trunk/src/undo.c

/*
 * Copyright (C) 2008 Till Harbaum <till@harbaum.org>.
 *
 * This file is part of OSM2Go.
 *
 * OSM2Go 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 3 of the License, or
 * (at your option) any later version.
 *
 * OSM2Go 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 OSM2Go.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "appdata.h"

/* return plain text of type */
char *undo_type_string(type_t type) {
  const struct { undo_type_t type; char *name; } types[] = {
    { UNDO_DELETE, "DELETE" },
    { UNDO_CREATE, "CREATE" },
    { UNDO_MODIFY, "MODIFY" },
    { 0, NULL }
  };

  int i;
  for(i=0;types[i].name;i++) 
    if(type == types[i].type)
      return types[i].name;

  return NULL;
}

static void undo_object_free(undo_object_t *obj) {
  char *msg = osm_object_string(obj->type, obj->data.ptr);
  printf("   object %s\n", msg);
  g_free(msg);

  if(obj->data.ptr) {
    switch(obj->type) {
    case NODE:
      osm_node_free(NULL, obj->data.node);
      break;
      
    default:
      printf("ERROR: unsupported object %s\n", 
             osm_type_string(obj->type));
      g_assert(0);
      break;
    }
  }

  g_free(obj);
}

static void undo_op_free(undo_op_t *op) {
  printf("  op: %s\n", undo_type_string(op->type));
  if(op->object) undo_object_free(op->object);
  g_free(op);
}

static void undo_state_free(undo_state_t *state) {
  printf(" state: %s\n", undo_type_string(state->type));

  undo_op_t *op = state->op;
  while(op) {
    undo_op_t *next = op->next;
    undo_op_free(op);
    op = next;
  }

  g_free(state);
}

/* free all undo states, thus forgetting the entire history */
/* called at program exit or e.g. at project change */
void undo_free(undo_state_t *state) {
  printf("Freeing all UNDO states:\n");

  while(state) {
    undo_state_t *next = state->next;
    undo_state_free(state);
    state = next;
  }
}

/* append a new state to the chain of undo states */
static undo_state_t *undo_append_state(appdata_t *appdata) {
  undo_state_t *new_state = NULL;

  /* create new undo state at end of undo chain */
  int undo_chain_length = 0;
  undo_state_t **undo_stateP = &appdata->undo.state;
  while(*undo_stateP) {
    undo_chain_length++;
    undo_stateP = &(*undo_stateP)->next;
  }

  /* append new entry to chain */
  new_state = *undo_stateP = g_new0(undo_state_t, 1);

  /* delete first entry if the chain is too long */
  if(undo_chain_length >= UNDO_QUEUE_LEN) {
    undo_state_t *second = appdata->undo.state->next;
    undo_state_free(appdata->undo.state);
    appdata->undo.state = second;
  }

  printf("UNDO: current chain length = %d\n", undo_chain_length);

  return new_state;
}

/* create a local copy of the entire object */
static undo_object_t *undo_object_copy(type_t type, void *object) {
  undo_object_t *ob = g_new0(undo_object_t, 1);
  ob->type = type;

  switch(type) {
  case NODE: {
    /* fields ignored in this copy operation: */
    /* ways, icon_buf, map_item_chain, next */

    node_t *node = (node_t*)object;
    ob->data.node = g_new0(node_t, 1);
    /* copy all important parts, omitting icon pointers etc. */
    ob->data.node->id = node->id;
    ob->data.node->lpos = node->lpos;
    ob->data.node->pos = node->pos;
    /* user is a pointer, but since the users list */
    /* is never touched it's ok */
    ob->data.node->user = node->user;
    ob->data.node->visible = node->visible;
    ob->data.node->time = node->time;
    ob->data.node->tag = osm_tags_copy(node->tag, FALSE);
    ob->data.node->flags = node->flags; 
    ob->data.node->zoom_max = node->zoom_max; 
    } break;

  default:
    printf("ERROR: unsupported object %s\n", osm_type_string(type));
    g_assert(0);
    break;
  }

  return ob;
}

void undo_remember_delete(appdata_t *appdata, type_t type, 
                          void *object) {
  printf("UNDO: remembering delete operation for %s\n", 
         osm_type_string(type));

  /* create a new undo state */
  undo_state_t *state = undo_append_state(appdata);
  state->type = UNDO_DELETE;

  /* a simple stand-alone node deletion is just a single */
  /* operation on the database/map so only one undo_op is saved */
  undo_op_t *op = state->op = g_new0(undo_op_t, 1);
  op->type = UNDO_DELETE;
  op->object = undo_object_copy(type, object);
}

/* undo the deletion of an object */
static void undo_operation_object_delete(appdata_t *appdata, 
                                         undo_object_t *obj) {

  char *msg = osm_object_string(obj->type, obj->data.ptr);
  printf("UNDO deletion of object %s\n", msg);
  g_free(msg);
  
  switch(obj->type) {
  case NODE: {
    node_t *node = obj->data.node;

