[First cut at navigation (i.e. back/forward) buttons.]

* e-shell-view.c: New member `history' in `EShellViewPrivate'.
(init): Initialize.
(destroy): Unref.
(e_shell_view_display_uri): Make it a no-op if the URI is the same
as the current one.  Also, moved code into `display_uri' and use
it.
(back_clicked_callback): New, callback for the back button on the
folder title bar.
(forward_clicked_callback): Likewise for the forward button.

* e-history.c: New.
* e-history.h: New.

svn path=/trunk/; revision=15798

1 files changed, 238 insertions, 0 deletions

diff --git a/shell/e-history.c b/shell/e-history.c
new file mode 100644
index 0000000000..99579871e1
--- /dev/null
+++ b/shell/e-history.c
@@ -0,0 +1,238 @@
+/* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
+/* e-history.c
+ *
+ * Copyright (C) 2002  Ximian, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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 <ettore@ximian.com>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "e-history.h"
+
+#include <gal/util/e-util.h>
+
+
+#define PARENT_TYPE gtk_object_get_type ()
+static GtkObjectClass *parent_class = NULL;
+
+struct _EHistoryPrivate {
+	EHistoryItemFreeFunc item_free_function;
+
+	GList *items;
+	GList *current_item;
+};
+
+
+/* GtkObject methods.  */
+
+static void
+impl_destroy (GtkObject *object)
+{
+	EHistory *history;
+	EHistoryPrivate *priv;
+	GList *p;
+
+	history = E_HISTORY (object);
+	priv = history->priv;
+
+	for (p = priv->items; p != NULL; p = p->next)
+		(* priv->item_free_function) (p->data);
+
+	g_list_free (priv->items);
+
+	g_free (priv);
+
+	(* GTK_OBJECT_CLASS (parent_class)->destroy) (object);
+}
+
+
+static void
+class_init (GtkObjectClass *object_class)
+{
+	parent_class = gtk_type_class (PARENT_TYPE);
+
+	object_class->destroy = impl_destroy;
+}
+
+static void
+init (EHistory *history)
+{
+	EHistoryPrivate *priv;
+
+	priv = g_new (EHistoryPrivate, 1);
+	priv->items        = NULL;
+	priv->current_item = NULL;
+
+	history->priv = priv;
+
+	GTK_OBJECT_UNSET_FLAGS (history, GTK_FLOATING);
+}
+
+
+void
+e_history_construct  (EHistory *history,
+		      EHistoryItemFreeFunc item_free_function)
+{
+	EHistoryPrivate *priv;
+
+	g_return_if_fail (history != NULL);
+	g_return_if_fail (E_IS_HISTORY (history));
+
+	priv = history->priv;
+
+	priv->item_free_function = item_free_function;
+}
+
+EHistory *
+e_history_new (EHistoryItemFreeFunc item_free_function)
+{
+	EHistory *history;
+
+	history = gtk_type_new (e_history_get_type ());
+	e_history_construct (history, item_free_function);
+
+	return history;
+}
+
+void *
+e_history_prev (EHistory *history)
+{
+	EHistoryPrivate *priv;
+
+	g_return_val_if_fail (history != NULL, NULL);
+	g_return_val_if_fail (E_IS_HISTORY (history), NULL);
+
+	priv = history->priv;
+
+	if (! e_history_has_prev (history))
+		return NULL;
+
+	priv->current_item = priv->current_item->prev;
+	return e_history_get_current (history);
+}
+
+gboolean
+e_history_has_prev (EHistory *history)
+{
+	EHistoryPrivate *priv;
+
+	g_return_val_if_fail (history != NULL, FALSE);
+	g_return_val_if_fail (E_IS_HISTORY (history), FALSE);
+
+	priv = history->priv;
+
+	if (priv->current_item == NULL)
+		return FALSE;
+
+	if (priv->current_item->prev == NULL)
+		return FALSE;
+	else
+		return TRUE;
+}
+
+void *
+e_history_next (EHistory *history)
+{
+	EHistoryPrivate *priv;
+
+	g_return_val_if_fail (history != NULL, NULL);
+	g_return_val_if_fail (E_IS_HISTORY (history), NULL);
+
+	priv = history->priv;
+
+	if (! e_history_has_next (history))
+		return NULL;
+
+	priv->current_item = priv->current_item->next;
+	return e_history_get_current (history);
+}
+
+gboolean
+e_history_has_next (EHistory *history)
+{
+	EHistoryPrivate *priv;
+
+	g_return_val_if_fail (history != NULL, FALSE);
+	g_return_val_if_fail (E_IS_HISTORY (history), FALSE);
+
+	priv = history->priv;
+
+	if (priv->current_item == NULL)
+		return FALSE;
+
+	if (priv->current_item->next == NULL)
+		return FALSE;
+	else
+		return TRUE;
+}
+
+void *
+e_history_get_current (EHistory *history)
+{
+	EHistoryPrivate *priv;
+
+	g_return_val_if_fail (history != NULL, NULL);
+	g_return_val_if_fail (E_IS_HISTORY (history), NULL);
+
+	priv = history->priv;
+
+	if (priv->current_item == NULL)
+		return NULL;
+
+	return priv->current_item->data;
+}
+
+void
+e_history_add (EHistory *history,
+	       void     *data)
+{
+	EHistoryPrivate *priv;
+
+	g_return_if_fail (history != NULL);
+	g_return_if_fail (E_IS_HISTORY (history));
+
+	priv = history->priv;
+
+	if (priv->current_item == NULL) {
+		priv->items = g_list_prepend (priv->items, data);
+		priv->current_item = priv->items;
+
+		return;
+	}
+
+	if (priv->current_item->next != NULL) {
+		GList *p;
+
+		for (p = priv->current_item->next; p != NULL; p = p->next)
+			(* priv->item_free_function) (p->data);
+
+		priv->current_item->next->prev = NULL;
+		g_list_free (priv->current_item->next);
+
+		priv->current_item->next = NULL;
+	}
+
+	g_list_append (priv->current_item, data);
+	priv->current_item = priv->current_item->next;
+}
+
+
+E_MAKE_TYPE (e_history, "EHistory", EHistory, class_init, init, GTK_TYPE_OBJECT)