[flexcoders] get rowIndex in datagird's mouseOver Function

[Dharmendra Chauhan]

My requiremnt is to get rowIndex in mouseover Function in DataGird so
that I can use that index to select perticuler row of 
datagrid.ItemRollover Function does not get called when I hold left 
mouse key and drag it over dg. 
I want to provide functionality where in user can select multiple 
rows in dg by holding left mouse key and dragging over the dg. 

I have also designed a sample app for this but Only issue with 
approach is that It(mOver.target.listData.rowIndex) does not 
consistently  return rowIndex ,sometimes It throws error `Property 
listData not found on mx.controls.listClasses.ListBaseContentHolder 
and there is no default value"  as a result of it ,few row left 
unselected. 

This error occurs only when user tries to select rows with fast 
mouse movement. 


Here is my sample app code  :- 


<?xml version="1.0" encoding="utf-8"?> 


<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"; 
layout="absolute" creationComplete="init()" 


      backgroundColor="#b3b4ae" > 


      <mx:Script > 


            <![CDATA[ 


                  import mx.charts.HitData; 


                  import 
mx.controls.dataGridClasses.DataGridItemRenderer; 


                  import mx.events.ListEvent; 


                  import flash.utils.describeType; 


                  import flash.utils.getDefinitionByName; 


                  import mx.controls.Alert; 


                  import mx.formatters.DateFormatter; 


                  import mx.collections.ArrayCollection; 


                  // include "MatsFormatter.as" 


             var selectedArr:Array = new Array(); 


           var arrCol:ArrayCollection     ; 


            function init():void{ 


             arrCol = new ArrayCollection([{name:'AA', age:25}, 
{name:'BB', age:15}, 


                                       {name:'CC', age:23},
{name:'DD', 
age:25}, {name:'EE', age:15}, 


                                       {name:'FF', age:23},
{name:'GG', 
age:25}, {name:'HH', age:15}, 


                                       {name:'II', age:23}]); 


            dg.dataProvider = arrCol; 


            } 


            var isMouseDown:Boolean = false; 


            public function mouseDownFunc 
(mDn:flash.events.MouseEvent  ):void{ 


            //Alert.show("mouseDownFunc"); 


            isMouseDown = true; 


            } 


            public function mouseUpFunc 
(mUp:flash.events.MouseEvent  ):void{ 


             // Alert.show("mouseUpFunc"); 


               isMouseDown = false; 


               // Work Around to select iterleaved unselected row 


             /*   var selectedArr2:Array = new Array(); 


               var firstRowIndex :int = dg.selectedIndices[0] 


               var lastRowIndex :int = dg.selectedIndices 
[dg.selectedIndices.length -1 ] 


               if(firstRowIndex < lastRowIndex){ 


                  for(var i:int = firstRowIndex; firstRowIndex<= 
lastRowIndex;firstRowIndex++) 


                       selectedArr2.push(firstRowIndex); 


               }else{ 


                  for(var j:int = lastRowIndex; lastRowIndex<= 
firstRowIndex;lastRowIndex++) 


                      selectedArr2.push(lastRowIndex); 


                } 


               dg.selectedIndices = selectedArr2; */ 


            } 


            public function mouseOverFunc 
(mOver:MouseEvent,dgCol:ListEvent = null ):void{ 


              var  rend:Object; 


              if(isMouseDown){ 


               try{ 


               selectedArr = dg.selectedIndices; 


               selectedArr.push(mOver.target.listData.rowIndex); 


               dg.selectedIndices = selectedArr; 


              }catch(e:Error){ 


              //  rend = mOver.relatedObject ; 


               } 


              } 


           } 


      /*     public function itemRollOverFunc 
(itmRollOver:ListEvent):void{ 


              if(isMouseDown){ 


                     try{ 


                     selectedArr = dg.selectedIndices; 


                     selectedArr.push(itmRollOver.rowIndex); 


                     dg.selectedIndices = selectedArr; 


                    }catch(e:Error){ 


                     trace(e.getStackTrace()); 


                    } 


                   } 


             } */ 


            ]]> 


      </mx:Script> 


    <mx:Style> 


             DataGrid { 


           backgroundColor:#b3b4ae; 


           borderColor:#66696B; 


           verticalGridLineColor :#808080; 


           horizontalGridLineColor :#808080; 


           themeColor:#0A246A; 


           borderStyle:solid; 


           fontSize: 8; 


           headerStyleName: "dgHeaderStyles"; 


          } 


        .dgHeaderStyles { 


            fontSize: 10; 


            textAlign: left; 


            backgroundColor: #d4d0c8; 


            fontFamily :san Sarif; 


          } 


     </mx:Style> 


<mx:Panel layout="absolute" title="MATS Trade Management Console" 
id="gridPanel" left="5" right="5" top="5" bottom="5" 
themeColor="#B3B4AE"> 


      <mx:DataGrid  width="50%" height="50%" 
headerColors="[#d4d0c8,#d4d0c8]" horizontalScrollPolicy="auto" 
allowMultipleSelection="true" id="dg" 


                   horizontalGridLines="true"    rowHeight="30" 


                  selectionColor="#FFFFFF"          top="0" 
bottom="0" 


                   mouseDown="mouseDownFunc(event)" 
mouseUp="mouseUpFunc(event)" mouseOver="mouseOverFunc(event)" 


               > 


            <mx:columns> 


                  <mx:DataGridColumn           id="status" 
wordWrap="false"  headerText="Name " dataField="name"/> 


                  <mx:DataGridColumn            id="age" 
dataField="age"      headerText="Age"/> 


            </mx:columns> 


      </mx:DataGrid> 


</mx:Panel> 


</mx:Application>