    /* there must be an "deleted" entry which needs to be */
    /* removed */
    node_t *orig = osm_get_node_by_id(appdata->osm, node->id);
    g_assert(orig);
    g_assert(orig->flags & OSM_FLAG_DELETED);
    way_chain_t *wchain = 
      osm_node_delete(appdata->osm, &appdata->icon, orig, TRUE, TRUE);
    g_assert(!wchain);

    /* then restore old node */
    osm_node_dump(node);
    osm_node_restore(appdata->osm, node);
    josm_elemstyles_colorize_node(appdata->map->style, node);
    map_node_draw(appdata->map, node);
    obj->data.ptr = NULL;
  } break;

  default:
    printf("Unsupported object type\n");
    break;
  }
}

/* undo a single operation */
static void undo_operation(appdata_t *appdata, undo_op_t *op) {
  printf("UNDO operation: %s\n", undo_type_string(op->type));

  switch(op->type) {
  case UNDO_DELETE:
    undo_operation_object_delete(appdata, op->object);
    break;

  default:
    printf("unsupported UNDO operation\n");
    g_assert(0);
    break;
  }
}

/* undo the last undo_state */
void undo(appdata_t *appdata) {
  undo_state_t *state = appdata->undo.state;
  printf("user selected undo\n");

  /* search last (newest) entry */
  while(state && state->next) state = state->next;

  if(!state) {
    banner_show_info(appdata, _("No further undo data"));
    return;
  }

  
  printf("UNDO state: %s\n", undo_type_string(state->type));

  /* since the operations list was built by prepending new */
  /* entries, just going through the list will run the operations */
  /* in reverse order. That's exactly what we want! */

  undo_op_t *op = state->op;
  while(op) {
    undo_operation(appdata, op);
    op = op->next;
  }

  /* remove this entry from chain */
  undo_state_t **stateP = &appdata->undo.state;
  while(*stateP && (*stateP)->next) stateP = &(*stateP)->next;

