src/client/menu.c

   1 /*
   2  * OpenDispense 2
   3  * UCC (University [of WA] Computer Club) Electronic Accounting System
   4  * - Dispense Client
   5  *
   6  * menu.c - ncurses dispense menu
   7  *
   8  * This file is licenced under the 3-clause BSD Licence. See the file
   9  * COPYING for full details.
  10  */
  11 #include <stdlib.h>
  12 #include <ncurses.h>
  13 #include <pwd.h>        // getpwuids
  14 #include <unistd.h>     // getuid
  15 #include "common.h"
  16
  17 // === CONSTANTS ===
  18 #define COLOURPAIR_CANTBUY      1
  19 #define COLOURPAIR_SELECTED     2
  20
  21 // === PROTOTYPES ===
  22  int    ShowItemAt(int Row, int Col, int Width, int Index, int bHilighted);
  23 void    PrintAlign(int Row, int Col, int Width, const char *Left, char Pad1, const char *Mid, char Pad2, const char *Right, ...);
  24
  25 // -------------------
  26 // --- NCurses GUI ---
  27 // -------------------
  28 /**
  29  * \brief Render the NCurses UI
  30  */
  31 int ShowNCursesUI(void)
  32 {
  33          int    ch;
  34          int    i, times;
  35          int    xBase, yBase;
  36         const int       displayMinWidth = 50;
  37         const char      *titleString = "Dispense";
  38          int    items_in_view;
  39          int    maxItemIndex;
  40          int    itemBase = 0;
  41          int    currentItem;
  42          int    ret = -2;       // -2: Used for marking "no return yet"
  43
  44         char    balance_str[5+1+2+1];   // If $9999.99 is too little, something's wrong
  45         char    *username;
  46         struct passwd *pwd;
  47
  48          int    height, width;
  49
  50         void _ItemDown(void)
  51         {
  52                 currentItem ++;
  53                 // Skip over spacers
  54                 while( ShowItemAt(0, 0, 0, currentItem, 0) == -1 )
  55                         currentItem ++;
  56
  57                 if( currentItem >= maxItemIndex ) {
  58                         currentItem = 0;
  59                         // Skip over spacers
  60                         while( ShowItemAt(0, 0, 0, currentItem, 0) == -1 )
  61                                 currentItem ++;
  62                 }
  63         }
  64
  65         void _ItemUp(void)
  66         {
  67                 currentItem --;
  68                 // Skip over spacers
  69                 while( ShowItemAt(0, 0, 0, currentItem, 0) == -1 )
  70                         currentItem --;
  71
  72                 if( currentItem < 0 ) {
  73                         currentItem = maxItemIndex - 1;
  74                         // Skip over spacers
  75                         while( ShowItemAt(0, 0, 0, currentItem, 0) == -1 )
  76                                 currentItem --;
  77                 }
  78         }
  79
  80         // Get Username
  81         if( gsEffectiveUser )
  82                 username = gsEffectiveUser;
  83         else {
  84                 pwd = getpwuid( getuid() );
  85                 username = pwd->pw_name;
  86         }
  87         // Get balance
  88         snprintf(balance_str, sizeof(balance_str), "$%i.%02i", giUserBalance/100, abs(giUserBalance)%100);
  89
  90         // Enter curses mode
  91         initscr();
  92         start_color();
  93         init_pair(COLOURPAIR_CANTBUY,  COLOR_BLACK,   COLOR_BLACK);     // Not avaliable
  94         init_pair(COLOURPAIR_SELECTED, COLOR_GREEN,  COLOR_BLACK);      // Selected
  95         cbreak(); noecho();
  96
  97         // Get max index
  98         maxItemIndex = ShowItemAt(0, 0, 0, -1, 0);
  99         // Get item count per screen
 100         // - 6: randomly chosen (Need at least 3)
 101         items_in_view = LINES - 6;
 102         if( items_in_view > maxItemIndex )
 103                 items_in_view = maxItemIndex;
 104         // Get first index
 105         currentItem = 0;
 106         while( ShowItemAt(0, 0, 0, currentItem, 0) == -1 )
 107                 currentItem ++;
 108
 109
 110         // Get dimensions
 111         height = items_in_view + 3;
 112         width = displayMinWidth;
 113
 114         // Get positions
 115         xBase = COLS/2 - width/2;
 116         yBase = LINES/2 - height/2;
 117
 118         for( ;; )
 119         {
 120                 // Header
 121                 PrintAlign(yBase, xBase, width, "/", '-', titleString, '-', "\\");
 122
 123                 // Items
 124                 for( i = 0; i < items_in_view; i ++ )
 125                 {
 126                          int    pos = 0;
 127
 128                         move( yBase + 1 + i, xBase );
 129                         printw("| ");
 130
 131                         pos += 2;
 132
 133                         // Check for the '...' row
 134                         // - Oh god, magic numbers!
