From 6492d1f65489e9a285579e2fbd1547539b036da6 Mon Sep 17 00:00:00 2001
From: Richard Fairhurst <richard@systemed.net>
Date: Fri, 26 Nov 2010 16:40:25 +0000
Subject: [PATCH] add the ability to lock entities against purging

---
 TODO.txt                                      |  1 -
 net/systemeD/halcyon/Map.as                   | 10 +++++++---
 net/systemeD/halcyon/connection/Connection.as |  4 ++--
 net/systemeD/halcyon/connection/Entity.as     |  2 +-
 net/systemeD/halcyon/connection/Way.as        |  7 +++++++
 5 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/TODO.txt b/TODO.txt
index d55d4c86..7fd5a9a3 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -42,7 +42,6 @@ Potlatch 2: main outstanding issues
 
 == Rendering (Halcyon) ==
 
-** Entities need some sort of .purgable attribute (like EntityUIs) - currently you can select an item, then pan off-screen, and the entity is deleted at next purge, causing an exception whenever P2 tries to access it (e.g. via the selection)
 * halcyon_viewer needs updating for new tileurl stuff
 * Shields
 * More line decoration (cliffs etc.), and implied values for 'dashes' if not supplied
diff --git a/net/systemeD/halcyon/Map.as b/net/systemeD/halcyon/Map.as
index 836c0e16..973878fb 100644
--- a/net/systemeD/halcyon/Map.as
+++ b/net/systemeD/halcyon/Map.as
@@ -274,15 +274,19 @@ package net.systemeD.halcyon {
 			if (paint.wayuis[way.id]) paint.wayuis[way.id].setHighlightOnNodes(settings);
         }
 
+		/* Protect Entities and EntityUIs against purging. This prevents the currently selected items
+		   from being purged even though they're off-screen. */
+
 		public function setPurgable(entities:Array, purgable:Boolean):void {
 			for each (var entity:Entity in entities) {
+				entity.locked=!purgable;
 				if ( entity is Way  ) {
 					var way:Way=entity as Way;
 					if (paint.wayuis[way.id]) { paint.wayuis[way.id].purgable=purgable; }
 					for (var i:uint=0; i<way.length; i++) {
-						if (paint.nodeuis[way.getNode(i).id]) {
-							paint.nodeuis[way.getNode(i).id].purgable=purgable;
-						}
+						var node:Node=way.getNode(i)
+						node.locked=!purgable;
+						if (paint.nodeuis[node.id]) { paint.nodeuis[node.id].purgable=purgable; }
 					}
 				} else if ( entity is Node && paint.nodeuis[entity.id]) { 
 					paint.nodeuis[entity.id].purgable=purgable;
diff --git a/net/systemeD/halcyon/connection/Connection.as b/net/systemeD/halcyon/connection/Connection.as
index 1000951f..3afe0457 100644
--- a/net/systemeD/halcyon/connection/Connection.as
+++ b/net/systemeD/halcyon/connection/Connection.as
@@ -312,12 +312,12 @@ package net.systemeD.halcyon.connection {
 
 		public function purgeOutside(left:Number, right:Number, top:Number, bottom:Number):void {
 			for each (var way:Way in ways) {
-				if (!way.within(left,right,top,bottom) && !way.isDirty) {
+				if (!way.within(left,right,top,bottom) && !way.isDirty && !way.locked && !way.hasLockedNodes()) {
 					killWayWithNodes(way.id);
 				}
 			}
 			for each (var poi:Node in pois) {
-				if (!poi.within(left,right,top,bottom) && !poi.isDirty) {
+				if (!poi.within(left,right,top,bottom) && !poi.isDirty && !poi.locked) {
 					killNode(poi.id);
 				}
 			}
diff --git a/net/systemeD/halcyon/connection/Entity.as b/net/systemeD/halcyon/connection/Entity.as
index b6b85703..0f441658 100644
--- a/net/systemeD/halcyon/connection/Entity.as
+++ b/net/systemeD/halcyon/connection/Entity.as
@@ -14,7 +14,7 @@ package net.systemeD.halcyon.connection {
         private var modified:Boolean = false;
 		private var _loaded:Boolean = true;
 		private var parents:Dictionary = new Dictionary();
-		private var locked:Boolean = false;
+		public var locked:Boolean = false;						// lock against purging when off-screen
 		public var deleted:Boolean = false;
 
         public function Entity(id:Number, version:uint, tags:Object, loaded:Boolean, uid:Number, timestamp:String) {
diff --git a/net/systemeD/halcyon/connection/Way.as b/net/systemeD/halcyon/connection/Way.as
index d64dec43..8ca13f2c 100644
--- a/net/systemeD/halcyon/connection/Way.as
+++ b/net/systemeD/halcyon/connection/Way.as
@@ -81,6 +81,13 @@ package net.systemeD.halcyon.connection {
 		public function hasOnceOnly(node:Node):Boolean {
 			return nodes.indexOf(node)==nodes.lastIndexOf(node);
 		}
+		
+		public function hasLockedNodes():Boolean {
+			for each (var node:Node in nodes) {
+				if (node.locked) { return true; }
+			}
+			return false;
+		}
 
 		public function removeNode(node:Node, performAction:Function):void {
 			performAction(new RemoveNodeFromWayAction(this, node, nodes));
-- 
2.30.0