Simplify nameToRGBColor() further: No need to create function in its own scope, simply use the inject scope to contain cache and context variables.

This commit is contained in:
Jürg Lehni 2011-03-13 22:55:20 +01:00
parent 21aa12271e
commit a842b5faa6

View file

@ -15,38 +15,38 @@
*/ */
var Color = this.Color = Base.extend(new function() { var Color = this.Color = Base.extend(new function() {
var nameToRGBColor = new function() {
var cache = {}, var colorCache = {},
context; colorContext;
return function(name) {
var color = cache[name]; function nameToRGBColor(name) {
if (!color) { var color = colorCache[name];
// Use a 1x1 Canvas to draw to with the given name and then if (!color) {
// retrieve the rgb values from. Build a cache for all these // Use a 1x1 Canvas to draw to with the given name and then
// colors on a per use basis. // retrieve the rgb values from. Build a cache for all these
if (!context) { // colors on a per use basis.
var canvas = CanvasProvider.getCanvas(Size.create(1, 1)); if (!colorContext) {
context = canvas.getContext('2d'); var canvas = CanvasProvider.getCanvas(Size.create(1, 1));
context.globalCompositeOperation = 'copy'; colorContext = canvas.getContext('2d');
} colorContext.globalCompositeOperation = 'copy';
// Set the fillStyle of the context to the passed name }
// and fill the canvas with it. Then retrieve the first pixel: // Set the fillStyle of the context to the passed name
context.fillStyle = name; // and fill the canvas with it. Then retrieve the first pixel:
context.fillRect(0, 0, 1, 1); colorContext.fillStyle = name;
var data = context.getImageData(0, 0, 1, 1).data, colorContext.fillRect(0, 0, 1, 1);
rgb = []; var data = colorContext.getImageData(0, 0, 1, 1).data,
for (var i = 0; i < 3; i++) rgb = [];
rgb[i] = data[i] / 255; for (var i = 0; i < 3; i++)
// If the name wasn't found, rgb is [0, 0, 0] rgb[i] = data[i] / 255;
if (rgb.join('') == '000' && name != 'black') { // If the name wasn't found, rgb is [0, 0, 0]
throw new Error('The named color "' + name if (rgb.join('') == '000' && name != 'black') {
+ '" does not exist.'); throw new Error('The named color "' + name
} else { + '" does not exist.');
color = cache[name] = RGBColor.read(rgb); } else {
} color = colorCache[name] = RGBColor.read(rgb);
} }
return color;
} }
return color;
} }
function hexToRGBColor(string) { function hexToRGBColor(string) {