1 /* -*- mode: c; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: t -*-
3 * Conky, a system monitor, based on torsmo
5 * Any original torsmo code is licensed under the BSD license
7 * All code written since the fork of torsmo is licensed under the GPL
9 * Please see COPYING for details
11 * Copyright (c) 2005-2009 Brenden Matthews, Philip Kovacs, et. al.
13 * All rights reserved.
15 * This program is free software: you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation, either version 3 of the License, or
18 * (at your option) any later version.
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program. If not, see <http://www.gnu.org/licenses/>.
27 * vim: ts=4 sw=4 noet ai cindent syntax=c
30 #include "text_object.h"
35 * this list is special. it looks like this:
36 * NULL <-- obj1 <--> obj2 <--> ... <--> objN --> NULL
37 * ^-------root_object----------^
38 * directions are reversed here
41 * - root_object points both to the start and end of the list
42 * - while traversing, the end of the list is always a NULL pointer
43 * (this works in BOTH directions)
46 /* append an object to the given root object's list */
47 int append_object(struct text_object *root, struct text_object *obj)
49 struct text_object *end;
57 CRIT_ERR(NULL, NULL, "huston, we have a lift-off");
66 /* ifblock handlers for the object list
68 * - each if points to it's else or endif
69 * - each else points to it's endif
73 /* possible ifblock types
74 * only used internally, so no need to make this public
82 /* linked list of ifblock objects, building a stack
83 * only used internally, so no need to make this public
85 struct ifblock_stack_obj {
86 enum ifblock_type type;
87 struct text_object *obj;
88 struct ifblock_stack_obj *next;
91 /* push an ifblock object onto the stack
92 * in fact, this does a lot more:
93 * - IFBLOCK_IF is just pushed onto the stack
94 * - IFBLOCK_ELSE updates the "next" pointer of the upmost
95 * object in the stack and is then pushed onto the stack
96 * - IFBLOCK_ENDIF updates the "next" pointer of the upmost
97 * object in the stack and then triggers stack popping of
98 * any optional IFBLOCK_ELSE along with it's IFBLOCK_IF
100 static int push_ifblock(struct ifblock_stack_obj **ifblock_stack_top,
101 struct text_object *obj, enum ifblock_type type)
103 struct ifblock_stack_obj *stackobj;
107 if (!(*ifblock_stack_top))
108 CRIT_ERR(NULL, NULL, "got an endif without matching if");
109 (*ifblock_stack_top)->obj->data.ifblock.next = obj;
110 /* if there's some else in between, remove and free it */
111 if ((*ifblock_stack_top)->type == IFBLOCK_ELSE) {
112 stackobj = *ifblock_stack_top;
113 *ifblock_stack_top = stackobj->next;
116 /* finally remove and free the if object */
117 stackobj = *ifblock_stack_top;
118 *ifblock_stack_top = stackobj->next;
122 if (!(*ifblock_stack_top))
123 CRIT_ERR(NULL, NULL, "got an else without matching if");
124 (*ifblock_stack_top)->obj->data.ifblock.next = obj;
127 stackobj = malloc(sizeof(struct ifblock_stack_obj));
128 stackobj->type = type;
130 stackobj->next = *ifblock_stack_top;
131 *ifblock_stack_top = stackobj;
134 CRIT_ERR(NULL, NULL, "push_ifblock() missuse detected!");
139 /* public functions for client use */
141 int obj_be_ifblock_if(void **opaque, struct text_object *obj)
143 return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_IF);
145 int obj_be_ifblock_else(void **opaque, struct text_object *obj)
147 return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_ELSE);
149 int obj_be_ifblock_endif(void **opaque, struct text_object *obj)
151 return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_ENDIF);
154 /* check if ifblock stack is empty
155 * if so, return true (!= 0)
157 int ifblock_stack_empty(void **opaque)
159 return *opaque == NULL;