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隠し要素の幅と高さが取得できない問題を解決する方法

小云云オリジナル: 2018-01-23 13:13:491745ブラウズ

実際の開発では、非表示要素の幅と高さを取得する必要が生じる場合があります。ここで説明する非表示要素は、表示が none に設定されている要素です。この記事では、参考値となるhidden要素(display:none)の幅(width)と高さ(height)が取得できない場合の解決方法を中心に紹介します。以下のエディターで見てみましょう。皆さんのお役に立てれば幸いです。

jQuery Actual Plugin プラグインを使用して完成させることができます。ソースコードは次のとおりです:

;( function ( $ ){
 $.fn.addBack = $.fn.addBack || $.fn.andSelf;
 $.fn.extend({
  actual : function ( method, options ){
   // check if the jQuery method exist
   if( !this[ method ]){
    throw &#39;$.actual => The jQuery method "&#39; + method + &#39;" you called does not exist&#39;;
   }
   var defaults = {
    absolute   : false,
    clone     : false,
    includeMargin : false,
    display    : &#39;block&#39;
   };
   var configs = $.extend( defaults, options );
   var $target = this.eq( 0 );
   var fix, restore;
   if( configs.clone === true ){
    fix = function (){
     var style = &#39;position: absolute !important; top: -1000 !important; &#39;;
     // this is useful with css3pie
     $target = $target.
      clone().
      attr( &#39;style&#39;, style ).
      appendTo( &#39;body&#39; );
    };
    restore = function (){
     // remove DOM element after getting the width
     $target.remove();
    };
   }else{
    var tmp  = [];
    var style = &#39;&#39;;
    var $hidden;
    fix = function (){
     // get all hidden parents
     $hidden = $target.parents().addBack().filter( &#39;:hidden&#39; );
     style  += &#39;visibility: hidden !important; display: &#39; + configs.display + &#39; !important; &#39;;
     if( configs.absolute === true ) style += &#39;position: absolute !important; &#39;;
     // save the origin style props
     // set the hidden el css to be got the actual value later
     $hidden.each( function (){
      // Save original style. If no style was set, attr() returns undefined
      var $this   = $( this );
      var thisStyle = $this.attr( &#39;style&#39; );
      tmp.push( thisStyle );
      // Retain as much of the original style as possible, if there is one
      $this.attr( &#39;style&#39;, thisStyle ? thisStyle + &#39;;&#39; + style : style );
     });
    };
    restore = function (){
     // restore origin style values
     $hidden.each( function ( i ){
      var $this = $( this );
      var _tmp = tmp[ i ];

      if( _tmp === undefined ){
       $this.removeAttr( &#39;style&#39; );
      }else{
       $this.attr( &#39;style&#39;, _tmp );
      }
     });
    };
   }
   fix();
   // get the actual value with user specific methed
   // it can be &#39;width&#39;, &#39;height&#39;, &#39;outerWidth&#39;, &#39;innerWidth&#39;... etc
   // configs.includeMargin only works for &#39;outerWidth&#39; and &#39;outerHeight&#39;
   var actual = /(outer)/.test( method ) ?
    $target[ method ]( configs.includeMargin ) :
    $target[ method ]();
   restore();
   // IMPORTANT, this plugin only return the value of the first element
   return actual;
  }
 });
})(jQuery);

もちろん、モジュール開発をサポートしたい場合は、ファイルを直接使用できます。公式ウェブサイトからダウンロードでき、ソースコードも掲載されています:

