VitaShell/hex.c

/*
  VitaShell
  Copyright (C) 2015-2018, TheFloW

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "main.h"
#include "browser.h"
#include "archive.h"
#include "file.h"
#include "text.h"
#include "hex.h"
#include "message_dialog.h"
#include "theme.h"
#include "language.h"
#include "utils.h"

static void hexListAddEntry(HexList *list, HexListEntry *entry) {
  entry->next = NULL;
  entry->previous = NULL;

  if (list->head == NULL) {
    list->head = entry;
    list->tail = entry;
  } else {
    HexListEntry *tail = list->tail;
    tail->next = entry;
    entry->previous = tail;
    list->tail = entry;
  }

  list->length++;
}

static void hexListEmpty(HexList *list) {
  HexListEntry *entry = list->head;

  while (entry) {
    HexListEntry *next = entry->next;
    free(entry);
    entry = next;
  }

  list->head = NULL;
  list->tail = NULL;
  list->length = 0;
}

static HexListEntry *hexListGetNthEntry(HexList *list, int n) {
  HexListEntry *entry = list->head;

  while (n > 0 && entry) {
    n--;
    entry = entry->next;
  }

  if (n != 0)
    return NULL;

  return entry;
}

int hexViewer(const char *file) {
  int text_viewer = 0;

  uint8_t *buffer = memalign(4096, BIG_BUFFER_SIZE);
  if (!buffer)
    return VITASHELL_ERROR_NO_MEMORY;

  int size = 0;

  if (isInArchive()) {
    size = ReadArchiveFile(file, buffer, BIG_BUFFER_SIZE);
  } else {
    size = ReadFile(file, buffer, BIG_BUFFER_SIZE);
  }

  if (size <= 0) {
    free(buffer);
    return size;
  }

  int modify_allowed = 1;

  if (isInArchive()) {
    modify_allowed = 0;
  }

  int changed = 0;

  int base_pos = 0, rel_pos = 0;
  uint8_t nibble_pos = 0;

  HexList list;
  memset(&list, 0, sizeof(HexList));

  int i;
  for (i = 0; i < 0x10; i++) {
    HexListEntry *entry = malloc(sizeof(HexListEntry));
    memcpy(entry->data, buffer + i * 0x10, 0x10);
    hexListAddEntry(&list, entry);
  }

  while (1) {
    readPad();

    if (!isMessageDialogRunning()) {
      if (hold_pad[PAD_UP] || hold2_pad[PAD_LEFT_ANALOG_UP]) {
        if (rel_pos > 0) {
          rel_pos -= 0x10;
        } else if (base_pos > 0) {
          base_pos -= 0x10;

          // Tail to head
          list.tail->next = list.head;
          list.head->previous = list.tail;
          list.head = list.tail;

          // Second last to tail
          list.tail = list.tail->previous;
          list.tail->next = NULL;

          // No previous
          list.head->previous = NULL;

          // Read
          memcpy(list.head->data, buffer + base_pos, 0x10);
        }
      } else if (hold_pad[PAD_DOWN] || hold2_pad[PAD_LEFT_ANALOG_DOWN]) {
        if ((rel_pos + 0x10) < size) {
          if ((rel_pos + 0x10) < ((MAX_POSITION - 1) * 0x10)) {
            rel_pos += 0x10;
          } else if ((base_pos + rel_pos + 0x10) < size) {
            base_pos += 0x10;

            // Head to tail
            list.head->previous = list.tail;
            list.tail->next = list.head;
            list.tail = list.head;

            // Second first to head
            list.head = list.head->next;
            list.head->previous = NULL;

            // No next
            list.tail->next = NULL;

            // Read
            memcpy(list.tail->data, buffer + base_pos + (0x10 - 1) * 0x10, 0x10);
          }
        }
      }

      // Page skip
      if (hold_pad[PAD_LTRIGGER] || hold_pad[PAD_RTRIGGER]) {
        if (hold_pad[PAD_LTRIGGER]) { // Skip page up
          base_pos = base_pos - 0x100;
          if (base_pos < 0) {
            base_pos = 0;
            rel_pos = 0;
          }
        } else { // Skip page down
          int last_line = ALIGN(size, 0x10);
          base_pos = base_pos + 0x100;
          if (base_pos >= last_line - 0xF0) {
            base_pos = MAX(last_line - 0xF0, 0);
            rel_pos = MIN(0xE0, last_line - 0x10);
          }
        }

        HexListEntry *entry = list.head;

        int i;
        for (i = 0; i < 0x10; i++) {
          memcpy(entry->data, buffer + base_pos + i * 0x10, 0x10);
          entry = entry->next;
        }
      }

      uint8_t max_nibble = (2 * 0x10) - 1;

      // Last line
      if ((base_pos + rel_pos + 0x10) >= size) {
        uint8_t rest = size % 0x10;

        if (rest == 0)
          rest = 0x10;

        max_nibble = 2 * rest - 1;
      }

      if (nibble_pos > max_nibble) {
        nibble_pos = max_nibble;
      }

      if (hold_pad[PAD_LEFT] || hold2_pad[PAD_LEFT_ANALOG_LEFT]) {
        if (nibble_pos > 0)
          nibble_pos--;
      } else if (hold_pad[PAD_RIGHT] || hold2_pad[PAD_LEFT_ANALOG_RIGHT]) {
        if (nibble_pos < max_nibble)
          nibble_pos++;
      }

