eliace/ergo-js

Ergo.alias('includes:list-navigator', {

    _construct: function(o) {

        var _w = this;

        this.navigator = {

            get selected() {
                return this.__sel;
            },

            set selected(item) {
                if(this.__sel)
                    this.__sel.states.unset('selected');

                this.__sel = item;

                if(this.__sel)
                    this.__sel.states.set('selected');
            },




            next: function() {
                var item = this.selected ? this.selected.next() : null;

                if(item == null) {
                    item = _w.items.first();
                }

                while(item) {
                    if(item._rendered)
                        break;
                    item = item.next();
                }

                this.scroll_to(item);

                this.selected = item;
            },

            prev: function() {
                var item = this.selected ? this.selected.prev() : null;

                if(item == null) {
                    item = _w.items.last();
                }

                while(item) {
                    if(item._rendered)
                        break;
                    item = item.prev();
                }

                this.scroll_to(item);

                this.selected = item;
            },


            scroll_to: function(item) {

                if(!item)    return;

                var h = _w.el.height();
                var s_top = _w.el.scrollTop();
                var hi = item.el.outerHeight();
                var p = item.el.position().top;
                if( p + hi > h) {
                    _w.el.scrollTop( s_top + p + hi - h );
                }
                else if ( p < 0) {
                    _w.el.scrollTop( s_top + p );
                }

            }

        };


    }


});