Pinterest風グリッドレイアウトを作ってみよう：jQuery×HTML5×CSS3を真面目に勉強（3）（3/4 ページ）

;(function($) {
    $.fn.pinterestGrid = function(options) {
        elements = $(this);
        winObject = $(window);
        opts = $.extend({}, $.fn.pinterestGrid.defaults, options);
 
        setCol();
        applyPinterestGrid();
 
        winObject.unbind('resize').resize(function() {
            var containerWidth;
            var winWidth = winObject.width() - opts.offsetX * 2;
            if(winWidth < colwidth * numOfCol) {
                setCol();
                containerWidth =  colwidth * (numOfCol - 1);
            } else if (winWidth > colwidth * (numOfCol + 1)) {
                setCol();
                containerWidth =  colwidth * (numOfCol + 1);
            }
            if (containerWidth) {
                var current = elements.width();
                elements.width(colwidth * numOfCol);
                applyPinterestGrid();
            }
        });
 
        return this;
    }
 
    // デフォルトオプション
    $.fn.pinterestGrid.defaults = {
        offsetX: 5,
        offsetY: 5,
        gridElement: 'div'
    };
 
    var elements,
        winObject,
        numOfCol,
        opts = {},
        colwidth,
        gridArray = [];
 
    //IE用にArray.indexOfメソッドを追加
    if (!Array.prototype.indexOf) {
        Array.prototype.indexOf = function(elt /*, from*/) {
            var len = this.length >>> 0;
 
            var from = Number(arguments[1]) || 0;
            from = (from < 0) ? Math.ceil(from) : Math.floor(from);
            if (from < 0) {
                from += len;
            }
 
            for (; from < len; from++) {
                if (from in this && this[from] === elt) {
                    return from;
                }
            }
            return -1;
        };
    }
 
    // 初期化
    function applyPinterestGrid() {
        createEmptyGridArray();
 
        elements.children(opts.gridElement).each(function(index) {
            setPosition($(this));
        });
 
        //最後にエレメントの高さを設定
        var heightarr = getHeightArray(0, gridArray.length);
        elements.height(heightarr.max + opts.offsetY);
    }
 
    // カラムの数とwidthを設定する
    function setCol() {
        colwidth = $(opts.gridElement).outerWidth() + opts.offsetX * 2;
        numOfCol = Math.floor((winObject.width() - opts.offsetX * 2) / colwidth);
    }
 
    //空のgridArrayを作成
    function createEmptyGridArray() {
        //最初にgridArrayを初期化
        gridArray = [];
        for(var i=0; i<numOfCol; i++) {
            pushGridArray(i, 0, 1, -opts.offsetY);
        }
    }
 
    //gridArrayに新しいgridを追加
    function pushGridArray(x, y, size, height) {
        //define grid object based on grid width
        for(var i=0; i<size; i++) {
            var grid = [];
            grid.x = x + i;
            grid.size = size;
            grid.endY = y + height + opts.offsetY*2;
 
            gridArray.push(grid);
        }
    }
 
    //gridArrayからgridを削除
    function removeGridArray(x, size) {
        for(var i=0; i<size; i++) {
            //remove grid beside
            var index = getGridIndex(x+i);
            gridArray.splice(index, 1);
        }
    }
 
    // gridのx値を基準にgridのインデックスを検索
    function getGridIndex(x) {
        for(var i=0; i<gridArray.length; i++) {
            var obj = gridArray[i];
            if(obj.x == x) {
                return i;
            }
        }
    }
 
    //gridのx値とサイズに基づいてgridArrayにある高さの最小値と最大値、最小値のあるx値を取得
    //retrun min and max height
    function getHeightArray(x, size) {
        var heightArray = [];
        var temps = [];
        for(var i=0; i<size; i++) {
            var idx = getGridIndex(x+i);
            temps.push(gridArray[idx].endY);
        }
        heightArray.min = Math.min.apply(Math, temps);
        heightArray.max = Math.max.apply(Math, temps);
        heightArray.x = temps.indexOf(heightArray.min);
 
        return heightArray;
    }
 
    //gridが配置されるx座標値、y座標値を取得
    function getGridPosition() {
        var pos = [];
        var tempHeight = getHeightArray(0, gridArray.length);
        pos.x = tempHeight.x;
        pos.y = tempHeight.min;
        return pos;
    }
 
    //gridを配置
    function setPosition(grid) {
        //check grid size
        if(!grid.data('size') || grid.data('size') < 0) {
            grid.data('size', 1);
        }
 
        //define grid data
        var pos = getGridPosition();
        var gridWidth = colwidth * grid.data('size') - (grid.outerWidth() - grid.width());
 
        //update style first before get grid height
        grid.css({
            'left': pos.x * colwidth,
            'top': pos.y,
            'position': 'absolute'
        });
 
        var gridHeight = grid.outerHeight();
 
        //gridArrayを新しいgridで更新
        removeGridArray(pos.x, grid.data('size'));
        pushGridArray(pos.x, pos.y, grid.data('size'), gridHeight);
    }
 
})(jQuery);

$(function() {
    $(window).on('load', function() {
        $('#container').pinterestGrid({
            offsetX: 8,
            offsetY: 8,
            gridElement: '.grid'
        });
    });
});