source: trunk/gli/src/org/greenstone/gatherer/file/FileSystemModel.java@ 4293

package org.greenstone.gatherer.file;

import java.io.File;
import java.util.*;
import java.util.regex.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import org.greenstone.gatherer.Gatherer;
import org.greenstone.gatherer.file.FileFilter;
import org.greenstone.gatherer.file.FileNode;
import org.greenstone.gatherer.file.FileOpenActionListener;
import org.greenstone.gatherer.gui.tree.DragTree;
import org.greenstone.gatherer.util.SynchronizedTreeModelTools;

public class FileSystemModel
     extends DefaultTreeModel 
     implements TreeExpansionListener, TreeWillExpandListener {

     private DragTree tree;
     private FileFilter current_filter;
     private FileFilter[] filters;
     static private FileFilter[] default_filters = { new FileFilter("\\..*", true), new FileFilter("metadata\\.xml", true) };

     public FileSystemModel(FileNode root) {
          super(root);
          current_filter = null;
          filters = null;
          tree = null;
          root.setModel(this);
          root.map();
     }

     public FileFilter[] getFilters() {
          if(filters == null) {
                if(current_filter != null) {
                     filters = new FileFilter[default_filters.length + 1];
                     filters[default_filters.length] = current_filter;
                }
                else {
                     filters = new FileFilter[default_filters.length];
                }
                System.arraycopy(default_filters, 0, filters, 0, default_filters.length);
          }
          return filters;
     }
     
     /** Retrieve the node denoted by the given tree path. Note that this isn't equivelent to saying path.lastPathComponent, as the references within the path may be stale. */
     public FileNode getNode(TreePath path) {
          ///ystem.err.println("**** getNode(" + path + ") ****");
          FileNode current = (FileNode)root;
          // Special case for the root node. Check the first path component is the root node.
          FileNode first_node = (FileNode)path.getPathComponent(0);
          if(current.equals(first_node)) {
                ///ystem.err.println("First path component matches root node.");
                // For each path with this tree path
                for(int i = 1; current != null && i < path.getPathCount(); i++) {
                     // Retrieve the stale path
                     FileNode stale_node = (FileNode) path.getPathComponent(i);
                     ///ystem.err.print("Searching for '" + stale_node + "': ");
                     // Locate the fresh node by searching current's children. Remember to ensure that current is mapped.
                     current.map();
                     boolean found = false;
                     for(int j = 0; !found && j < current.getChildCount(); j++) {
                          FileNode child_node = (FileNode) current.getChildAt(j);
                          ///ystem.err.print(child_node + " ");
                          if(stale_node.equals(child_node)) {
                                found = true;
                                current = child_node;
                                ///ystem.err.println("Found!");
                          }
                          child_node = null;
                     }
                     // If no match is found, then set current to null and exit.
                     if(!found) {
                          current = null;
                          ///ystem.err.println("Not Found!");
                     }
                     // Repeat as necessary
                }
          }
          ///ystem.err.println("Returning node: " + new TreePath(current.getPath()));
          return current;
     }

     public void insertNodeInto(MutableTreeNode newChild, MutableTreeNode parent, int index) {
          ///ystem.err.println("insertNodeInto(" + newChild + ", " + parent + ", " + index + ")");
          super.insertNodeInto(newChild, parent, index);
     }

     public void mapDirectory(File directory, String title) {
          FileNode node = new FileNode(directory, this, title, true);
          SynchronizedTreeModelTools.insertNodeInto(this, (FileNode)root, node);
     }

