Add the basic I/O functions init_screen(), end_screen() and center()

src/Makefile.am

@@ -32,6 +32,7 @@ bin_PROGRAMS	= trader
 trader_SOURCES	= \
 	trader.c	trader.h	\
 	globals.c	globals.h	\
+	intf.c		intf.h		\
 	utils.c		utils.h		\
 			system.h
 

src/intf.c

@@ -30,3 +30,132 @@
 
 #include "system.h"
 #include "intf.h"
+#include "utils.h"
+
+
+/************************************************************************
+*             Basic text input/output function definitions              *
+************************************************************************/
+
+
+/*-----------------------------------------------------------------------
+  Function:   init_screen  - Initialise the screen (terminal)
+  Arguments:  (none)
+  Returns:    (nothing)
+
+  This function initialises the input (keyboard) and output (screen)
+  using the Curses library.
+*/
+
+void init_screen (void)
+{
+    initscr();
+
+    if ((COLS < MIN_COLUMNS) || (LINES < MIN_LINES)) {
+	err_exit("terminal size is too small (%d x %d required)",
+		 MIN_COLUMNS, MIN_LINES);
+    }
+
+    noecho();
+    curs_set(CURS_INVISIBLE);
+    raw();
+
+    if (has_colors()) {
+	start_color();
+
+	init_pair(WHITE_ON_BLACK, COLOR_WHITE,  COLOR_BLACK);
+	init_pair(WHITE_ON_BLUE,  COLOR_WHITE,  COLOR_BLUE);
+	init_pair(YELLOW_ON_CYAN, COLOR_YELLOW, COLOR_CYAN);
+	init_pair(WHITE_ON_RED,   COLOR_WHITE,  COLOR_RED);
+	init_pair(BLACK_ON_WHITE, COLOR_BLACK,  COLOR_WHITE);
+
+	bkgd(COLOR_PAIR(WHITE_ON_BLACK));
+    }
+
+    clear();
+    move(0, 0);
+
+    attrset(has_colors() ? COLOR_PAIR(YELLOW_ON_CYAN) | A_BOLD :
+	    A_REVERSE | A_BOLD);
+    center(stdscr, true, PACKAGE_NAME);
+    attrset(A_NORMAL);
+
+    refresh();
+}
+
+
+/*-----------------------------------------------------------------------
+  Function:   end_screen  - End using the screen (terminal)
+  Arguments:  (none)
+  Returns:    (nothing)
+
+  This function closes the input (keyboard) and output (screen) using the
+  Curses library.  It makes sure the screen is cleared before doing so.
+*/
+
+void end_screen (void)
+{
+    clear();
+    refresh();
+    endwin();
+}
+
+
+/*-----------------------------------------------------------------------
+  Function:   center   - Centre a string on the current line
+  Arguments:  win      - Window to use
+              clrline  - True to print spaces on both sides of line
+              format   - printf()-like format string
+              ...      - printf()-like arguments
+  Returns:    int      - Return code from wprintw()
+
+  This function prints a string (formated with wprintw(format, ...)) in
+  the centre of the current line in the window win.  If clrline is TRUE,
+  spaces are printed before and after the line to make sure the current
+  attributes are set.  The cursor is then moved to the start of the next
+  line, or the start of the current line (if already on the last line of
+  the screen).  Please note that wrefresh() is NOT called.
+*/
+
+int center (WINDOW *win, const bool clrline, const char *format, ...)
+{
+    va_list args;
+
+    int len, ret;
+    int y, x, maxy, maxx;
+    int fill;
+
+    char *buf = malloc(OUTBUFSIZE);
+    if (buf == NULL) {
+	err_exit("out of memory");
+    }
+
+    va_start(args, format);
+    len = vsnprintf(buf, OUTBUFSIZE, format, args);
+    if (len < 0) {
+	return ERR;
+    }
+
+    getyx(win, y, x);
+    getmaxyx(win, maxy, maxx);
+
+    fill = (maxx - len) / 2;
+
+    if (clrline) {
+	wmove(win, y, 0);
+	if (fill > 0) {
+	    wprintw(win, "%*c", fill, ' ');
+	}
+	ret = wprintw(win, "%s", buf);
+	if (maxx - len - fill > 0) {
+	    wprintw(win, "%*c", maxx - len - fill, ' ');
+	}
+    } else {
+	ret = mvwprintw(win, y, fill > 0 ? fill : 0, "%s", buf);
+    }
+
+    wmove(win, (y + 1 >= maxy ? y : y + 1), 0);
+
+    free(buf);
+    return ret;
+}

src/intf.h

@@ -32,6 +32,9 @@
 #define included_INTF_H 1
 
 
+#include "system.h"
+
+
 /************************************************************************
 *                    Constants and type declarations                    *
 ************************************************************************/
@@ -39,5 +42,29 @@
 #define MIN_COLUMNS	(80)	/* Minimum number of columns in terminal */
 #define MIN_LINES	(24)	/* Minimum number of lines in terminal */
 
