badge/ui/menu.c

   1 #include "menu.h"
   2
   3 #include "event.h"
   4 #include "font.h"
   5 #include "sprite.h"
   6
   7 #include <stdbool.h>
   8
   9 enum {
  10   MENU_ARROW_UP,
  11   MENU_ARROW_DOWN
  12 };
  13
  14 static badge_sprite const arrows[] = {
  15   { 5, 7, (uint8_t const *) "\x04\xc3\xdf\x40" },
  16   { 5, 7, (uint8_t const *) "\x10\xd8\x1f\x06\x01" }
  17 };
  18
  19 enum {
  20   MENU_MARGIN_TOP      = 2,
  21   MENU_MARGIN_BOTTOM   = 3,
  22   MENU_MARGIN_LEFT     = 3,
  23   MENU_ENTRIES_HEIGHT  = 1 + BADGE_FONT_HEIGHT,
  24   MENU_ENTRIES_VISIBLE = (BADGE_DISPLAY_HEIGHT - MENU_MARGIN_TOP - MENU_MARGIN_BOTTOM) / MENU_ENTRIES_HEIGHT
  25 };
  26
  27 static void badge_menu_show(char const *const *menu,
  28                             size_t n,
  29                             size_t first_visible,
  30                             size_t selected)
  31 {
  32   badge_framebuffer fb = { { { 0 } } };
  33   bool arrow_up   = true;
  34   bool arrow_down = true;
  35
  36   size_t first_used_row = 0;
  37   size_t used_rows = MENU_ENTRIES_VISIBLE;
  38
  39   if(n <= MENU_ENTRIES_VISIBLE) {
  40     first_visible  = 0;
  41     used_rows      = n;
  42     first_used_row = (MENU_ENTRIES_VISIBLE - used_rows) / 2;
  43   }
  44
  45   if(first_visible == 0) {
  46     arrow_up = false;
  47   }
  48
  49   if(first_visible + MENU_ENTRIES_VISIBLE >= n) {
  50     arrow_down = false;
  51   }
  52
  53   for(size_t i = 0; i < used_rows; ++i) {
  54     badge_framebuffer_render_text(&fb,
  55                                   (int8_t) (MENU_MARGIN_LEFT + BADGE_FONT_WIDTH),
  56                                   (int8_t) (MENU_MARGIN_TOP  + (first_used_row + i) * MENU_ENTRIES_HEIGHT),
  57                                   menu[first_visible + i]);
  58   }
  59
  60   badge_framebuffer_render_char(&fb, MENU_MARGIN_LEFT, MENU_MARGIN_TOP + MENU_ENTRIES_HEIGHT * (selected - first_visible + first_used_row), '*');
  61   if(arrow_up  ) { badge_framebuffer_blt(&fb, MENU_MARGIN_LEFT, MENU_MARGIN_TOP,                                                    &arrows[MENU_ARROW_UP  ], 0); }
  62   if(arrow_down) { badge_framebuffer_blt(&fb, MENU_MARGIN_LEFT, MENU_MARGIN_TOP + (MENU_ENTRIES_VISIBLE - 1) * MENU_ENTRIES_HEIGHT, &arrows[MENU_ARROW_DOWN], 0); }
  63
  64   badge_framebuffer_flush(&fb);
  65 }
  66
  67 size_t badge_menu(char const *const *menu,
  68                    size_t  n,
  69                    size_t *first_visible,
  70                    size_t  selected)
  71 {
  72   for(;;) {
  73     badge_menu_show(menu, n, *first_visible, selected);
  74
  75     badge_event_t ev;
  76
  77     do {
  78       ev = badge_event_wait();
  79     } while(badge_event_type(ev) != BADGE_EVENT_USER_INPUT);
  80
  81     uint8_t old_state = badge_event_old_input_state(ev);
  82     uint8_t new_state = badge_event_new_input_state(ev);
  83     uint8_t new_buttons = new_state & (old_state ^ new_state);
  84
  85     if(new_buttons & (BADGE_EVENT_KEY_BTN_A | BADGE_EVENT_KEY_BTN_B)) {
  86       return selected;
  87     } else if((new_buttons & BADGE_EVENT_KEY_UP  ) && selected != 0) {
  88       --selected;
  89       if(*first_visible != 0 && selected <= *first_visible) {
  90         *first_visible = selected - 1;
  91       }
  92     } else if(new_buttons & BADGE_EVENT_KEY_DOWN && selected + 1 < n) {
  93       ++selected;
  94       if(*first_visible + (MENU_ENTRIES_VISIBLE - 2 + (selected + 1 == n)) < selected) {
  95         *first_visible = selected - (MENU_ENTRIES_VISIBLE - 2 + (selected + 1 == n));
  96       }
  97     }
  98   }
  99 }