1 /* -*- mode: c; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: t -*-
2 * vim: ts=4 sw=4 noet ai cindent syntax=c
4 * Conky, a system monitor, based on torsmo
6 * Any original torsmo code is licensed under the BSD license
8 * All code written since the fork of torsmo is licensed under the GPL
10 * Please see COPYING for details
12 * Copyright (c) 2005-2009 Brenden Matthews, Philip Kovacs, et. al.
14 * All rights reserved.
16 * This program is free software: you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation, either version 3 of the License, or
19 * (at your option) any later version.
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
25 * You should have received a copy of the GNU General Public License
26 * along with this program. If not, see <http://www.gnu.org/licenses/>.
29 #include "text_object.h"
34 * this list is special. it looks like this:
35 * NULL <-- obj1 <--> obj2 <--> ... <--> objN --> NULL
36 * ^-------root_object----------^
37 * directions are reversed here
40 * - root_object points both to the start and end of the list
41 * - while traversing, the end of the list is always a NULL pointer
42 * (this works in BOTH directions)
45 /* append an object to the given root object's list */
46 int append_object(struct text_object *root, struct text_object *obj)
48 struct text_object *end;
56 CRIT_ERR(NULL, NULL, "huston, we have a lift-off");
65 /* ifblock handlers for the object list
67 * - each if points to it's else or endif
68 * - each else points to it's endif
72 /* possible ifblock types
73 * only used internally, so no need to make this public
81 /* linked list of ifblock objects, building a stack
82 * only used internally, so no need to make this public
84 struct ifblock_stack_obj {
85 enum ifblock_type type;
86 struct text_object *obj;
87 struct ifblock_stack_obj *next;
90 /* push an ifblock object onto the stack
91 * in fact, this does a lot more:
92 * - IFBLOCK_IF is just pushed onto the stack
93 * - IFBLOCK_ELSE updates the "next" pointer of the upmost
94 * object in the stack and is then pushed onto the stack
95 * - IFBLOCK_ENDIF updates the "next" pointer of the upmost
96 * object in the stack and then triggers stack popping of
97 * any optional IFBLOCK_ELSE along with it's IFBLOCK_IF
99 static int push_ifblock(struct ifblock_stack_obj **ifblock_stack_top,
100 struct text_object *obj, enum ifblock_type type)
102 struct ifblock_stack_obj *stackobj;
106 if (!(*ifblock_stack_top))
107 CRIT_ERR(NULL, NULL, "got an endif without matching if");
108 (*ifblock_stack_top)->obj->data.ifblock.next = obj;
109 /* if there's some else in between, remove and free it */
110 if ((*ifblock_stack_top)->type == IFBLOCK_ELSE) {
111 stackobj = *ifblock_stack_top;
112 *ifblock_stack_top = stackobj->next;
115 /* finally remove and free the if object */
116 stackobj = *ifblock_stack_top;
117 *ifblock_stack_top = stackobj->next;
121 if (!(*ifblock_stack_top))
122 CRIT_ERR(NULL, NULL, "got an else without matching if");
123 (*ifblock_stack_top)->obj->data.ifblock.next = obj;
126 stackobj = malloc(sizeof(struct ifblock_stack_obj));
127 stackobj->type = type;
129 stackobj->next = *ifblock_stack_top;
130 *ifblock_stack_top = stackobj;
133 CRIT_ERR(NULL, NULL, "push_ifblock() missuse detected!");
138 /* public functions for client use */
140 int obj_be_ifblock_if(void **opaque, struct text_object *obj)
142 return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_IF);
144 int obj_be_ifblock_else(void **opaque, struct text_object *obj)
146 return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_ELSE);
148 int obj_be_ifblock_endif(void **opaque, struct text_object *obj)
150 return push_ifblock((struct ifblock_stack_obj **)opaque, obj, IFBLOCK_ENDIF);
153 /* check if ifblock stack is empty
154 * if so, return true (!= 0)
156 int ifblock_stack_empty(void **opaque)
158 return *opaque == NULL;