 135                         if( (i == 0 && itemBase > 0)
 136                          || (i == items_in_view - 1 && itemBase < maxItemIndex - items_in_view) )
 137                         {
 138                                 printw("     ...");     pos += 8;
 139                                 times = (width - pos) - 1;
 140                                 while(times--)  addch(' ');
 141                         }
 142                         // Show an item
 143                         else {
 144                                 ShowItemAt(
 145                                         yBase + 1 + i, xBase + pos,     // Position
 146                                         (width - pos) - 3,      // Width
 147                                         itemBase + i,   // Index
 148                                         !!(currentItem == itemBase + i) // Hilighted
 149                                         );
 150                                 printw("  ");
 151                         }
 152
 153                         // Scrollbar (if needed)
 154                         if( maxItemIndex > items_in_view ) {
 155                                 if( i == 0 ) {
 156                                         addch('A');
 157                                 }
 158                                 else if( i == items_in_view - 1 ) {
 159                                         addch('V');
 160                                 }
 161                                 else {
 162                                          int    percentage = itemBase * 100 / (maxItemIndex-items_in_view);
 163                                         if( i-1 == percentage*(items_in_view-3)/100 ) {
 164                                                 addch('#');
 165                                         }
 166                                         else {
 167                                                 addch('|');
 168                                         }
 169                                 }
 170                         }
 171                         else {
 172                                 addch('|');
 173                         }
 174                 }
 175
 176                 // Footer
 177                 PrintAlign(yBase+height-2, xBase, width, "\\", '-', "", '-', "/");
 178
 179                 // User line
 180                 // - Username, balance, flags
 181                 PrintAlign(yBase+height-1, xBase+1, width-2,
 182                         username, ' ', balance_str, ' ', gsUserFlags);
 183                 PrintAlign(yBase+height, xBase+1, width-2,
 184                         "q: Quit", ' ', "Arrows: Select", ' ', "Enter: Buy");
 185
 186
 187                 // Get input
 188                 ch = getch();
 189
 190                 if( ch == '\x1B' ) {
 191                         ch = getch();
 192                         if( ch == '[' ) {
 193                                 ch = getch();
 194
 195                                 switch(ch)
 196                                 {
 197                                 case 'B':       _ItemDown();    break;
 198                                 case 'A':       _ItemUp();      break;
 199                                 }
 200                         }
 201                         else if( ch == ERR || ch == '\x1b' ) {
 202                                 ret = -1;
 203                                 break;
 204                         }
 205                         else {
 206                                 fprintf(stderr, "Unknown character 0x%x\n", ch);
 207                         }
 208                 }
 209                 else {
 210                         switch(ch)
 211                         {
 212                         case '\n':
 213                                 ret = ShowItemAt(0, 0, 0, currentItem, 0);
 214                                 break;
 215                         case 'h':       break;
 216                         case 'j':       _ItemDown();    break;
 217                         case 'k':       _ItemUp();      break;
 218                         case 'l':       break;
 219                         case 'q':
 220                                 ret = -1;       // -1: Return with no dispense
 221                                 break;
 222                         }
 223
 224                         // Check if the return value was changed
 225                         if( ret != -2 ) break;
 226                 }
 227
 228                 // Scroll only if needed
 229                 if( items_in_view < maxItemIndex )
 230                 {
 231                         // - If the current item is above the second item shown, and we're not at the top
 232                         if( currentItem < itemBase + 2 && itemBase > 0 ) {
 233                                 itemBase = currentItem - 2;
 234                                 if(itemBase < 0)        itemBase = 0;
 235                         }
 236                         // - If the current item is below the second item show, and we're not at the bottom
 237                         if( currentItem > itemBase + items_in_view - 2 && itemBase + items_in_view < maxItemIndex ) {
 238                                 itemBase = currentItem - items_in_view + 2;
 239                                 if( itemBase > maxItemIndex - items_in_view )
 240                                         itemBase = maxItemIndex - items_in_view;
 241                         }
 242                 }
 243         }
 244
 245
 246         // Leave
 247         endwin();
 248         return ret;
 249 }
 250
 251 /**
 252  * \brief Show item \a Index at (\a Col, \a Row)
 253  * \return Dispense index of item
 254  * \note Part of the NCurses UI
 255  */
 256 int ShowItemAt(int Row, int Col, int Width, int Index, int bHilighted)
 257 {
 258         char    *name = NULL;
 259          int    price = 0;
 260          int    status = -1;
 261
 262         switch(giUIMode)
 263         {
 264         // Standard UI
 265         // - This assumes that
 266         case UI_MODE_STANDARD:
 267                 // Bounds check
 268                 // Index = -1, request limit
