jquery要素相対位置決めコード

 
  
/** 
  
*jQuery rposition 
  
*fix:       
  
*rel：        
  
*options:{},align:    ;vlign:    ;xleft:     ;xleft:     ;adjust:          ;rwindow:       (align&vlign center        ); 
  
*/ 
  
(function(win,$){ 
  
win.rposition=function(fix,rel,options){ 
  
var rectLeft,rectTop,rectH=fix.outerHeight(),rectW=fix.outerWidth(),wh=$(window).height(),ww=$(window).width(), 
  
sT=$(document).scrollTop(),sL=$(document).scrollLeft(), 
  
defaults={ 
  
align:"left", 
  
vlign:"top", 
  
xleft:0, 
  
xtop:0, 
  
adjust:true, 
  
rwindow:false 
  
}, 
  
options = $.extend(defaults, options); 
  
var rectRel={ 
  
l:$(rel).offset().left, 
  
t:$(rel).offset().top, 
  
w:$(rel).outerWidth(), 
  
h:$(rel).outerHeight() 
  
}; 
  
switch(options.align){ 
  
case "left": 
  
rectLeft=rectRel.l;break; 
  
case "right": 
  
rectLeft=rectRel.l+rectRel.w;break; 
  
case "center": 
  
rectLeft=rectRel.l+rectRel.w/2;break; 
  
case "rleft": 
  
rectLeft=rectRel.l-rectW;break; 
  
default: 
  
rectLeft=rectRel.l; 
  
}; 
  
switch(options.vlign){ 
  
case "top": 
  
rectTop=rectRel.t;break; 
  
case "center": 
  
rectTop=rectRel.t+rectRel.h/2;break; 
  
case "vbottom": 
  
rectTop=rectRel.t-rectH; break; 
  
case "bottom": 
  
default: 
  
rectTop=rectRel.t+rectRel.h; 
  
}; 
  
if(options.rwindow){ 
  
if(options.align=="center")rectLeft=(ww-rectW)/2+sL; 
  
if(options.vlign=="center")rectTop=(wh-rectH)/2+sT; 
  
}; 
  
if(options.adjust){ 
  
if(rectLeft+rectW>ww+sL){rectLeft-=(rectLeft+rectW)-(ww+sL)} 
  
if(rectTop+rectH>wh+sT){rectTop=rectRel.t-rectH;} 
  
}; 
  
$(fix).css({"left":rectLeft+options.xleft,"top":rectTop+options.xtop}); 
  
} 
  
})(window,jQuery)