src/hscroll.c

   1 /* ncmpc (Ncurses MPD Client)
   2  * (c) 2004-2009 The Music Player Daemon Project
   3  * Project homepage: http://musicpd.org
   4
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "hscroll.h"
  21 #include "charset.h"
  22
  23 #include <assert.h>
  24 #include <string.h>
  25
  26 char *
  27 strscroll(struct hscroll *hscroll, const char *str, const char *separator,
  28           unsigned width)
  29 {
  30         gchar *tmp, *buf;
  31
  32         assert(hscroll != NULL);
  33         assert(str != NULL);
  34         assert(separator != NULL);
  35
  36         /* create a buffer containing the string and the separator */
  37         tmp = replace_locale_to_utf8(g_strconcat(str, separator,
  38                                                  str, separator, NULL));
  39
  40         if (hscroll->offset >= (unsigned)g_utf8_strlen(tmp, -1) / 2)
  41                 hscroll->offset = 0;
  42
  43         /* create the new scrolled string */
  44         buf = g_utf8_offset_to_pointer(tmp, hscroll->offset);
  45         utf8_cut_width(buf, width);
  46
  47         /* convert back to locale */
  48         buf = utf8_to_locale(buf);
  49         g_free(tmp);
  50         return buf;
  51 }
  52
  53 /**
  54  * This timer scrolls the area by one and redraws.
  55  */
  56 static gboolean
  57 hscroll_timer_callback(gpointer data)
  58 {
  59         struct hscroll *hscroll = data;
  60
  61         hscroll_step(hscroll);
  62         hscroll_draw(hscroll);
  63         wrefresh(hscroll->w);
  64         return true;
  65 }
  66
  67 void
  68 hscroll_set(struct hscroll *hscroll, unsigned x, unsigned y, unsigned width,
  69             const char *text)
  70 {
  71         assert(hscroll != NULL);
  72         assert(hscroll->w != NULL);
  73         assert(text != NULL);
  74
  75         if (hscroll->text != NULL && hscroll->x == x && hscroll->y == y &&
  76             hscroll->width == width && strcmp(hscroll->text, text) == 0)
  77                 /* no change, do nothing (and, most importantly, do
  78                    not reset the current offset!) */
  79                 return;
  80
  81         hscroll_clear(hscroll);
  82
  83         hscroll->x = x;
  84         hscroll->y = y;
  85         hscroll->width = width;
  86
  87         /* obtain the ncurses attributes and the current color, store
  88            them */
  89         wattr_get(hscroll->w, &hscroll->attrs, &hscroll->pair, NULL);
  90
  91         hscroll->text = g_strdup(text);
  92         hscroll->offset = 0;
  93         hscroll->source_id = g_timeout_add_seconds(1, hscroll_timer_callback,
  94                                                    hscroll);
  95 }
  96
  97 void
  98 hscroll_clear(struct hscroll *hscroll)
  99 {
 100         assert(hscroll != NULL);
 101
 102         if (hscroll->text == NULL)
 103                 return;
 104
 105         g_source_remove(hscroll->source_id);
 106
 107         g_free(hscroll->text);
 108         hscroll->text = NULL;
 109 }
 110
 111 void
 112 hscroll_draw(struct hscroll *hscroll)
 113 {
 114         attr_t old_attrs;
 115         short old_pair;
 116         char *p;
 117
 118         assert(hscroll != NULL);
 119         assert(hscroll->w != NULL);
 120         assert(hscroll->text != NULL);
 121
 122         /* set stored attributes and color */
 123         wattr_get(hscroll->w, &old_attrs, &old_pair, NULL);
 124         wattr_set(hscroll->w, hscroll->attrs, hscroll->pair, NULL);
 125
 126         /* scroll the string, and draw it */
 127         p = strscroll(hscroll, hscroll->text, hscroll->separator,
 128                       hscroll->width);
 129         mvwaddstr(hscroll->w, hscroll->y, hscroll->x, p);
 130         g_free(p);
 131
 132         /* restore previous attributes and color */
 133         wattr_set(hscroll->w, old_attrs, old_pair, NULL);
 134 }