path: root/shell/e-folder-tree.c

/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
/* e-folder-set.c
 *
 * Copyright (C) 2000, 2001 Ximian, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * 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.
 *
 * Author: Ettore Perazzoli
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "e-folder-tree.h"

#include "e-shell-constants.h"

#include <string.h>
#include <glib.h>


struct _Folder {
    struct _Folder *parent;
    char *path;
    void *data;
    GList *subfolders;
};
typedef struct _Folder Folder;

struct _EFolderTree {
    GHashTable *path_to_folder;
    GHashTable *data_to_path;

    EFolderDestroyNotify folder_destroy_notify;
    void *folder_destroy_notify_closure;
};


/* Utility functions.  */

static char *
get_parent_path (const char *path)
{
    const char *last_separator;

    g_assert (g_path_is_absolute (path));

    last_separator = strrchr (path, E_PATH_SEPARATOR);

    if (last_separator == path)
        return g_strdup (E_PATH_SEPARATOR_S);

    return g_strndup (path, last_separator - path);
}

static void
traverse_subtree (EFolderTree *tree,
          Folder *root_folder,
          EFolderTreeForeachFunc foreach_func,
          void *data)
{
    GList *p;

    g_assert (foreach_func != NULL);

    (* foreach_func) (tree, root_folder->path, root_folder->data, data);

    for (p = root_folder->subfolders; p != NULL; p = p->next) {
        Folder *folder;

        folder = (Folder *) p->data;
        traverse_subtree (tree, folder, foreach_func, data);
    }
}


/* Folder handling.  */

static Folder *
folder_new (const char *path,
        void *data)
{
    Folder *folder;

    folder = g_new (Folder, 1);
    folder->parent     = NULL;
    folder->path       = g_strdup (path);
    folder->data       = data;
    folder->subfolders = NULL;

    return folder;
}

static void
folder_remove_subfolder (Folder *folder,
             Folder *subfolder)
{
    folder->subfolders = g_list_remove (folder->subfolders, subfolder);
    subfolder->parent = NULL;
}

static void
folder_add_subfolder (Folder *folder,
              Folder *subfolder)
{
    folder->subfolders = g_list_prepend (folder->subfolders, subfolder);
    subfolder->parent = folder;
}

static void
folder_destroy (Folder *folder)
{
    g_assert (folder->subfolders == NULL);

    if (folder->parent != NULL)
        folder_remove_subfolder (folder->parent, folder);

    g_free (folder->path);

    g_free (folder);
}

static void
remove_folder (EFolderTree *folder_tree,
           Folder *folder)
{
    if (folder->subfolders != NULL) {
        GList *p;

        for (p = folder->subfolders; p != NULL; p = p->next) {
            Folder *subfolder;

            subfolder = (Folder *) p->data;
            subfolder->parent = NULL;
            remove_folder (folder_tree, subfolder);
        }

        g_list_free (folder->subfolders);
        folder->subfolders = NULL;
    }

    g_hash_table_remove (folder_tree->path_to_folder, folder->path);
    g_hash_table_remove (folder_tree->data_to_path, folder->data);

    if (folder_tree->folder_destroy_notify != NULL)
        (* folder_tree->folder_destroy_notify) (folder_tree,
                            folder->path,
                            folder->data,
                            folder_tree->folder_destroy_notify_closure);

    folder_destroy (folder);
}


/**
 * e_folder_tree_new:
 * @folder_destroy_notify: Function to be called when a folder gets removed from the tree
 * @closure: Additional data to pass to @folder_destroy_notify
 * 
 * Create a new EFolderTree.
 * 
 * Return value: A pointer to the newly created EFolderTree.
 **/
EFolderTree *
e_folder_tree_new (EFolderDestroyNotify folder_destroy_notify,
           void *closure)
{
    EFolderTree *new;

    new = g_new (EFolderTree, 1);

    new->folder_destroy_notify         = folder_destroy_notify;
    new->folder_destroy_notify_closure = closure;

