gnome-shell/js/ui/separator.js

// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-

const Cairo = imports.cairo;
const Lang = imports.lang;
const St = imports.gi.St;

const HorizontalSeparator = new Lang.Class({
    Name: 'HorizontalSeparator',

    _init: function (params) {
        this.actor = new St.DrawingArea(params);
        this.actor.connect('repaint', Lang.bind(this, this._onRepaint));
    },

    _onRepaint: function(area) {
        let cr = area.get_context();
        let themeNode = area.get_theme_node();
        let [width, height] = area.get_surface_size();
        let margin = themeNode.get_length('-margin-horizontal');
        let gradientHeight = themeNode.get_length('-gradient-height');
        let startColor = themeNode.get_color('-gradient-start');
        let endColor = themeNode.get_color('-gradient-end');

        let gradientWidth = (width - margin * 2);
        let gradientOffset = (height - gradientHeight) / 2;
        let pattern = new Cairo.LinearGradient(margin, gradientOffset, width - margin, gradientOffset + gradientHeight);
        pattern.addColorStopRGBA(0, startColor.red / 255, startColor.green / 255, startColor.blue / 255, startColor.alpha / 255);
        pattern.addColorStopRGBA(0.5, endColor.red / 255, endColor.green / 255, endColor.blue / 255, endColor.alpha / 255);
        pattern.addColorStopRGBA(1, startColor.red / 255, startColor.green / 255, startColor.blue / 255, startColor.alpha / 255);
        cr.setSource(pattern);
        cr.rectangle(margin, gradientOffset, gradientWidth, gradientHeight);
        cr.fill();
        cr.$dispose();
    }
});