I try to make a menu with ncurses library, I made a switch with a getch() that takes the input. When I'm moving in the menu I need to press twice the keys to get the right input. For example if I want to go to the "exit" line from "options" line I need to press twice the KEY_DOWN, if I press only one time the cursor doesn't move. This is the code:

#include <iostream>
#include <cstring>
#include <ncurses.h>

void start(){
    initscr();
    noecho();
    raw();
    cbreak();
}
void position(WINDOW* win, int curr, char string1[], char string2[], char string3[]){
    if(curr==1){
        mvwaddstr(win, 7, 21, string2);             
        mvwaddstr(win, 8, 21, string3);
        wattron(win, A_REVERSE);
        mvwaddstr(win, 6, 21, string1);           
        wrefresh(win);
    }
    else if(curr==2){
        mvwaddstr(win, 6, 21, string1);
        mvwaddstr(win, 8, 21, string3);
        wattron(win, A_REVERSE);
        mvwaddstr(win, 7, 21, string2);
        wrefresh(win);
    }
    else{
        mvwaddstr(win, 6, 21, string1);
        mvwaddstr(win, 7, 21, string2);
        wattron(win, A_REVERSE);
        mvwaddstr(win, 8, 21, string3);
        wrefresh(win);
    }
    wattroff(win, A_REVERSE);
}

int main (){
    start();

    WINDOW * win = newwin (20, 50, 0, 0);
    refresh(); 
    box (win, 0, 0);
    wrefresh(win);
    keypad(win, TRUE);

    int length = 20, current = 1;
    char string1[length], string2[length], string3[length];

    strncpy(string1, "NEW GAME", 10);
    strncpy(string2, "OPTIONS", 10);
    strncpy(string3, "EXIT", 10);

    mvwaddstr(win, 7, 21, string2);
    mvwaddstr(win, 8, 21, string3);
    mvwaddstr(win, 6, 21, string1);
    wrefresh(win);

    while(getch()!='x'){
        int push = wgetch(win);             
        switch(push){
            case KEY_UP:
                current--;
                if(current==0){             
                    current=1;
                }
                break;
            case KEY_DOWN:
                current  ;
                if(current==4){
                    current=3;
                }
                break;
            case 10:            
                break;
         default:
                break;
        }
        position(win, current, string1, string2, string3);
    }

    getch();
    endwin();

   return 0;
}

CodePudding user response：

You call (w)getch twice in the loop:

while(getch()!='x'){
    int push = wgetch(win);
    // ...
}

Try this to get the character and check for the loop condition at the same time:

int push;
while ((push = wgetch(win)) != 'x'){
    // ...
}