imgui_memory_editor.h

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#pragma once
 
#include <stdint.h>  // uint8_t, etc.
#include <stdio.h>   // sprintf, scanf
 
#include "app/gui/core/icons.h"
 
#ifdef _MSC_VER
#define _PRISizeT "I"
#define ImSnprintf _snprintf
#else
#define _PRISizeT "z"
#define ImSnprintf snprintf
#endif
 
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4996)  // warning C4996: 'sprintf': This function or \
                                 // variable may be unsafe.
#endif
 
namespace yaze {
namespace gui {
 
struct MemoryEditorWidget {
  enum DataFormat {
    DataFormat_Bin = 0,
    DataFormat_Dec = 1,
    DataFormat_Hex = 2,
    DataFormat_COUNT
  };
 
  // Settings
  bool Open;  // = true   // set to false when DrawWindow() was closed. ignore
              // if not using DrawWindow().
  bool ReadOnly;        // = false  // disable any editing.
  int Cols;             // = 16     // number of columns to display.
  bool OptShowOptions;  // = true   // display options button/context menu. when
                        // disabled, options will be locked unless you provide
                        // your own UI for them.
  bool OptShowDataPreview;  // = false  // display a footer previewing the
                            // decimal/binary/hex/float representation of the
                            // currently selected bytes.
  bool OptShowHexII;  // = false  // display values in HexII representation
                      // instead of regular hexadecimal: hide null/zero bytes,
                      // ascii values as ".X".
  bool OptShowAscii;  // = true   // display ASCII representation on the right
                      // side.
  bool OptGreyOutZeroes;  // = true   // display null/zero bytes using the
                          // TextDisabled color.
  bool OptUpperCaseHex;   // = true   // display hexadecimal values as "FF"
                          // instead of "ff".
  int OptMidColsCount;  // = 8      // set to 0 to disable extra spacing between
                        // every mid-cols.
  int OptAddrDigitsCount;      // = 0      // number of addr digits to display
                               // (default calculated based on maximum displayed
                               // addr).
  float OptFooterExtraHeight;  // = 0      // space to reserve at the bottom of
                               // the widget to add custom widgets
  ImU32 HighlightColor;  //          // background color of highlighted bytes.
  ImU8 (*ReadFn)(const ImU8* data,
                 size_t off);  // = 0      // optional handler to read bytes.
  void (*WriteFn)(ImU8* data, size_t off,
                  ImU8 d);  // = 0      // optional handler to write bytes.
  bool (*HighlightFn)(
      const ImU8* data,
      size_t off);  //= 0      // optional handler to return Highlight property
                    //(to support non-contiguous highlighting).
 
  // [Internal State]
  bool ContentsWidthChanged;
  size_t DataPreviewAddr;
  size_t DataEditingAddr;
  bool DataEditingTakeFocus;
  char DataInputBuf[32];
  char AddrInputBuf[32];
  size_t GotoAddr;
  size_t HighlightMin, HighlightMax;
  int PreviewEndianess;
  ImGuiDataType PreviewDataType;
 
  // Expanded
  ImU8* ComparisonData;
 
  void SetComparisonData(void* data) { ComparisonData = (ImU8*)data; }
 
  MemoryEditorWidget() {
    // Settings
    Open = true;
    ReadOnly = false;
    Cols = 16;
    OptShowOptions = true;
    OptShowDataPreview = false;
    OptShowHexII = false;
    OptShowAscii = true;
    OptGreyOutZeroes = true;
    OptUpperCaseHex = true;
    OptMidColsCount = 8;
    OptAddrDigitsCount = 0;
    OptFooterExtraHeight = 0.0f;
    HighlightColor = IM_COL32(255, 255, 255, 50);
    ReadFn = nullptr;
    WriteFn = nullptr;
    HighlightFn = nullptr;
 
