Added basic undo/redo functionality with a history size of 15.

manifest.mf

@@ -1,3 +1,3 @@
 Manifest-Version: 1.0
-Class-Path: js.jar
+Class-Path: js.jar commons-lang3-3.0-beta.jar
 

src/EditScriptMinecraftContext.java

@@ -22,6 +22,17 @@
  * @author Albert
  */
 public class EditScriptMinecraftContext {
+    private EditSession editSession;
+
+    /**
+     * Construct this Minecraft object with an EditSession.
+     * 
+     * @param editSession
+     */
+    public EditScriptMinecraftContext(EditSession editSession) {
+        this.editSession = editSession;
+    }
+    
     /**
      * Sets the block at position x, y, z with a block type.
      *
@@ -32,7 +43,7 @@ public class EditScriptMinecraftContext {
      * @return
      */
     public boolean setBlock(int x, int y, int z, int blockType) {
-        return etc.getMCServer().e.d(x, y, z, blockType);
+        return editSession.setBlock(x, y, z, blockType);
     }
 
     /**
@@ -44,6 +55,6 @@ public class EditScriptMinecraftContext {
      * @return
      */
     public int getBlock(int x, int y, int z) {
-        return etc.getMCServer().e.a(x, y, z);
+        return editSession.getBlock(x, y, z);
     }
 }

src/EditSession.java

@@ -0,0 +1,107 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010 sk89q <http://www.sk89q.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+import java.util.Map;
+import java.util.HashMap;
+import com.sk89q.worldedit.*;
+
+/**
+ *
+ * @author Albert
+ */
+public class EditSession {
+    /**
+     * Stores the original blocks before modification.
+     */
+    private HashMap<Point,Integer> original = new HashMap<Point,Integer>();
+    private HashMap<Point,Integer> current = new HashMap<Point,Integer>();
+
+    /**
+     * Sets a block without changing history.
+     * 
+     * @param x
+     * @param y
+     * @param z
+     * @param blockType
+     * @return Whether the block changed
+     */
+    private boolean rawSetBlock(int x, int y, int z, int blockType) {
+        return etc.getMCServer().e.d(x, y, z, blockType);
+    }
+    
+    /**
+     * Sets the block at position x, y, z with a block type.
+     *
+     * @param x
+     * @param y
+     * @param z
+     * @param blockType
+     * @return Whether the block changed
+     */
+    public boolean setBlock(int x, int y, int z, int blockType) {
+        Point pt = new Point(x, y, z);
+        if (!original.containsKey(pt)) {
+            original.put(pt, getBlock(x, y, z));
+        }
+        current.put(pt, blockType);
+        return rawSetBlock(x, y, z, blockType);
+    }
+
+    /**
+     * Gets the block type at a position x, y, z.
+     *
+     * @param x
+     * @param y
+     * @param z
+     * @return Block type
+     */
+    public int getBlock(int x, int y, int z) {
+        return etc.getMCServer().e.a(x, y, z);
+    }
+
+    /**
+     * Restores all blocks to their initial state.
+     */
+    public void undo() {
+        for (Map.Entry<Point,Integer> entry : original.entrySet()) {
+            Point pt = (Point)entry.getKey();
+            rawSetBlock((int)pt.getX(), (int)pt.getY(),(int)pt.getZ(),
+                        (int)entry.getValue());
+        }
+    }
+
+    /**
+     * Sets to new state.
+     */
+    public void redo() {
+        for (Map.Entry<Point,Integer> entry : current.entrySet()) {
+            Point pt = (Point)entry.getKey();
+            rawSetBlock((int)pt.getX(), (int)pt.getY(),(int)pt.getZ(),
+                        (int)entry.getValue());
+        }
+    }
+
+    /**
+     * Get the number of changed blocks.
+     * 
+     */
+    public int size() {
+        return original.size();
+    }
+}

src/WorldEdit.java

@@ -39,6 +39,8 @@ public class WorldEdit extends Plugin {
 
         commands.put("/editpos1", "Set editing position #1");
         commands.put("/editpos2", "Set editing position #2");
+        commands.put("/editundo", "Undo");
+        commands.put("/editredo", "Redo");
         commands.put("/editsize", "Get size of selected region");
         commands.put("/editset", "<Type> - Set all  blocks inside region");
         commands.put("/editreplace", "<ID> - Replace all existing blocks inside region");
@@ -128,31 +130,6 @@ public class WorldEdit extends Plugin {
         }
     }
 
