source: trunk/gli/src/org/greenstone/gatherer/file/FileSystemModel.java@ 6255

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.Dictionary;
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;
    /** The filters in place for any file system model. */
    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 int getChildCount(Object parent) {
    return ((TreeNode)parent).getChildCount();
    }

    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) {
    ///atherer.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)) {
        ///atherer.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);
        ///atherer.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;

        // First we search through the mapped children
        for(int j = 0; !found && j < current.getChildCount(); j++) {
            FileNode child_node = (FileNode) current.getChildAt(j);
            ///atherer.print(child_node + " ");
            if(stale_node.equals(child_node)) {
            found = true;
            current = child_node;
            ///atherer.println("Found!");
            }
            child_node = null;
        }
        // Failing that we search through all the children, including filtered files
        for(int j = 0; !found && j < current.size(); j++) {
            FileNode child_node = (FileNode) current.get(j);
            ///atherer.print(child_node + " ");
            if(stale_node.equals(child_node)) {
            found = true;
            current = child_node;
            ///atherer.println("Found!");
            }
            child_node = null;
        }
        // If no match is found, then set current to null and exit.
        if(!found) {
            current = null;
            ///atherer.println("Not Found!");
        }
        // Repeat as necessary
        }
    }
    ///atherer.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. The exception being Greenstone Collections, as it is a dummy node but we can map/unmap it
        if(node.getFile() == null && !node.toString().equals(Dictionary.get("Tree.World"))) {
        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;
    }

    /* private void setPermanentFilter(String pattern) {
    if(pattern != null) {
        FileFilter new_filter = new FileFilter(pattern, false);
        FileFilter temp[] = new FileFilter[default_filters.length + 1];
        System.arraycopy(default_filters, 0, temp, 0, default_filters.length);
        temp[default_filters.length] = new_filter;
        default_filters = temp;
        temp = 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();
    ///ystem.err.println("Unmap: " + node);
    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();
    ///ystem.err.println("Mapping: " + node);
    node.map();
    ///ystem.err.println(" -> node has " + node.getChildCount() + " children");
    nodeStructureChanged(node);
    // Restore the cursor.
    Gatherer.g_man.wait(false);
    }
}