    // State/Internals
    ContentsWidthChanged = false;
    DataPreviewAddr = DataEditingAddr = (size_t)-1;
    DataEditingTakeFocus = false;
    memset(DataInputBuf, 0, sizeof(DataInputBuf));
    memset(AddrInputBuf, 0, sizeof(AddrInputBuf));
    GotoAddr = (size_t)-1;
    HighlightMin = HighlightMax = (size_t)-1;
    PreviewEndianess = 0;
    PreviewDataType = ImGuiDataType_S32;
  }
 
  void GotoAddrAndHighlight(size_t addr_min, size_t addr_max) {
    GotoAddr = addr_min;
    HighlightMin = addr_min;
    HighlightMax = addr_max;
  }
 
  struct Sizes {
    int AddrDigitsCount;
    float LineHeight;
    float GlyphWidth;
    float HexCellWidth;
    float SpacingBetweenMidCols;
    float PosHexStart;
    float PosHexEnd;
    float PosAsciiStart;
    float PosAsciiEnd;
    float WindowWidth;
 
    Sizes() { memset(this, 0, sizeof(*this)); }
  };
 
  void CalcSizes(Sizes& s, size_t mem_size, size_t base_display_addr) {
    ImGuiStyle& style = ImGui::GetStyle();
    s.AddrDigitsCount = OptAddrDigitsCount;
    if (s.AddrDigitsCount == 0)
      for (size_t n = base_display_addr + mem_size - 1; n > 0; n >>= 4)
        s.AddrDigitsCount++;
    s.LineHeight = ImGui::GetTextLineHeight();
    s.GlyphWidth =
        ImGui::CalcTextSize("F").x + 1;  // We assume the font is mono-space
    s.HexCellWidth =
        (float)(int)(s.GlyphWidth *
                     2.5f);  // "FF " we include trailing space in the width to
                             // easily catch clicks everywhere
    s.SpacingBetweenMidCols =
        (float)(int)(s.HexCellWidth * 0.25f);  // Every OptMidColsCount columns
                                               // we add a bit of extra spacing
    s.PosHexStart = (s.AddrDigitsCount + 2) * s.GlyphWidth;
    s.PosHexEnd = s.PosHexStart + (s.HexCellWidth * Cols);
    s.PosAsciiStart = s.PosAsciiEnd = s.PosHexEnd;
    if (OptShowAscii) {
      s.PosAsciiStart = s.PosHexEnd + s.GlyphWidth * 1;
      if (OptMidColsCount > 0)
        s.PosAsciiStart +=
            (float)((Cols + OptMidColsCount - 1) / OptMidColsCount) *
            s.SpacingBetweenMidCols;
      s.PosAsciiEnd = s.PosAsciiStart + Cols * s.GlyphWidth;
    }
    s.WindowWidth = s.PosAsciiEnd + style.ScrollbarSize +
                    style.WindowPadding.x * 2 + s.GlyphWidth;
  }
 
  // Standalone Memory Editor window
  void DrawWindow(const char* title, void* mem_data, size_t mem_size,
                  size_t base_display_addr = 0x0000) {
    Sizes s;
    CalcSizes(s, mem_size, base_display_addr);
    ImGui::SetNextWindowSize(ImVec2(s.WindowWidth, s.WindowWidth * 0.60f),
                             ImGuiCond_FirstUseEver);
    ImGui::SetNextWindowSizeConstraints(ImVec2(0.0f, 0.0f),
                                        ImVec2(s.WindowWidth, FLT_MAX));
 
    Open = true;
    if (ImGui::Begin(title, &Open, ImGuiWindowFlags_NoScrollbar)) {
      if (ImGui::IsWindowHovered(ImGuiHoveredFlags_RootAndChildWindows) &&
          ImGui::IsMouseReleased(ImGuiMouseButton_Right))
        ImGui::OpenPopup("context");
      DrawContents(mem_data, mem_size, base_display_addr);
      if (ContentsWidthChanged) {
        CalcSizes(s, mem_size, base_display_addr);
        ImGui::SetWindowSize(ImVec2(s.WindowWidth, ImGui::GetWindowSize().y));
      }
    }
    ImGui::End();
  }
 
