+/**
+ * Converts any valid CSS color (hex, rgb(), named color) to an RGB tuple.
+ *
+ * @param {!string} colorStr Any valid CSS color string.
+ * @return {{r:number,g:number,b:number}} Parsed RGB tuple.
+ * @private
+ */
+Dygraph.toRGB_ = function(colorStr) {
+ // TODO(danvk): cache color parses to avoid repeated DOM manipulation.
+ var div = document.createElement('div');
+ div.style.backgroundColor = colorStr;
+ div.style.visibility = 'hidden';
+ document.body.appendChild(div);
+ var rgbStr = window.getComputedStyle(div, null).backgroundColor;
+ document.body.removeChild(div);
+ var bits = /^rgb\((\d{1,3}),\s*(\d{1,3}),\s*(\d{1,3})\)$/.exec(rgbStr);
+ return {
+ r: parseInt(bits[1], 10),
+ g: parseInt(bits[2], 10),
+ b: parseInt(bits[3], 10)
+ };
+};
+
+/**
+ * Checks whether the browser supports the <canvas> tag.
+ * @param {HTMLCanvasElement=} opt_canvasElement Pass a canvas element as an
+ * optimization if you have one.
+ * @return {boolean} Whether the browser supports canvas.
+ */
+Dygraph.isCanvasSupported = function(opt_canvasElement) {
+ try {
+ var canvas = opt_canvasElement || document.createElement("canvas");
+ canvas.getContext("2d");
+ } catch (e) {
+ return false;
+ }
+ return true;
+};
+
+/**
+ * Parses the value as a floating point number. This is like the parseFloat()
+ * built-in, but with a few differences:
+ * - the empty string is parsed as null, rather than NaN.
+ * - if the string cannot be parsed at all, an error is logged.
+ * If the string can't be parsed, this method returns null.
+ * @param {string} x The string to be parsed
+ * @param {number=} opt_line_no The line number from which the string comes.
+ * @param {string=} opt_line The text of the line from which the string comes.
+ */
+Dygraph.parseFloat_ = function(x, opt_line_no, opt_line) {
+ var val = parseFloat(x);
+ if (!isNaN(val)) return val;
+
+ // Try to figure out what happeend.
+ // If the value is the empty string, parse it as null.
+ if (/^ *$/.test(x)) return null;
+
+ // If it was actually "NaN", return it as NaN.
+ if (/^ *nan *$/i.test(x)) return NaN;
+
+ // Looks like a parsing error.
+ var msg = "Unable to parse '" + x + "' as a number";
+ if (opt_line !== undefined && opt_line_no !== undefined) {
+ msg += " on line " + (1+(opt_line_no||0)) + " ('" + opt_line + "') of CSV.";
+ }
+ console.error(msg);
+
+ return null;
+};
+
+})();