-    /**
-     * Sets the block at position x, y, z with a block type.
-     *
-     * @param x
-     * @param y
-     * @param z
-     * @param blockType
-     * @return
-     */
-    private boolean setBlock(int x, int y, int z, int blockType) {
-        return etc.getMCServer().e.d(x, y, z, blockType);
-    }
-
-    /**
-     * Gets the block type at a position x, y, z.
-     *
-     * @param x
-     * @param y
-     * @param z
-     * @return
-     */
-    private int getBlock(int x, int y, int z) {
-        return etc.getMCServer().e.a(x, y, z);
-    }
-
     /**
      *
      * @override
@@ -214,6 +191,7 @@ public class WorldEdit extends Plugin {
                    InsufficientArgumentsException, DisallowedItemException
     {
         WorldEditSession session = getSession(player);
+        EditSession editSession = new EditSession();
 
         // Set edit position #1
         if (split[0].equalsIgnoreCase("/editpos1")) {
@@ -231,6 +209,24 @@ public class WorldEdit extends Plugin {
             player.sendMessage(Colors.LightPurple + "Second edit position set.");
             return true;
 
+        // Undo
+        } else if (split[0].equalsIgnoreCase("/editundo")) {
+            if (session.undo()) {
+                player.sendMessage(Colors.LightPurple + "Undo successful.");
+            } else {
+                player.sendMessage(Colors.Rose + "Nothing to undo.");
+            }
+            return true;
+
+        // Redo
+        } else if (split[0].equalsIgnoreCase("/editredo")) {
+            if (session.redo()) {
+                player.sendMessage(Colors.LightPurple + "Redo successful.");
+            } else {
+                player.sendMessage(Colors.Rose + "Nothing to redo.");
+            }
+            return true;
+
         // Fill a hole
         } else if (split[0].equalsIgnoreCase("/editfill")) {
             checkArgs(split, 1);
@@ -243,11 +239,14 @@ public class WorldEdit extends Plugin {
             int cz = (int)Math.floor(player.getZ());
             int minY = Math.max(-128, cy - depth);
 
-            int affected = fill(cx, cz, cx, cy, cz, blockType, radius, minY);
+            int affected = fill(editSession, cx, cz, cx, cy, cz,
+                                blockType, radius, minY);
 
             logger.log(Level.INFO, player.getName() + " used /editfill");
             player.sendMessage(Colors.LightPurple + affected + " block(s) have been created.");
 
+            session.remember(editSession);
+
             return true;
 
         // Remove blocks above current position
@@ -262,8 +261,8 @@ public class WorldEdit extends Plugin {
             for (int x = cx - size; x <= cx + size; x++) {
                 for (int z = cz - size; z <= cz + size; z++) {
                     for (int y = cy; y <= 127; y++) {
-                        if (getBlock(x, y, z) != 0) {
+                        if (editSession.getBlock(x, y, z) != 0) {
-                            setBlock(x, y, z, 0);
+                            editSession.setBlock(x, y, z, 0);
                             affected++;
                         }
                     }
@@ -273,6 +272,8 @@ public class WorldEdit extends Plugin {
             logger.log(Level.INFO, player.getName() + " used /removeabove");
             player.sendMessage(Colors.LightPurple + affected + " block(s) have been removed.");
 
+            session.remember(editSession);
+
             return true;
 
         // Run an editscript
@@ -321,7 +322,8 @@ public class WorldEdit extends Plugin {
                             Context.javaToJS(scriptPlayer, scope));
 
                         // Add Minecraft context
-                        EditScriptMinecraftContext minecraft = new EditScriptMinecraftContext();
+                        EditScriptMinecraftContext minecraft =
+                            new EditScriptMinecraftContext(editSession);
                         ScriptableObject.putProperty(scope, "minecraft",
                             Context.javaToJS(minecraft, scope));
 