  // Memory Editor contents only
  void DrawContents(void* mem_data_void, size_t mem_size,
                    size_t base_display_addr = 0x0000) {
    if (Cols < 1)
      Cols = 1;
 
    ImU8* mem_data = (ImU8*)mem_data_void;
    Sizes s;
    CalcSizes(s, mem_size, base_display_addr);
    ImGuiStyle& style = ImGui::GetStyle();
 
    // We begin into our scrolling region with the 'ImGuiWindowFlags_NoMove' in
    // order to prevent click from moving the window. This is used as a facility
    // since our main click detection code doesn't assign an ActiveId so the
    // click would normally be caught as a window-move.
    const float height_separator = style.ItemSpacing.y;
    float footer_height = OptFooterExtraHeight;
    if (OptShowOptions)
      footer_height +=
          height_separator + ImGui::GetFrameHeightWithSpacing() * 1;
    if (OptShowDataPreview)
      footer_height += height_separator +
                       ImGui::GetFrameHeightWithSpacing() * 1 +
                       ImGui::GetTextLineHeightWithSpacing() * 3;
    ImGui::BeginChild("##scrolling", ImVec2(0, -footer_height), false,
                      ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoNav);
    ImDrawList* draw_list = ImGui::GetWindowDrawList();
 
    ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0, 0));
    ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(0, 0));
 
    // We are not really using the clipper API correctly here, because we rely
    // on visible_start_addr/visible_end_addr for our scrolling function.
    const int line_total_count = (int)((mem_size + Cols - 1) / Cols);
    ImGuiListClipper clipper;
    clipper.Begin(line_total_count, s.LineHeight);
 
    bool data_next = false;
 
    if (ReadOnly || DataEditingAddr >= mem_size)
      DataEditingAddr = (size_t)-1;
    if (DataPreviewAddr >= mem_size)
      DataPreviewAddr = (size_t)-1;
 
    size_t preview_data_type_size =
        OptShowDataPreview ? DataTypeGetSize(PreviewDataType) : 0;
 
    size_t data_editing_addr_next = (size_t)-1;
    if (DataEditingAddr != (size_t)-1) {
      // Move cursor but only apply on next frame so scrolling with be
      // synchronized (because currently we can't change the scrolling while the
      // window is being rendered)
      if (ImGui::IsKeyPressed(ImGuiKey_UpArrow) &&
          (ptrdiff_t)DataEditingAddr >= (ptrdiff_t)Cols) {
        data_editing_addr_next = DataEditingAddr - Cols;
      } else if (ImGui::IsKeyPressed(ImGuiKey_DownArrow) &&
                 (ptrdiff_t)DataEditingAddr < (ptrdiff_t)mem_size - Cols) {
        data_editing_addr_next = DataEditingAddr + Cols;
      } else if (ImGui::IsKeyPressed(ImGuiKey_LeftArrow) &&
                 (ptrdiff_t)DataEditingAddr > (ptrdiff_t)0) {
        data_editing_addr_next = DataEditingAddr - 1;
      } else if (ImGui::IsKeyPressed(ImGuiKey_RightArrow) &&
                 (ptrdiff_t)DataEditingAddr < (ptrdiff_t)mem_size - 1) {
        data_editing_addr_next = DataEditingAddr + 1;
      }
    }
 
