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指定サイズ以内の画像幅、高さを算出、img要素にそのサイズを適用するスクリプト
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/** | |
* 指定サイズ以内の画像幅、高さを算出、 | |
* img要素にそのサイズを適用する | |
* | |
* 使い方: | |
* | |
* 例) 幅150px, 高さ200px以内で画像を表示する | |
* var img = document.createElement('img'); | |
* img.src = 'http://hoge.com/img/fuga.jpg'; | |
* imgResize.resize(img, 150, 200); | |
*/ | |
var imgResize = { | |
w_limit : null, | |
h_limit : null, | |
org_img : document.createElement('img'), | |
resize : function(img, w_limit, h_limit){ | |
if(! img) return; | |
this.org_img.src = img.src; | |
var w = this.org_img.width; | |
var h = this.org_img.height; | |
this.w_limit = w_limit; | |
this.h_limit = h_limit; | |
if(w <= w_limit && h <= h_limit) return img; | |
var size = this.getSize(w, h); | |
img.width = size.w; | |
img.height = size.h; | |
return img; // テスト用に戻す | |
}, | |
getSize : function(w, h){ | |
if(w > this.w_limit){ | |
width_ratio = this.w_limit/w; | |
w = this.w_limit; | |
h = h * width_ratio; | |
} | |
if(h > this.h_limit){ | |
height_ratio = this.h_limit/h; | |
h = this.h_limit; | |
w = w * height_ratio; | |
} | |
return { | |
w : Math.round(w), | |
h : Math.round(h) | |
}; | |
} | |
}; |
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