/*
Copyright (c) 2005 Thomas Fakes (http://craz8.com)
http://blog.craz8.com/articles/2005/12/01/make-your-divs-resizeable#comment-13

This code is substantially based on code from script.aculo.us which has the 
following copyright and permission notice

Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

1.於scriptaculous.js內加上resize,令script自動讀取resize.js
(includes ? includes[1] : 'builder,effects,dragdrop,controls,slider').split(',').each(
to 
(includes ? includes[1] : 'builder,effects,dragdrop,controls,slider,resize').split(',').each(

2.自行加了四個parameter starteffect,endeffect,duringeffect,snaps, example:
new Resizeable(‘foo’, {resize: function(el) { alert(‘Done!’); } } ); 
*/

var Resizeable = Class.create();
Resizeable.prototype = {
  initialize: function(element) {
    var options = Object.extend({
      top: 6,
      bottom: 6,
      left: 6,
      right: 6,
      minHeight: 0,
      minWidth: 0,
      zindex: 1000,
      starteffect: null,
      duringeffect: null,
      endeffect: null,
      snap:null
    }, arguments[1] || {});

    this.element      = $(element);
    this.handle 	  = this.element;

    Element.makePositioned(this.element); // fix IE    

    this.options      = options;

    this.active       = false;
    this.resizing     = false;   
    this.currentDirection = '';

    this.eventMouseDown = this.startResize.bindAsEventListener(this);
    this.eventMouseUp   = this.endResize.bindAsEventListener(this);
    this.eventMouseMove = this.update.bindAsEventListener(this);
    this.eventCursorCheck = this.cursor.bindAsEventListener(this);
    this.eventKeypress  = this.keyPress.bindAsEventListener(this);
    
    this.registerEvents();
  },
  
  destroy: function() {
    this.unregisterEvents();
  },
  
  registerEvents: function() {
    Event.observe(document, "mouseup", this.eventMouseUp);
    Event.observe(document, "mousemove", this.eventMouseMove);
    Event.observe(document, "keypress", this.eventKeypress);
    Event.observe(this.handle, "mousedown", this.eventMouseDown);
    Event.observe(this.element, "mousemove", this.eventCursorCheck);
  },
  
  unregisterEvents: function() {
    //if(!this.active) return;
    Event.stopObserving(document, "mouseup", this.eventMouseUp);
    Event.stopObserving(document, "mousemove", this.eventMouseMove);
    Event.stopObserving(document, "keypress", this.eventKeypress);
    Event.stopObserving(this.handle, "mousedown", this.eventMouseDown);
    Event.stopObserving(this.element, "mousemove", this.eventCursorCheck);
  },
  
  startResize: function(event) {
    if(Event.isLeftClick(event)) {
      
      // abort on form elements, fixes a Firefox issue
      var src = Event.element(event);
      if(src.tagName && (
        src.tagName=='INPUT' ||
        src.tagName=='SELECT' ||
        src.tagName=='BUTTON' ||
        src.tagName=='TEXTAREA')) return;

	  var dir = this.directions(event);
	  if (dir.length > 0) {      
	      if (this.options.starteffect) {
            this.options.starteffect(this.element);
          }
	      this.active = true;
    	  var offsets = Position.cumulativeOffset(this.element);
	      this.startTop = offsets[1];
	      this.startLeft = offsets[0];
	      this.startWidth = parseInt(Element.getStyle(this.element, 'width'));
	      this.startHeight = parseInt(Element.getStyle(this.element, 'height'));
	      this.startX = event.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
	      this.startY = event.clientY + document.body.scrollTop + document.documentElement.scrollTop;
	      
	      this.currentDirection = dir;
	      Event.stop(event);
	  }
    }
  },
  
  finishResize: function(event, success) {
    this.active = false;
    this.resizing = false;

    if(this.options.zindex)
      this.element.style.zIndex = this.originalZ;
      

