complete redesign: use nodejs on server instead of php - documentation to be updated

nodejs/node_modules/stylus/lib/functions/image.js

@@ -0,0 +1,162 @@
+
+
+/*!
+ * Stylus - plugin - url
+ * Copyright (c) Automattic <developer.wordpress.com>
+ * MIT Licensed
+ */
+
+/**
+ * Module dependencies.
+ */
+
+var utils = require('../utils')
+  , nodes = require('../nodes')
+  , fs = require('fs')
+  , path = require('path')
+  , sax = require('sax');
+
+/**
+ * Initialize a new `Image` with the given `ctx` and `path.
+ *
+ * @param {Evaluator} ctx
+ * @param {String} path
+ * @api private
+ */
+
+var Image = module.exports = function Image(ctx, path) {
+  this.ctx = ctx;
+  this.path = utils.lookup(path, ctx.paths);
+  if (!this.path) throw new Error('failed to locate file ' + path);
+};
+
+/**
+ * Open the image for reading.
+ *
+ * @api private
+ */
+
+Image.prototype.open = function(){
+  this.fd = fs.openSync(this.path, 'r');
+  this.length = fs.fstatSync(this.fd).size;
+  this.extname = path.extname(this.path).slice(1);
+};
+
+/**
+ * Close the file.
+ *
+ * @api private
+ */
+
+Image.prototype.close = function(){
+  if (this.fd) fs.closeSync(this.fd);
+};
+
+/**
+ * Return the type of image, supports:
+ *
+ *  - gif
+ *  - png
+ *  - jpeg
+ *  - svg
+ *
+ * @return {String}
+ * @api private
+ */
+
+Image.prototype.type = function(){
+  var type
+    , buf = new Buffer(4);
+  
+  fs.readSync(this.fd, buf, 0, 4, 0);
+
+  // GIF
+  if (0x47 == buf[0] && 0x49 == buf[1] && 0x46 == buf[2]) type = 'gif';
+
+  // PNG
+  else if (0x50 == buf[1] && 0x4E == buf[2] && 0x47 == buf[3]) type = 'png';
+
+  // JPEG
+  else if (0xff == buf[0] && 0xd8 == buf[1]) type = 'jpeg';
+
+  // SVG
+  else if ('svg' == this.extname) type = this.extname;
+
+  return type;
+};
+
+/**
+ * Return image dimensions `[width, height]`.
+ *
+ * @return {Array}
+ * @api private
+ */
+
+Image.prototype.size = function(){
+  var type = this.type()
+    , width
+    , height
+    , buf
+    , offset
+    , blockSize
+    , parser;
+
+  function uint16(b) { return b[1] << 8 | b[0]; }
+  function uint32(b) { return b[0] << 24 | b[1] << 16 | b[2] << 8 | b[3]; } 
+
+  // Determine dimensions
+  switch (type) {
+    case 'jpeg':
+      buf = new Buffer(this.length);
+      fs.readSync(this.fd, buf, 0, this.length, 0);
+      offset = 4;
+      blockSize = buf[offset] << 8 | buf[offset + 1];
+
+      while (offset < this.length) {
+        offset += blockSize;
+        if (offset >= this.length || 0xff != buf[offset]) break;
+        // SOF0 or SOF2 (progressive)
+        if (0xc0 == buf[offset + 1] || 0xc2 == buf[offset + 1]) {
+          height = buf[offset + 5] << 8 | buf[offset + 6];
+          width = buf[offset + 7] << 8 | buf[offset + 8];
+        } else {
+          offset += 2;
+          blockSize = buf[offset] << 8 | buf[offset + 1];
+        }
+      }
+      break;
+    case 'png':
+      buf = new Buffer(8);
+      // IHDR chunk width / height uint32_t big-endian
+      fs.readSync(this.fd, buf, 0, 8, 16);
+      width = uint32(buf);
+      height = uint32(buf.slice(4, 8));
+      break;
+    case 'gif':
+      buf = new Buffer(4);
+      // width / height uint16_t little-endian
+      fs.readSync(this.fd, buf, 0, 4, 6);
+      width = uint16(buf);
+      height = uint16(buf.slice(2, 4));
+      break;
+    case 'svg':
+      offset = Math.min(this.length, 1024);
+      buf = new Buffer(offset);
+      fs.readSync(this.fd, buf, 0, offset, 0);
+      buf = buf.toString('utf8');
+      parser = sax.parser(true);
+      parser.onopentag = function(node) {
+        if ('svg' == node.name && node.attributes.width && node.attributes.height) {
+          width = parseInt(node.attributes.width, 10);
+          height = parseInt(node.attributes.height, 10);
+        }
+      };
+      parser.write(buf).close();
+      break;
+  }
+
+  if ('number' != typeof width) throw new Error('failed to find width of "' + this.path + '"');
+  if ('number' != typeof height) throw new Error('failed to find height of "' + this.path + '"');
+
+  return [width, height];
+};