nc.c

#include <ncurses.h>
#include <panel.h>
#include <stdbool.h>
#include <string.h>
#include <locale.h>

#define WIDTH 80
#define HEIGHT 20
#define MAXTAB 10

WINDOW *debugwin;

typedef struct {
    WINDOW *win;
    PANEL *panel;
    char title[50];
    int beforelen;
    int afterlen;
} TAB;

typedef struct {
    int height;
    int width;
    int y;
    int x;
    WINDOW *tabbarw;
    PANEL *tabbarp;
    int active_tab;
    int tab_cnt;
    TAB tabs[MAXTAB];
} TABINFO;
        
void init_colors() {
    init_pair(1, COLOR_WHITE, COLOR_BLUE);
    init_pair(2, COLOR_WHITE, COLOR_BLUE);
    init_pair(3, COLOR_BLACK, COLOR_WHITE);
}

int draw_tab_title(TABINFO *tabinfo, int offset, const char *str, bool selected) {
    wattron(tabinfo->tabbarw, COLOR_PAIR(1));
    if (selected) {
        wattron(tabinfo->tabbarw, A_BOLD);
    } else {
        wattroff(tabinfo->tabbarw, A_BOLD);
    }

    mvwprintw(tabinfo->tabbarw, 0, offset, " %s ", str);

    wattroff(tabinfo->tabbarw, COLOR_PAIR(1));
    wattroff(tabinfo->tabbarw, A_BOLD);

    return strlen(str) + 2;
}

WINDOW *add_tab(TABINFO *tabinfo, char *str, bool deflt) {
    WINDOW *newtabwin = newwin(HEIGHT - 3, WIDTH - 4, 2, 2);
    PANEL *panel = new_panel(newtabwin);
    TAB *nexttab = &(tabinfo->tabs[tabinfo->tab_cnt]);
    TAB *nowtab = (tabinfo->tab_cnt ? &(tabinfo->tabs[tabinfo->tab_cnt - 1]) : NULL);

    nexttab->win = newtabwin;
    nexttab->panel = panel;
    strcpy(nexttab->title, str);
    nexttab->beforelen = (nowtab == NULL ? 0 : nowtab->afterlen);
    nexttab->afterlen = (nowtab == NULL ? 0 : nowtab->afterlen) + draw_tab_title(tabinfo, nexttab->beforelen, str, deflt);
    
    if (deflt) {
        tabinfo->active_tab = tabinfo->tab_cnt;
    } else {
        hide_panel(panel);
    }

    tabinfo->tab_cnt += 1;

    update_panels();

    return newtabwin;
}

void init_tab(TABINFO *tabinfo, int h, int w, int y, int x) {
    tabinfo->height = h;
    tabinfo->width = w;
    tabinfo->y = y;
    tabinfo->x = x;
    tabinfo->tabbarw = newwin(h, w, y, x);
    tabinfo->tabbarp = new_panel(tabinfo->tabbarw);
    tabinfo->active_tab = 0;
    tabinfo->tab_cnt = 0;

    wbkgd(tabinfo->tabbarw, COLOR_PAIR(3));

    WINDOW *boxwin = newwin(h - 1, w, y + 1, x);
    new_panel(boxwin);
    box(boxwin, 0, 0);

    update_panels();
}

void debug(const char *fmt, ...) {
    static int debugn = 0;
    va_list ap;
    char buf[500];

    va_start(ap, fmt);
    vsnprintf(buf, sizeof buf, fmt, ap);
    va_end(ap);
    
    mvwprintw(debugwin, debugn++, 0, buf);

    if (debugn > 20) {
        wclear(debugwin);
        debugn = 0;
    }

    wrefresh(debugwin);
}

void switch_tab(TABINFO *tabinfo, int tab) {
    if (tabinfo->active_tab != tab) {
        for (int i = 0; i < tabinfo->tab_cnt; i++) {
            if (i == tabinfo->active_tab) {
                draw_tab_title(tabinfo, tabinfo->tabs[i].beforelen, tabinfo->tabs[i].title, false);
            } else if (i == tab) {
                draw_tab_title(tabinfo, tabinfo->tabs[i].beforelen, tabinfo->tabs[i].title, true);
            }
        }
    
        hide_panel(tabinfo->tabs[tabinfo->active_tab].panel);

        tabinfo->active_tab = tab;
        show_panel(tabinfo->tabs[tabinfo->active_tab].panel);

        update_panels();
    }
}

int is_tab_clicked(TABINFO *tabinfo, int y, int x) {
    if (y == tabinfo->y && x >= tabinfo->x && x < (tabinfo->x + tabinfo->width)) {
        for (int i = 0; i < tabinfo->tab_cnt; i++) {
            if (x >= tabinfo->tabs[i].beforelen && x < tabinfo->tabs[i].afterlen) {
                return i;
            }
        }
    }