  },
  
  keyPress: function(event) {
    if(this.active) {
      if(event.keyCode==Event.KEY_ESC) {
        this.finishResize(event, false);
        Event.stop(event);
      }
    }
  },
  
  endResize: function(event) {
    if(this.active && this.resizing) {
      this.finishResize(event, true);
      Event.stop(event);
    }
    this.active = false;
    this.resizing = false;
    
    if (this.options.endeffect) {
    	this.options.endeffect(this.element);
    } 
  },
  
  draw: function(event) {
    var pointer = [Event.pointerX(event), Event.pointerY(event)];
    
    if (this.options.snap) {
        this.options.snap=parseInt(this.options.snap);
        pointer[0] = Math.round(pointer[0] / this.options.snap) * this.options.snap;
        pointer[1] = Math.round(pointer[1] / this.options.snap) * this.options.snap;
    }
     
    var style = this.element.style;
    if (this.currentDirection.indexOf('n') != -1) {
    	var pointerMoved = this.startY - pointer[1];
    	var margin = Element.getStyle(this.element, 'margin-top') || "0";
    	var newHeight = this.startHeight + pointerMoved;
    	if (newHeight > this.options.minHeight) {
    		style.height = newHeight + "px";
    		style.top = (this.startTop - pointerMoved - parseInt(margin)) + "px";
    	}
    }
    if (this.currentDirection.indexOf('w') != -1) {
    	var pointerMoved = this.startX - pointer[0];
    	var margin = Element.getStyle(this.element, 'margin-left') || "0";
    	var newWidth = this.startWidth + pointerMoved;
    	if (newWidth > this.options.minWidth) {
    		style.left = (this.startLeft - pointerMoved - parseInt(margin))  + "px";
    		style.width = newWidth + "px";
    	}
    }
    if (this.currentDirection.indexOf('s') != -1) {
    	var newHeight = this.startHeight + pointer[1] - this.startY;
    	if (newHeight > this.options.minHeight) {
    		style.height = newHeight + "px";
    	}
    }
    if (this.currentDirection.indexOf('e') != -1) {
    	var newWidth = this.startWidth + pointer[0] - this.startX;
    	if (newWidth > this.options.minWidth) {
    		style.width = newWidth + "px";
    	}
    }
    if(style.visibility=="hidden") style.visibility = ""; // fix gecko rendering
    
    

  },
  
  between: function(val, low, high) {
  	return (val >= low && val < high);
  },
  
  directions: function(event) {
    var pointer = [Event.pointerX(event), Event.pointerY(event)];
    var offsets = Position.cumulativeOffset(this.element);
   
	var cursor = '';
	if (this.between(pointer[1] - offsets[1], 0, this.options.top)) cursor += 'n';
	if (this.between((offsets[1] + this.element.offsetHeight) - pointer[1], 0, this.options.bottom)) cursor += 's';
	if (this.between(pointer[0] - offsets[0], 0, this.options.left)) cursor += 'w';
	if (this.between((offsets[0] + this.element.offsetWidth) - pointer[0], 0, this.options.right)) cursor += 'e';

	return cursor;
  },
  
  cursor: function(event) {
  	var cursor = this.directions(event);
	if (cursor.length > 0) {
		cursor += '-resize';
	} else {
		cursor = '';
	}
	this.element.style.cursor = cursor;		
  },
  
  update: function(event) {
   if(this.active) {
      if(!this.resizing) {
        var style = this.element.style;
        this.resizing = true;
        
        if(Element.getStyle(this.element,'position')=='') 
          style.position = "relative";
        
        if(this.options.zindex) {
          this.originalZ = parseInt(Element.getStyle(this.element,'z-index') || 0);
          style.zIndex = this.options.zindex;
        }
      }
      this.draw(event);
      
      if (this.options.duringeffect) {
    	this.options.duringeffect(this.element);
      }

      // fix AppleWebKit rendering
      if(navigator.appVersion.indexOf('AppleWebKit')>0) window.scrollBy(0,0); 
      Event.stop(event);
      return false;
   }
  }
}