鼠標拖拉按比例縮放的JavaScript

2024-09-05 12:21:42

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利用JS寫的一個拖拉縮放框，可以設置按比例縮入、像PS軟件一樣的裁切區域，代碼可要費的勁看哦，要不然看不懂的。

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312" /><title>拖拉縮放效果</title></head><body><script>var isIE = (document.all) ? true : false;var $ = function (id) { return "string" == typeof id ? document.getElementById(id) : id;};var Class = { create: function() {  return function() { this.initialize.apply(this, arguments); } }}var Extend = function(destination, source) { for (var property in source) {  destination[property] = source[property]; }}var Bind = function(object, fun) { return function() {  return fun.apply(object, arguments); }}var BindAsEventListener = function(object, fun) { var args = Array.prototype.slice.call(arguments).slice(2); return function(event) {  return fun.apply(object, [event || window.event].concat(args)); }}var CurrentStyle = function(element){ return element.currentStyle || document.defaultView.getComputedStyle(element, null);}function addEventHandler(oTarget, sEventType, fnHandler) { if (oTarget.addEventListener) {  oTarget.addEventListener(sEventType, fnHandler, false); } else if (oTarget.attachEvent) {  oTarget.attachEvent("on" + sEventType, fnHandler); } else {  oTarget["on" + sEventType] = fnHandler; }};function removeEventHandler(oTarget, sEventType, fnHandler) {    if (oTarget.removeEventListener) {        oTarget.removeEventListener(sEventType, fnHandler, false);    } else if (oTarget.detachEvent) {        oTarget.detachEvent("on" + sEventType, fnHandler);    } else {         oTarget["on" + sEventType] = null;    }};//縮放程序var Resize = Class.create();Resize.prototype = {initialize: function(obj, options) { this._obj = $(obj);//縮放對象  this._styleWidth = this._styleHeight = this._styleLeft = this._styleTop = 0;//樣式參數 this._sideRight = this._sideDown = this._sideLeft = this._sideUp = 0;//坐標參數 this._fixLeft = this._fixTop = 0;//定位參數 this._scaleLeft = this._scaleTop = 0;//定位坐標  this._mxSet = function(){};//范圍設置 this._mxRightWidth = this._mxDownHeight = this._mxUpHeight = this._mxLeftWidth = 0;//范圍參數 this._mxScaleWidth = this._mxScaleHeight = 0;//比例范圍參數 this._fun = function(){};//縮放執行程序 //獲取邊框寬度 var _style = CurrentStyle(this._obj); this._borderX = (parseInt(_style.borderLeftWidth) || 0) + (parseInt(_style.borderRightWidth) || 0); this._borderY = (parseInt(_style.borderTopWidth) || 0) + (parseInt(_style.borderBottomWidth) || 0); //事件對象(用于綁定移除事件) this._fR = BindAsEventListener(this, this.Resize); this._fS = Bind(this, this.Stop);  this.SetOptions(options); //范圍限制 this.Max = !!this.options.Max; this._mxContainer = $(this.options.mxContainer) || null; this.mxLeft = Math.round(this.options.mxLeft); this.mxRight = Math.round(this.options.mxRight); this.mxTop = Math.round(this.options.mxTop); this.mxBottom = Math.round(this.options.mxBottom); //寬高限制 this.Min = !!this.options.Min; this.minWidth = Math.round(this.options.minWidth); this.minHeight = Math.round(this.options.minHeight); //按比例縮放 this.Scale = !!this.options.Scale; this.Ratio = Math.max(this.options.Ratio, 0); this.onResize = this.options.onResize; this._obj.style.position = "absolute"; !this._mxContainer || CurrentStyle(this._mxContainer).position == "relative" || (this._mxContainer.style.position = "relative");  },  //設置默認屬性  SetOptions: function(options) {    this.options = {//默認值  Max:  false,//是否設置范圍限制(為true時下面mx參數有用)  mxContainer:"",//指定限制在容器內  mxLeft:  0,//左邊限制  mxRight: 