(function($) {

    $.registerLiquidCanvasPlugin({
        name: "rect",
        paint: function(area) {
            area.ctx.beginPath();
            area.ctx.rect(0, 0, area.width, area.height);
            area.ctx.closePath();
            if (this.action) this.action.paint(area);  // for chaining
        }
    });

    $.registerLiquidCanvasPlugin({
        name: "roundedRect",
        defaultOpts: { radius:20 },
        paint: function(area) {
            var ctx = area.ctx;
            var opts = this.opts;
            ctx.beginPath();
            ctx.moveTo(0, opts.radius);
            ctx.lineTo(0, area.height - opts.radius);
            ctx.quadraticCurveTo(0, area.height, opts.radius, area.height);
            ctx.lineTo(area.width - opts.radius, area.height);
            ctx.quadraticCurveTo(area.width, area.height, area.width, area.height - opts.radius);
            ctx.lineTo(area.width, opts.radius);
            ctx.quadraticCurveTo(area.width, 0, area.width - opts.radius, 0);
            ctx.lineTo(opts.radius, 0);
            ctx.quadraticCurveTo(0, 0, 0, opts.radius);
            ctx.closePath();
            if (this.action) this.action.paint(area);  // for chaining
        },
        shrink: function(area, steps) {
            this.defaultShrink(area, steps);
            this.opts.radius -= steps;
        }
    });

    // This is a Liquid Canvas Plugin
    $.registerLiquidCanvasPlugin({
        name: "fill",
        defaultOpts: { color:"#aaa" },
        paint: function(area) {
            area.ctx.fillStyle = this.opts.color;
            this.action.paint(area);
            area.ctx.fill();
        }
    });

    $.registerLiquidCanvasPlugin({  // hmmmmmmm, no rotation? no width??? ah patterns!
        name: "image",
        defaultOpts: { url:"http://www.ruzee.com/files/liquid-canvas-image.png" },
        paint: function(area) {
            var image = new Image();
            image.src = this.opts.url;
            image.onload = function() { 
                area.ctx.drawImage(this, 0, 0); 
            };
        }
    });

    // This is a Liquid Canvas Plugin
    $.registerLiquidCanvasPlugin({
        name: "gradient",
        defaultOpts: { from: "#fff", to:"#666" },
        paint: function(area) {
            var grad = area.ctx.createLinearGradient(0, 0, 0, area.height);
            grad.addColorStop(0, this.opts.from);
            grad.addColorStop(1, this.opts.to);
            area.ctx.fillStyle = grad;
            this.action.paint(area);
            area.ctx.fill();
        }
    });
    // End of Liquid Canvas Plugin

    $.registerLiquidCanvasPlugin({
        name: "shadow",
        defaultOpts: { width:3, color:'#000', shift:2, alpha:0.8 },
        paint: function(area) {
            var sw = this.opts.width;

            area.ctx.fillStyle = this.opts.color; 
            area.ctx.globalAlpha = this.opts.alpha;
            //area.ctx.globalAlpha = 1.0 / sw;
            for (var s = 0; s < sw; ++s) {
                this.action.paint(area);
                area.ctx.fill();
                this.action.shrink(area, 1);
            }
            area.ctx.globalAlpha = 1;
            area.ctx.translate(0, -this.opts.shift);
        }
    });

    $.registerLiquidCanvasPlugin({
        name: "border",
        defaultOpts: { color:'#8f4', width:3 },
        paint: function(area) {
            var bw = this.opts.width;
            area.ctx.strokeStyle = this.opts.color;
            area.ctx.lineWidth = bw;
            this.action.shrink(area, bw / 2);
            this.action.paint(area);
            area.ctx.stroke();
            this.action.shrink(area, bw / 2);
        }
    });

    $.registerLiquidCanvasPlugin({
        name: "partialRoundedRect",
        defaultOpts: { radius:10, tl:"yes", tr:"yes", bl:"yes", br:"yes" },
        paint: function(area) {
            var ctx = area.ctx;
            var opts = this.opts;
            ctx.beginPath();
            ctx.moveTo(0, opts.radius);
            if (opts.bl == "yes") {
                ctx.lineTo(0, area.height - opts.radius);
                ctx.quadraticCurveTo(0, area.height, opts.radius, area.height);
            }
            else {
                ctx.lineTo(0, area.height);
            }
            if (opts.br == "yes") {
                ctx.lineTo(area.width - opts.radius, area.height);
                ctx.quadraticCurveTo(area.width, area.height, area.width, area.height - opts.radius);
            }
            else {
                ctx.lineTo(area.width, area.height);
            }
            if (opts.tr == "yes") {
                ctx.lineTo(area.width, opts.radius);
                ctx.quadraticCurveTo(area.width, 0, area.width - opts.radius, 0);
            }
            else {
                ctx.lineTo(area.width, 0);
            }
            if (opts.tl == "yes") {
                ctx.lineTo(opts.radius, 0);
                ctx.quadraticCurveTo(0, 0, 0, opts.radius);
            }
            else {
                ctx.lineTo(0, 0);
                ctx.lineTo(0, opts.radius);
            }
            ctx.closePath();
            if (this.action) this.action.paint(area); // for chaining
        }
    });  

})(jQuery);