Add comments

megameklab/src/megameklab/ui/MegaMekLabTabbedUI.java

@@ -91,6 +91,9 @@ public MegaMekLabTabbedUI(MegaMekLabMainUI... entities) {
         // Enable opening unit and mul files by drag-and-drop
         setTransferHandler(new MMLFileDropTransferHandler(this));
 
+        // If you can think of a way to detect when the user makes a change to the entity, let me know.
+        // I can't, so we just poll the entity for changed to set the "unsaved work" indicator periodically
+        // --Pavel Braginskiy (cat /dev/random)
         new Timer(500, e -> checkChanged(tabs.getSelectedIndex())).start();
 
         // Remember the size and position of the window from last time MML was launched
@@ -240,6 +243,7 @@ private boolean exitPrompt() {
         if (CConfig.getBooleanParam(CConfig.MISC_SKIP_SAFETY_PROMPTS)) {
             return true;
         }
+        // No editors have changes, no need to prompt for saving
         if (editors.stream().limit(editors.size() - 1).noneMatch(EntityChangedUtil::hasEntityChanged)) {
             return true;
         }
@@ -251,13 +255,16 @@ private boolean exitPrompt() {
         if (savePrompt == JOptionPane.NO_OPTION) {
             return true;
         }
+        // For each editor with unsaved changes, switch to that editor and save it.
         if (savePrompt == JOptionPane.YES_OPTION) {
             return editors.stream().limit(editors.size() - 1)
                 .filter(EntityChangedUtil::hasEntityChanged)
                 .noneMatch(editor -> {
                     tabs.setSelectedComponent(editor.getContentPane());
+                    // paintImmediately means that the user can see which unit they're about to pick a file for
+                    // because it updates the UI without waiting for this method to return
                     tabs.paintImmediately(tabs.getBounds());
-                    return !editor.getMMLMenuBar().saveUnit();
+                    return !menuBar.saveUnit();
                 });
         }
         return false;

megameklab/src/megameklab/util/EntityChangedUtil.java

@@ -33,17 +33,28 @@
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
+/**
+ * Helps to determine if a tab should have an "Unsaved Work" indicator and if the "would you like to save" prompt should appear.
+ */
 public class EntityChangedUtil {
     private static final MMLogger logger = MMLogger.create(EntityChangedUtil.class);
 
     private static final Map<String, Entity> cache = new ConcurrentHashMap<>();
 
+    /**
+     * Determines if the editor has unsaved changes.
+     * @param editor The MainUI to check for changes
+     * @return true if saving the unit would produce a different unit than the one saved already, or if there is no existing file for the unit.
+     */
     public static boolean hasEntityChanged(MegaMekLabMainUI editor) {
         var filename = editor.getFileName();
         if (filename == null || filename.isBlank()) {
             return true;
         }
 
+        // The idea behind how this works is to store a copy of the unit based on that unit's current file.
+        // By encoding both the original and current version of the entity to mtf/blk at the same time,
+        // We ensure that identical units will encode to identical mtf/blk strings, which indicates no unsaved work.
 
         if (!cache.containsKey(filename)) {
             var f = new File(filename);
@@ -70,6 +81,10 @@ public static boolean hasEntityChanged(MegaMekLabMainUI editor) {
         }
     }
 
+    /**
+     *
+     * @param editor The editor containing the unit that was just saved.
+     */
     public static void editorSaved(MegaMekLabMainUI editor) {
         var filename = editor.getFileName();
         if (filename == null || filename.isBlank()) {