1 /* Conky, a system monitor, based on torsmo
3 * Any original torsmo code is licensed under the BSD license
5 * All code written since the fork of torsmo is licensed under the GPL
7 * Please see COPYING for details
9 * Copyright (c) 2004, Hannu Saransaari and Lauri Hakkarainen
10 * Copyright (c) 2005-2009 Brenden Matthews, Philip Kovacs, et. al.
12 * All rights reserved.
14 * This program is free software: you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation, either version 3 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program. If not, see <http://www.gnu.org/licenses/>.
27 #include "text_object.h"
32 * this list is special. it looks like this:
33 * NULL <-- obj1 <--> obj2 <--> ... <--> objN --> NULL
34 * ^-------root_object----------^
35 * directions are reversed here
38 * - root_object points both to the start and end of the list
39 * - while traversing, the end of the list is always a NULL pointer
40 * (this works in BOTH directions)
43 /* append an object to the given root object's list */
44 int append_object(struct text_object *root, struct text_object *obj)
46 struct text_object *end;
54 CRIT_ERR("huston, we have a lift-off");
63 /* ifblock handlers for the object list
65 * - each if points to it's else or endif
66 * - each else points to it's endif
70 /* possible ifblock types
71 * only used internally, so no need to make this public
79 /* linked list of ifblock objects, building a stack
80 * only used internally, so no need to make this public
82 struct ifblock_stack_obj {
83 enum ifblock_type type;
84 struct text_object *obj;
85 struct ifblock_stack_obj *next;
88 /* push an ifblock object onto the stack
89 * in fact, this does a lot more:
90 * - IFBLOCK_IF is just pushed onto the stack
91 * - IFBLOCK_ELSE updates the "next" pointer of the upmost
92 * object in the stack and is then pushed onto the stack
93 * - IFBLOCK_ENDIF updates the "next" pointer of the upmost
94 * object in the stack and then triggers stack popping of
95 * any optional IFBLOCK_ELSE along with it's IFBLOCK_IF
97 static int push_ifblock(struct ifblock_stack_obj **ifblock_stack_top,
98 struct text_object *obj, enum ifblock_type type)
100 struct ifblock_stack_obj *stackobj;
104 if (!(*ifblock_stack_top))
105 CRIT_ERR("got an endif without matching if");
106 (*ifblock_stack_top)->obj->data.ifblock.next = obj;
107 /* if there's some else in between, remove and free it */
108 if ((*ifblock_stack_top)->type == IFBLOCK_ELSE) {
109 stackobj = *ifblock_stack_top;
110 *ifblock_stack_top = stackobj->next;
113 /* finally remove and free the if object */
114 stackobj = *ifblock_stack_top;
115 *ifblock_stack_top = stackobj->next;
119 if (!(*ifblock_stack_top))
120 CRIT_ERR("got an else without matching if");
121 (*ifblock_stack_top)->obj->data.ifblock.next = obj;
124 stackobj = malloc(sizeof(struct ifblock_stack_obj));
125 stackobj->type = type;
127 stackobj->next = *ifblock_stack_top;
128 *ifblock_stack_top = stackobj;
131 CRIT_ERR("push_ifblock() missuse detected!");
136 /* public functions for client use */
138 int obj_be_ifblock_if(void **opaque, struct text_object *obj)
140 return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_IF);
142 int obj_be_ifblock_else(void **opaque, struct text_object *obj)
144 return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_ELSE);
146 int obj_be_ifblock_endif(void **opaque, struct text_object *obj)
148 return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_ENDIF);
151 /* check if ifblock stack is empty
152 * if so, return true (!= 0)
154 int ifblock_stack_empty(void **opaque)
156 return *opaque == NULL;