src/hscroll.c

   1 /* ncmpc (Ncurses MPD Client)
   2  * (c) 2004-2017 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 #include "ncfix.h"
  23
  24 #include <assert.h>
  25 #include <string.h>
  26
  27 char *
  28 strscroll(struct hscroll *hscroll, const char *str, const char *separator,
  29           unsigned width)
  30 {
  31         assert(hscroll != NULL);
  32         assert(str != NULL);
  33         assert(separator != NULL);
  34
  35         /* create a buffer containing the string and the separator */
  36         char *tmp = replace_locale_to_utf8(g_strconcat(str, separator,
  37                                                        str, separator, NULL));
  38         if (hscroll->offset >= (unsigned)g_utf8_strlen(tmp, -1) / 2)
  39                 hscroll->offset = 0;
  40
  41         /* create the new scrolled string */
  42         char *buf = g_utf8_offset_to_pointer(tmp, hscroll->offset);
  43         utf8_cut_width(buf, width);
  44
  45         /* convert back to locale */
  46         buf = utf8_to_locale(buf);
  47         g_free(tmp);
  48         return buf;
  49 }
  50
  51 /**
  52  * This timer scrolls the area by one and redraws.
  53  */
  54 static gboolean
  55 hscroll_timer_callback(gpointer data)
  56 {
  57         struct hscroll *hscroll = data;
  58
  59         hscroll_step(hscroll);
  60         hscroll_draw(hscroll);
  61         wrefresh(hscroll->w);
  62         return true;
  63 }
  64
  65 void
  66 hscroll_set(struct hscroll *hscroll, unsigned x, unsigned y, unsigned width,
  67             const char *text)
  68 {
  69         assert(hscroll != NULL);
  70         assert(hscroll->w != NULL);
  71         assert(text != NULL);
  72
  73         if (hscroll->text != NULL && hscroll->x == x && hscroll->y == y &&
  74             hscroll->width == width && strcmp(hscroll->text, text) == 0)
  75                 /* no change, do nothing (and, most importantly, do
  76                    not reset the current offset!) */
  77                 return;
  78
  79         hscroll_clear(hscroll);
  80
  81         hscroll->x = x;
  82         hscroll->y = y;
  83         hscroll->width = width;
  84
  85         /* obtain the ncurses attributes and the current color, store
  86            them */
  87         fix_wattr_get(hscroll->w, &hscroll->attrs, &hscroll->pair, NULL);
  88
  89         hscroll->text = g_strdup(text);
  90         hscroll->offset = 0;
  91         hscroll->source_id = g_timeout_add_seconds(1, hscroll_timer_callback,
  92                                                    hscroll);
  93 }
  94
  95 void
  96 hscroll_clear(struct hscroll *hscroll)
  97 {
  98         assert(hscroll != NULL);
  99
 100         if (hscroll->text == NULL)
 101                 return;
 102
 103         g_source_remove(hscroll->source_id);
 104
 105         g_free(hscroll->text);
 106         hscroll->text = NULL;
 107 }
 108
 109 void
 110 hscroll_draw(struct hscroll *hscroll)
 111 {
 112         assert(hscroll != NULL);
 113         assert(hscroll->w != NULL);
 114         assert(hscroll->text != NULL);
 115
 116         /* set stored attributes and color */
 117         attr_t old_attrs;
 118         short old_pair;
 119         fix_wattr_get(hscroll->w, &old_attrs, &old_pair, NULL);
 120         wattr_set(hscroll->w, hscroll->attrs, hscroll->pair, NULL);
 121
 122         /* scroll the string, and draw it */
 123         char *p = strscroll(hscroll, hscroll->text, hscroll->separator,
 124                             hscroll->width);
 125         mvwaddstr(hscroll->w, hscroll->y, hscroll->x, p);
 126         g_free(p);
 127
 128         /* restore previous attributes and color */
 129         wattr_set(hscroll->w, old_attrs, old_pair, NULL);
 130 }