Bug Summary

File:uinterface.c
Location:line 33, column 19
Description:Access to field 'w' results in a dereference of a null pointer (loaded from variable 'swin')

Annotated Source Code

1/*
2 * Copyright (c) 2010, 2011 Ryan Flannery <ryan.flannery@gmail.com>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17#include "uinterface.h"
18
19/* the global user interface object */
20uinterface ui;
21
22/*****************************************************************************
23 * scrollable window stuff
24 ****************************************************************************/
25
26swindow*
27swindow_new(int h, int w, int y, int x)
28{
29 swindow *swin = malloc(sizeof(swindow));
2
←
'swin' initialized here
→
30 if (swin == NULL((void *)0))
3
←
Assuming 'swin' is equal to null
→
4
←
Assuming pointer value is null
→
5
←
Taking true branch
→
31 err(1, "swindow_new failed to allocate swin");
32
33 swin->w = w;
6
←
Access to field 'w' results in a dereference of a null pointer (loaded from variable 'swin')
34 swin->h = h;
35 swin->voffset = 0;
36 swin->hoffset = 0;
37 swin->crow = 0;
38 swin->nrows = 0;
39 swin->cwin = newwin(h, w, y, x);
40 if (swin->cwin == NULL((void *)0))
41 errx(1, "swindow_new: failed to create window");
42
43 return swin;
44}
45
46void
47swindow_resize(swindow *win, int h, int w, int y, int x)
48{
49 wresize(win->cwin, h, w);
50 mvwin(win->cwin, y, x);
51
52 win->w = w;
53 win->h = h;
54
55 if (win->crow >= h)
56 win->crow = h - 1;
57}
58
59void
60swindow_free(swindow *win)
61{
62 delwin(win->cwin);
63 free(win);
64}
65
66void
67swindow_scroll(swindow *win, Direction d, int n)
68{
69 switch (d) {
70 case UP:
71 win->voffset -= n;
72 if (win->voffset < 0)
73 win->voffset = 0;
74 break;
75
76 case DOWN:
77 win->voffset += n;
78 if (win->voffset >= win->nrows - win->h)
79 win->voffset = win->nrows - win->h;
80 if (win->voffset < 0)
81 win->voffset = 0;
82 break;
83
84 case LEFT:
85 win->hoffset -= n;
86 if (win->hoffset < 0)
87 win->hoffset = 0;
88 break;
89
90 case RIGHT:
91 win->hoffset += n;
92 /* NOTE: "overflow" here is handled elsewhere.
93 * see input_handlers.c, scroll_col()
94 */
95 break;
96
97 default:
98 err(1, "swindow_scroll: bad direction");
99 }
100}
101
102/*****************************************************************************
103 * UI Create / Resize / Destroy Functions
104 ****************************************************************************/
105
106void
107ui_init(int library_width)
108{
109 int lines, cols;
110
111 /* ncurses init */
112 initscr();
113 raw();
114 noecho();
115 nonl();
116 keypad(stdscr, TRUE1);
117 start_color();
118 curs_set(0);
119 ESCDELAY = 0;
120 refresh()wrefresh(stdscr);
121
122 getmaxyx(stdscr, lines, cols)(lines = ((stdscr) ? ((stdscr)->_maxy + 1) : (-1)), cols =
((stdscr) ? ((stdscr)->_maxx + 1) : (-1)));
123
124 /* setup width of library window */
125 ui.lwidth = library_width;
126 ui.lhide = false0;
127
128 /* create the player and command windows */
129 ui.player = newwin(1, cols, 0, 0);
130 ui.command = newwin(1, cols, lines - 1, 0);
131 if (ui.player == NULL((void *)0) || ui.command == NULL((void *)0))
132 errx(1, "ui_init: failed to create player/command windows");
133
134 /* and the rest */
135 ui.library = swindow_new(lines - 3, ui.lwidth, 2, 0);
1
Calling 'swindow_new'
→
136 ui.playlist = swindow_new(lines - 3, cols - ui.lwidth - 1, 2, ui.lwidth + 1);