+#define OUTBUFSIZE	(1024)	/* Output string buffer size */
+
+
+// Colour pairs used in Star Traders
+enum color_pairs {
+    DEFAULT_COLORS = 0,
+    WHITE_ON_BLACK,
+    WHITE_ON_BLUE,
+    WHITE_ON_RED,
+    YELLOW_ON_CYAN,
+    BLACK_ON_WHITE,
+};
+
+
+/************************************************************************
+*             Basic text input/output function declarations             *
+************************************************************************/
+
+extern void init_screen (void);
+extern void end_screen (void);
+
+extern int center (WINDOW *win, const bool clrline, const char *format, ...)
+    __attribute__((format (printf, 3, 4)));
+
 
 #endif /* included_INTF_H */

src/trader.c

@@ -62,21 +62,7 @@ int main (int argc, char *argv[])
 
 
     // Testing...
-    initscr();
-    noecho();
-    curs_set(CURS_INVISIBLE);
-    timeout(-1);
-    keypad(stdscr, true);
-    raw();
-
-    if (has_colors() == true) {
-	start_color();
-	init_pair(1, COLOR_WHITE, COLOR_BLACK);
-	init_pair(2, COLOR_WHITE, COLOR_BLUE);
-	bkgd(COLOR_PAIR(1));
-    }
-    clear();
-    move(0, 0);
+    init_screen();
 
     printw("Program name:   %s\n", program_name());
     printw("Home directory: %s\n", home_directory());
@@ -93,16 +79,20 @@ int main (int argc, char *argv[])
     WINDOW *w1, *w2;
 
     w1 = newwin(0, 0, 7, 0);
-    wbkgd(w1, COLOR_PAIR(2));
+    wbkgd(w1, COLOR_PAIR(WHITE_ON_BLUE));
     box(w1, 0, 0);
     wrefresh(w1);
 
     w2 = newwin(LINES - 9, COLS - 8, 8, 4);
-    wbkgd(w2, COLOR_PAIR(2));
+    wbkgd(w2, COLOR_PAIR(WHITE_ON_BLUE));
+
+    wattrset(w2, has_colors() ? COLOR_PAIR(WHITE_ON_RED) | A_BOLD : A_REVERSE | A_BOLD);
+    center(w2, true, "Type some keys (^C to exit):");
+    wattrset(w2, A_NORMAL);
 
-    mvwprintw(w2, 0, 0, "Type some keys (^C to exit):\n\n");
     wrefresh(w2);
 
+    scrollok(w2, true);
     keypad(w2, true);
     meta(w2, true);
     wtimeout(w2, -1);
@@ -124,9 +114,7 @@ int main (int argc, char *argv[])
 	wrefresh(w2);
     }
 
-    clear();
-    refresh();
-    endwin();
+    end_screen();
 
     return EXIT_SUCCESS;
 }

src/trader.h

@@ -45,6 +45,7 @@
 
 #include "system.h"
 #include "globals.h"
+#include "intf.h"
 #include "utils.h"
 
 

src/utils.c

@@ -30,6 +30,7 @@
 
 #include "system.h"
 #include "utils.h"
+#include "intf.h"
 
 
 /************************************************************************
@@ -238,9 +239,7 @@ void err_exit (const char *format, ...)
     va_list args;
 
 
-    clear();
-    refresh();
-    endwin();
+    end_screen();
 
     fprintf(stderr, "%s: ", program_name());
     va_start(args, format);
@@ -273,9 +272,7 @@ void errno_exit (const char *format, ...)
     int saved_errno = errno;
 
 
-    clear();
-    refresh();
-    endwin();
+    end_screen();
 
     fprintf(stderr, "%s: ", program_name());
     if (format != NULL) {