Fix #3367. Every time the Background dropdown is opened now, it checks to see if it needs to update its selectedIndex.

git-svn-id: http://svn.openstreetmap.org/applications/editors/potlatch2@25524 b9d5c4c9-76e1-0310-9c85-f3177eceb1e4

Author: stevage

net/systemeD/potlatch2/BackgroundSelector.mxml

@@ -30,6 +30,15 @@
 		import mx.collections.ArrayCollection;
 		import mx.managers.PopUpManager;
 
+		/** Sets the currently selected item by consulting Imagery.instance() */
+		public function updateSelectedIndex() {
+			if(background.selectedIndex==-1) {
+			    var im:Imagery = Imagery.instance(); 
+			    var i = im.collection.indexOf(im.findBackgroundWithName(im.selected.name));
+			    background.selectedIndex = i;
+			}
+		}
+
 		public function setDimming(v:Boolean):void {
 			Application.application.theMap.setDimming(dim.selected);
 			Application.application.yahoo.alpha = dim.selected ? 0.5 : 1;

net/systemeD/potlatch2/collections/Imagery.as

@@ -10,12 +10,14 @@ package net.systemeD.potlatch2.collections {
 	import net.systemeD.potlatch2.FunctionKeyManager;
 	import net.systemeD.potlatch2.Yahoo;
 	import mx.collections.ArrayCollection;
-
-	/*
-		There's lots of further tidying we can do:
-		- remove all the horrid Yahoo stuff
-		- remove the backreferences to _map and send events instead
-		but this will do for now and help remove the clutter from potlatch2.mxml.
+	
+	/** Manages the different choices of background imagery, dealing with details like retrieving lists of imagery,
+	 * saving and retrieving the current choice, etc.
+	 *	
+	 *  TODO There's lots of further tidying we can do:
+	 *	- remove all the horrid Yahoo stuff
+	 *	- remove the backreferences to _map and send events instead
+	 *	but this will do for now and help remove the clutter from potlatch2.mxml.
 	*/
 
 	public class Imagery extends EventDispatcher {
@@ -172,7 +174,7 @@ package net.systemeD.potlatch2.collections {
 			obj.flush();
 		}
 
-		private function findBackgroundWithName(name:String):Object {
+		public function findBackgroundWithName(name:String):Object {
 			for each (var bg:Object in collection) {
 				if (bg.name==name) { return bg; }
 			}

potlatch2.mxml

@@ -29,7 +29,8 @@
 
     <mx:ApplicationControlBar dock="true">
         <mx:PopUpButton id="bgButton" label="Background" openAlways="true" styleName="appBarButton"
-            creationComplete="bgButton.popUp = new BackgroundSelector();"/>
+            creationComplete="bgButton.popUp = new BackgroundSelector();"
+            open="(bgButton.popUp as BackgroundSelector).updateSelectedIndex();"/>
         <mx:PopUpButton id="styleButton" label="Map Style" openAlways="true" styleName="appBarButton"
             creationComplete="styleButton.popUp = new StyleSelector();"/>
 		<mx:PopUpMenuButton id="gpsButton" styleName="appBarButton"