Added support for different tree generation types and a callback.

src/main/java/org/bukkit/BlockChangeDelegate.java

@@ -0,0 +1,42 @@
+package org.bukkit;
+
+/**
+ * A delegate for handling block changes. This serves as a direct interface
+ * between generation algorithms in the server implementation and utilizing
+ * code.
+ * 
+ * @author sk89q
+ */
+public interface BlockChangeDelegate {
+    /**
+     * Set a block type at the specified coordinates.
+     * 
+     * @param x
+     * @param y
+     * @param z
+     * @param typeId
+     * @return true if the block was set successfully
+     */
+    public boolean setTypeId(int x, int y, int z, int typeId);
+
+    /**
+     * Set a block type and data at the specified coordinates.
+     * 
+     * @param x
+     * @param y
+     * @param z
+     * @param typeId
+     * @param data
+     * @return true if the block was set successfully
+     */
+    public boolean setTypeIdAndData(int x, int y, int z, int typeId, int data);
+    
+    /**
+     * Get the block type at the location.
+     * @param x
+     * @param y
+     * @param z
+     * @return
+     */
+    public int getTypeId(int x, int y, int z);
+}

src/main/java/org/bukkit/TreeType.java

@@ -0,0 +1,14 @@
+package org.bukkit;
+
+/**
+ * Tree type.
+ * 
+ * @author sk89q
+ */
+public enum TreeType {
+    TREE,
+    BIG_TREE,
+    REDWOOD,
+    TALL_REDWOOD,
+    BIRCH
+}

src/main/java/org/bukkit/World.java

@@ -115,17 +115,21 @@ public interface World {
      * Spawns a tree at a location.
      * 
      * @param loc
+     * @param type
      * @return whether the tree was created
      */
-    public boolean generateTree(Location loc);
+    public boolean generateTree(Location loc, TreeType type);
     
     /**
-     * Spawns a big tree at a location.
+     * Spawns a tree at a location.
      * 
      * @param loc
+     * @param type
+     * @param delegate
      * @return whether the tree was created
      */
-    public boolean generateBigTree(Location loc);
+    public boolean generateTree(Location loc, TreeType type,
+            BlockChangeDelegate delegate);
 
     /**
      * Spawns a regular passenger minecart.