(function(err, chunk, len){
+    if (err) {
+      self.emit('error', err);
+    } else if (len) {
+      self.push(chunk);
+    } else {
+      self.push(null);
+    }
+  }, self.options);
+};