[Patch] Relation members sorting in conflict editor

[josm@…]

Relation conflict editor could list all the relations in some defined order, so only changes in membership will be affected. This would help a lot in resolving conflicts

Proposed simple patch:

Index: src/org/openstreetmap/josm/gui/conflict/pair/relation/RelationMemberListMergeModel.java
===================================================================
--- src/org/openstreetmap/josm/gui/conflict/pair/relation/RelationMemberListMergeModel.java	(revision 6453)
+++ src/org/openstreetmap/josm/gui/conflict/pair/relation/RelationMemberListMergeModel.java	(working copy)
@@ -3,6 +3,8 @@
 
 import static org.openstreetmap.josm.tools.I18n.tr;
 
+import java.util.Collections;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 
@@ -67,12 +69,24 @@
     public void populate(Relation my, Relation their, Map<PrimitiveId, PrimitiveId> mergedMap) {
         initPopulate(my, their, mergedMap);
 
+        final Comparator<RelationMember> relationMemberComparator = new Comparator<RelationMember>() {
+            @Override
+            public int compare(RelationMember o1, RelationMember o2) {
+                return Long.compare(o1.getUniqueId(), o2.getUniqueId());
+            }
+
+        };
+
         for (RelationMember n : my.getMembers()) {
             getMyEntries().add(n);
         }
+        Collections.sort(getMyEntries(), relationMemberComparator);
+
         for (RelationMember n : their.getMembers()) {
             getTheirEntries().add(n);
         }
+        Collections.sort(getTheirEntries(), relationMemberComparator);
+
         if (myAndTheirEntriesEqual()) {
             for (RelationMember m : getMyEntries()) {
                 getMergedEntries().add(cloneEntryForMergedList(m));

[skyper]

Order is important but you are right that the colouring is misleading, if you have only one extra member one one side.

[Don-vip]

Your patch does not compile with Java 6. Please supply a new one, because we won't switch to Java 7 before May at best.

The method ​Long.compare(long,long) has been introduced in Java 7.

[josm@…]

RelationMemberListMergeModel.java.patch

[josm@…]

Attached updated patch. Though I'm concerened with Don comment - I haven't meet relations, where order is important, but I'm not an advanced user and I put confidence in JOSM sorting for proper ordering in relation.

On the other hand, I digged a bit into colouring algorithms and as I understand, the colours should provide already information, whether object is on list or not (but this is not explicit). So I'm not sure, whether this patch should be at all commited.

[Don-vip]

Sorry I should have looked at patch first. Yes, order of members is important, we cannot mess with it like this.

However I do agree the display in conflict editor is misleading. It looks like the "diff" code is pretty naive in conflict dialog regarding to the code existing in history dialog, which is much more efficient.

Colors are simple enough: red items are deleted on their side while orange/brown items are modified. The problem is that the conflict dialog thinks items are modified when they are not.

Please create another enhancement ticket for improving the display (reusing history code in some way would be the better approach). If you manage to get a working patch we'll probably take it with great pleasure :)