137
138 ui.active = ui.library;
139}
140
141bool_Bool
142ui_is_init()
143{
144 return (ui.active != NULL((void *)0)) && !isendwin();
145}
146
147void
148ui_destroy()
149{
150 /* destroy each window (this also free()'s the mem for each window) */
151 delwin(ui.player);
152 delwin(ui.command);
153 swindow_free(ui.playlist);
154 if (ui.library != NULL((void *)0))
155 swindow_free(ui.library);
156
157 /* reset other properties of the ui to sane 'empty' defaults */
158 ui.player = NULL((void *)0);
159 ui.command = NULL((void *)0);
160 ui.library = NULL((void *)0);
161 ui.playlist = NULL((void *)0);
162 ui.active = NULL((void *)0);
163
164 /* end ncurses */
165 endwin();
166}
167
168void
169ui_resize()
170{
171 struct winsize ws;
172
173 /* get new dimensions and check for changes */
174 if (ioctl(STDIN_FILENO0, TIOCGWINSZ((unsigned long)0x40000000 | ((sizeof(struct winsize) & 0x1fff
) << 16) | ((('t')) << 8) | ((104))), &ws) < 0)
175 err(1, "ui_resize: ioctl failed");
176
177 /* can we even handle the new display size? if not, just exit */
178 if (ws.ws_col < ui.lwidth + 2) {
179 endwin();
180 errx(1, "ui_resize: not enough columns to render vitunes nicely");
181 }
182 if (ws.ws_row < 4) {
183 endwin();
184 errx(1, "ui_resize: not enough rows to render vitunes nicely");
185 }
186
187 /* resize ncurses */
188 resizeterm(ws.ws_row, ws.ws_col);
189
190 /* resize player & command windows */
191 wresize(ui.player, 1, ws.ws_col);
192 wresize(ui.command, 1, ws.ws_col);
193
194 /* resize library and playlist windows */
195 if (ui.library->cwin == NULL((void *)0))
196 swindow_resize(ui.playlist, ws.ws_row - 3, ws.ws_col, 2, 0);
197 else {
198 swindow_resize(ui.library, ws.ws_row - 3, ui.lwidth, 2, 0);
199 swindow_resize(ui.playlist, ws.ws_row - 3, ws.ws_col - ui.lwidth - 1, 2, ui.lwidth + 1);
200 }
201
202 /* move the command window to the new bottom row */
203 mvwin(ui.command, ws.ws_row - 1, 0);
204
205}
206
207void
208ui_hide_library()
209{
210 int w, h;
211
212 /* if already hidden, nothing to do */
213 if (ui.library->cwin == NULL((void *)0)) return;
214
215 /* remove library window */
216 delwin(ui.library->cwin);
217 ui.library->cwin = NULL((void *)0);
218
219 /* resize & move playlist window */
220 getmaxyx(stdscr, h, w)(h = ((stdscr) ? ((stdscr)->_maxy + 1) : (-1)), w = ((stdscr
) ? ((stdscr)->_maxx + 1) : (-1)));
221 swindow_resize(ui.playlist, h - 3, w, 2, 0);
222}
223
224void
225ui_unhide_library()
226{
227 int w, h;
228
229 /* if not hidden, nothing to do */
230 if (ui.library->cwin != NULL((void *)0)) return;
231
232 getmaxyx(stdscr, h, w)(h = ((stdscr) ? ((stdscr)->_maxy + 1) : (-1)), w = ((stdscr
) ? ((stdscr)->_maxx + 1) : (-1)));
233
234 /* create library window */
235 ui.library->cwin = newwin(h - 3, ui.lwidth, 2, 0);
236 if (ui.library->cwin == NULL((void *)0))
237 errx(1, "ui_unhide_library: failed to create newwin");
238
239 /* resize & move playlist window */
240 swindow_resize(ui.playlist, h - 3, w - ui.lwidth - 1, 2, ui.lwidth + 1);
241}
242
243void
244ui_clear()
245{
246 wclear(ui.player);
247 wclear(ui.command);
248 wclear(ui.library->cwin);
249 wclear(ui.playlist->cwin);
250 clear()wclear(stdscr);
251
252 wrefresh(ui.player);
253 wrefresh(ui.command);
254 wrefresh(ui.library->cwin);
255 wrefresh(ui.playlist->cwin);
256 refresh()wrefresh(stdscr); /* XXX needed? */
257}