Adding DisplayColumn and updating tests and the rest of FileStore to use or support it.

lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/DiskFileStoreAdapter.java

@@ -22,13 +22,14 @@ package com.webcodepro.applecommander.storage;
 import com.webcodepro.applecommander.storage.os.prodos.ProdosDirectoryEntry;
 import com.webcodepro.applecommander.storage.os.prodos.ProdosFormatDisk;
 import org.applecommander.capability.Capability;
-import org.applecommander.filestore.DirectoryEntry;
-import org.applecommander.filestore.Entry;
+import org.applecommander.filestore.Directory;
+import org.applecommander.filestore.DisplayColumn;
 import org.applecommander.filestore.FileEntry;
 import org.applecommander.filestore.FileStore;
 import org.applecommander.util.Container;
 
 import java.util.*;
+import java.util.function.Function;
 
 /**
  * The DiskFileStoreAdapter is a shim that allows FormattedDisk to be mapped into the
@@ -52,8 +53,8 @@ public class DiskFileStoreAdapter implements FileStore {
     }
 
     @Override
-    public DirectoryEntry getRootDirectory() {
-        return new DiskDirectoryEntryAdapter(this, null, disk);
+    public DiskDirectoryAdapter getRootDirectory() {
+        return new DiskDirectoryAdapter(this, null, disk);
     }
 
     @Override
@@ -73,46 +74,73 @@ public class DiskFileStoreAdapter implements FileStore {
         };
     }
 
-    public abstract static class DiskEntryAdapter implements Entry {
-        protected final DiskFileStoreAdapter adapter;
-        protected final DirectoryEntry parent;
-
-        DiskEntryAdapter(DiskFileStoreAdapter adapter, DirectoryEntry parent) {
-            this.adapter = adapter;
-            this.parent = parent;
-        }
-
-        public DirectoryEntry getParent() {
-            return parent;
-        }
-        public FileStore getFileStore() {
-            return adapter;
+    /**
+     * Translate the "legacy" FormattedDisk FileColumnHeader to the new DisplayColumn structure.
+     * Note that we need to track what has been seen as well as where it comes from and the index
+     * values in order to replicate most of the capability. This does not solve for type since the
+     * old API pre-formats everything as a String.
+     */
+    @Override
+    public List<DisplayColumn> getDisplayColumns() {
+        List<DisplayColumn> columns = new ArrayList<>();
+        Set<String> alreadySeenKeys = new HashSet<>();
+        for (int displayMode : List.of(FormattedDisk.FILE_DISPLAY_NATIVE,
+                                       FormattedDisk.FILE_DISPLAY_DETAIL)) {
+            List<FormattedDisk.FileColumnHeader> headers = disk.getFileColumnHeaders(displayMode);
+            DisplayColumn.Mode mode = DisplayColumn.Mode.DETAIL;
+            if (displayMode == FormattedDisk.FILE_DISPLAY_NATIVE) {
+                mode = DisplayColumn.Mode.NATIVE;
+            };
+            for (int i = 0; i<headers.size(); i++) {
+                var header = headers.get(i);
+                DisplayColumn.Alignment alignment = switch(header.getAlignment()) {
+                    case FormattedDisk.FileColumnHeader.ALIGN_CENTER -> DisplayColumn.Alignment.CENTER;
+                    case FormattedDisk.FileColumnHeader.ALIGN_RIGHT -> DisplayColumn.Alignment.RIGHT;
+                    default -> DisplayColumn.Alignment.LEFT;
+                };
+                if (!alreadySeenKeys.contains(header.getKey())) {
+                    alreadySeenKeys.add(header.getKey());
+                    final int headerIndex = i;
+                    Function<FileEntry,String> mappingFn = entry -> {
+                        // TODO investigate to see if generics work across these interfaces
+                        if (entry instanceof DiskFileEntryAdapter fileEntryAdapter) {
+                            return fileEntryAdapter.fileEntry.getFileColumnData(displayMode).get(headerIndex);
+                        }
+                        throw new RuntimeException("Unexpected file entry type: " + entry.getClass().getName());
+                    };
+                    DisplayColumn displayColumn = new DisplayColumn(header.getTitle(),
+                            alignment, mappingFn::apply, "%s", mode);
+                    columns.add(displayColumn);
+                }
+            }
         }
+        return columns;
     }
+
     /**
      * The DiskFileEntryAdapter is a shim that allows a FileEntry to be mapped into the
      * new/evolving FileEntry interface(s).
      */
     public static class DiskFileEntryAdapter implements FileEntry {
         private final DiskFileStoreAdapter adapter;
-        private final DirectoryEntry parent;
+        private final DiskDirectoryAdapter parent;
         private final com.webcodepro.applecommander.storage.FileEntry fileEntry;
-        private final DirectoryEntry subdirectory;
+        private final DiskDirectoryAdapter subdirectory;
 
