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, NULL, orig, TRUE, TRUE);
    g_assert(!wchain);

    /* then restore old node */
    osm_node_dump(node);
    osm_node_restore(appdata->osm, 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	harbaum	54	/*
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	harbaum	64	/* 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	harbaum	54	static void undo_state_free(undo_state_t *state) {
68	harbaum	64	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	harbaum	54	g_free(state);
78			}
79
80	harbaum	64	/* free all undo states, thus forgetting the entire history */
81			/* called at program exit or e.g. at project change */
82	harbaum	54	void undo_free(undo_state_t *state) {
83	harbaum	64	printf("Freeing all UNDO states:\n");
84
85	harbaum	54	while(state) {
86			undo_state_t *next = state->next;
87			undo_state_free(state);
88			state = next;
89			}
90			}
91
92	harbaum	64	/* append a new state to the chain of undo states */
93	harbaum	54	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	harbaum	64	/* 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	harbaum	54
124	harbaum	64	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	harbaum	54	undo_state_t *state = undo_append_state(appdata);
161	harbaum	64	state->type = UNDO_DELETE;
162	harbaum	54
163	harbaum	64	/* 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	harbaum	54	}
169	harbaum	64
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, NULL, 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			map_node_draw(appdata->map, node);
195			obj->data.ptr = NULL;
196			} break;
197
198			default:
199			printf("Unsupported object type\n");
200			break;
201			}
202			}
203
204			/* undo a single operation */
205			static void undo_operation(appdata_t appdata, undo_op_t op) {
206			printf("UNDO operation: %s\n", undo_type_string(op->type));
207
208			switch(op->type) {
209			case UNDO_DELETE:
210			undo_operation_object_delete(appdata, op->object);
211			break;
212
213			default:
214			printf("unsupported UNDO operation\n");
215			g_assert(0);
216			break;
217			}
218			}
219
220			/* undo the last undo_state */
221			void undo(appdata_t *appdata) {
222			undo_state_t *state = appdata->undo_state;
223			printf("user selected undo\n");
224
225			/* search last (newest) entry */
226			while(state && state->next) state = state->next;
227
228			if(!state) {
229			banner_show_info(appdata, _("No further undo data"));
230			return;
231			}
232
233
234			printf("UNDO state: %s\n", undo_type_string(state->type));
235
236			/* since the operations list was built by prepending new */
237			/* entries, just going through the list will run the operations */
238			/* in reverse order. That's exactly what we want! */
239
240			undo_op_t *op = state->op;
241			while(op) {
242			undo_operation(appdata, op);
243			op = op->next;
244			}
245
246			/* remove this entry from chain */
247			undo_state_t **stateP = &appdata->undo_state;
248			while(stateP && (stateP)->next) stateP = &(*stateP)->next;
249
250			undo_state_free(*stateP);
251			*stateP = NULL;
252			}