1 files changed, 63 insertions, 0 deletions
diff --git a/base/src/main/java/bjc/utils/ioutils/blocks/ToggledBlockReader.java b/base/src/main/java/bjc/utils/ioutils/blocks/ToggledBlockReader.java
new file mode 100644
index 0000000..8f39b8f
--- /dev/null
+++ b/base/src/main/java/bjc/utils/ioutils/blocks/ToggledBlockReader.java
@@ -0,0 +1,63 @@
+package bjc.utils.ioutils.blocks;
+
+import java.io.IOException;
+
+import bjc.utils.data.BooleanToggle;
+
+public class ToggledBlockReader implements BlockReader {
+	private BlockReader leftSource;
+	private BlockReader rightSource;
+
+	/*
+	 * We choose the left source when this is true.
+	 */
+	private BooleanToggle leftToggle;
+
+	private int blockNo;
+
+	public ToggledBlockReader(BlockReader left, BlockReader right) {
+		leftSource  = left;
+		rightSource = right;
+
+		blockNo = 0;
+
+		leftToggle = new BooleanToggle();
+	}
+
+	@Override
+	public boolean hasNextBlock() {
+		if(leftToggle.peek()) return leftSource.hasNextBlock();
+		else                  return rightSource.hasNextBlock();
+	}
+
+	@Override
+	public Block getBlock() {
+		if(leftToggle.peek()) return leftSource.getBlock();
+		else                  return rightSource.getBlock();
+	}
+
+	@Override
+	public boolean nextBlock() {
+		boolean succ;
+
+		if(leftToggle.get()) {
+			succ = leftSource.nextBlock();
+		} else {
+			succ = rightSource.nextBlock();
+		}
+
+		if(succ) blockNo += 1;
+		return succ;
+	}
+
+	@Override
+	public int getBlockCount() {
+		return blockNo;
+	}
+	
+	@Override
+	public void close() throws IOException {
+		leftSource.close();
+		rightSource.close();
+	}
+}