source: Dev/branches/rest-dojo-ui/client/util/docscripts/cheat/floatup.js @ 256

dojo.provide("util.docscripts.cheat.floatup");
(function(d){
        
        function getMax(list){
                return Math.max.apply(Math, list)
        }

        function getMin(list){
                return Math.min.apply(Math, list);
        }

        function sum(ar){
                var t = 0;
                dojo.forEach(ar, function(v){ t += v });
                return t;
        }

        d.NodeList.prototype.floatup = function(selector){
                
                selector = selector || "> *";
                
                return this.forEach(function(n){
                   
                        var targets = d.query(selector, n),
                                colWidth = 254,
                                cols = 4,
                                useHighest = true,
                                numTargets = targets.length,
                                targetData = d.map(targets, function(n){ return [n, Math.floor(d.position(n).h)] });
                                heights = d.map(targetData, function(o){ return o[1]; }),
                                totalHeight = sum(heights),
                                // optimum is either the largest height or an average of the total height over the cols
                                avgHeight = totalHeight / cols,
                                maxHeight = getMax(heights),
                                optimumHeight = Math.max(avgHeight, maxHeight),
                                threshold = 75 // pixels to allow over/under optimum
                        ;

                        function inBounds(val){
                                // returns bool if passed height is within bounds of optimum
                                var upper = optimumHeight + threshold, lower = optimumHeight - threshold;
                                if(val == optimumHeight || (val <= upper && val >= lower)){
                                        return true;
                                }else{
                                        return false;
                                }
                        }

                        function getOptimumPositions(data, sizes, cols){
                                // return an Array of Arrays. Each item in the top level array will be an Array
                                //      of reference to the nodes that needs to be in the corresponding col

                                var col = 0;
                                var ret = new Array(cols + 1);
                                d.forEach(ret, function(i, idx){ ret[idx] = []; });

                                function colFromHeap(ar){
                                        //console.warn("making col", col, ar, sum(ar), sizes.length, data.length, ret[col]);
                                        d.forEach(ar, function(size){
                                                var idx = d.indexOf(sizes, size);
                                                if(~idx){
                                                        ret[col].push(data[idx][0]);
                                                        data.splice(idx, 1);
                                                        sizes.splice(idx, 1);
                                                }else{
                                                        // console.warn("ugh?", size, sizes, idx);
                                                }

                                        });
                                        // console.log(ret[col]);
                                        col++;
                                }
                                var pass = 0;

                                while(sizes.length){

                                        var heap = [];

                                        // first size
                                        heap.push(useHighest ? getMax(sizes) : sizes[0]);
                                        if(!inBounds(sum(heap))){
                                                d.forEach(sizes, function(size){
                                                        var now = sum(heap);
                                                        if(inBounds(now + size) || size < optimumHeight - now){
                                                                heap.push(size);
                                                        }
                                                });
                                        }

                                        colFromHeap(heap);
                                }

                                return ret;
                        }
                                
                        var stuff = getOptimumPositions(targetData, heights, cols);
                        d.forEach(stuff, function(col, idx){

                                var colNode = d.create("div", {
                                        style:{ width: colWidth + "px", "float":"left" }
                                }, n);

                                d.forEach(col, function(node){
                                        d.place(node, colNode);
                                });
                        });
                        
                });
                
        };

})(dojo);