  undo_state_free(*stateP);
  *stateP = NULL;
}
1	/*
2	* Copyright (C) 2008 Till Harbaum <till@harbaum.org>.
3	*
4	* This file is part of OSM2Go.
5	*
6	* OSM2Go is free software: you can redistribute it and/or modify
7	* it under the terms of the GNU General Public License as published by
8	* the Free Software Foundation, either version 3 of the License, or
9	* (at your option) any later version.
10	*
11	* OSM2Go is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with OSM2Go. If not, see <http://www.gnu.org/licenses/>.
18	*/
19
20	#include "appdata.h"
21
22	/* return plain text of type */
23	char *undo_type_string(type_t type) {
24	const struct { undo_type_t type; char *name; } types[] = {
25	{ UNDO_DELETE, "DELETE" },
26	{ UNDO_CREATE, "CREATE" },
27	{ UNDO_MODIFY, "MODIFY" },
28	{ 0, NULL }
29	};
30
31	int i;
32	for(i=0;types[i].name;i++)
33	if(type == types[i].type)
34	return types[i].name;
35
36	return NULL;
37	}
38
39	static void undo_object_free(undo_object_t *obj) {
40	char *msg = osm_object_string(obj->type, obj->data.ptr);
41	printf(" object %s\n", msg);
42	g_free(msg);
43
44	if(obj->data.ptr) {
45	switch(obj->type) {
46	case NODE:
47	osm_node_free(NULL, obj->data.node);
48	break;
49
50	default:
51	printf("ERROR: unsupported object %s\n",
52	osm_type_string(obj->type));
53	g_assert(0);
54	break;
55	}
56	}
57
58	g_free(obj);
59	}
60
61	static void undo_op_free(undo_op_t *op) {
62	printf(" op: %s\n", undo_type_string(op->type));
63	if(op->object) undo_object_free(op->object);
64	g_free(op);
65	}
66
67	static void undo_state_free(undo_state_t *state) {
68	printf(" state: %s\n", undo_type_string(state->type));
69
70	undo_op_t *op = state->op;
71	while(op) {
72	undo_op_t *next = op->next;
73	undo_op_free(op);
74	op = next;
75	}
76
77	g_free(state);
78	}
79
80	/* free all undo states, thus forgetting the entire history */
81	/* called at program exit or e.g. at project change */
82	void undo_free(undo_state_t *state) {
83	printf("Freeing all UNDO states:\n");
84
85	while(state) {
86	undo_state_t *next = state->next;
87	undo_state_free(state);
88	state = next;
89	}
90	}
91
92	/* append a new state to the chain of undo states */
93	static undo_state_t undo_append_state(appdata_t appdata) {
94	undo_state_t *new_state = NULL;
95
96	/* create new undo state at end of undo chain */
97	int undo_chain_length = 0;
98	undo_state_t **undo_stateP = &appdata->undo.state;
99	while(*undo_stateP) {
100	undo_chain_length++;
101	undo_stateP = &(*undo_stateP)->next;
102	}
103
104	/* append new entry to chain */
105	new_state = *undo_stateP = g_new0(undo_state_t, 1);
106
107	/* delete first entry if the chain is too long */
108	if(undo_chain_length >= UNDO_QUEUE_LEN) {
109	undo_state_t *second = appdata->undo.state->next;
110	undo_state_free(appdata->undo.state);
111	appdata->undo.state = second;
112	}
113
114	printf("UNDO: current chain length = %d\n", undo_chain_length);
115
116	return new_state;
117	}
118
119	/* create a local copy of the entire object */
120	static undo_object_t undo_object_copy(type_t type, void object) {
121	undo_object_t *ob = g_new0(undo_object_t, 1);
122	ob->type = type;
123
124	switch(type) {
125	case NODE: {
126	/* fields ignored in this copy operation: */
127	/* ways, icon_buf, map_item_chain, next */
128
129	node_t node = (node_t)object;
130	ob->data.node = g_new0(node_t, 1);
131	/* copy all important parts, omitting icon pointers etc. */
132	ob->data.node->id = node->id;
133	ob->data.node->lpos = node->lpos;
134	ob->data.node->pos = node->pos;
135	/* user is a pointer, but since the users list */
136	/* is never touched it's ok */
137	ob->data.node->user = node->user;
138	ob->data.node->visible = node->visible;
139	ob->data.node->time = node->time;
140	ob->data.node->tag = osm_tags_copy(node->tag, FALSE);
141	ob->data.node->flags = node->flags;
142	ob->data.node->zoom_max = node->zoom_max;
143	} break;
144
145	default:
146	printf("ERROR: unsupported object %s\n", osm_type_string(type));
147	g_assert(0);
148	break;
149	}
150
151	return ob;
152	}
153
154	void undo_remember_delete(appdata_t *appdata, type_t type,
155	void *object) {
156	printf("UNDO: remembering delete operation for %s\n",
157	osm_type_string(type));
158
159	/* create a new undo state */
160	undo_state_t *state = undo_append_state(appdata);
161	state->type = UNDO_DELETE;
162
163	/* a simple stand-alone node deletion is just a single */
164	/* operation on the database/map so only one undo_op is saved */
165	undo_op_t *op = state->op = g_new0(undo_op_t, 1);
166	op->type = UNDO_DELETE;
167	op->object = undo_object_copy(type, object);
168	}
169
170	/* undo the deletion of an object */
171	static void undo_operation_object_delete(appdata_t *appdata,
172	undo_object_t *obj) {
173
174	char *msg = osm_object_string(obj->type, obj->data.ptr);
175	printf("UNDO deletion of object %s\n", msg);
176	g_free(msg);
177
178	switch(obj->type) {
179	case NODE: {
180	node_t *node = obj->data.node;
181
182	/* there must be an "deleted" entry which needs to be */
183	/* removed */
184	node_t *orig = osm_get_node_by_id(appdata->osm, node->id);
185	g_assert(orig);
186	g_assert(orig->flags & OSM_FLAG_DELETED);
187	way_chain_t *wchain =
188	osm_node_delete(appdata->osm, &appdata->icon, orig, TRUE, TRUE);
189	g_assert(!wchain);
190
191	/* then restore old node */
192	osm_node_dump(node);
193	osm_node_restore(appdata->osm, node);
194	josm_elemstyles_colorize_node(appdata->map->style, node);
195	map_node_draw(appdata->map, node);
196	obj->data.ptr = NULL;
197	} break;
198
199	default:
200	printf("Unsupported object type\n");
201	break;
202	}
203	}
204
205	/* undo a single operation */
206	static void undo_operation(appdata_t appdata, undo_op_t op) {
207	printf("UNDO operation: %s\n", undo_type_string(op->type));
208
209	switch(op->type) {
210	case UNDO_DELETE:
211	undo_operation_object_delete(appdata, op->object);
212	break;
213
214	default:
215	printf("unsupported UNDO operation\n");
216	g_assert(0);
217	break;
218	}
219	}
220
221	/* undo the last undo_state */
222	void undo(appdata_t *appdata) {
223	undo_state_t *state = appdata->undo.state;
224	printf("user selected undo\n");
225
226	/* search last (newest) entry */
227	while(state && state->next) state = state->next;
228
229	if(!state) {
230	banner_show_info(appdata, _("No further undo data"));
231	return;
232	}
233
234
235	printf("UNDO state: %s\n", undo_type_string(state->type));
236
237	/* since the operations list was built by prepending new */
238	/* entries, just going through the list will run the operations */
239	/* in reverse order. That's exactly what we want! */
240
241	undo_op_t *op = state->op;
242	while(op) {
243	undo_operation(appdata, op);
244	op = op->next;
245	}
246
247	/* remove this entry from chain */
248	undo_state_t **stateP = &appdata->undo.state;
249	while(stateP && (stateP)->next) stateP = &(*stateP)->next;
250
251	undo_state_free(*stateP);
252	*stateP = NULL;
253	}