     /** Used to refresh the contents of the FileNode indicated by the tree path. While the refresh itself is a piece of the proverbial, the restoring of expanded folders afterwards is a nightmare, mainly because all of the tree paths are no longer valid (remember that refresh involves throwing away the node currents children and remapping them).
      * @param path The TreePath to the node to be refreshed.
      */
     public void refresh(TreePath path) {
          // If no path is set, take the path to the root node (ie update the whole tree)
          if(path == null) {
                ///ystem.err.println("Refresh entire tree.");
                path = new TreePath(((FileNode)root).getPath());
          }
          else {
                ///ystem.err.println("Refresh: " + path.getLastPathComponent());
          }
          // Only a valid action if this model is currently being displayed in a tree.
          if(tree != null) {
                // Retrieve the error node.
                FileNode node = (FileNode) path.getLastPathComponent();
                // If this error node is a dummy node (ie has no associated file) we can't unmap it, so we iterate through its children refreshing each in turn.
                if(node.getFile() == null) {
                     for(int i = 0; i < node.getChildCount(); i++) {
                          FileNode child = (FileNode) node.getChildAt(i);
                          refresh(new TreePath(child.getPath()));
                          child = null;
                     }
                }
                // Otherwise we refresh this node.
                else {
                     // Record all of the expanded paths under this node. How come getExpandedDescendants returns more results each time.
                     Enumeration old_tree_paths = tree.getExpandedDescendants(path);
                     // Refresh the tree structure.
                     node.unmap();
                     node.map();
                     // Fire the appropriate event.
                     nodeStructureChanged(node);
                     // Then (painfully) restore the expanded paths. Note that the paths stored in the enumeration no longer exist, so I have to restore by node matching.
                     //counter = 0;
                     ///ystem.err.println("After:");
                     while(old_tree_paths != null && old_tree_paths.hasMoreElements()) {
                          //counter++;
                          FileNode current_node = node;
                          TreePath old_tree_path = (TreePath) old_tree_paths.nextElement();
                          ///ystem.err.println(counter + ". " + old_tree_path);
                          TreePath new_tree_path = new TreePath(path.getPath()); // Why isn't there a treepath copy constructor!
                          boolean not_found = false;
                          while(!not_found && old_tree_path.getPathCount() > new_tree_path.getPathCount()) {
                                // Retrieve the new node in the old tree path
                                FileNode old_path_node = (FileNode) old_tree_path.getPathComponent(new_tree_path.getPathCount());
                                // Ensure the current node is mapped
                                current_node.map();
                                // Now attempt to match it to a child of the new paths last node.
                                boolean found = false;
                                for(int i = 0; !found && i < current_node.getChildCount(); i++) {
                                     FileNode target = (FileNode) current_node.getChildAt(i);
                                     ///ystem.err.println("Comparing " + old_path_node.toString() + " with " + target);
                                     if(target.toString().equals(old_path_node.toString())) {
                                          current_node = target;
                                          found = true;
                                     }
                                     target = null;
                                }
                                old_path_node = null;
                                // If we found a match, we add that to the new Tree Path and continue.
                                if(found) {
                                     ///ystem.err.println("Found a match!");
                                     new_tree_path = new_tree_path.pathByAddingChild(current_node);
                                }
                                // We also have to record if we were unable to find a match in the current nodes children.
                                else {
                                     ///ystem.err.println("Node not found.");
                                     not_found = true;
                                }
                          }
                          old_tree_path = null;
                          // If we've got this far, and haven't hit a not found, then we can assume we have the appropriate path, and ask the program to expand the new tree path
                          if(!not_found) {
                                tree.expandPath(new_tree_path);
                                ///ystem.err.println(" -> Expanded " + new_tree_path);
                          }
                          else {
                                ///ystem.err.println(" -> Cannot Expand " + new_tree_path);
                          }
                          new_tree_path = null;
                          current_node = null;
                     }
                     node = null;
                }
          }
          else {
                ///ystem.err.println("No Tree!");
          }
     }

     public void setFilter(String pattern) {
          if(pattern != null) {
                current_filter = new FileFilter(pattern, false);
          }
          else {
                current_filter = null;
          }
          filters = null;
     }

     public void setTree(DragTree tree) {
          this.tree = tree;
     }

     public String toString() {
          if(tree != null) {
                return tree.toString();
          }
          return "FileSystemModel";
     }

     /** Called whenever an item in the tree has been collapsed. */
     public void treeCollapsed(TreeExpansionEvent event) {
          // Deallocate the affected nodes children. Don't need to do this in a swing worker, as the nodes children are currently not visable.
          TreePath path = event.getPath();
          FileNode node = (FileNode) path.getLastPathComponent();
          node.unmap();
          // Fire the appropriate event.
          nodeStructureChanged(node);
     }

     /** Called whenever an item in the tree has been expanded. */
     public void treeExpanded(TreeExpansionEvent event) {
     }

     /** Invoked whenever a node in the tree is about to be collapsed. */
     public void treeWillCollapse(TreeExpansionEvent event) 
          throws ExpandVetoException {
          // Veto the event if the user is attempting to collapse the root node (regardless of whether it is visible.
          TreePath path = event.getPath();
          if(path.getPathCount() == 1) {
                throw new ExpandVetoException(event, "Cannot collapse root node!");
          }
     }
     
     /** Invoked whenever a node in the tree is about to be expanded. */
     public void treeWillExpand(TreeExpansionEvent event) 
          throws ExpandVetoException {
          // Set the wait cursor.
          Gatherer.g_man.wait(true);
          // Allocate the children. Don't need to do this in a swing worker, as the nodes children are currently not visable.
          TreePath path = event.getPath();
          FileNode node = (FileNode) path.getLastPathComponent();
          node.map();
          nodeStructureChanged(node);
          // Restore the cursor.
          Gatherer.g_man.wait(false);
     }
}