all hsitory types can summarize

worldedit-core/src/main/java/com/boydti/fawe/object/changeset/DiskStorageHistory.java

@@ -399,6 +399,7 @@ public class DiskStorageHistory extends FaweStreamChangeSet {
         return new SimpleChangeSetSummary(getOriginX(), getOriginZ());
     }
 
+    @Override
     public SimpleChangeSetSummary summarize(Region region, boolean shallow) {
         if (bdFile.exists()) {
             int ox = getOriginX();

worldedit-core/src/main/java/com/boydti/fawe/object/changeset/SimpleChangeSetSummary.java

@@ -1,3 +1,5 @@
+package com.boydti.fawe.object.changeset;
+
 import com.sk89q.worldedit.history.changeset.ChangeSetSummary;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockTypesCache;
@@ -14,6 +16,14 @@ public class SimpleChangeSetSummary implements ChangeSetSummary {
     public int maxX;
     public int maxZ;
 
+    public SimpleChangeSetSummary() {
+        blocks = new int[BlockTypesCache.states.length];
+        this.minX = Integer.MAX_VALUE;
+        this.minZ = Integer.MAX_VALUE;
+        this.maxX = Integer.MIN_VALUE;
+        this.maxZ = Integer.MIN_VALUE;
+    }
+
     public SimpleChangeSetSummary(int x, int z) {
         blocks = new int[BlockTypesCache.states.length];
         minX = x;

worldedit-core/src/main/java/com/sk89q/worldedit/history/changeset/ArrayListHistory.java

@@ -21,8 +21,12 @@ package com.sk89q.worldedit.history.changeset;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
+import com.boydti.fawe.object.changeset.SimpleChangeSetSummary;
 import com.google.common.collect.Lists;
+import com.sk89q.worldedit.history.change.BlockChange;
 import com.sk89q.worldedit.history.change.Change;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.regions.Region;
 
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -70,4 +74,16 @@ public class ArrayListHistory implements ChangeSet {
         return changes.size();
     }
 
+    @Override
+    public ChangeSetSummary summarize(Region region, boolean shallow) {
+        SimpleChangeSetSummary summary = new SimpleChangeSetSummary();
+        for (Change change : changes) {
+            if (change instanceof BlockChange) {
+                BlockChange blockChange = (BlockChange) change;
+                BlockVector3 pos = blockChange.getPosition();
+                summary.add(pos.getX(), pos.getZ(), blockChange.getCurrent().getOrdinal());
+            }
+        }
+        return summary;
+    }
 }

worldedit-core/src/main/java/com/sk89q/worldedit/history/changeset/ChangeSet.java

@@ -97,19 +97,13 @@ public interface ChangeSet extends Closeable {
      */
     default void delete() {}
 
-    ChangeSetSummary summarize(Region region, boolean shallow) {
+    /**
-        return new ChangeSetSummary() {
+     * Get a summary of this changeset
-            @Override
+     * @param region
-            public Map<BlockState, Integer> getBlocks() {
+     * @param shallow
-                return Collections.emptyMap();
+     * @return
-            }
+     */
-
+    ChangeSetSummary summarize(Region region, boolean shallow);
-            @Override
-            public int getSize() {
-                return size();
-            }
-        };
-    }
 
     /**
      * Get if the changeset is empty (i.e. size == 0)