1 files changed, 70 insertions, 0 deletions
diff --git a/base/src/main/java/bjc/utils/ioutils/blocks/TriggeredBlockReader.java b/base/src/main/java/bjc/utils/ioutils/blocks/TriggeredBlockReader.java
new file mode 100644
index 0000000..3a1e393
--- /dev/null
+++ b/base/src/main/java/bjc/utils/ioutils/blocks/TriggeredBlockReader.java
@@ -0,0 +1,70 @@
+package bjc.utils.ioutils.blocks;
+
+import java.io.IOException;
+
+/**
+ * A block reader that fires an action before a block is actually read.
+ *
+ * @author bjculkin
+ *
+ */
+public class TriggeredBlockReader implements BlockReader {
+	private final BlockReader source;
+
+	private int blockNo;
+
+	/*
+	 * The action to fire.
+	 */
+	private final Runnable action;
+
+	/**
+	 * Create a new triggered reader with the specified source/action.
+	 *
+	 * @param source
+	 *                The block reader to read blocks from.
+	 *
+	 * @param action
+	 *                The action to execute before reading a block.
+	 */
+	public TriggeredBlockReader(final BlockReader source, final Runnable action) {
+		this.source = source;
+		this.action = action;
+
+		blockNo = 0;
+	}
+
+	@Override
+	public boolean hasNextBlock() {
+		action.run();
+
+		return source.hasNextBlock();
+	}
+
+	@Override
+	public Block getBlock() {
+		return source.getBlock();
+	}
+
+	@Override
+	public boolean nextBlock() {
+		blockNo += 1;
+
+		return source.nextBlock();
+	}
+
+	@Override
+	public int getBlockCount() {
+		return blockNo;
+	}
+
+	@Override
+	public void close() throws IOException {
+		source.close();
+	}
+
+	@Override
+	public String toString() {
+		return String.format("TriggeredBlockReader [source=%s]", source);
+	}
+}