@@ -332,6 +334,7 @@ public class WorldEdit extends Plugin {
                         re.printStackTrace();
                     } finally {
                         Context.exit();
+                        session.remember(editSession);
                     }
 
                     return true;
@@ -363,7 +366,7 @@ public class WorldEdit extends Plugin {
             for (int x = lowerX; x <= upperX; x++) {
                 for (int y = lowerY; y <= upperY; y++) {
                     for (int z = lowerZ; z <= upperZ; z++) {
-                        setBlock(x, y, z, blockType);
+                        editSession.setBlock(x, y, z, blockType);
                         affected++;
                     }
                 }
@@ -372,6 +375,8 @@ public class WorldEdit extends Plugin {
             logger.log(Level.INFO, player.getName() + " used /editset");
             player.sendMessage(Colors.LightPurple + affected + " block(s) have been set.");
 
+            session.remember(editSession);
+
             return true;
 
         // Replace all blocks in the region
@@ -384,8 +389,8 @@ public class WorldEdit extends Plugin {
             for (int x = lowerX; x <= upperX; x++) {
                 for (int y = lowerY; y <= upperY; y++) {
                     for (int z = lowerZ; z <= upperZ; z++) {
-                        if (getBlock(x, y, z) != 0) {
+                        if (editSession.getBlock(x, y, z) != 0) {
-                            setBlock(x, y, z, blockType);
+                            editSession.setBlock(x, y, z, blockType);
                             affected++;
                         }
                     }
@@ -395,6 +400,8 @@ public class WorldEdit extends Plugin {
             logger.log(Level.INFO, player.getName() + " used /editreplace");
             player.sendMessage(Colors.LightPurple + affected + " block(s) have been replaced.");
 
+            session.remember(editSession);
+
             return true;
 
         // Lay blocks over an area
@@ -411,8 +418,8 @@ public class WorldEdit extends Plugin {
             for (int x = lowerX; x <= upperX; x++) {
                 for (int z = lowerZ; z <= upperZ; z++) {
                     for (int y = upperY; y >= lowerY; y--) {
-                        if (y + 1 <= 127 && getBlock(x, y, z) != 0 && getBlock(x, y + 1, z) == 0) {
+                        if (y + 1 <= 127 && editSession.getBlock(x, y, z) != 0 && editSession.getBlock(x, y + 1, z) == 0) {
-                            setBlock(x, y + 1, z, blockType);
+                            editSession.setBlock(x, y + 1, z, blockType);
                             affected++;
                             break;
                         }
@@ -423,13 +430,16 @@ public class WorldEdit extends Plugin {
             logger.log(Level.INFO, player.getName() + " used /editoverlay");
             player.sendMessage(Colors.LightPurple + affected + " block(s) have been overlayed.");
 
+            session.remember(editSession);
+
             return true;
         }
 
         return false;
     }
 
-    private int fill(int x, int z, int cx, int cy, int cz, int blockType, int radius, int minY) {
+    private int fill(EditSession editSession, int x, int z, int cx, int cy,
+                     int cz, int blockType, int radius, int minY) {
         double dist = Math.sqrt(Math.pow(cx - x, 2) + Math.pow(cz - z, 2));
         int affected = 0;
         
@@ -437,26 +447,27 @@ public class WorldEdit extends Plugin {
             return 0;
         }
 
-        if (getBlock(x, cy, z) == 0) {
+        if (editSession.getBlock(x, cy, z) == 0) {
-            affected = fillY(x, cy, z, blockType, minY);
+            affected = fillY(editSession, x, cy, z, blockType, minY);
         } else {
             return 0;
         }
         