-        public DiskFileEntryAdapter(DiskFileStoreAdapter adapter, DirectoryEntry parent,
+        public DiskFileEntryAdapter(DiskFileStoreAdapter adapter, DiskDirectoryAdapter parent,
                                     com.webcodepro.applecommander.storage.FileEntry fileEntry) {
             this.adapter = adapter;
             this.parent = parent;
             this.fileEntry = fileEntry;
             if (fileEntry instanceof ProdosDirectoryEntry prodosDirectoryEntry) {
-                this.subdirectory = new DiskDirectoryEntryAdapter(adapter, parent, prodosDirectoryEntry);
+                this.subdirectory = new DiskDirectoryAdapter(adapter, parent, prodosDirectoryEntry);
             }
             else {
                 this.subdirectory = null;
             }
         }
         @Override
-        public DirectoryEntry getParent() {
+        public DiskDirectoryAdapter getParent() {
             return parent;
         }
         @Override
@@ -168,18 +196,22 @@ public class DiskFileStoreAdapter implements FileStore {
      * The DiskDirectoryEntryAdapter is a shim that allows a FormattedDisk or DirectoryEntry to be mapped into the
      * new/evolving DirectoryEntry interface(s).
      */
-    public static class DiskDirectoryEntryAdapter implements DirectoryEntry {
+    public static class DiskDirectoryAdapter implements Directory {
         private final DiskFileStoreAdapter adapter;
-        private final DirectoryEntry parent;
+        private final DiskDirectoryAdapter parent;
         private final com.webcodepro.applecommander.storage.DirectoryEntry directoryEntry;
 
-        public DiskDirectoryEntryAdapter(DiskFileStoreAdapter adapter, DirectoryEntry parent,
-                                         com.webcodepro.applecommander.storage.DirectoryEntry directoryEntry) {
+        public DiskDirectoryAdapter(DiskFileStoreAdapter adapter, DiskDirectoryAdapter parent,
+                                    com.webcodepro.applecommander.storage.DirectoryEntry directoryEntry) {
             this.adapter = adapter;
             this.parent = parent;
             this.directoryEntry = directoryEntry;
         }
         @Override
+        public Optional<Directory> getParent() {
+            return Optional.ofNullable(parent);
+        }
+        @Override
         public List<FileEntry> getFiles() {
             try {
                 List<FileEntry> entries = new ArrayList<>();
@@ -191,6 +223,10 @@ public class DiskFileStoreAdapter implements FileStore {
                 throw new RuntimeException(e);
             }
         }
+        @Override
+        public DiskFileStoreAdapter getFileStore() {
+            return adapter;
+        }
     }
 }
 

lib/ac-api/src/main/java/org/applecommander/filestore/Directory.java

@@ -28,7 +28,15 @@ import java.util.stream.Collectors;
  * FileStores that don't naturally support a directory do contain a root directory,
  * so there will be a directory associated to each FileStore.
  */
-public interface DirectoryEntry {
+public interface Directory {
+    /**
+     * Get the parent directory. If this is the root directory, it returns empty.
+     */
+    Optional<Directory> getParent();
+    /**
+     * Returns the FileStore that this Directory belongs to.
+     */
+    FileStore getFileStore();
     /**
      * Return all entries that are stored in this directory.
      */
@@ -36,10 +44,11 @@ public interface DirectoryEntry {
     /**
      * Filter out the <code>DirectoryEntry</code> entries in this directory.
      */
-    default List<DirectoryEntry> getDirectories() {
+    default List<Directory> getDirectories() {
         return getFiles().stream()
-                .filter(fileEntry -> fileEntry instanceof DirectoryEntry)
-                .map(fileEntry -> (DirectoryEntry)fileEntry)
+                .map(fileEntry -> fileEntry.get(Directory.class))
+                .filter(Optional::isPresent)
+                .map(Optional::get)
                 .collect(Collectors.toList());
     }
     /**
@@ -50,9 +59,9 @@ public interface DirectoryEntry {
             if (name.equalsIgnoreCase(fileEntry.getName())) {
                 return Optional.of(fileEntry);
             }
-            Optional<DirectoryEntry> directoryEntry = fileEntry.get(DirectoryEntry.class);
-            if (directoryEntry.isPresent()) {
-                Optional<FileEntry> finding = directoryEntry.get().findFile(name);
+            Optional<Directory> directory = fileEntry.get(Directory.class);
+            if (directory.isPresent()) {
+                Optional<FileEntry> finding = directory.get().findFile(name);
                 if (finding.isPresent()) {
                     return finding;
                 }

