forked from: basic scrollBar

/**
 * Copyright tepe ( http://wonderfl.net/user/tepe )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/aRlw
 */

// forked from _ryotaros's basic scrollBar
package {
    import flash.display.Sprite;
    import flash.events.MouseEvent;
    import flash.events.Event;
    import flash.text.*;
    
    public class FlashTest extends Sprite {
            
        public function FlashTest() {
            var sb:ScrollBar = new ScrollBar();
            addChild(sb);
        }
        
        
    }
}

import flash.display.*;
import flash.events.*;
class ScrollBar extends Sprite{
        
            public var scrollArea:Box;
            public var scrollBar:Box;
            public var scrollBarshadow:Box;
            //public var element:Box;
            public var elementArea:Sprite;
            //public var elements:Array;
            
            
            public var bardist:Number;
            public var elementAreaDist:Number;
            public var targetDist:Number;
            //public var ElementAreaLength:Number;
            public var scrollBarPoint:Number;
            
            public function ScrollBar(){
                init();    
            }
            
            public function init(o:DisplayObject=null):void{
                 scrollArea = new Box(0,0,200,350); 
                 scrollArea.x = 100;
                 scrollArea.y = 50;
                 addChild(scrollArea);
                 
                 //スクロールバー配置
                 scrollBarshadow = new Box(0, 0, 15, scrollArea.height , 1 , 0xCCCCCC);
                 scrollBar = new Box(0, 0, 15, 100, 1, 0x000000);
                 scrollBarshadow.x = scrollBar.x = scrollArea.x + scrollArea.width + 10;
                 scrollBarshadow.y = scrollArea.y;
                 scrollBar.y = scrollArea.y + scrollArea.height - scrollBar.height;
                 addChild(scrollBarshadow);
                 addChild(scrollBar);
                 
                 bardist = scrollArea.height - scrollBar.height;
                 
                 elementArea = new Sprite();
                 
                 elementAreaDist = elementArea.height - scrollArea.height + 10;
                
                 elementArea.y -= elementArea.height - scrollArea.height; 
                 
                 elementArea.mask = scrollArea;
                 
                 addEventListener(Event.ENTER_FRAME, xinitMoveScroll);                 
                 
            }
            
            public function xinitMoveScroll(e:Event):void{
                
                //スクロール
                var vy:Number = (scrollArea.y - scrollBar.y) / 10; 
                var vy2:Number= ((scrollArea.y) - elementArea.y) /10;
                scrollBar.y += vy;
                elementArea.y += vy2;
                
                
                if((scrollBar.y-scrollArea.y) < 0.1 && (elementArea.y - scrollArea.y) < 0){
                    scrollBar.y = scrollArea.y;
                    elementArea.y = scrollArea.y;
                    removeEventListener(Event.ENTER_FRAME, xinitMoveScroll);
                    scrollBar.addEventListener(MouseEvent.MOUSE_DOWN, _scrollbarHandler);
                    stage.addEventListener(MouseEvent.MOUSE_UP, _scrollbarUpHandler);
                }
            }
            
            
            public function _scrollbarHandler(e:MouseEvent):void{
                scrollBarPoint = scrollBar.height - (scrollBar.y + scrollBar.height - mouseY);
                addEventListener(Event.ENTER_FRAME, _onScrollArea );
            }
            public function _scrollbarUpHandler(e:MouseEvent):void{
                removeEventListener(Event.ENTER_FRAME, _onScrollArea );
            }
             
            public function _onScrollArea(e:Event = null):void{
                scrollBar.y = mouseY - scrollBarPoint;
                if(scrollBar.y + scrollBar.height  > scrollArea.y + scrollArea.height) {
                    scrollBar.y = scrollArea.y + scrollArea.height - scrollBar.height;
                }
                if(scrollBar.y < scrollArea.y ) {
                    scrollBar.y = scrollArea.y;    
                }
                targetDist = scrollArea.y - (elementAreaDist * ((scrollBar.y - scrollArea.y)/bardist)); 
                elementArea.y += (targetDist - elementArea.y) * 0.2; 
                
            }
    }


import flash.display.Sprite;
class Box extends Sprite {
    public function Box(x:Number,y:Number,width:Number = 20,height:Number = 20,line:Number = 1,color:uint = 0xFF0000):void{
                with(this.graphics) {
                    beginFill(color);
                    lineStyle(line);
                    drawRect(x,y,width,height);
                    endFill();
                }
            }   
    
}