Made Directory a CapabilitiesProvider. WritableDirectory now extends the Directory interface.

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

@@ -19,6 +19,7 @@
  */
 package org.applecommander.archive.shrinkit;
 
+import org.applecommander.capability.Capability;
 import org.applecommander.filestore.Directory;
 import org.applecommander.filestore.FileEntry;
 
@@ -34,6 +35,11 @@ public class ShrinkitDirectory implements Directory {
         this.files = files;
     }
 
+    @Override
+    public boolean can(Capability capability) {
+        return false;
+    }
+
     @Override
     public Optional<Directory> getParent() {
         return Optional.empty();

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

@@ -19,6 +19,7 @@
  */
 package org.applecommander.archive.zip;
 
+import org.applecommander.capability.Capability;
 import org.applecommander.filestore.Directory;
 import org.applecommander.filestore.FileEntry;
 import org.applecommander.filestore.FileStore;
@@ -39,6 +40,11 @@ public class ZipDirectory implements Directory {
         this.entries = entries;
     }
 
+    @Override
+    public boolean can(Capability capability) {
+        return false;
+    }
+
     @Override
     public Optional<Directory> getParent() {
         return Optional.empty();

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

@@ -19,35 +19,30 @@
  */
 package org.applecommander.filestore;
 
+import org.applecommander.capability.CapabilityProvider;
+
 import java.util.List;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
-/**
- * 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.
- */
-public interface Directory {
-    /**
-     * Get the parent directory. If this is the root directory, it returns empty.
-     */
+/// A `Directory` represents a directory in a `FileStore`.  Note that even
+/// file stores that don't naturally support a directory do contain a root directory,
+/// so there will be a directory associated to each `FileStore`.
+public interface Directory extends CapabilityProvider {
+
+    /// Get the parent directory. If this is the root directory, it returns empty.
     Optional<Directory> getParent();
-    /**
-     * Returns the FileStore that this Directory belongs to.
-     */
+
+    /// Returns the FileStore that this Directory belongs to.
     FileStore getFileStore();
-    /**
-     * Returns the name of this directory.
-     */
+
+    /// Returns the name of this directory.
     String getName();
-    /**
-     * Return all entries that are stored in this directory.
-     */
+
+    /// Return all entries that are stored in this directory.
     List<FileEntry> getFiles();
-    /**
-     * Filter out the <code>DirectoryEntry</code> entries in this directory.
-     */
+
+    /// Filter out the `DirectoryEntry` entries in this directory.
     default List<Directory> getDirectories() {
         return getFiles().stream()
                 .map(fileEntry -> fileEntry.get(Directory.class))
@@ -55,9 +50,8 @@ public interface Directory {
                 .map(Optional::get)
                 .collect(Collectors.toList());
     }
-    /**
-     * Locate a given file of the given name recursively on the disk.
-     */
+
+    /// Locate a given file of the given name recursively on the disk.
     default Optional<FileEntry> findFile(String name) {
         for (FileEntry fileEntry : getFiles()) {
             if (name.equalsIgnoreCase(fileEntry.getName())) {

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

@@ -19,8 +19,28 @@
  */
 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();
+import org.applecommander.capability.Capability;
+
+/// A WritableDirectory is a Directory that allows general directory modification.
+/// Since not all directories can perform all tasks, check the capability first,
+/// otherwise an exception will be generated.
+public interface WritableDirectory extends Directory {
+
+    /// Create a file. By definition, any file created is a `WritableFileEntry`.
+    /// @see Capability#CREATE_FILES
+    default WritableFileEntry createFile(String fileName) {
+        throw new UnsupportedOperationException("unable to create files");
+    }
+
+    /// Create a directory. By definition, any directory create is a `WritableDirectory`.
+    /// @see Capability#CREATE_DIRECTORIES
+    default WritableDirectory createDirectory(String directoryName) {
+        throw new UnsupportedOperationException("unable to create directories");
+    }
+
+    /// Delete a file.
+    /// @see Capability#DELETE_FILES
+    default void deleteFile(FileEntry fileEntry) {
+        throw new UnsupportedOperationException("unable to delete files");
+    }
 }

lib/ac-api/src/main/java/org/applecommander/os/gamedos/GamedosDirectory.java

@@ -19,6 +19,7 @@
  */
 package org.applecommander.os.gamedos;
 
+import org.applecommander.capability.Capability;
 import org.applecommander.device.TrackSectorDevice;
 import org.applecommander.filestore.Directory;
 import org.applecommander.filestore.FileEntry;
@@ -28,8 +29,10 @@ import org.applecommander.util.DataBuffer;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
+import java.util.Set;
 
 public class GamedosDirectory implements Directory, GamedosConstants {
+    private static final Set<Capability> CAPABILITIES = Set.of(Capability.WRITE_FILES, Capability.CREATE_FILES);
     private final GamedosFileStore fileStore;
     private final TrackSectorDevice device;
 
@@ -38,6 +41,11 @@ public class GamedosDirectory implements Directory, GamedosConstants {
         this.device = fileStore.get(TrackSectorDevice.class).orElseThrow();
     }
 
+    @Override
+    public boolean can(Capability capability) {
+        return CAPABILITIES.contains(capability);
+    }
+
     @Override
     public Optional<Directory> getParent() {
         return Optional.empty();