Decision: Separate "writable" interfaces for FileEntry and Directory.

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

@@ -28,14 +28,13 @@ import com.webcodepro.applecommander.storage.os.prodos.ProdosDirectoryEntry;
 import com.webcodepro.applecommander.storage.os.prodos.ProdosFormatDisk;
 import com.webcodepro.applecommander.storage.os.rdos.RdosFormatDisk;
 import org.applecommander.capability.Capability;
-import org.applecommander.filestore.Directory;
-import org.applecommander.filestore.DisplayColumn;
+import org.applecommander.filestore.*;
 import org.applecommander.filestore.FileEntry;
-import org.applecommander.filestore.FileStore;
 import org.applecommander.usage.BlockUsage;
 import org.applecommander.usage.DiskUsage;
 import org.applecommander.usage.SectorUsage;
 import org.applecommander.util.Container;
+import org.applecommander.util.DataBuffer;
 
 import java.util.ArrayList;
 import java.util.BitSet;
@@ -174,7 +173,7 @@ public class DiskFileStoreAdapter implements FileStore {
      * 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 {
+    public static class DiskFileEntryAdapter implements WritableFileEntry {
         private final DiskFileStoreAdapter adapter;
         private final DiskDirectoryAdapter parent;
         private final com.webcodepro.applecommander.storage.FileEntry fileEntry;
@@ -213,15 +212,15 @@ public class DiskFileStoreAdapter implements FileStore {
             throw new RuntimeException("Not supported by the legacy AppleCommander.");
         }
         @Override
-        public void setDataFork(byte[] fileData) {
+        public void setDataFork(DataBuffer fileData) {
             try {
-                fileEntry.setFileData(fileData);
+                fileEntry.setFileData(fileData.asBytes());
             } catch (DiskFullException e) {
                 throw new RuntimeException(e);
             }
         }
         @Override
-        public void setResourceFork(byte[] data) {
+        public void setResourceFork(DataBuffer data) {
             throw new RuntimeException("Not supported by the legacy AppleCommander.");
         }
         @Override

lib/ac-api/src/main/java/org/applecommander/archive/shrinkit/ShrinkitFileEntry.java

@@ -61,11 +61,6 @@ public class ShrinkitFileEntry implements FileEntry {
         return headerBlock.getFilename();
     }
 
-    @Override
-    public void setName(String name) {
-        throw new UnsupportedOperationException();
-    }
-
     @Override
     public long getSize() {
         return headerBlock.getUncompressedSize();
@@ -197,16 +192,6 @@ public class ShrinkitFileEntry implements FileEntry {
         return decompress(headerBlock.getResourceForkThreadRecord());
     }
 
-    @Override
-    public void setDataFork(byte[] data) {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public void setResourceFork(byte[] data) {
-        throw new UnsupportedOperationException();
-    }
-
     @Override
     public <T> Optional<T> get(Class<T> iface) {
         return Container.get(iface, headerBlock);

lib/ac-api/src/main/java/org/applecommander/archive/zip/ZipFileEntry.java

@@ -65,11 +65,6 @@ public class ZipFileEntry implements FileEntry {
         return entry.getName();
     }
 
-    @Override
-    public void setName(String name) {
-        throw new UnsupportedOperationException();
-    }
-
     @Override
     public long getSize() {
         return entry.getSize();
@@ -133,16 +128,6 @@ public class ZipFileEntry implements FileEntry {
         throw new UnsupportedOperationException();
     }
 
-    @Override
-    public void setDataFork(byte[] data) {
-        throw new UnsupportedOperationException();
-    }
-
-    @Override
-    public void setResourceFork(byte[] data) {
-        throw new UnsupportedOperationException();
-    }
-
     @Override
     public <T> Optional<T> get(Class<T> iface) {
         return Container.get(iface, fileStore, entry);

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

@@ -24,11 +24,10 @@ import java.util.Optional;
 import java.util.stream.Collectors;
 
 /**
- * A DirectoryEntry represents a directory in a FileStore.  Note that even
+ * A Directory represents a directory in a FileStore.  Note that even
  * FileStores that don't naturally support a directory do contain a root directory,
  * so there will be a directory associated to each FileStore.
  */
-// TODO FUTURE should create file be deferred to a container operation? Not everything will support file creation.
 public interface Directory {
     /**
      * Get the parent directory. If this is the root directory, it returns empty.

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

@@ -45,11 +45,6 @@ public interface FileEntry extends Container {
      * Note that depending on context, this may be a computed field.
      */
     String getName();
-    /**
-     * Allows the name of this entry to be changed (depending on the {@link Capability}
-     * allowed by the underlying {@link FileStore}).
-     */
-    void setName(String name);
     /**
      * Returns the size, in bytes, of this item.
      * It may be approximate (based off a sector count, for instance).
@@ -73,17 +68,4 @@ public interface FileEntry extends Container {
     // TODO should resource form reading and writing be deferred to a container operation?
     //  ... Then we don't need capability (which is our test) and we don't have to implement no-op functions.
     byte[] getResourceFork();
-    /**
-     * Store the file's data.
-     * This does not include any metadata that may be embedded with the file.
-     */
-    // TODO should write capability be deferred to a resource as well?
-    void setDataFork(byte[] data);
-    /**
-     * Store the resource fork data.
-     * This may not be supported and may throw an exception.
-     * @see Capability
-     */
-    // TODO ditto...
-    void setResourceFork(byte[] data);
 }

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

@@ -0,0 +1,26 @@
+/*
+ * 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;
+
+/// A WritableDirectory is a Directory that allows file creation.
+public interface WritableDirectory {
+    /// Create a file. By definition, any file created is a WritableFileEntry.
+    WritableFileEntry createFile();
+}

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

@@ -0,0 +1,46 @@
+/*
+ * 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 org.applecommander.capability.Capability;
+import org.applecommander.util.Container;
+import org.applecommander.util.DataBuffer;
+
+/**
+ * A WritableFileEntry represents a single, writable file on disk.
+ */
+public interface WritableFileEntry extends FileEntry, Container {
+    /**
+     * Allows the name of this entry to be changed (depending on the {@link Capability}
+     * allowed by the underlying {@link FileStore}).
+     */
+    void setName(String name);
+    /**
+     * Store the file's data.
+     * This does not include any metadata that may be embedded with the file.
+     */
+    void setDataFork(DataBuffer data);
+    /**
+     * Store the resource fork data.
+     * This may not be supported and may throw an exception.
+     * @see Capability
+     */
+    void setResourceFork(DataBuffer data);
+}