javascript 图片裁剪技巧解读

  学php gd库 看到有图片裁剪 正好整一个 嗯 其实挺简单的

  php版

  

复制代码 代码如下:

  <!DOCTYPE html>

  <html xmlns="http://www.w3.org/1999/xhtml">

  <head>

  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

  <title>Resize</title>

  <style type="text/css">

  *{ padding:0; margin:0;}

  ul{ list-style-type:none; overflow:hidden; zoom:1; width:1000px; margin:30px auto; }

  li{ float:left; width:500px;}

  #container{width:480px; height:480px; margin:0 auto; border:1px solid #999; position:relative;background:url(http://images.cnblogs.com/cnblogs_com/wtcsy/192373/r_xx.jpg);}

  #container .block{height:100px; width:100px; border:1px solid #000000; position:absolute; left:50px; top:50px; background:#fff;filter:alpha(opacity=30);opacity:0.3; cursor:move;}

  .rRightDown,.rLeftDown,.rLeftUp,.rRightUp,.rRight,.rLeft,.rUp,.rDown{

  position:absolute;background:#f00;width:6px;height:6px;z-index:5;font-size:0;}

  .rLeftDown,.rRightUp{cursor:ne-resize;}

  .rRightDown,.rLeftUp{cursor:nw-resize;}

  .rRight,.rLeft{cursor:e-resize;}

  .rUp,.rDown{cursor:n-resize;}

  .rRightDown{ bottom:-3px; right:-3px;}

  .rLeftDown{ bottom:-3px; left:-3px;}

  .rRightUp{ top:-3px; right:-3px;}

  .rLeftUp{ top:-3px; left:-3px;}

  .rRight{ right:-3px; top:50%}

  .rLeft{ left:-3px; top:50%}

  .rUp{ top:-3px; left:50%}

  .rDown{ bottom:-3px; left:50%}

  #imgC{ border:1px solid #CCC; width:0; height:0; margin:0 auto;background:url(http://images.cnblogs.com/cnblogs_com/wtcsy/192373/r_xx.jpg);}

  </style>

  </head>

  <body>

  <ul>

  <li>

  <div id="container"></div>

  </li>

  <li>

  <div id="imgC"></div>

  </li>

  </ul>

  <script type="text/javascript" src="http://common.cnblogs.com/script/jquery.js"></script>

  <script type="text/javascript">

  (function(){

  var dBody = document.body,

  dDoc = document.documentElement;

  var clip = function(options){

  this.init.call(this,options);

  }

  clip.prototype = {

  options :{

  moveCallBack : function(){},

  className : "block"

  },

  init : function(options){

  $.extend(this,this.options,options||{});

  if(!this.container || !this.imgC){

  return;

  }

  this.container = $(this.container);

  var self = this;

  this.block = $('<div class="'+this.className+'">\

  <div action="rightDown" class="rRightDown"></div>\

  <div action="leftDown" class="rLeftDown"></div>\

  <div action="rightUp" class="rRightUp"></div>\

  <div action="leftUp" class="rLeftUp"></div>\

  <div action="right" class="rRight"></div>\

  <div action="left" class="rLeft"></div>\

  <div action="up" class="rUp"></div>\

  <div action="down" class="rDown" ></div>\

  </div>')

  .bind("mousedown.r",function(e){self.start(e)})

  .appendTo(this.container[0]);

  this.setImg();

  },

  setImg : function(){

  var block = this.block;

  this.imgC.css({

  height: block.height(),

  width : block.width(),

  "background-position" : "-"+block.css("left")+" -"+block.css("top")

  });

  },

  start : function(e){

  var $elem = $(e.target),

  block = this.block,

  self = this,

  move = false,

  container = this.container,

  action = $elem.attr("action");

  //这个 每次都要计算 基本dom结构的改变 浏览器的缩放 都会让里面的值发生改变

  this.offset = $.extend({height:container.height(),width:container.width()},container.offset());

  this.blockOriginal = {height:block.height(),width:block.width(),left:parseInt(block.css("left")),top:parseInt(block.css("top"))};

  if(action){

  this.fun = this[action];

  }else{

  this.x = e.clientX - this.offset.left - this.blockOriginal.left ;

  this.y = e.clientY - this.offset.top - this.blockOriginal.top;

  move = true;

