gui: Implement undo engine [WIP]

src/main/java/me/jamiemansfield/symphony/undo/MappingUndoables.java

@@ -0,0 +1,38 @@
+//******************************************************************************
+// Copyright (c) Jamie Mansfield <https://jamiemansfield.me/>
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+//******************************************************************************
+
+package me.jamiemansfield.symphony.undo;
+
+import org.cadixdev.lorenz.model.Mapping;
+
+public final class MappingUndoables {
+
+    public static Undoable remapMapping(final Mapping<?, ?> mapping, final String deobf) {
+        // Store original deobf value
+        final String originalDeobf = mapping.getDeobfuscatedName();
+        return new Undoable() {
+            @Override
+            public String getTitle() {
+                return "Remapping " + originalDeobf;
+            }
+
+            @Override
+            public void apply() {
+                mapping.setDeobfuscatedName(deobf);
+            }
+
+            @Override
+            public void unapply() {
+                mapping.setDeobfuscatedName(originalDeobf);
+            }
+        };
+    }
+
+    private MappingUndoables() {
+    }
+
+}

src/main/java/me/jamiemansfield/symphony/undo/UndoManager.java

@@ -0,0 +1,12 @@
+//******************************************************************************
+// Copyright (c) Jamie Mansfield <https://jamiemansfield.me/>
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+//******************************************************************************
+
+package me.jamiemansfield.symphony.undo;
+
+public class UndoManager {
+
+}

src/main/java/me/jamiemansfield/symphony/undo/Undoable.java

@@ -0,0 +1,35 @@
+//******************************************************************************
+// Copyright (c) Jamie Mansfield <https://jamiemansfield.me/>
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+//******************************************************************************
+
+package me.jamiemansfield.symphony.undo;
+
+/**
+ * An action that can be undone, and redone.
+ *
+ * @author Jamie Mansfield
+ * @since 0.1.0
+ */
+public interface Undoable {
+
+    /**
+     * Gets the title of the undoable action.
+     *
+     * @return The title
+     */
+    String getTitle();
+
+    /**
+     * Applies the action.
+     */
+    void apply();
+
+    /**
+     * Un-applies the action, reverting to the original state.
+     */
+    void unapply();
+
+}