path: root/widgets/text/e-reflow-model.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 *
 * Authors:
 *      Chris Lahey <clahey@ximian.com>
 * Copyright (C) 1999-2008 Novell, Inc. (www.novell.com)
 *
 */

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

#include "e-util/e-util.h"

#include "e-reflow-model.h"

G_DEFINE_TYPE (EReflowModel, e_reflow_model, G_TYPE_OBJECT)

#define d(x)

d (static gint depth = 0;)

enum {
    MODEL_CHANGED,
    COMPARISON_CHANGED,
    MODEL_ITEMS_INSERTED,
    MODEL_ITEM_CHANGED,
    MODEL_ITEM_REMOVED,
    LAST_SIGNAL
};

static guint e_reflow_model_signals[LAST_SIGNAL] = { 0, };

/**
 * e_reflow_model_set_width:
 * @e_reflow_model: The e-reflow-model to operate on
 * @width: The new value for the width of each item.
 */
void
e_reflow_model_set_width (EReflowModel *e_reflow_model,
                          gint width)
{
    g_return_if_fail (e_reflow_model != NULL);
    g_return_if_fail (E_IS_REFLOW_MODEL (e_reflow_model));

    E_REFLOW_MODEL_GET_CLASS (e_reflow_model)->set_width (e_reflow_model, width);
}

/**
 * e_reflow_model_count:
 * @e_reflow_model: The e-reflow-model to operate on
 *
 * Returns: the number of items in the reflow model.
 */
gint
e_reflow_model_count (EReflowModel *e_reflow_model)
{
    g_return_val_if_fail (e_reflow_model != NULL, 0);
    g_return_val_if_fail (E_IS_REFLOW_MODEL (e_reflow_model), 0);

    return E_REFLOW_MODEL_GET_CLASS (e_reflow_model)->count (e_reflow_model);
}

/**
 * e_reflow_model_height:
 * @e_reflow_model: The e-reflow-model to operate on
 * @n: The item number to get the height of.
 * @parent: The parent GnomeCanvasItem.
 *
 * Returns: the height of the nth item.
 */
gint
e_reflow_model_height (EReflowModel *e_reflow_model,
                       gint n,
                       GnomeCanvasGroup *parent)
{
    g_return_val_if_fail (e_reflow_model != NULL, 0);
    g_return_val_if_fail (E_IS_REFLOW_MODEL (e_reflow_model), 0);

    return E_REFLOW_MODEL_GET_CLASS (e_reflow_model)->height (e_reflow_model, n, parent);
}

/**
 * e_reflow_model_incarnate:
 * @e_reflow_model: The e-reflow-model to operate on
 * @n: The item to create.
 * @parent: The parent GnomeCanvasItem to create a child of.
 *
 * Create a GnomeCanvasItem to represent the nth piece of data.
 *
 * Returns: the new GnomeCanvasItem.
 */
GnomeCanvasItem *
e_reflow_model_incarnate (EReflowModel *e_reflow_model,
                          gint n,
                          GnomeCanvasGroup *parent)
{
    g_return_val_if_fail (e_reflow_model != NULL, NULL);
    g_return_val_if_fail (E_IS_REFLOW_MODEL (e_reflow_model), NULL);

    return E_REFLOW_MODEL_GET_CLASS (e_reflow_model)->incarnate (e_reflow_model, n, parent);
}

/**
 * e_reflow_model_create_cmp_cache:
 * @e_reflow_model: The e-reflow-model to operate on
 *
 * Creates a compare cache for quicker sorting. The sorting function
 * may not depend on the cache, but it should benefit from it if available.
 *
 * Returns: Newly created GHashTable with cached compare values. This will be
 * automatically freed with g_hash_table_destroy() when no longer needed.
 **/
GHashTable *
e_reflow_model_create_cmp_cache (EReflowModel *e_reflow_model)
{
    g_return_val_if_fail (e_reflow_model != NULL, NULL);
    g_return_val_if_fail (E_IS_REFLOW_MODEL (e_reflow_model), NULL);

    if (!E_REFLOW_MODEL_GET_CLASS (e_reflow_model)->create_cmp_cache)
        return NULL;

    return E_REFLOW_MODEL_GET_CLASS (e_reflow_model)->create_cmp_cache (e_reflow_model);
}

