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Mini Shell
Mini Shell
/**
* Module dependencies.
*/
var stylus = require('stylus'),
Canvas = require('canvas'),
nodes = stylus.nodes,
utils = stylus.utils;
/**
* Expose `Gradient`.
*/
exports = module.exports = Gradient;
/**
* Create a new `Gradient` node with the given `size`
* and `start` position.
*
* @param {Number} size
* @param {String|Ident|Literal} start
* @return {Gradient}
* @api public
*/
exports.create = function(size, start){
utils.assertType(size, 'unit', 'size');
utils.assertString(start, 'start');
return new Gradient(size.val, start.string);
};
/**
* Add color stop to `grad`.
*
* @param {Gradient} grad
* @param {Unit} pos
* @param {HSLA|RGBA} color
* @return {Null}
* @api public
*/
exports.addColorStop = function(grad, pos, color){
utils.assertType(grad, 'gradient', 'grad');
utils.assertType(pos, 'unit', 'pos');
utils.assertColor(color, 'color');
grad.addColorStop(pos.val / 100, color.rgba.toString());
return nodes.null;
};
/**
* Return the data URI for `grad`.
*
* @param {Gradient} grad
* @return {String}
* @api public
*/
exports.dataURL = function(grad){
utils.assertType(grad, 'gradient');
return new nodes.String(grad.toDataURL());
};
/**
* Initialize a new `Gradient` node with the given `size`
* and `start` position.
*
* @param {Number} size
* @param {String} start
* @api private
*/
function Gradient(size, start) {
this.size = size;
this.canvas = new Canvas(1, 1);
this.setStartPosition(start);
this.ctx = this.canvas.getContext('2d');
this.grad = this.ctx.createLinearGradient(
this.from[0], this.from[1],
this.to[0], this.to[1]);
}
/**
* Inspect the gradient.
*
* @return {String}
* @api private
*/
Gradient.prototype.toString = function(){
return 'Gradient(' + this.size + 'px ' + this.stops.map(function(stop){
return stop[0] + ' ' + stop[1];
}).join(', ') + ')';
};
/**
* Set `start` position.
*
* @param {String} start
* @api private
*/
Gradient.prototype.setStartPosition = function(start){
var size = this.size,
canvas = this.canvas;
switch (start) {
case 'top':
canvas.height = size;
this.from = [canvas.width / 2, 0];
this.to = [canvas.width / 2, canvas.height];
break;
case 'bottom':
canvas.height = size;
this.from = [canvas.width / 2, canvas.height];
this.to = [canvas.width / 2, 0];
break;
case 'left':
canvas.width = size;
this.from = [0, 0];
this.to = [canvas.width, canvas.height];
break;
case 'right':
canvas.width = size;
this.from = [canvas.width, canvas.height];
this.to = [0, 0];
break;
default:
throw new Error('invalid start position "' + start + '"');
}
};
/**
* Add color stop `pos` / `color`.
*
* @param {Number} pos
* @param {String} color
* @api private
*/
Gradient.prototype.addColorStop = function(pos, color){
this.grad.addColorStop(pos, color);
};
/**
* Return data URI string.
*
* @return {String}
* @api private
*/
Gradient.prototype.toDataURL = function(){
var canvas = this.canvas,
ctx = this.ctx;
ctx.fillStyle = this.grad;
ctx.fillRect(0, 0, canvas.width, canvas.height);
return canvas.toDataURL();
};
/**
* Inherit from `nodes.Node.prototype`.
*/
Gradient.prototype.__proto__ = nodes.Node.prototype;
Zerion Mini Shell 1.0