From 65a8ff63bae4f6f2e025e3dbf0b7b8eb64193039 Mon Sep 17 00:00:00 2001
From: Erlend Åmdal
Date: Sun, 12 May 2019 09:47:41 +0200
Subject: Add forward and backward reference history with mouse navigation
 (#132)

* Add History

* Add forward and backward reference history

* Update PopupMenuBar text for history

* Fix indentation

* Fix more indentation
---
 src/main/java/cuchaz/enigma/gui/util/History.java | 49 +++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 src/main/java/cuchaz/enigma/gui/util/History.java

(limited to 'src/main/java/cuchaz/enigma/gui/util')

diff --git a/src/main/java/cuchaz/enigma/gui/util/History.java b/src/main/java/cuchaz/enigma/gui/util/History.java
new file mode 100644
index 0000000..94f3105
--- /dev/null
+++ b/src/main/java/cuchaz/enigma/gui/util/History.java
@@ -0,0 +1,49 @@
+package cuchaz.enigma.gui.util;
+
+import com.google.common.collect.Queues;
+
+import java.util.Deque;
+
+public class History<T> {
+	private final Deque<T> previous = Queues.newArrayDeque();
+	private final Deque<T> next = Queues.newArrayDeque();
+	private T current;
+
+	public History(T initial) {
+		current = initial;
+	}
+
+	public T getCurrent() {
+		return current;
+	}
+
+	public void push(T value) {
+		previous.addLast(current);
+		current = value;
+		next.clear();
+	}
+
+	public void replace(T value) {
+		current = value;
+	}
+
+	public boolean canGoBack() {
+		return !previous.isEmpty();
+	}
+
+	public T goBack() {
+		next.addFirst(current);
+		current = previous.removeLast();
+		return current;
+	}
+
+	public boolean canGoForward() {
+		return !next.isEmpty();
+	}
+
+	public T goForward() {
+		previous.addLast(current);
+		current = next.removeFirst();
+		return current;
+	}
+}
-- 
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