9999,//右邊限制  mxTop:  0,//上邊限制  mxBottom: 9999,//下邊限制  Min:  false,//是否最小寬高限制(為true時下面min參數有用)  minWidth: 50,//最小寬度  minHeight: 50,//最小高度  Scale:  false,//是否按比例縮放  Ratio:  0,//縮放比例(寬/高)  onResize: function(){}//縮放時執行    };    Extend(this.options, options || {});  },  //設置觸發對象  Set: function(resize, side) { var resize = $(resize), fun; if(!resize) return; //根據方向設置 switch (side.toLowerCase()) { case "up" :  fun = this.Up;  break; case "down" :  fun = this.Down;  break; case "left" :  fun = this.Left;  break; case "right" :  fun = this.Right;  break; case "left-up" :  fun = this.LeftUp;  break; case "right-up" :  fun = this.RightUp;  break; case "left-down" :  fun = this.LeftDown;  break; case "right-down" : default :  fun = this.RightDown; }; //設置觸發對象 addEventHandler(resize, "mousedown", BindAsEventListener(this, this.Start, fun));  },  //準備縮放  Start: function(e, fun, touch) {  //防止冒泡(跟拖放配合時設置) e.stopPropagation ? e.stopPropagation() : (e.cancelBubble = true); //設置執行程序 this._fun = fun; //樣式參數值 this._styleWidth = this._obj.clientWidth; this._styleHeight = this._obj.clientHeight; this._styleLeft = this._obj.offsetLeft; this._styleTop = this._obj.offsetTop; //四條邊定位坐標 this._sideLeft = e.clientX - this._styleWidth; this._sideRight = e.clientX + this._styleWidth; this._sideUp = e.clientY - this._styleHeight; this._sideDown = e.clientY + this._styleHeight; //top和left定位參數 this._fixLeft = this._styleLeft + this._styleWidth; this._fixTop = this._styleTop + this._styleHeight; //縮放比例 if(this.Scale){  //設置比例  this.Ratio = Math.max(this.Ratio, 0) || this._styleWidth / this._styleHeight;  //left和top的定位坐標  this._scaleLeft = this._styleLeft + this._styleWidth / 2;  this._scaleTop = this._styleTop + this._styleHeight / 2; }; //范圍限制 if(this.Max){  //設置范圍參數  var mxLeft = this.mxLeft, mxRight = this.mxRight, mxTop = this.mxTop, mxBottom = this.mxBottom;  //如果設置了容器，再修正范圍參數  if(!!this._mxContainer){   mxLeft = Math.max(mxLeft, 0);   mxTop = Math.max(mxTop, 0);   mxRight = Math.min(mxRight, this._mxContainer.clientWidth);   mxBottom = Math.min(mxBottom, this._mxContainer.clientHeight);  };  //根據最小值再修正  mxRight = Math.max(mxRight, mxLeft + (this.Min ? this.minWidth : 0) + this._borderX);  mxBottom = Math.max(mxBottom, mxTop + (this.Min ? this.minHeight : 0) + this._borderY);  //由于轉向時要重新設置所以寫成function形式  this._mxSet = function(){   this._mxRightWidth = mxRight - this._styleLeft - this._borderX;   this._mxDownHeight = mxBottom - this._styleTop - this._borderY;   this._mxUpHeight = Math.max(this._fixTop - mxTop, this.Min ? this.minHeight : 0);   this._mxLeftWidth = Math.max(this._fixLeft - mxLeft, this.Min ? this.minWidth : 0);  };  this._mxSet();  //有縮放比例下的范圍限制  if(this.Scale){   this._mxScaleWidth = Math.min(this._scaleLeft - mxLeft, mxRight - this._scaleLeft - this._borderX) * 2;   this._mxScaleHeight = Math.min(this._scaleTop - mxTop, mxBottom - this._scaleTop - this._borderY) * 2;  }; }; //mousemove時縮放 mouseup時停止 addEventHandler(document, "mousemove", this._fR); addEventHandler(document, "mouseup", this._fS); if(isIE){  addEventHandler(this._obj, "losecapture", this._fS);  this._obj.setCapture(); }else{  addEventHandler(window, "blur", this._fS);  e.preventDefault(); };  },  //縮放  Resize: function(e) { //清除選擇 window.getSelection ? window.getSelection().removeAllRanges() : document.selection.empty(); //執行縮放程序 this._fun(e); //設置樣式，變量必須大于等于0否則ie出錯 with(this._obj.style){  width = this._styleWidth + "px"; height = this._styleHeight + "px";  top = this._styleTop + "px"; left = this._styleLeft + "px"; } //附加程序 this.onResize();  },  //縮放程序  //上  Up: function(e) { this.RepairY(this._sideDown - e.clientY, this._mxUpHeight); this.RepairTop(); this.TurnDown(this.Down);  },  //下  Down: function(e) { this.RepairY(e.clientY - this._sideUp, this._mxDownHeight); this.TurnUp(this.Up);  },  //右  Right: function(e) { this.RepairX(e.clientX - this._sideLeft, this._mxRightWidth); this.TurnLeft(this.Left);  },  //左  Left: function(e) { this.RepairX(this._sideRight - e.clientX, this._mxLeftWidth); this.RepairLeft(); this.TurnRight(this.Right);  },  //右下  RightDown: function(e) { this.RepairAngle(  e.clientX - this._sideLeft, this._mxRightWidth,  e.clientY - this._sideUp, this._mxDownHeight ); this.TurnLeft(this.LeftDown) || this.TurnUp(this.RightUp);  },  //右上  RightUp: function(e) { this.RepairAngle(  e.clientX - this._sideLeft, this._mxRightWidth,  this._sideDown - e.clientY, this._mxUpHeight ); this.RepairTop(); this.TurnLeft(this.LeftUp) || this.TurnDown(this.RightDown);  },  //左下  LeftDown: function(e) { this.RepairAngle(  this._sideRight - e.clientX, this._mxLeftWidth,  e.clientY - this._sideUp, this._mxDownHeight ); this.RepairLeft(); this.TurnRight(this.RightDown) || this.TurnUp(this.LeftUp);  },  //左上  LeftUp: function(e) { this.RepairAngle(  this._sideRight - e.clientX, this._mxLeftWidth,  this._sideDown - e.clientY, this._mxUpHeight ); this.RepairTop(); this.RepairLeft(); this.TurnRight(this.RightUp) || this.TurnDown(this.LeftDown);  },  //修正程序  //水平方向  RepairX: function(iWidth, mxWidth) { iWidth = this.RepairWidth(iWidth, mxWidth); if(this.Scale){  var iHeight = Math.round(iWidth / this.Ratio);  if(this.Max  &&  iHeight > this._mxScaleHeight){   iWidth = Math.round((iHeight = this._mxScaleHeight) * this.Ratio);  }else if(this.Min  &&  iHeight < this.minHeight){   var tWidth = Math.round(this.minHeight * this.Ratio);   if(tWidth < mxWidth){ iHeight = this.minHeight; iWidth = tWidth; }  }  this._styleHeight = iHeight;  this._styleTop = this._scaleTop - iHeight / 2; } this._styleWidth = iWidth;  },  //垂直方向  RepairY: function(iHeight, mxHeight) { iHeight = this.RepairHeight(iHeight, mxHeight); if(this.Scale){  var iWidth = Math.round(iHeight * this.Ratio);  if(this.Max  &&  iWidth > this._mxScaleWidth){   iHeight = Math.round((iWidth = this._mxScaleWidth) / this.Ratio);  }else if(this.Min  &&  iWidth < this.minWidth){   var tHeight = Math.round(this.minWidth / this.Ratio);   if(tHeight < mxHeight){ iWidth = this.minWidth; iHeight = tHeight; }  }  this._styleWidth = iWidth;  this._styleLeft = this._scaleLeft - iWidth / 2; } this._styleHeight = iHeight;  },  //對角方向  RepairAngle: function(iWidth, mxWidth, iHeight, mxHeight) { iWidth = this.RepairWidth(iWidth, mxWidth);  if(this.Scale){  iHeight = Math.round(iWidth / this.Ratio);  if(this.Max  &&  iHeight > mxHeight){   iWidth = Math.round((iHeight = mxHeight) * this.Ratio);  }else if(this.Min  &&  iHeight < this.minHeight){   var tWidth = Math.round(this.minHeight * this.Ratio);   if(tWidth < mxWidth){ iHeight = this.minHeight; iWidth = tWidth; }  } }else{  iHeight = this.RepairHeight(iHeight, mxHeight); } this._styleWidth = iWidth; this._styleHeight = iHeight;  },  //top  RepairTop: function() { this._styleTop = this._fixTop - this._styleHeight;  },  //left  RepairLeft: function() { this._styleLeft = this._fixLeft - this._styleWidth;  },  //height  RepairHeight: function(iHeight, mxHeight) { iHeight = Math.min(this.Max ? mxHeight : iHeight, iHeight); iHeight = Math.max(this.Min ? this.minHeight : iHeight, iHeight, 0); return iHeight;  },  //width  RepairWidth: function(iWidth, mxWidth) { iWidth = Math.min(this.Max ? mxWidth : iWidth, iWidth); iWidth = Math.max(this.Min ? this.minWidth : iWidth, iWidth, 0); return iWidth;  },  //轉向程序  //轉右  TurnRight: function(fun) { if(!