ziffer-handling: backspace-support, range check, nur ziffern

diff --git a/src/kasse.c b/src/kasse.c
index 4883ef8f34c8d5a533956d2d08882c36aa7bfa68..7e652e0814c209072d90ac42102762e6e81a3622 100644 (file)
--- a/src/kasse.c
+++ b/src/kasse.c
@@ -130,7 +130,7 @@ static signed int buy(char *name, unsigned int price) {
        int negative = 1;
        char entered[5] = {'1', 0, 0, 0, 0};
        BYTE i = 0, matches = 0;
-       BYTE c, nickname_len;
+       BYTE c, x, y, nickname_len;
        int einheiten;
        char *input;
        char nickname[11];
@@ -142,21 +142,48 @@ static signed int buy(char *name, unsigned int price) {
 
        clrscr();
        cprintf("Wieviel Einheiten \"%s\"? [1] \r\n", name);
+       x = wherex();
+       y = wherey();
        while (1) {
+               /* Buffer-Ende erreicht? */
+               if (i == 4)
+                       break;
+
                c = cgetc();
+               /* Enter */
                if (c == 13)
                        break;
-               cputc(c);
+               /* Backspace */
+               if (c == 20) {
+                       if (i == 0)
+                               continue;
+                       entered[--i] = '\0';
+                       cputcxy(x+i, y, ' ');
+                       gotoxy(x+i, y);
+                       continue;
+               }
                if (c == 27) {
                        cprintf("Kauf abgebrochen, druecke RETURN...\r\n");
                        get_input();
                        return 1;
-               } else if (c == '-' && i == 0)
+               }
+               if (c == '-' && i == 0) {
                        negative = -1;
-               else if (c > 47 && c < 58)
+                       cputc(c);
+               } else if (c > 47 && c < 58) {
                        entered[i++] = c;
+                       cputc(c);
+               }
+
+               /* Ungültige Eingabe (keine Ziffer), einfach ignorieren */
        }
        einheiten = atoi(entered) * negative;
+
+       if (einheiten > 100 || einheiten < -100 || einheiten == 0) {
+               cprintf("\r\nEinheit nicht in [-100, 100] oder 0, Abbruch, druecke RETURN...\r\n");
+               cgetc();
+               return 1;
+       }
        
        toggle_videomode();
        cprintf("\r\n             *** VERKAUF ***\r\n\r\n");