    new->path_to_folder = g_hash_table_new (g_str_hash, g_str_equal);
    new->data_to_path = g_hash_table_new (g_direct_hash, g_direct_equal);

    e_folder_tree_add (new, E_PATH_SEPARATOR_S, NULL);

    return new;
}

/**
 * e_folder_tree_destroy:
 * @folder_tree: A pointer to an EFolderTree
 * 
 * Destroy @folder_tree.
 **/
void
e_folder_tree_destroy (EFolderTree *folder_tree)
{
    Folder *root_folder;

    g_return_if_fail (folder_tree != NULL);

    root_folder = g_hash_table_lookup (folder_tree->path_to_folder, E_PATH_SEPARATOR_S);
    remove_folder (folder_tree, root_folder);

    g_hash_table_destroy (folder_tree->path_to_folder);
    g_hash_table_destroy (folder_tree->data_to_path);

    g_free (folder_tree);
}

/**
 * e_folder_tree_add:
 * @folder_tree: A pointer to an EFolderTree
 * @path: Path at which the new folder must be added
 * @data: Data associated with the new folder
 * 
 * Insert a new folder at @path, with the specified @data.
 *
 * Return value: %TRUE if successful, %FALSE if failed.
 **/
gboolean
e_folder_tree_add (EFolderTree *folder_tree,
           const char *path,
           void *data)
{
    Folder *parent_folder;
    Folder *folder;
    const char *existing_path;
    char *parent_path;

    g_return_val_if_fail (folder_tree != NULL, FALSE);
    g_return_val_if_fail (path != NULL, FALSE);
    g_return_val_if_fail (g_path_is_absolute (path), FALSE);

    /* Can only "add" a new root folder if the tree is empty */
    if (! strcmp (path, E_PATH_SEPARATOR_S)) {
        folder = g_hash_table_lookup (folder_tree->path_to_folder, path);
        if (folder) {
            if (folder->subfolders) {
                g_warning ("e_folder_tree_add() -- Trying to change root folder after adding children");
                return FALSE;
            }
            remove_folder (folder_tree, folder);
        }

        folder = folder_new (path, data);
        g_hash_table_insert (folder_tree->path_to_folder, folder->path, folder);
        g_hash_table_insert (folder_tree->data_to_path, data, folder->path);
        return TRUE;
    }

    parent_path = get_parent_path (path);

    parent_folder = g_hash_table_lookup (folder_tree->path_to_folder, parent_path);
    if (parent_folder == NULL) {
        g_warning ("e_folder_tree_add() -- Trying to add a subfolder to a path that does not exist yet -- %s",
               parent_path);
        return FALSE;
    }

    folder = g_hash_table_lookup (folder_tree->path_to_folder, path);
    if (folder != NULL) {
        g_warning ("e_folder_tree_add() -- Trying to add a subfolder for a path that already exists -- %s",
               path);
        return FALSE;
    }

    existing_path = g_hash_table_lookup (folder_tree->data_to_path, data);
    if (existing_path != NULL) {
        g_warning ("e_folder_tree_add() -- Trying to add a folder with duplicate data -- %s",
               path);
        return FALSE;
    }

    folder = folder_new (path, data);
    folder_add_subfolder (parent_folder, folder);

    g_hash_table_insert (folder_tree->path_to_folder, folder->path, folder);
    g_hash_table_insert (folder_tree->data_to_path, data, folder->path);

    g_free (parent_path);

    return TRUE;
}

/**
 * e_folder_tree_remove:
 * @folder_tree: A pointer to an EFolderTree
 * @path: Path of the folder to remove
 * 
 * Remove the folder at @path from @folder_tree.
 *
 * Return value: %TRUE if successful, %FALSE if failed.
 **/
gboolean
e_folder_tree_remove (EFolderTree *folder_tree,
              const char *path)
{
    Folder *folder;

    g_return_val_if_fail (folder_tree != NULL, FALSE);
    g_return_val_if_fail (path != NULL, FALSE);
    g_return_val_if_fail (g_path_is_absolute (path), FALSE);

    folder = g_hash_table_lookup (folder_tree->path_to_folder, path);
    if (folder == NULL)
        return FALSE;

    remove_folder (folder_tree, folder);
    return TRUE;
}

static void
count_nodes (EFolderTree *tree,
         const char *path,
         void *data,
         void *closure)
{
    int *count = closure;
    
