1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/* Dia -- an diagram creation/manipulation program
* Copyright (C) 1999 Alexander Larsson
*
* 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.
*/
#include <config.h>
#include "object.h"
/******** ObjectChange for object that just need to get/set state: *****/
typedef struct _ObjectStateChange ObjectStateChange;
struct _ObjectStateChange {
ObjectChange obj_change;
GetStateFunc get_state;
SetStateFunc set_state;
ObjectState *saved_state;
DiaObject *obj;
};
static void
object_state_change_apply_revert(ObjectStateChange *change, DiaObject *obj)
{
ObjectState *old_state;
old_state = change->get_state(change->obj);
change->set_state(change->obj, change->saved_state);
change->saved_state = old_state;
}
static void
object_state_change_free(ObjectStateChange *change)
{
if ((change) && (change->saved_state)) {
if (change->saved_state->free)
(*change->saved_state->free)(change->saved_state);
g_free(change->saved_state);
}
}
ObjectChange *new_object_state_change(DiaObject *obj,
ObjectState *old_state,
GetStateFunc get_state,
SetStateFunc set_state )
{
ObjectStateChange *change;
g_return_val_if_fail (get_state != NULL && set_state != NULL, NULL);
change = g_new(ObjectStateChange, 1);
change->obj_change.apply =
(ObjectChangeApplyFunc) object_state_change_apply_revert;
change->obj_change.revert =
(ObjectChangeRevertFunc) object_state_change_apply_revert;
change->obj_change.free =
(ObjectChangeFreeFunc) object_state_change_free;
change->get_state = get_state;
change->set_state = set_state;
change->obj = obj;
change->saved_state = old_state;
return (ObjectChange *)change;
}
typedef struct _ObjectChangeList ObjectChangeList;
struct _ObjectChangeList {
ObjectChange object_change;
GPtrArray *changes;
};
static void
_change_list_apply (ObjectChange *change_list, DiaObject *obj)
{
ObjectChangeList *list = (ObjectChangeList *)change_list;
guint i;
for (i = 0; i < list->changes->len; ++i) {
ObjectChange * change = (ObjectChange *)g_ptr_array_index(list->changes, i);
change->apply (change, obj /*?*/);
}
}
static void
_change_list_revert (ObjectChange *change_list, DiaObject *obj)
{
ObjectChangeList *list = (ObjectChangeList *)change_list;
guint i;
if (list->changes->len < 1)
return; /* avoid overflow below */
for (i = list->changes->len - 1;/* i >= 0 */; --i) {
ObjectChange * change = (ObjectChange *)g_ptr_array_index(list->changes, i);
change->revert (change, obj /*?*/);
if (i == 0)
break; /* break here, i>=0 does not work as loop condition (it's always TRUE) */
}
}
static void
_change_list_free (ObjectChange *change_list)
{
ObjectChangeList *list = (ObjectChangeList *)change_list;
guint i;
for (i = 0; i < list->changes->len; ++i) {
ObjectChange * change = (ObjectChange *)g_ptr_array_index(list->changes, i);
if (change->free)
change->free (change);
}
g_ptr_array_free (list->changes, FALSE);
/* must not delete the object itself, so no:
g_free (change_list);
*/
}
/* An empty list of changes to accumulate many to one change */
ObjectChange *
change_list_create (void)
{
ObjectChangeList *list = g_new (ObjectChangeList, 1);
list->object_change.apply = _change_list_apply;
list->object_change.revert = _change_list_revert;
list->object_change.free = _change_list_free;
list->changes = g_ptr_array_new ();
return (ObjectChange *)list;
}
void
change_list_add (ObjectChange *change_list, ObjectChange *change)
{
ObjectChangeList *list = (ObjectChangeList *)change_list;
if (change)
g_ptr_array_add (list->changes, change);
}
|