  }

  $(document)

  .bind("mousemove.r",function(e){self.move(e,move)})

  .bind("mouseup.r",function(){self.end()});

  },

  end : function(){

  $(document)

  .unbind("mousemove.r")

  .unbind("mouseup.r");

  },

  move : function(e,isMove){

  window.getSelection

  ? window.getSelection().removeAllRanges()

  : document.selection.empty();

  var block = this.block;

  if(isMove){

  var left = Math.max(0,e.clientX - this.offset.left - this.x);

  left = Math.min(left,this.offset.width - this.blockOriginal.width);

  var top = Math.max(0,e.clientY - this.offset.top - this.y);

  top = Math.min(top,this.offset.height - this.blockOriginal.height);

  block.css({left:left,top:top});

  }else{

  var offset = this.fun(e);

  block.css(offset);

  }

  this.setImg();

  this.moveCallBack();

  },

  down : function(e){

  var blockOriginal = this.blockOriginal,

  sTop = Math.max(dBody.scrollTop,dDoc.scrollTop), //出现垂直方向滚动条时候 要计算这个

  offset = this.offset;

  if(e.clientY-offset.top>=blockOriginal.top-sTop){

  var height = Math.min(offset.height - blockOriginal.top,e.clientY-offset.top-blockOriginal.top+sTop),

  top = blockOriginal.top;

  }else{

  var height = Math.min(offset.top+blockOriginal.top-e.clientY-sTop,blockOriginal.top),

  top = Math.max(e.clientY - offset.top+sTop,0);

  }

  return {height:height, top:top};

  },

  up : function(e){

  var blockOriginal = this.blockOriginal,

  sTop = Math.max(dBody.scrollTop,dDoc.scrollTop),

  offset = this.offset;

  if(e.clientY-offset.top-blockOriginal.height<=blockOriginal.top-sTop){

  var top = Math.max(e.clientY-offset.top+sTop,0),

  maxHeight = blockOriginal.top + blockOriginal.height,

  height = Math.min(maxHeight,blockOriginal.top + blockOriginal.height -(e.clientY-offset.top)-sTop);

  }else{

  var height = Math.min(e.clientY-offset.top-blockOriginal.top-blockOriginal.height+sTop,offset.height-blockOriginal.top-blockOriginal.height),

  top = blockOriginal.top+blockOriginal.height;

  }

  return {height:height, top:top};

  },

  left : function(e){

  var blockOriginal = this.blockOriginal,

  offset = this.offset;

  if(e.clientX - offset.left - blockOriginal.width - blockOriginal.left<=0){

  var left = Math.max(e.clientX - offset.left,0),

  width = Math.min(blockOriginal.left + blockOriginal.width,blockOriginal.left + blockOriginal.width -(e.clientX-offset.left));

  }else{

  var width = Math.min(e.clientX-offset.left-blockOriginal.left-blockOriginal.width,offset.width-blockOriginal.left-blockOriginal.width),

  left = blockOriginal.left + blockOriginal.width;

  }

  return {left : left, width : width};

  },

  right : function(e){

  var blockOriginal = this.blockOriginal,

  offset = this.offset;

  if(e.clientX-offset.left>=blockOriginal.left){

  var width = Math.min(offset.width - blockOriginal.left,e.clientX - offset.left - blockOriginal.left),

  left = blockOriginal.left;

  }else{

  var width = Math.min(offset.left + blockOriginal.left - e.clientX,blockOriginal.left),

  left = Math.max(e.clientX - offset.left,0);

  }

  return {left : left, width : width};

  },

  rightDown : function(e){

  return $.extend(this.right(e),this.down(e));

  },

  leftDown : function(e){

  return $.extend(this.left(e),this.down(e));

  },

  rightUp : function(e){

  return $.extend(this.right(e),this.up(e));

  },

  leftUp : function(e){

  return $.extend(this.left(e),this.up(e));

  },

  getValue : function(){

  var block = this.block;

  return {

  left : parseInt(block.css("left")),

  top : parseInt(block.css("top")),

  width : block.width(),

  height : block.height()

  }

  }

  }

  $.fn.clip = function(options){

  options.container = this;

  return new clip(options);

  }

  })();

  $("#container").clip({

  imgC : $("#imgC")

  })

  </script>

  </body>

  </html>