    (*count)++;
}

/**
 * e_folder_tree_get_count:
 * @folder_tree: A pointer to an EFolderTree
 * 
 * Gets the number of folders in the tree
 * 
 * Return value: The number of folders in the tree
 **/
int
e_folder_tree_get_count (EFolderTree *folder_tree)
{
    int count = 0;
    
    e_folder_tree_foreach (folder_tree, count_nodes, &count);
    
    return count;
}
                          
/**
 * e_folder_tree_get_folder:
 * @folder_tree: A pointer to an EFolderTree
 * @path: Path of the folder for which we want to get the data
 * 
 * Get the data for the folder at @path.
 * 
 * Return value: The pointer to the data for the folder at @path.
 **/
void *
e_folder_tree_get_folder (EFolderTree *folder_tree,
              const char *path)
{
    Folder *folder;

    g_return_val_if_fail (folder_tree != NULL, NULL);
    g_return_val_if_fail (path != NULL, NULL);
    g_return_val_if_fail (g_path_is_absolute (path), NULL);

    folder = g_hash_table_lookup (folder_tree->path_to_folder, path);
    if (folder == NULL)
        return NULL;

    return folder->data;
}

/**
 * e_folder_tree_get_subfolders:
 * @folder_tree: A pointer to an EFolderTree
 * @path: A path in @folder_tree
 * 
 * Get a list of the paths of the subfolders of @path.
 * 
 * Return value: A list of pointers to the paths of the subfolders.  The list
 * and the strings must be freed by the caller.
 **/
GList *
e_folder_tree_get_subfolders (EFolderTree *folder_tree,
                  const char *path)
{
    Folder *folder;
    GList *list;
    GList *p;

    g_return_val_if_fail (folder_tree != NULL, NULL);
    g_return_val_if_fail (path != NULL, NULL);
    g_return_val_if_fail (g_path_is_absolute (path), NULL);

    folder = g_hash_table_lookup (folder_tree->path_to_folder, path);
    if (folder == NULL)
        return NULL;

    list = NULL;
    for (p = folder->subfolders; p != NULL; p = p->next) {
        const Folder *folder;

        folder = (const Folder *) p->data;
        list = g_list_prepend (list, g_strdup (folder->path));
    }

    return list;
}


/**
 * e_folder_tree_foreach:
 * @folder_tree: 
 * @foreach_func: 
 * @data: 
 * 
 * Call @foreach_func with the specified @data for all the folders
 * in @folder_tree, starting at the root node.
 **/
void
e_folder_tree_foreach (EFolderTree *folder_tree,
               EFolderTreeForeachFunc foreach_func,
               void *data)
{
    Folder *root_node;

    g_return_if_fail (folder_tree != NULL);
    g_return_if_fail (foreach_func != NULL);

    root_node = g_hash_table_lookup (folder_tree->path_to_folder,
                     E_PATH_SEPARATOR_S);
    if (root_node == NULL) {
        g_warning ("e_folder_tree_foreach -- What?!  No root node!?");
        return;
    }

    traverse_subtree (folder_tree, root_node, foreach_func, data);
}


/**
 * e_folder_tree_get_path_for_data:
 * @folder_tree: A pointer to an EFolderTree
 * @data: The data for the folder for which the path is needed
 * 
 * Look up the path for the specified @data.
 * 
 * Return value: The path for the folder that holds that @data.
 **/
const char *
e_folder_tree_get_path_for_data  (EFolderTree *folder_tree,
                  const void *data)
{
    g_return_val_if_fail (folder_tree != NULL, NULL);
    g_return_val_if_fail (data != NULL, NULL);

    return (const char *) g_hash_table_lookup (folder_tree->data_to_path, data);
}