/**
 * e_reflow_model_compare:
 * @e_reflow_model: The e-reflow-model to operate on
 * @n1: The first item to compare
 * @n2: The second item to compare
 * @cmp_cache: #GHashTable of cached compare values, created by
 *    e_reflow_model_create_cmp_cache(). This can be NULL, when
 *    caching is not available, even when @e_reflow_model defines
 *    the create_cmp_cache function.
 *
 * Compares item n1 and item n2 to see which should come first.
 *
 * Returns: strcmp like semantics for the comparison value.
 */
gint
e_reflow_model_compare (EReflowModel *e_reflow_model,
                        gint n1,
                        gint n2,
                        GHashTable *cmp_cache)
{
#if 0
    g_return_val_if_fail (e_reflow_model != NULL, 0);
    g_return_val_if_fail (E_IS_REFLOW_MODEL (e_reflow_model), 0);
#endif

    return E_REFLOW_MODEL_GET_CLASS (e_reflow_model)->compare (e_reflow_model, n1, n2, cmp_cache);
}

/**
 * e_reflow_model_reincarnate:
 * @e_reflow_model: The e-reflow-model to operate on
 * @n: The item to create.
 * @item: The item to reuse.
 *
 * Update item to represent the nth piece of data.
 */
void
e_reflow_model_reincarnate (EReflowModel *e_reflow_model,
                            gint n,
                            GnomeCanvasItem *item)
{
    g_return_if_fail (e_reflow_model != NULL);
    g_return_if_fail (E_IS_REFLOW_MODEL (e_reflow_model));

    E_REFLOW_MODEL_GET_CLASS (e_reflow_model)->reincarnate (e_reflow_model, n, item);
}

static void
e_reflow_model_class_init (EReflowModelClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS (klass);

    e_reflow_model_signals[MODEL_CHANGED] =
        g_signal_new ("model_changed",
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (EReflowModelClass, model_changed),
                  NULL, NULL,
                  g_cclosure_marshal_VOID__VOID,
                  G_TYPE_NONE, 0);

    e_reflow_model_signals[COMPARISON_CHANGED] =
        g_signal_new ("comparison_changed",
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (EReflowModelClass, comparison_changed),
                  NULL, NULL,
                  g_cclosure_marshal_VOID__VOID,
                  G_TYPE_NONE, 0);

    e_reflow_model_signals[MODEL_ITEMS_INSERTED] =
        g_signal_new ("model_items_inserted",
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (EReflowModelClass, model_items_inserted),
                  NULL, NULL,
                  e_marshal_NONE__INT_INT,
                  G_TYPE_NONE, 2, G_TYPE_INT, G_TYPE_INT);

    e_reflow_model_signals[MODEL_ITEM_CHANGED] =
        g_signal_new ("model_item_changed",
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (EReflowModelClass, model_item_changed),
                  NULL, NULL,
                  g_cclosure_marshal_VOID__INT,
                  G_TYPE_NONE, 1, G_TYPE_INT);

    e_reflow_model_signals[MODEL_ITEM_REMOVED] =
        g_signal_new ("model_item_removed",
                  G_OBJECT_CLASS_TYPE (object_class),
                  G_SIGNAL_RUN_LAST,
                  G_STRUCT_OFFSET (EReflowModelClass, model_item_removed),
                  NULL, NULL,
                  g_cclosure_marshal_VOID__INT,
                  G_TYPE_NONE, 1, G_TYPE_INT);

    klass->set_width            = NULL;
    klass->count                = NULL;
    klass->height               = NULL;
    klass->incarnate            = NULL;
    klass->reincarnate          = NULL;

    klass->model_changed        = NULL;
    klass->comparison_changed   = NULL;
    klass->model_items_inserted = NULL;
    klass->model_item_removed   = NULL;
    klass->model_item_changed   = NULL;
}

static void
e_reflow_model_init (EReflowModel *e_reflow_model)
{
}

#if d(!)0
static void
print_tabs (void)
{
    gint i;
    for (i = 0; i < depth; i++)
        g_print("\t");
}
#endif

