diff options
Diffstat (limited to 'libslang/demo/pager.c')
| -rw-r--r-- | libslang/demo/pager.c | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/libslang/demo/pager.c b/libslang/demo/pager.c new file mode 100644 index 0000000..b094a0a --- /dev/null +++ b/libslang/demo/pager.c @@ -0,0 +1,280 @@ +/* This file pager demo illustrates the screen management and + * keyboard routines. + */ + +#include <stdio.h> +#include <string.h> + +#include <stdlib.h> + +#include <signal.h> + +#ifdef unix +# include <unistd.h> +#endif + +#include <slang.h> + +#include "demolib.c" + +static void usage (char *pgm) +{ + fprintf (stderr, "Usage: %s [FILENAME]\n", pgm); + exit (1); +} + +static int read_file (char *); +static void main_loop (void); + +static char *File_Name; /* if NULL, use stdin */ + +int main (int argc, char **argv) +{ + if (argc == 2) + { + File_Name = argv[1]; + } + else if ((argc != 1) || (1 == isatty (fileno(stdin)))) + usage (argv[0]); + + + if (-1 == read_file (File_Name)) + { + fprintf (stderr, "Unable to read %s\n", File_Name); + return 1; + } + + /* This sets up the terminal, signals, screen management routines, etc... */ + if (-1 == demolib_init_terminal (1, 1)) + { + fprintf (stderr, "Unable to initialize terminal."); + return 1; + } + +#define APP_KEY_EOB 0x1001 +#define APP_KEY_BOB 0x1002 + + /* Add a few application defined keysyms. 0x1000 and above are for + * applications. + */ + (void) SLkp_define_keysym ("\033>", APP_KEY_EOB); + (void) SLkp_define_keysym ("\033<", APP_KEY_BOB); + + main_loop (); /* should not return */ + return 1; +} + + +/* The SLscroll routines will be used for pageup/down commands. They assume + * a linked list of lines. The first element of the structure MUST point to + * the NEXT line, the second MUST point to the PREVIOUS line. + */ +typedef struct _File_Line_Type +{ + struct _File_Line_Type *next; + struct _File_Line_Type *prev; + char *data; /* pointer to line data */ +} +File_Line_Type; + +static File_Line_Type *File_Lines; + +/* The SLscroll routines will use this structure. */ +static SLscroll_Window_Type Line_Window; + +static void free_lines (void) +{ + File_Line_Type *line, *next; + + line = File_Lines; + while (line != NULL) + { + next = line->next; + if (line->data != NULL) free (line->data); + free (line); + line = next; + } + File_Lines = NULL; +} + +static File_Line_Type *create_line (char *buf) +{ + File_Line_Type *line; + + line = (File_Line_Type *) malloc (sizeof (File_Line_Type)); + if (line == NULL) return NULL; + + memset ((char *) line, sizeof (File_Line_Type), 0); + + line->data = SLmake_string (buf); /* use a slang routine */ + if (line->data == NULL) + { + free (line); + return NULL; + } + + return line; +} + + +static int read_file (char *file) +{ + FILE *fp; + char buf [1024]; + File_Line_Type *line, *last_line; + unsigned int num_lines; + + if (file == NULL) + fp = stdin; + else fp = fopen (file, "r"); + + if (fp == NULL) return -1; + + last_line = NULL; + num_lines = 0; + + while (NULL != fgets (buf, sizeof(buf), fp)) + { + num_lines++; + + if (NULL == (line = create_line (buf))) + { + fprintf (stderr, "Out of memory."); + free_lines (); + return -1; + } + + if (last_line == NULL) + File_Lines = line; + else + last_line->next = line; + + line->prev = last_line; + line->next = NULL; + + last_line = line; + } + + memset ((char *)&Line_Window, 0, sizeof (SLscroll_Window_Type)); + + Line_Window.current_line = (SLscroll_Type *) File_Lines; + Line_Window.lines = (SLscroll_Type *) File_Lines; + Line_Window.line_num = 1; + Line_Window.num_lines = num_lines; + /* Line_Window.border = 3; */ + + return 0; +} + + +static void update_display (void) +{ + unsigned int row, nrows; + File_Line_Type *line; + + /* All well behaved applications should block signals that may affect + * the display while performing screen update. + */ + SLsig_block_signals (); + + Line_Window.nrows = nrows = SLtt_Screen_Rows - 1; + + /* Always make the current line equal to the top window line. */ + if (Line_Window.top_window_line != NULL) + Line_Window.current_line = Line_Window.top_window_line; + + SLscroll_find_top (&Line_Window); + + row = 0; + line = (File_Line_Type *) Line_Window.top_window_line; + + SLsmg_normal_video (); + + while (row < Line_Window.nrows) + { + SLsmg_gotorc (row, 0); + + if (line != NULL) + { + SLsmg_write_string (line->data); + line = line->next; + } + SLsmg_erase_eol (); + row++; + } + + SLsmg_gotorc (row, 0); + SLsmg_reverse_video (); + SLsmg_printf ("%s", (File_Name == NULL) ? "<stdin>" : File_Name); + SLsmg_erase_eol (); + SLsmg_refresh (); + + SLsig_unblock_signals (); +} + +static int Screen_Start; + +static void main_loop (void) +{ + int screen_start; + + while (1) + { + update_display (); + switch (SLkp_getkey ()) + { + case SL_KEY_ERR: + case 'q': + case 'Q': + demolib_exit (0); + break; + + case SL_KEY_RIGHT: + Screen_Start += 1; + screen_start = Screen_Start; + SLsmg_set_screen_start (NULL, &screen_start); + break; + + case SL_KEY_LEFT: + Screen_Start -= 1; + if (Screen_Start < 0) Screen_Start = 0; + screen_start = Screen_Start; + SLsmg_set_screen_start (NULL, &screen_start); + break; + + case SL_KEY_UP: + SLscroll_prev_n (&Line_Window, 1); + Line_Window.top_window_line = Line_Window.current_line; + break; + + case '\r': + case SL_KEY_DOWN: + SLscroll_next_n (&Line_Window, 1); + Line_Window.top_window_line = Line_Window.current_line; + break; + + case SL_KEY_NPAGE: + case ' ': case 4: + SLscroll_pagedown (&Line_Window); + break; + + case SL_KEY_PPAGE: + case 127: case 21: + SLscroll_pageup (&Line_Window); + break; + + case APP_KEY_BOB: + while (-1 != SLscroll_pageup (&Line_Window)) + ; + break; + + case APP_KEY_EOB: + while (-1 != SLscroll_pagedown (&Line_Window)) + ; + break; + + default: + SLtt_beep (); + } + } +} |