-        affected += fill(x + 1, z, cx, cy, cz, blockType, radius, minY);
+        affected += fill(editSession, x + 1, z, cx, cy, cz, blockType, radius, minY);
-        affected += fill(x - 1, z, cx, cy, cz, blockType, radius, minY);
+        affected += fill(editSession, x - 1, z, cx, cy, cz, blockType, radius, minY);
-        affected += fill(x, z + 1, cx, cy, cz, blockType, radius, minY);
+        affected += fill(editSession, x, z + 1, cx, cy, cz, blockType, radius, minY);
-        affected += fill(x, z - 1, cx, cy, cz, blockType, radius, minY);
+        affected += fill(editSession, x, z - 1, cx, cy, cz, blockType, radius, minY);
 
         return affected;
     }
 
-    private int fillY(int x, int cy, int z, int blockType, int minY) {
+    private int fillY(EditSession editSession, int x, int cy,
+                      int z, int blockType, int minY) {
         int affected = 0;
         
         for (int y = cy; y > minY; y--) {
-            if (getBlock(x, y, z) == 0) {
+            if (editSession.getBlock(x, y, z) == 0) {
-                setBlock(x, y, z, blockType);
+                editSession.setBlock(x, y, z, blockType);
                 affected++;
             } else {
                 break;

src/WorldEditSession.java

@@ -18,16 +18,71 @@
 */
 
 import com.sk89q.worldedit.*;
+import java.util.LinkedList;
 
 /**
  *
  * @author sk89q
  */
 public class WorldEditSession {
+    public static final int MAX_HISTORY_SIZE = 15;
     private int[] pos1 = new int[3];
     private int[] pos2 = new int[3];
     private boolean hasSetPos1 = false;
     private boolean hasSetPos2 = false;
+    private LinkedList<EditSession> history = new LinkedList<EditSession>();
+    private int historyPointer = 0;
+
+    /**
+     * Get the edit session.
+     *
+     * @return
+     */
+    public void remember(EditSession editSession) {
+        // Don't store anything if no changes were made
+        if (editSession.size() == 0) { return; }
+
+        // Destroy any sessions after this undo point
+        while (historyPointer < history.size()) {
+            history.remove(historyPointer);
+        }
+        history.add(editSession);
+        while (history.size() > MAX_HISTORY_SIZE) {
+            history.remove(0);
+        }
+        historyPointer = history.size();
+    }
+
+    /**
+     * Undo.
+     *
+     * @return whether anything was undoed
+     */
+    public boolean undo() {
+        historyPointer--;
+        if (historyPointer >= 0) {
+            history.get(historyPointer).undo();
+            return true;
+        } else {
+            historyPointer = 0;
+            return false;
+        }
+    }
+
+    /**
+     * Redo.
+     *
+     * @return whether anything was redoed
+     */
+    public boolean redo() {
+        if (historyPointer < history.size()) {
+            history.get(historyPointer).redo();
+            historyPointer++;
+            return true;
+        }
+
+        return false;
+    }
 
     private void checkPos1() throws IncompleteRegionException {
         if (!hasSetPos1) {

src/com/sk89q/worldedit/Point.java

@@ -0,0 +1,75 @@
+// $Id$
+/*
+ * WorldEdit
+ * Copyright (C) 2010 sk89q <http://www.sk89q.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package com.sk89q.worldedit;
+
+import org.apache.commons.lang3.builder.HashCodeBuilder;
+
+/**
+ *
+ * @author Albert
+ */
+public final class Point {
+    private final double x, y, z;
+
+    public Point(double x, double y, double z) {
+        this.x = x;
+        this.y = y;
+        this.z = z;
+    }
+
+    /**
+     * @return the x
+     */
+    public double getX() {
+        return x;
+    }
+
+
+    /**
+     * @return the y
+     */
+    public double getY() {
+        return y;
+    }
+
+    /**
+     * @return the z
+     */
+    public double getZ() {
+        return z;
+    }
+
+    public boolean equals(Object obj) {
+        if (!(obj instanceof Point)) {
+            return false;
+        }
+        Point other = (Point)obj;
+        return other.x == x && other.y == y && other.z == z;
+    }
+
+    public int hashCode() {
+        return new HashCodeBuilder(451, 41).
+            append(x).
+            append(y).
+            append(z).
+            toHashCode();
+    }
+
+}