      // Cancel or switch to text viewer
      if (pressed_pad[PAD_CANCEL] || pressed_pad[PAD_SQUARE]) {
        if (pressed_pad[PAD_CANCEL]) {
          text_viewer = 0;
        } else {
          text_viewer = 1;
        }

        if (changed) {
          initMessageDialog(SCE_MSG_DIALOG_BUTTON_TYPE_YESNO, language_container[SAVE_MODIFICATIONS]);
        } else {
          break;
        }
      }

      // Increase nibble
      if (modify_allowed && hold_pad[PAD_ENTER]) {
        changed = 1;
        int cur_pos = rel_pos + base_pos + nibble_pos / 2;

        uint8_t ch = buffer[cur_pos];
        uint8_t high_nibble = (ch >> 4) & 0xF;
        uint8_t low_nibble = ch & 0xF;

        int low = (nibble_pos % 2);
        uint8_t nibble = low ? (ch & 0xF) : ((ch >> 4) & 0xF);

        if (nibble < 0xF) {
          nibble++;
        } else {
          nibble = 0;
        }

        HexListEntry *entry = hexListGetNthEntry(&list, rel_pos / 0x10);

        if (low) {
          uint8_t byte = (high_nibble << 4) | nibble;
          buffer[cur_pos] = byte;
          entry->data[nibble_pos/2] = byte;
        } else {
          uint8_t byte = (nibble << 4) | low_nibble;
          buffer[cur_pos] = byte;
          entry->data[nibble_pos/2] = byte;
        }
      }
    } else {
      int msg_result = updateMessageDialog();
      if (msg_result == MESSAGE_DIALOG_RESULT_YES) {
        SceUID fd = sceIoOpen(file, SCE_O_WRONLY, 0777);
        if (fd >= 0) {
          sceIoWrite(fd, buffer, size);
          sceIoClose(fd);
        }

        break;
      } else if (msg_result == MESSAGE_DIALOG_RESULT_NO) {
        break;
      }
    }

    // Start drawing
    startDrawing(bg_hex_image);

    // Draw shell info
    drawShellInfo(file);

    // Draw scroll bar
    int pos = (base_pos - (base_pos % 0x10)) / 0x10 + ((base_pos % 0x10) ? 1 : 0);
    int n_lines = (size - (size % 0x10)) / 0x10 + ((size % 0x10) ? 1 : 0);
    drawScrollBar(pos, n_lines);

    // Offset/size
    pgf_draw_textf(HEX_CHAR_X, START_Y, HEX_OFFSET_COLOR, "%08X/%08X", rel_pos+base_pos, size);

    // Offset x
    pgf_draw_text(SHELL_MARGIN_X, START_Y, HEX_OFFSET_COLOR, language_container[OFFSET]);

    int x;
    for (x = 0; x < 0x10; x++) {
      pgf_draw_textf(HEX_OFFSET_X + (x * HEX_OFFSET_SPACE), START_Y, HEX_OFFSET_COLOR, "%02X", x);
    }

    HexListEntry *entry = list.head;

    int y;
    for (y = 0; y < 0x10; y++) {
      int x;
      for (x = 0; x < 0x10; x++) {
        uint8_t nibble_x = x * 2;

        uint8_t ch = entry->data[x];

        uint32_t offset = base_pos + x + y * 0x10;
        if (offset >= size)
          break;

        uint32_t color = HEX_COLOR;

        int on_line = 0;
        if (rel_pos == (y * 0x10)) {
          color = FOCUS_COLOR;
          on_line = 1;
        }

        // Character hex
        uint8_t high_nibble = (ch >> 4) & 0xF;
        uint8_t low_nibble = ch & 0xF;
        int w = pgf_draw_textf(HEX_OFFSET_X + (x * HEX_OFFSET_SPACE), START_Y + ((y + 1) * FONT_Y_SPACE),
                               (on_line && nibble_x == nibble_pos) ? HEX_NIBBLE_COLOR : color, "%01X", high_nibble);
        pgf_draw_textf(HEX_OFFSET_X + (x * HEX_OFFSET_SPACE) + w, START_Y + ((y + 1) * FONT_Y_SPACE),
                       (on_line && (nibble_x + 1) == nibble_pos) ? HEX_NIBBLE_COLOR : color, "%01X", low_nibble);

        // Character
        ch = (ch >= 0x20) ? ch : '.';
        int width = font_size_cache[(int)ch];
        uint8_t byte_nibble_pos = nibble_pos - (nibble_pos % 2);
        pgf_draw_textf(HEX_CHAR_X + (x * FONT_X_SPACE) + (FONT_X_SPACE - width) / 2.0f, START_Y + ((y + 1) * FONT_Y_SPACE),
                       (on_line && nibble_x == byte_nibble_pos) ? HEX_NIBBLE_COLOR : color, "%c", ch);
      }

      // Offset y
      if (x > 0)
        pgf_draw_textf(SHELL_MARGIN_X, START_Y + ((y + 1) * FONT_Y_SPACE), HEX_OFFSET_COLOR, "%08X", base_pos + (y * 0x10));

      // It's the end, break
      if (x < 0x10)
        break;

      // Next
      entry = entry->next;
    }

    // End drawing
    endDrawing();
  }

  hexListEmpty(&list);

  free(buffer);

  if (text_viewer)
    textViewer(file);

  return 0;
}