;( function ( factory ) {
if ( typeof define === &#39;function&#39; && define.amd ) {
  // AMD. Register module depending on jQuery using requirejs define.
  define( [&#39;jquery&#39;], factory );
} else {
  // No AMD.
  factory( jQuery );
}
}( function ( $ ){
 $.fn.addBack = $.fn.addBack || $.fn.andSelf;
 $.fn.extend({
  actual : function ( method, options ){
   // check if the jQuery method exist
   if( !this[ method ]){
    throw &#39;$.actual => The jQuery method "&#39; + method + &#39;" you called does not exist&#39;;
   }
   var defaults = {
    absolute   : false,
    clone     : false,
    includeMargin : false,
    display    : &#39;block&#39;
   };
   var configs = $.extend( defaults, options );
   var $target = this.eq( 0 );
   var fix, restore;
   if( configs.clone === true ){
    fix = function (){
     var style = &#39;position: absolute !important; top: -1000 !important; &#39;;
     // this is useful with css3pie
     $target = $target.
      clone().
      attr( &#39;style&#39;, style ).
      appendTo( &#39;body&#39; );
    };
    restore = function (){
     // remove DOM element after getting the width
     $target.remove();
    };
   }else{
    var tmp  = [];
    var style = &#39;&#39;;
    var $hidden;
    fix = function (){
     // get all hidden parents
     $hidden = $target.parents().addBack().filter( &#39;:hidden&#39; );
     style  += &#39;visibility: hidden !important; display: &#39; + configs.display + &#39; !important; &#39;;
     if( configs.absolute === true ) style += &#39;position: absolute !important; &#39;;
     // save the origin style props
     // set the hidden el css to be got the actual value later
     $hidden.each( function (){
      // Save original style. If no style was set, attr() returns undefined
      var $this   = $( this );
      var thisStyle = $this.attr( &#39;style&#39; );
      tmp.push( thisStyle );
      // Retain as much of the original style as possible, if there is one
      $this.attr( &#39;style&#39;, thisStyle ? thisStyle + &#39;;&#39; + style : style );
     });
    };
    restore = function (){
     // restore origin style values
     $hidden.each( function ( i ){
      var $this = $( this );
      var _tmp = tmp[ i ];

      if( _tmp === undefined ){
       $this.removeAttr( &#39;style&#39; );
      }else{
       $this.attr( &#39;style&#39;, _tmp );
      }
     });
    };
   }
   fix();
   // get the actual value with user specific methed
   // it can be &#39;width&#39;, &#39;height&#39;, &#39;outerWidth&#39;, &#39;innerWidth&#39;... etc
   // configs.includeMargin only works for &#39;outerWidth&#39; and &#39;outerHeight&#39;
   var actual = /(outer)/.test( method ) ?
    $target[ method ]( configs.includeMargin ) :
    $target[ method ]();
   restore();
   // IMPORTANT, this plugin only return the value of the first element
   return actual;
  }
 });
}));

コード例:

//get hidden element actual width
$(&#39;.hidden&#39;).actual(&#39;width&#39;);
//get hidden element actual innerWidth
$(&#39;.hidden&#39;).actual(&#39;innerWidth&#39;);
//get hidden element actual outerWidth
$(&#39;.hidden&#39;).actual(&#39;outerWidth&#39;);
//get hidden element actual outerWidth and set the `includeMargin` argument
$(&#39;.hidden&#39;).actual(&#39;outerWidth&#39;,{includeMargin:true});
//get hidden element actual height
$(&#39;.hidden&#39;).actual(&#39;height&#39;);
//get hidden element actual innerHeight
$(&#39;.hidden&#39;).actual(&#39;innerHeight&#39;);
//get hidden element actual outerHeight
$(&#39;.hidden&#39;).actual(&#39;outerHeight&#39;);
// get hidden element actual outerHeight and set the `includeMargin` argument
$(&#39;.hidden&#39;).actual(&#39;outerHeight&#39;,{includeMargin:true});
//if the page jumps or blinks, pass a attribute &#39;{ absolute : true }&#39;
//be very careful, you might get a wrong result depends on how you makrup your html and css
$(&#39;.hidden&#39;).actual(&#39;height&#39;,{absolute:true});
// if you use css3pie with a float element
// for example a rounded corner navigation menu you can also try to pass a attribute &#39;{ clone : true }&#39;
// please see demo/css3pie in action
$(&#39;.hidden&#39;).actual(&#39;width&#39;,{clone:true});

隠し要素の幅と高さが取得できない問題を解決する方法

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