Clean up some code in HistoryPanel. No logic changes. (#10482)

game-app/game-core/src/main/java/games/strategy/triplea/ui/history/HistoryPanel.java

@@ -1,5 +1,6 @@
 package games.strategy.triplea.ui.history;
 
+import com.google.common.base.Preconditions;
 import games.strategy.engine.data.GameData;
 import games.strategy.engine.data.GamePlayer;
 import games.strategy.engine.history.HistoryNode;
@@ -12,11 +13,13 @@
 import java.awt.GridBagLayout;
 import java.awt.Insets;
 import java.awt.Rectangle;
+import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 import java.awt.event.MouseListener;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Deque;
 import java.util.Enumeration;
 import java.util.Optional;
@@ -57,19 +60,11 @@ public HistoryPanel(
       final HistoryDetailsPanel details,
       final JPopupMenu popup,
       final UiContext uiContext) {
-    mouseOverPanel = false;
-    mouseWasOverPanel = false;
+    Preconditions.checkState(data.areChangesOnlyInSwingEventThread());
+    this.data = data;
+    this.details = details;
     final MouseListener mouseFocusListener =
-        new MouseListener() {
-          @Override
-          public void mouseReleased(final MouseEvent e) {}
-
-          @Override
-          public void mousePressed(final MouseEvent e) {}
-
-          @Override
-          public void mouseClicked(final MouseEvent e) {}
-
+        new MouseAdapter() {
           @Override
           public void mouseExited(final MouseEvent e) {
             mouseOverPanel = false;
@@ -81,12 +76,7 @@ public void mouseEntered(final MouseEvent e) {
           }
         };
     addMouseListener(mouseFocusListener);
-    this.data = data;
-    this.details = details;
     setLayout(new BorderLayout());
-    if (!this.data.areChangesOnlyInSwingEventThread()) {
-      throw new IllegalStateException();
-    }
     tree = new JTree(this.data.getHistory());
     // Register the tree with the tooltip manager to make the tooltips we set work.
     ToolTipManager.sharedInstance().registerComponent(tree);
@@ -166,7 +156,7 @@ public void popupMenuWillBecomeVisible(final PopupMenuEvent pme) {}
             0));
     add(buttons, BorderLayout.SOUTH);
     tree.addMouseListener(
-        new MouseListener() {
+        new MouseAdapter() {
           @Override
           public void mouseClicked(final MouseEvent me) {
             if (SwingUtilities.isRightMouseButton(me)) {
@@ -204,12 +194,6 @@ public void mouseEntered(final MouseEvent me) {
           public void mouseExited(final MouseEvent me) {
             mouseOverPanel = false;
           }
-
-          @Override
-          public void mousePressed(final MouseEvent me) {}
-
-          @Override
-          public void mouseReleased(final MouseEvent me) {}
         });
     tree.addTreeSelectionListener(this::treeSelectionChanged);
   }
@@ -219,8 +203,7 @@ private void previous() {
       tree.setSelectionInterval(0, 0);
       return;
     }
-    final TreePath path = tree.getSelectionPath();
-    final TreeNode selected = (TreeNode) path.getLastPathComponent();
+    final TreeNode selected = getCurrentNode();
     final Enumeration<TreeNode> nodeEnum =
         ((DefaultMutableTreeNode) tree.getModel().getRoot()).depthFirstEnumeration();
     TreeNode previous = null;
@@ -261,8 +244,7 @@ private void next() {
       tree.setSelectionInterval(0, 0);
       return;
     }
-    final TreePath path = tree.getSelectionPath();
-    final TreeNode selected = (TreeNode) path.getLastPathComponent();
+    final TreeNode selected = getCurrentNode();
     final Enumeration<TreeNode> nodeEnum =
         ((DefaultMutableTreeNode) tree.getModel().getRoot()).preorderEnumeration();
     TreeNode next = null;
@@ -318,14 +300,6 @@ public void clearCurrentPopupNode() {
     currentPopupNode = null;
   }
 
-  private void addToStayExpanded(final Enumeration<TreePath> paths) {
-    final Collection<TreePath> expandPaths = new ArrayList<>();
-    while (paths.hasMoreElements()) {
-      expandPaths.add(paths.nextElement());
-    }
-    stayExpandedPaths.addAll(expandPaths);
-  }
-
   /**
    * collapses parents of last path if it is not in the list of expanded path until the new path is
    * a descendant.
@@ -348,12 +322,7 @@ private void collapseUpFromLastParent(final TreePath newPath) {
    * @param parentPath tree path for which descendants should be check.
    */
   private boolean stayExpandedContainsDescendantOf(final TreePath parentPath) {
-    for (final TreePath currentPath : stayExpandedPaths) {
-      if (parentPath.isDescendant(currentPath)) {
-        return true;
-      }
-    }
-    return false;
+    return stayExpandedPaths.stream().anyMatch(parentPath::isDescendant);
   }
 
   /**
@@ -392,11 +361,8 @@ private void collapseExpanded(final TreePath newPath) {
   /** Selects the most recent history node, expanding the tree if necessary. */
   public void goToEnd() {
     final HistoryNode last;
-    try {
-      data.acquireWriteLock();
+    try (GameData.Unlocker ignored = data.acquireWriteLock()) {
       last = data.getHistory().getLastNode();
-    } finally {
-      data.releaseWriteLock();
     }
     final TreePath path = new TreePath(last.getPath());
     final TreePath parent = path.getParentPath();
@@ -411,7 +377,7 @@ public void goToEnd() {
       collapseExpanded(path);
       collapseUpFromLastParent(parent);
       final Rectangle rect = tree.getPathBounds(path);
-      rect.setRect(0, rect.getY(), rect.getWidth(), rect.getHeight());
+      rect.x = 0;
       tree.scrollRectToVisible(rect);
     } else {
       if (!mouseWasOverPanel) {
@@ -422,7 +388,7 @@ public void goToEnd() {
           root = root.getParentPath();
         }
         final Enumeration<TreePath> expandedDescendants = tree.getExpandedDescendants(root);
-        addToStayExpanded(expandedDescendants);
+        stayExpandedPaths.addAll(Collections.list(expandedDescendants));
       } else {
         collapseUpFromLastParent(parent);
       }