/**
 * m5noticeDisplay
 *
 * @version   1.1
 * @author    nori (norimania@gmail.com)
 * @copyright 5509 (http://5509.me/)
 * @license   The MIT License
 * @link      http://5509.me/log/m5noticedisplay
 *
 * @modified  2011/03/17 11:43:32.
 */

;(function($) {
    
    $.fn.m5noticeDisplay = function(options) {
        var conf = $.extend({
                noticeBlock : "#noticeBlock",
                animateIn   : "slideDown", // or fadeIn, slideDown
                animateOut  : "slideUp", // or fadeOut, slideUp
                duration    : "600",
                easing      : "swing",
                callback    : function() {}        
            }, options),
            $this = this,
            chkClientSize = function() {
                return {
                    y: $("html").attr("clientHeight")
                }
            },
            chkScrollPos = function() {
                return {
                    y: document.body.scrollTop || document.documentElement.scrollTop
                }
            },
            clientSize = chkClientSize(),
            scrollPos = chkScrollPos(),
            $thisContent = $this.html(),
            noticeBlock = $(conf.noticeBlock),
            noticeElmChkOffset = { top: 0, left: 0 },
            noticeElmChk = $("<span class=\"noticeElmChk\">.</span>")
                .css({
                    height  : 1,
                    width   : 1,
                    opacity : 0
                }),
            noticeBlockShow = function() {
                if ( noticeBlock.is(":visible") ) return false;
                if ( conf.animateIn !== "slide" ) {
                    noticeBlock
                        .stop(true, true)
                        [conf.animateIn](conf.duration, conf.easing, conf.callback);
                } else {
                    noticeBlock
                        .show()
                        .css("top", -noticeBlockSize.height)
                        .animate({
                            top      : 0
                        }, {
                            queue    : false,
                            duration : conf.duration,
                            easing   : conf.easing
                        });
                }
            },
            noticeBlockHide = function() {
                if ( noticeBlock.is(":visible") && !noticeBlock.is(":animated") ) {
                    if ( conf.animateOut !== "slide" ) {
                        noticeBlock
                            .stop(true, true)
                            [conf.animateOut](conf.duration, conf.callback);
                    } else {
                        noticeBlock
                            .animate({
                                top      : -noticeBlockSize.height
                            }, {
                                queue    : false,
                                duration : conf.duration,
                                easing   : conf.easing,
                                complete : function() { noticeBlock.hide() }
                            });
                    }
                }
            },
            displayNoticeBlock = function() {
                if ( noticeElmChkOffset.top < (clientSize.y + scrollPos.y) ) {
                    noticeBlockShow();
                } else {
                    noticeBlockHide();
                }
            };
        
        // 対象要素の表示位置チェック用の要素追加
        $this
            .html("")
            .append(
                noticeElmChk,
                $thisContent
            )
            
        noticeElmChkOffset = noticeElmChk.offset();
        
        // サイズを取得して非表示にしておく
        $(conf.noticeBlock).show();
        var noticeBlockSize = {
            width  : noticeBlock.attr("offsetWidth"),
            height : noticeBlock.attr("offsetHeight")
        }
        $(conf.noticeBlock).hide();
        
        // トリガーのバインド
        $(window)
            .scroll(function() {
                scrollPos = chkScrollPos();
                displayNoticeBlock();
            })
            .resize(function() {
                clientSize = chkClientSize();
                displayNoticeBlock();
            })
    }

}(jQuery));