 269                 if( Index < 0 || Index >= giNumItems+2 )
 270                         return giNumItems+2;
 271                 // Drink label
 272                 if( Index == 0 )
 273                 {
 274                         price = 0;
 275                         name = "Coke Machine";
 276                         Index = -1;     // -1 indicates a label
 277                         break;
 278                 }
 279                 Index --;
 280                 // Drinks 0 - 6
 281                 if( Index <= 6 )
 282                 {
 283                         name = gaItems[Index].Desc;
 284                         price = gaItems[Index].Price;
 285                         status = gaItems[Index].Status;
 286                         break;
 287                 }
 288                 Index -= 7;
 289                 // EPS label
 290                 if( Index == 0 )
 291                 {
 292                         price = 0;
 293                         name = "Electronic Payment System";
 294                         Index = -1;     // -1 indicates a label
 295                         break;
 296                 }
 297                 Index --;
 298                 Index += 7;
 299                 name = gaItems[Index].Desc;
 300                 price = gaItems[Index].Price;
 301                 status = gaItems[Index].Status;
 302                 break;
 303         default:
 304                 return -1;
 305         }
 306
 307         // Width = 0, don't print
 308         if( Width > 0 )
 309         {
 310                 // 4 preceding, 5 price
 311                 int nameWidth = Width - 4 - snprintf(NULL, 0, " %4i", price);
 312                 move( Row, Col );
 313
 314                 if( Index >= 0 )
 315                 {
 316                         // Show hilight and status
 317                         switch( status )
 318                         {
 319                         case 0:
 320                                 if( bHilighted ) {
 321                                         color_set( COLOURPAIR_SELECTED, NULL );
 322                                         printw("->  ");
 323                                 }
 324                                 else if( price > giUserBalance ) {
 325                                         attrset(A_BOLD);
 326                                         color_set( COLOURPAIR_CANTBUY, NULL );
 327                                         printw("    ");
 328                                 }
 329                                 else {
 330                                         color_set( 0, NULL );
 331                                         printw("    ");
 332                                 }
 333                                 break;
 334                         case 1:
 335                                 attrset(A_BOLD);
 336                                 color_set( COLOURPAIR_CANTBUY, NULL );
 337                                 printw("SLD ");
 338                                 break;
 339
 340                         default:
 341                         case -1:
 342                                 color_set( COLOURPAIR_CANTBUY, NULL );
 343                                 printw("ERR ");
 344                                 break;
 345                         }
 346
 347                         printw("%-*.*s", nameWidth, nameWidth, name);
 348
 349                         printw(" %4i", price);
 350                         color_set(0, NULL);
 351                         attrset(A_NORMAL);
 352                 }
 353                 else
 354                 {
 355                         printw("-- %-*.*s ", Width-4, Width-4, name);
 356                 }
 357         }
 358
 359         // If the item isn't availiable for sale, return -1 (so it's skipped)
 360         if( status || (price > giUserBalance && gbDisallowSelectWithoutBalance) )
 361                 Index = -1;
 362
 363         return Index;
 364 }
 365
 366 /**
 367  * \brief Print a three-part string at the specified position (formatted)
 368  * \note NCurses UI Helper
 369  *
 370  * Prints \a Left on the left of the area, \a Right on the righthand side
 371  * and \a Mid in the middle of the area. These are padded with \a Pad1
 372  * between \a Left and \a Mid, and \a Pad2 between \a Mid and \a Right.
 373  *
 374  * ::printf style format codes are allowed in \a Left, \a Mid and \a Right,
 375  * and the arguments to these are read in that order.
 376  */
 377 void PrintAlign(int Row, int Col, int Width, const char *Left, char Pad1,
 378         const char *Mid, char Pad2, const char *Right, ...)
 379 {
 380          int    lLen, mLen, rLen;
 381          int    times;
 382
 383         va_list args;
 384
 385         // Get the length of the strings
 386         va_start(args, Right);
 387         lLen = vsnprintf(NULL, 0, Left, args);
 388         mLen = vsnprintf(NULL, 0, Mid, args);
 389         rLen = vsnprintf(NULL, 0, Right, args);
 390         va_end(args);
 391
 392         // Sanity check
 393         if( lLen + mLen/2 > Width/2 || mLen/2 + rLen > Width/2 ) {
 394                 return ;        // TODO: What to do?
 395         }
 396
 397         move(Row, Col);
 398
 399         // Render strings
 400         va_start(args, Right);
 401         // - Left
 402         {
 403                 char    tmp[lLen+1];
 404                 vsnprintf(tmp, lLen+1, Left, args);
 405                 addstr(tmp);
 406         }
 407         // - Left padding
 408         times = (Width - mLen)/2 - lLen;
 409         while(times--)  addch(Pad1);
 410         // - Middle
 411         {
 412                 char    tmp[mLen+1];
 413                 vsnprintf(tmp, mLen+1, Mid, args);
 414                 addstr(tmp);
 415         }
 416         // - Right Padding
 417         times = (Width - mLen)/2 - rLen;
 418         if( (Width - mLen) % 2 )        times ++;
 419         while(times--)  addch(Pad2);
 420         // - Right
 421         {
 422                 char    tmp[rLen+1];
 423                 vsnprintf(tmp, rLen+1, Right, args);
 424                 addstr(tmp);
 425         }
 426 }
 427