src/main.c

   1 /* cmover: moves a character over the screen using curses */
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <curses.h>
   5
   6 static void quit (void);
   7 static void update_screen (void);
   8 static void update_mainview (void);
   9 static void update_statusline (void);
  10 static void check_size (void);
  11 static void create_windows (void);
  12 static int can_move (int, int);
  13 static WINDOW * mainview = NULL;
  14 static WINDOW * statusline = NULL;
  15 static unsigned int lines, cols;        /* size to work with */
  16 static unsigned int x, y;               /* coordinates */
  17 static char c='X';                      /* character to use */
  18
  19 int main (int argc, char ** argv)
  20 {
  21         int input;
  22         int mv_x, mv_y;
  23
  24         atexit (quit);
  25
  26         initscr ();
  27         noecho ();
  28         clear ();
  29
  30         lines = LINES;
  31         cols = COLS;
  32         x = cols / 2;
  33         y = lines / 2;
  34
  35         create_windows ();
  36         update_screen ();
  37
  38         while (1) {
  39                 input = wgetch (mainview);
  40                 mv_x = mv_y = 0;
  41                 switch (input) {
  42                         case 'h':
  43                         case KEY_LEFT:
  44                                 mv_x=-1;
  45                                 break;
  46                         case 'j':
  47                         case KEY_DOWN:
  48                                 mv_y=1;
  49                                 break;
  50                         case 'k':
  51                         case KEY_UP:
  52                                 mv_y=-1;
  53                                 break;
  54                         case 'l':
  55                         case KEY_RIGHT:
  56                                 mv_x=1;
  57                                 break;
  58                         case 'y':
  59                                 mv_x=-1;
  60                                 mv_y=-1;
  61                                 break;
  62                         case 'u':
  63                                 mv_x=1;
  64                                 mv_y=-1;
  65                                 break;
  66                         case 'b':
  67                                 mv_x=-1;
  68                                 mv_y=1;
  69                                 break;
  70                         case 'n':
  71                                 mv_x=1;
  72                                 mv_y=1;
  73                                 break;
  74                         case 'q':
  75                                 exit (0);
  76                                 break;
  77                 }
  78                 check_size ();
  79                 if ((mv_x || mv_y) && can_move (mv_x, mv_y)) {
  80                         x += mv_x;
  81                         y += mv_y;
  82                         update_screen();
  83                 }
  84         }
  85
  86         return 0;
  87 }
  88
  89 static void quit (void)
  90 {
  91         endwin ();
  92         printf ("exiting...\n");
  93 }
  94
  95 static void check_size (void)
  96 {
  97         if (LINES != lines || COLS != cols) {
  98                 lines = LINES;
  99                 cols = COLS;
 100                 create_windows ();
 101                 clear ();
 102                 if (y >= lines-1) y = lines-2;
 103                 if (x >= cols) x = cols-1;
 104                 update_screen ();
 105         }
 106 }
 107
 108 /* (re)creates the two windows. this is needed after resizing the screen */
 109 static void create_windows (void)
 110 {
 111         if (mainview) delwin (mainview);
 112         if (statusline) delwin (statusline);
 113         mainview = newwin (lines-1, 0, 0, 0);
 114         statusline = newwin (0, 0, lines-1, 0);
 115         keypad (mainview, TRUE); /* make arrow keys usable */
 116 }
 117
 118 static void update_screen (void)
 119 {
 120         update_mainview ();
 121         update_statusline ();
 122 }
 123
 124 static void update_mainview (void)
 125 {
 126         waddch (mainview, ' ');
 127         mvwaddch (mainview, y, x, c);
 128         wmove (mainview, y, x);
 129         wrefresh (mainview);
 130 }
 131
 132 /* width and height are the size of the whole terminal, not just the mainview. */
 133 static void update_statusline (void)
 134 {
 135         mvwprintw (statusline, 0, 0, "x: %i, y: %i, width: %i, height: %i",
 136                         x, y, cols, lines);
 137         wclrtoeol (statusline);
 138         wrefresh (statusline);
 139 }
 140
 141 static int can_move (const int mv_x, const int mv_y)
 142 {
 143         return (mv_x+x<cols && mv_y+y<lines-1);
 144 }