    return -1;
}

bool is_click_in_tab_area(TABINFO *tabinfo, int y, int x) {
    return (x >= tabinfo->x+2 && x < tabinfo->x+tabinfo->width-2 &&
            y >= tabinfo->y+2 && y < tabinfo->y+tabinfo->height-1);
}

typedef struct {
    WINDOW *win;
    char title[50];
    int y;
    int x1;
    int x2;
} TEXTBOX;


void draw_text_box(TEXTBOX *textbox, TABINFO *tabinfo, WINDOW *tabwin, int y, int x, const char *str) {
    mvwprintw(tabwin, y, x, "%s: ", str);
    int len = strlen(str) + 2;

    textbox->win = derwin(tabwin, 1, tabinfo->width - 4 - len, y, x + len);
    wbkgd(textbox->win, COLOR_PAIR(3));
    wrefresh(textbox->win);

    strcpy(textbox->title, str);
    textbox->y = y;
    textbox->x1 = x + len;
    textbox->x2 = tabinfo->width - 4;
}

bool is_textbox_clicked(TEXTBOX *textbox, int y, int x) {
    if (y == textbox->y && x >= textbox->x1 && x < textbox->x2) {
        debug("textbox %s is clicked", textbox->title);
        return true;
    }

    return false;
}

void focus_textbox(TEXTBOX *textbox) {
    wmove(textbox->win, 0, 0);
    wattron(textbox->win, COLOR_PAIR(3));
    wrefresh(textbox->win);
}

void convert_tab_xy(TABINFO *tabinfo, int *newy, int *newx, int eventy, int eventx) {
    *newy = eventy - tabinfo->y - 2;
    *newx = eventx - tabinfo->x - 2;
}

void line_edit(WINDOW *win, int ch) {
    int cury, curx;
    getyx(win, cury, curx);

    switch (ch) {
    case 127:
        wmove(win, cury, curx - 1);
        wdelch(win);
        break;
    case KEY_LEFT:
        wmove(win, cury, curx - 1);
        debug("KEY_LEFT");
        break;
    case KEY_RIGHT:
        wmove(win, cury, curx + 1);
        debug("KEY_RIGHT");
        break;
    case KEY_DC:
        wdelch(win);
        debug("KEY_RIGHT");
        break;
    default:
        waddch(win, ch);
        break;
    }
}

int main()
{
    MEVENT event = {0};
    int ch;
    TABINFO tabinfo = {0};

    setlocale(LC_ALL, "");

	initscr();			/* Start curses mode 		  */
    keypad(stdscr, TRUE);
    noecho();
    cbreak();
    mousemask(ALL_MOUSE_EVENTS, NULL);

    // color for tab button
    start_color();
    init_colors();

    // init debug window
    debugwin = newwin(20, 80, 30, 0);
    new_panel(debugwin);
    
    // create tabwin
    init_tab(&tabinfo, HEIGHT, WIDTH, 0, 0);

    // print the buttons
    WINDOW *tab1 = add_tab(&tabinfo, "Main", true);
    WINDOW *tab2 = add_tab(&tabinfo, "Options", false);

    TEXTBOX textbox[10] = {0};
    WINDOW *focuswin = NULL;

    int n = 0;
    draw_text_box(&textbox[n++], &tabinfo, tab1, 0, 0, "TextBoxA");
    draw_text_box(&textbox[n++], &tabinfo, tab1, 1, 0, "T_ext_Box_B");

    /* draw_text_box(&textbox[n++], &tabinfo, tab2, 0, 0, "Version"); */

    update_panels();
    doupdate();

    for (;;) {
        ch = getch();
        debug("ch=%d", ch);

        if (ch == KEY_MOUSE) {

            focuswin = NULL;
            
            if (getmouse(&event) == OK) {
                debug("evx=%d,evy=%d", event.x, event.y);
                if (event.bstate & BUTTON1_CLICKED) {
                    // did we click on tab bar
                    int tab_clicked = is_tab_clicked(&tabinfo, event.y, event.x);
                    if (tab_clicked >= 0) {
                        switch_tab(&tabinfo, tab_clicked);
                        doupdate();
                    }

                    if (is_click_in_tab_area(&tabinfo, event.y, event.x)) {
                        int tabx, taby;
                        convert_tab_xy(&tabinfo, &taby, &tabx, event.y, event.x);
                        for (int i = 0; i < n; i++) {
                            if (is_textbox_clicked(&textbox[i], taby, tabx)) {
                                focus_textbox(&textbox[i]);
                                focuswin = textbox[i].win;
                            }
                        }
                    }
                }
            }
        } else {
            // line-editing mode
            if (focuswin != NULL) {
                line_edit(focuswin, ch);
                wrefresh(focuswin);
            }

            if (ch == 'q') {
                goto END;
            }
        }
    }

  END:
	endwin();			/* End curses mode		  */

	return 0;
}