Added ExtentBuffer to buffer changes to Extents.

src/main/java/com/sk89q/worldedit/extent/ExtentBuffer.java

@@ -0,0 +1,171 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * 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.extent;
+
+import com.sk89q.worldedit.BlockVector;
+import com.sk89q.worldedit.Extent;
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.blocks.BaseBlock;
+import com.sk89q.worldedit.blocks.BlockID;
+import com.sk89q.worldedit.function.mask.Mask;
+import com.sk89q.worldedit.function.mask.Masks;
+import com.sk89q.worldedit.patterns.Pattern;
+import com.sk89q.worldedit.regions.AbstractRegion;
+import com.sk89q.worldedit.regions.Region;
+import com.sk89q.worldedit.regions.RegionOperationException;
+
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Buffers changes to an {@link Extent} and allows later retrieval of buffered
+ * changes for actual setting.
+ */
+public class ExtentBuffer implements Extent, Pattern {
+
+    private static final BaseBlock AIR = new BaseBlock(BlockID.AIR);
+
+    private final Extent delegate;
+    private final Map<BlockVector, BaseBlock> buffer = new LinkedHashMap<BlockVector, BaseBlock>();
+    private final Mask mask;
+    private Vector min = null;
+    private Vector max = null;
+
+    /**
+     * Create a new extent buffer that will buffer every change.
+     *
+     * @param delegate the delegate extent for {@link Extent#getBlock(Vector)}, etc. calls
+     */
+    public ExtentBuffer(Extent delegate) {
+        this(delegate, Masks.alwaysTrue());
+    }
+
+    /**
+     * Create a new extent buffer that will buffer changes that meet the criteria
+     * of the given mask.
+     *
+     * @param delegate the delegate extent for {@link Extent#getBlock(Vector)}, etc. calls
+     * @param mask the mask
+     */
+    public ExtentBuffer(Extent delegate, Mask mask) {
+        checkNotNull(delegate);
+        checkNotNull(mask);
+        this.delegate = delegate;
+        this.mask = mask;
+    }
+
+    @Override
+    public BaseBlock getBlock(Vector location) {
+        return delegate.getBlock(location);
+    }
+
+    @Override
+    public int getBlockType(Vector location) {
+        return delegate.getBlockType(location);
+    }
+
+    @Override
+    public int getBlockData(Vector location) {
+        return delegate.getBlockData(location);
+    }
+
+    @Override
+    public boolean setBlock(Vector location, BaseBlock block, boolean notifyAdjacent) throws WorldEditException {
+        // Update minimum
+        if (min == null) {
+            min = location;
+        } else {
+            min = Vector.getMinimum(min, location);
+        }
+
+        // Update maximum
+        if (max == null) {
+            max = location;
+        } else {
+            max = Vector.getMaximum(max, location);
+        }
+
+        BlockVector blockVector = location.toBlockVector();
+        if (mask.test(blockVector)) {
+            buffer.put(blockVector, block);
+            return true;
+        } else {
+            return delegate.setBlock(location, block, notifyAdjacent);
+        }
+    }
+
+    @Override
+    public BaseBlock next(Vector pos) {
+        BaseBlock block = buffer.get(pos.toBlockVector());
+        if (block != null) {
+            return block;
+        } else {
+            return AIR;
+        }
+    }
+
+    @Override
+    public BaseBlock next(int x, int y, int z) {
+        return next(new Vector(x, y, z));
+    }
+
+    /**
+     * Return a region representation of this buffer.
+     *
+     * @return a region
+     */
+    public Region asRegion() {
+        return new AbstractRegion(null) {
+            @Override
+            public Vector getMinimumPoint() {
+                return min != null ? min : new Vector();
+            }
+
+            @Override
+            public Vector getMaximumPoint() {
+                return max != null ? max : new Vector();
+            }
+
+            @Override
+            public void expand(Vector... changes) throws RegionOperationException {
+                throw new UnsupportedOperationException("Cannot change the size of this region");
+            }
+
+            @Override
+            public void contract(Vector... changes) throws RegionOperationException {
+                throw new UnsupportedOperationException("Cannot change the size of this region");
+            }
+
+            @Override
+            public boolean contains(Vector pt) {
+                return buffer.containsKey(pt.toBlockVector());
+            }
+
+            @Override
+            public Iterator<BlockVector> iterator() {
+                return buffer.keySet().iterator();
+            }
+        };
+    }
+}