(this.Min || this._styleWidth)){  this._fun = fun;  this._sideLeft = this._sideRight;  this.Max  &&  this._mxSet();  return true; }  },  //轉左  TurnLeft: function(fun) { if(!(this.Min || this._styleWidth)){  this._fun = fun;  this._sideRight = this._sideLeft;  this._fixLeft = this._styleLeft;  this.Max  &&  this._mxSet();  return true; }  },  //轉上  TurnUp: function(fun) { if(!(this.Min || this._styleHeight)){  this._fun = fun;  this._sideDown = this._sideUp;  this._fixTop = this._styleTop;  this.Max  &&  this._mxSet();  return true; }  },  //轉下  TurnDown: function(fun) { if(!(this.Min || this._styleHeight)){  this._fun = fun;  this._sideUp = this._sideDown;  this.Max  &&  this._mxSet();  return true; }  },  //停止縮放  Stop: function() { removeEventHandler(document, "mousemove", this._fR); removeEventHandler(document, "mouseup", this._fS); if(isIE){  removeEventHandler(this._obj, "losecapture", this._fS);  this._obj.releaseCapture(); }else{  removeEventHandler(window, "blur", this._fS); }  }};</script><script type="text/javascript" src="http://files.cnblogs.com/cloudgamer/Drag.js"></script><style type="text/css">#rRightDown,#rLeftDown,#rLeftUp,#rRightUp,#rRight,#rLeft,#rUp,#rDown{ position:absolute; background:#C00; width:7px; height:7px; 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;}#rLeftDown{left:-4px;bottom:-4px;}#rRightUp{right:-4px;top:-4px;}#rRightDown{right:-4px;bottom:-4px;background-color:#00F;}#rLeftUp{left:-4px;top:-4px;}#rRight{right:-4px;top:50%;margin-top:-4px;}#rLeft{left:-4px;top:50%;margin-top:-4px;}#rUp{top:-4px;left:50%;margin-left:-4px;}#rDown{bottom:-4px;left:50%;margin-left:-4px;}#bgDiv{width:600px; height:300px; border:10px solid #666666; position:relative;}#dragDiv{border:1px solid #000000; width:100px; height:60px; top:50px; left:50px; background:#fff;}</style><div   class="iwvjtn8m0"   id="bgDiv">  <div   class="iwvjtn8m0"   id="dragDiv">    <div   class="iwvjtn8m0"   id="rRightDown"> </div>    <div   class="iwvjtn8m0"   id="rLeftDown"> </div>    <div   class="iwvjtn8m0"   id="rRightUp"> </div>    <div   class="iwvjtn8m0"   id="rLeftUp"> </div>    <div   class="iwvjtn8m0"   id="rRight"> </div>    <div   class="iwvjtn8m0"   id="rLeft"> </div>    <div   class="iwvjtn8m0"   id="rUp"> </div>    <div   class="iwvjtn8m0"   id="rDown"></div>  </div></div><div><input id="idScale" type="button" value="設置比例" /><input id="idMin" type="button" value="設置最小范圍" /></div><script>var rs = new Resize("dragDiv", { Max: true, mxContainer: "bgDiv" });rs.Set("rRightDown", "right-down");rs.Set("rLeftDown", "left-down");rs.Set("rRightUp", "right-up");rs.Set("rLeftUp", "left-up");rs.Set("rRight", "right");rs.Set("rLeft", "left");rs.Set("rUp", "up");rs.Set("rDown", "down");$("idScale").onclick = function(){ if(rs.Scale){  this.value = "設置比例";  rs.Scale = false; }else{  this.value = "取消比例";  rs.Scale = true; }}$("idMin").onclick = function(){ if(rs.Min){  this.value = "設置最小范圍";  rs.Min = false; }else{  this.value = "取消最小范圍";  rs.Min = true; }}new Drag("dragDiv", { Limit: true, mxContainer: "bgDiv" });</script></body></html>

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