lib/ac-api/src/main/java/org/applecommander/filestore/DisplayColumn.java

@@ -0,0 +1,60 @@
+/*
+ * AppleCommander - An Apple ][ image utility.
+ * Copyright (C) 2026 by Robert Greene and others
+ * robgreene at users.sourceforge.net
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+package org.applecommander.filestore;
+
+import java.util.Set;
+import java.util.function.Function;
+
+/**
+ * A DisplayColumn supports formatted output from various FileStores in a 
+ * dynamic fashion. The intent is to provide a flexible display interface
+ * that does not rely on hard-coded implementations.
+ */
+public record DisplayColumn(String headerText, Alignment alignment, Function<FileEntry,Object> valueFn, String fmt, Mode... modes) {
+	/**
+	 * Indicates if this DisplayColumn supports the mode. In this manner, the columns
+	 * can be filtered out. Or it can be ignored to display everything.
+	 */
+	public boolean supports(Mode mode) {
+		return Set.of(modes).contains(mode);
+	}
+	/**
+	 * Helper method to convert the column into a formatted string for display.
+	 */
+	public String formatAsText(FileEntry fileEntry) {
+		return String.format(fmt, valueFn.apply(fileEntry));
+	}
+
+	/**
+	 * Indicates the display mode to help filter columns to users' preference.
+	 */
+	public enum Mode {
+		NATIVE,
+		DETAIL
+	}
+	/**
+	 * Indicates how this column should be formatted.
+	 */
+	public enum Alignment {
+		LEFT,
+		CENTER,
+		RIGHT
+	}
+}

lib/ac-api/src/main/java/org/applecommander/filestore/FileEntry.java

@@ -29,7 +29,7 @@ public interface FileEntry extends Container {
     /**
      * The parent <code>DirectoryEntry</code>, if applicable. Can return <code>null</code>.
      */
-    DirectoryEntry getParent();
+    Directory getParent();
     /**
      * Indicates if this <code>Entry</code> is deleted.
      */

lib/ac-api/src/main/java/org/applecommander/filestore/FileStore.java

@@ -22,6 +22,8 @@ package org.applecommander.filestore;
 import org.applecommander.capability.CapabilityProvider;
 import org.applecommander.util.Container;
 
+import java.util.List;
+
 /**
  * A FileStore is a generic interface for all archive and filesystem objects.
  */
@@ -33,8 +35,10 @@ public interface FileStore extends CapabilityProvider, Container {
      */
     String getLabel();
     /** All FileStores support a "root" directory that references all files. */
-    DirectoryEntry getRootDirectory();
+    Directory getRootDirectory();
     /** This is the path separator character. */
     // TODO there has to be a better / dynamic way to do this (applies to ProDOS, ShrinkIt only?)
     String getPathSeparator();
+    /** Yields a list of columns to be used in this display mode. */
+    List<DisplayColumn> getDisplayColumns();
 }

lib/ac-api/src/test/java/com/webcodepro/applecommander/storage/DiskFileStoreTest.java

@@ -21,7 +21,6 @@ package com.webcodepro.applecommander.storage;
 
 import org.applecommander.capability.Capability;
 import org.applecommander.filestore.*;
-import org.applecommander.filestore.DirectoryEntry;
 import org.applecommander.filestore.FileEntry;
 import org.applecommander.source.Source;
 import org.applecommander.source.Sources;
@@ -248,20 +247,30 @@ public class DiskFileStoreTest {
         return ctx.fileStores;
     }
 
-    protected void showFiles(DirectoryEntry parent, String indent) {
+    protected void showFiles(Directory parent, String indent) {
+        FileStore fileStore = parent.getFileStore();
+        List<DisplayColumn> displayColumns = fileStore.getDisplayColumns();
+        if (parent.getParent().isEmpty()) {
+            // Print columns only at the top
+            System.out.print(indent);
+            displayColumns.forEach(column -> {
+                System.out.print(column.headerText());
+                System.out.print(" ");
+            });
+            System.out.println();
+        }
         for (FileEntry file : parent.getFiles()) {
             if (!file.isDeleted()) {
-                //List<String> data = entry.getFileColumnData(FormattedDisk.FILE_DISPLAY_NATIVE);
-                //System.out.print(indent);
-                //for (int d=0; d<data.size(); d++) {
-                //    System.out.print(data.get(d));
-                //    System.out.print(" ");
-                //}
-                //System.out.println();
-                System.out.printf("%s%s %s %d\n", indent, file.getName(), file.getFiletype(), file.getSize());
+                System.out.print(indent);
+                displayColumns.forEach(column -> {
+                    System.out.print(column.formatAsText(file));
+                    System.out.print(" ");
+                });
+                System.out.println();
+
+                Optional<Directory> subdirectory = file.get(Directory.class);
+                subdirectory.ifPresent(directoryEntry -> showFiles(directoryEntry, indent + "  "));
             }
-            Optional<DirectoryEntry> subdirectory = file.get(DirectoryEntry.class);
-            subdirectory.ifPresent(directoryEntry -> showFiles(directoryEntry, indent + "  "));
         }
     }
 
@@ -313,9 +322,9 @@ public class DiskFileStoreTest {
         }
     }
 
-    protected void assertCanReadFiles(DirectoryEntry parent) throws DiskException {
+    protected void assertCanReadFiles(Directory parent) throws DiskException {
         for (FileEntry fileEntry : parent.getFiles()) {
-            Optional<DirectoryEntry> subdirectory = fileEntry.get(DirectoryEntry.class);
+            Optional<Directory> subdirectory = fileEntry.get(Directory.class);
             if (fileEntry.isDeleted()) {
                 System.out.printf("Skipping deleted file: %s\n", fileEntry.getName());
             }