menu.c

#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <curses.h>

#include "menu.h"
#include "keys.h"

#define CHOICE_STR "->"
#define CLEAR_CHOICE_STR "  "
#define PAUSE_STR " PAUSED "
#define CHOICE_STR_LEN (sizeof(CHOICE_STR)-1)
#define PAUSE_STR_LEN (sizeof(PAUSE_STR)-1)

/* Creates a window centered in the terminal. */
WINDOW* createCenteredWindow(int width, int height);

/* Draws the window, including all the choices and the current choice
 * indicator. */
void drawChoices(WINDOW* win, char* title, int choiceCount, int currentChoice,
        char** choices);

int menu_choice(char* title, int choiceCount, char** choices) {
    int winHeight, winWidth, i, choice, c;
    bool chosen;
    size_t longestChoice;
    WINDOW* menuWin;

    winHeight = choiceCount + 1 /* for the title bar */ +
        2 /* for the top and bottom bar */;

    longestChoice = 0;
    for (i = 0; i < choiceCount; i++) {
        size_t newLen = strlen(choices[i]);
        if (newLen > longestChoice) {
            longestChoice = newLen;
        }
    }
    winWidth = (int)(longestChoice + CHOICE_STR_LEN * 2 + 2);

    menuWin = createCenteredWindow(winHeight, winWidth);

    // drawing
    choice = 0;
    chosen = false;

    while (!chosen) {
        drawChoices(menuWin, title, choiceCount, choice, choices);
        c = getch();
        switch (c) {
            case KEY_ENTER:
                chosen = true;
                break;
            case KEY_UP:
                if (choice > 0) {
                    choice--;
                }
                break;
            case KEY_DOWN:
                if (choice < choiceCount-1) {
                    choice++;
                }
                break;
        }
    }
    delwin(menuWin);

    if (chosen) {
        return choice;
    } else {
        return -1;
    }
}

void menu_pauseMenu() {
    int winHeight = 3; // height of a line plus a padding
    int winWidth = PAUSE_STR_LEN + 2;

    WINDOW* pauseWin = createCenteredWindow(winHeight, winWidth);
    mvwprintw(pauseWin, 1, 1, PAUSE_STR);
    box(pauseWin, 0, 0);
    wrefresh(pauseWin);

    while (getch() != KEY_PAUSE) {}

    delwin(pauseWin);
}

WINDOW* createCenteredWindow(int height, int width) {
    int termWidth = 0, termHeight = 0;
    getmaxyx(stdscr, termHeight, termWidth);
    return newwin(height, width, (termHeight-height)/2, (termWidth-width)/2);
}

void drawChoices(WINDOW* win, char* title, int choiceCount, int currentChoice,
        char** choices) {
    int winWidth, winHeight, i;
    getmaxyx(win, winHeight, winWidth);
    box(win, 0, 0);
    mvwprintw(win, 1, (winWidth-(int)strlen(title))/2, title);
    for (i = 0; i < choiceCount; i++) {
        mvwprintw(win, i+2, CHOICE_STR_LEN+1, choices[i]);
        if (i == currentChoice) {
            mvwprintw(win, i+2, 1, CHOICE_STR);
        } else {
            mvwprintw(win, i+2, 1, CLEAR_CHOICE_STR);
        }
    }
    wrefresh(win);
}