Sample code of vispyjs

vispy.js

require(["widgets/js/widget"], function(WidgetManager){
    var Widget = IPython.DOMWidgetView.extend({
        render: function(){
            this.$canvas = $('<canvas />')
                .attr('id', 'canvas')
                .attr('tabindex', '1')
                .appendTo(this.$el);
        },

        events: {
            'mousemove': 'mouse_move',
        },

        mouse_move: function(e) {
            // Generate and send event 
            var event = gen_mouse_event(this.c, e, "mouse_move");
            if(pos[0] != last_pos[0] || pos[1] != last_pos[1])
                this.send(event);
        },

        // Update, whenever value attribute of our widget changes
        update : function(){
            var img_str = this.model.get("value");
            var img = new Image();
            img.src = "data:image/png;base64," + img_str;
            this.canvas2d.drawImage(img, 0, 0);
        },
    })
    WidgetManager.register_widget_view("Widget", Widget);
});