/**
 * e_reflow_model_changed:
 * @e_reflow_model: the reflow model to notify of the change
 *
 * Use this function to notify any views of this reflow model that
 * the contents of the reflow model have changed.  This will emit
 * the signal "model_changed" on the @e_reflow_model object.
 *
 * It is preferable to use the e_reflow_model_item_changed() signal to
 * notify of smaller changes than to invalidate the entire model, as
 * the views might have ways of caching the information they render
 * from the model.
 */
void
e_reflow_model_changed (EReflowModel *e_reflow_model)
{
    g_return_if_fail (e_reflow_model != NULL);
    g_return_if_fail (E_IS_REFLOW_MODEL (e_reflow_model));

    d (print_tabs ());
    d(g_print("Emitting model_changed on model 0x%p.\n", e_reflow_model));
    d (depth++);
    g_signal_emit (e_reflow_model,
               e_reflow_model_signals[MODEL_CHANGED], 0);
    d (depth--);
}

/**
 * e_reflow_model_comparison_changed:
 * @e_reflow_model: the reflow model to notify of the change
 *
 * Use this function to notify any views of this reflow model that the
 * sorting has changed.  The actual contents of the items hasn't, so
 * there's no need to re-query the model for the heights of the
 * individual items.
 */
void
e_reflow_model_comparison_changed (EReflowModel *e_reflow_model)
{
    g_return_if_fail (e_reflow_model != NULL);
    g_return_if_fail (E_IS_REFLOW_MODEL (e_reflow_model));

    d (print_tabs ());
    d(g_print("Emitting comparison_changed on model 0x%p.\n", e_reflow_model));
    d (depth++);
    g_signal_emit (e_reflow_model,
               e_reflow_model_signals[COMPARISON_CHANGED], 0);
    d (depth--);
}

/**
 * e_reflow_model_items_inserted:
 * @e_reflow_model: The model changed.
 * @position: The position the items were insert in.
 * @count: The number of items inserted.
 *
 * Use this function to notify any views of the reflow model that a number of items have been inserted.
 **/
void
e_reflow_model_items_inserted (EReflowModel *e_reflow_model,
                               gint position,
                               gint count)
{
    g_return_if_fail (e_reflow_model != NULL);
    g_return_if_fail (E_IS_REFLOW_MODEL (e_reflow_model));

    d (print_tabs ());
    d(g_print("Emitting items_inserted on model 0x%p, position=%d, count=%d.\n", e_reflow_model, position, count));
    d (depth++);
    g_signal_emit (e_reflow_model,
               e_reflow_model_signals[MODEL_ITEMS_INSERTED], 0,
               position, count);
    d (depth--);
}

/**
 * e_reflow_model_item_removed:
 * @e_reflow_model: The model changed.
 * @n: The position from which the items were removed.
 *
 * Use this function to notify any views of the reflow model that an
 * item has been removed.
 **/
void
e_reflow_model_item_removed (EReflowModel *e_reflow_model,
                             gint n)
{
    g_return_if_fail (e_reflow_model != NULL);
    g_return_if_fail (E_IS_REFLOW_MODEL (e_reflow_model));

    d (print_tabs ());
    d(g_print("Emitting item_removed on model 0x%p, n=%d.\n", e_reflow_model, n));
    d (depth++);
    g_signal_emit (e_reflow_model,
               e_reflow_model_signals[MODEL_ITEM_REMOVED], 0,
               n);
    d (depth--);
}

/**
 * e_reflow_model_item_changed:
 * @e_reflow_model: the reflow model to notify of the change
 * @item: the item that was changed in the model.
 *
 * Use this function to notify any views of the reflow model that the
 * contents of item @item have changed in model such that the height
 * has changed or the item needs to be reincarnated.  This function
 * will emit the "model_item_changed" signal on the @e_reflow_model
 * object
 */
void
e_reflow_model_item_changed (EReflowModel *e_reflow_model,
                             gint n)
{
    g_return_if_fail (e_reflow_model != NULL);
    g_return_if_fail (E_IS_REFLOW_MODEL (e_reflow_model));

    d (print_tabs ());
    d(g_print("Emitting item_changed on model 0x%p, n=%d.\n", e_reflow_model, n));
    d (depth++);
    g_signal_emit (e_reflow_model,
               e_reflow_model_signals[MODEL_ITEM_CHANGED], 0,
               n);
    d (depth--);
}