Monday, October 26, 2009

Dynamically position a Flex popup relative to a button mouse click

I was having trouble with positioning a wide popup window that was in a component nested several containers deep.  The PopUpManager.centerPopUp method would center on the container and push the window off the right edge of the screen.  To correct this, I moved the popup over 100 pixels using:

popup.x = popup.x – 100;

That worked, but the problem would come back if the window grew wider.  Bush league.  To make it a bit more reliable, I changed to use the mouseEvent localX/Y properties.  Note you have to convert the “local” coordinates to “global”:

 

      private function showPopup(event:MouseEvent):void

        {

            pop = EnotaryRegReturnPopup(PopUpManager.createPopUp(this,EnotaryRegReturnPopup,true));

            pop.title = "Please select return reasons.";

            pop.showCloseButton =true;

            pop.enotaryRegReturnList = this.enotaryRegReturnList;

            pop.buildUnselectedReturns();

           

                  // position the window next to the "add" button

            var pt:Point = new Point(event.localX, event.localY);

            pt = event.target.localToGlobal(pt);

            pop.x = pt.x - pop.width;

            pop.y = pt.y;

           

            pop.addEventListener("close",removeMe);

            pop["cancelButton"].addEventListener("click", removeMe);

            pop["okButton"].addEventListener("click",processReturns);

        }

 

 

Monday, October 5, 2009

Delete rows from DataTable using DataRow

I was surprised by the delete functionality in DataTable.  It was my understanding that when you call DataRow.Delete it marks the row for deletion, but waits for a DataTable.AcceptChanges call before actually removing them, but when I tried to delete inside a For Each dr as DataRow in dt.Rows I was getting an error “Collection was modified”.  Thankfully I ran across a thread that suggested walking backwards through the collection to avoid those types of errors.  I ended up with this to solve my problem:

 

        Do While i >= 0

            If dt.Rows(i)("KEEP_ME"))) = False Then dt.Rows(i).Delete()

            i -= 1

        Loop

        dt.AcceptChanges()