GT-3222 - review fixes

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/NextPreviousDataTypeAction.java

@@ -66,22 +66,17 @@ public NextPreviousDataTypeAction(DataTypesProvider provider, String owner, bool
 
 	@Override
 	public void actionPerformed(ActionContext context) {
-		if (isNext) {
-			history.goForward();
-		}
-		else {
-			history.goBack();
-		}
+		// rely on the individual actions to navigate, as they know them item that is being
+		// navigated to, allowing them to skip through the list
+		List<DockingActionIf> actions = getActionList(context);
+		DockingActionIf action = actions.get(0);
+		action.actionPerformed(context);
 		provider.contextChanged();
 	}
 
 	@Override
 	public boolean isEnabledForContext(ActionContext context) {
-
-		if (isNext) {
-			return history.hasNext();
-		}
-		return history.hasPrevious();
+		return !getActionList(context).isEmpty();
 	}
 
 	@Override
@@ -111,7 +106,7 @@ private List<DockingActionIf> createNavigationActions() {
 				results.add(createHorizontalRule(lastDtm, dtm));
 			}
 
-			results.add(new NavigationAction(dt.getDisplayName()));
+			results.add(new NavigationAction(url, dt));
 			lastDtm = dtm;
 		}
 
@@ -129,21 +124,28 @@ private DockingActionIf createHorizontalRule(DataTypeManager lastDtm, DataTypeMa
 
 	private class NavigationAction extends DockingAction {
 
-		private NavigationAction(String dtDisplayName) {
+		private DataTypeUrl url;
+
+		private NavigationAction(DataTypeUrl url, DataType dt) {
 			super("DataTypeNavigationAction_" + ++navigationActionIdCount, owner);
+			this.url = url;
 
-			setMenuBarData(new MenuData(new String[] { dtDisplayName }));
+			setMenuBarData(new MenuData(new String[] { dt.getDisplayName() }));
 			setEnabled(true);
 			setHelpLocation(new HelpLocation("DataTypeManagerPlugin", "Navigation_Actions"));
 		}
 
 		@Override
 		public void actionPerformed(ActionContext context) {
+
+			// note: we use 'goBackTo()' and 'goForwardTo()' since items in the history list
+			//       may not have been added to the multi-action; we have to tell the list
+			//       to skip those items.
 			if (isNext) {
-				history.goForward();
+				history.goForwardTo(url);
 			}
 			else {
-				history.goBack();
+				history.goBackTo(url);
 			}
 			provider.contextChanged();
 		}

Ghidra/Framework/Generic/src/main/java/util/HistoryList.java

@@ -175,6 +175,18 @@ public void goBack() {
 		broadcast(t);
 	}
 
+	/**
+	 * Performs a {@link #goBack()} until the given item becomes the current item.  This is 
+	 * useful if you wish to go backward to a specific item in the list.
+	 * 
+	 * @param t the item
+	 */
+	public void goBackTo(T t) {
+		while (!getCurrentHistoryItem().equals(t) && hasPrevious()) {
+			goBack();
+		}
+	}
+
 	/**
 	 * Moves this history list's current item pointer forward one and then calls the user-provided
 	 * callback to signal the newly selected item.
@@ -190,6 +202,18 @@ public void goForward() {
 		broadcast(t);
 	}
 
+	/**
+	 * Performs a {@link #goForward()} until the given item becomes the current item.  This is 
+	 * useful if you wish to go forward to a specific item in the list.
+	 * 
+	 * @param t the item
+	 */
+	public void goForwardTo(T t) {
+		while (!getCurrentHistoryItem().equals(t) && hasNext()) {
+			goForward();
+		}
+	}
+
 	/**
 	 * Returns the item currently pointed to within the list of items.  When an item is 
 	 * added, this will be that item.  Otherwise, it will be the last item navigated.

Ghidra/Framework/Generic/src/test/java/util/HistoryListTest.java

@@ -15,7 +15,7 @@
  */
 package util;
 
-import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
 
 import java.util.LinkedList;
@@ -425,6 +425,32 @@ public void testGetPreviousAndNextHistoryItems() {
 		assertNextItems();
 	}
 
+	@Test
+	public void testBackToItem() {
+
+		addHistory(A);
+		addHistory(B);
+		addHistory(C);
+
+		historyList.goBackTo(A);
+		assertCurrentItem(A);
+	}
+
+	@Test
+	public void testForwardToItem() {
+
+		addHistory(A);
+		addHistory(B);
+		addHistory(C);
+		goBack();
+		goBack();
+		goBack();
+		assertCurrentItem(A);
+
+		historyList.goForwardTo(C);
+		assertCurrentItem(C);
+	}
+
 //==================================================================================================
 // Private Methods
 //==================================================================================================