    // Draw vertical separator
    ImVec2 window_pos = ImGui::GetWindowPos();
    if (OptShowAscii)
      draw_list->AddLine(
          ImVec2(window_pos.x + s.PosAsciiStart - s.GlyphWidth, window_pos.y),
          ImVec2(window_pos.x + s.PosAsciiStart - s.GlyphWidth,
                 window_pos.y + 9999),
          ImGui::GetColorU32(ImGuiCol_Border));
 
    const ImU32 color_text = ImGui::GetColorU32(ImGuiCol_Text);
    const ImU32 color_disabled = OptGreyOutZeroes
                                     ? ImGui::GetColorU32(ImGuiCol_TextDisabled)
                                     : color_text;
 
    const char* format_address =
        OptUpperCaseHex ? "%0*" _PRISizeT "X: " : "%0*" _PRISizeT "x: ";
    const char* format_data =
        OptUpperCaseHex ? "%0*" _PRISizeT "X" : "%0*" _PRISizeT "x";
    const char* format_byte = OptUpperCaseHex ? "%02X" : "%02x";
    const char* format_byte_space = OptUpperCaseHex ? "%02X " : "%02x ";
 
    while (clipper.Step())
      for (int line_i = clipper.DisplayStart; line_i < clipper.DisplayEnd;
           line_i++)  // display only visible lines
      {
        size_t addr = (size_t)(line_i * Cols);
        ImGui::Text(format_address, s.AddrDigitsCount,
                    base_display_addr + addr);
 
        // Draw Hexadecimal
        for (int n = 0; n < Cols && addr < mem_size; n++, addr++) {
          float byte_pos_x = s.PosHexStart + s.HexCellWidth * n;
          if (OptMidColsCount > 0)
            byte_pos_x +=
                (float)(n / OptMidColsCount) * s.SpacingBetweenMidCols;
          ImGui::SameLine(byte_pos_x);
 
          // Draw highlight
          bool is_highlight_from_user_range =
              (addr >= HighlightMin && addr < HighlightMax);
          bool is_highlight_from_user_func =
              (HighlightFn && HighlightFn(mem_data, addr));
          bool is_highlight_from_preview =
              (addr >= DataPreviewAddr &&
               addr < DataPreviewAddr + preview_data_type_size);
          if (is_highlight_from_user_range || is_highlight_from_user_func ||
              is_highlight_from_preview) {
            ImVec2 pos = ImGui::GetCursorScreenPos();
            float highlight_width = s.GlyphWidth * 2;
            bool is_next_byte_highlighted =
                (addr + 1 < mem_size) &&
                ((HighlightMax != (size_t)-1 && addr + 1 < HighlightMax) ||
                 (HighlightFn && HighlightFn(mem_data, addr + 1)));
            if (is_next_byte_highlighted || (n + 1 == Cols)) {
              highlight_width = s.HexCellWidth;
              if (OptMidColsCount > 0 && n > 0 && (n + 1) < Cols &&
                  ((n + 1) % OptMidColsCount) == 0)
                highlight_width += s.SpacingBetweenMidCols;
            }
            draw_list->AddRectFilled(
                pos, ImVec2(pos.x + highlight_width, pos.y + s.LineHeight),
                HighlightColor);
          }
 
          bool comparison_rom_diff = false;
          if (ComparisonData != nullptr) {
            int a = mem_data[addr];
            int b = ComparisonData[addr];
            if (a != b) {
              ImVec2 pos = ImGui::GetCursorScreenPos();
              float highlight_width = s.GlyphWidth * 2;
              bool is_next_byte_highlighted =
                  (addr + 1 < mem_size) &&
                  ((HighlightMax != (size_t)-1 && addr + 1 < HighlightMax) ||
                   (HighlightFn && HighlightFn(mem_data, addr + 1)));
              if (is_next_byte_highlighted || (n + 1 == Cols)) {
                highlight_width = s.HexCellWidth;
                if (OptMidColsCount > 0 && n > 0 && (n + 1) < Cols &&
                    ((n + 1) % OptMidColsCount) == 0)
                  highlight_width += s.SpacingBetweenMidCols;
              }
              draw_list->AddRectFilled(
                  pos, ImVec2(pos.x + highlight_width, pos.y + s.LineHeight),
                  IM_COL32(255, 0, 0, 50));
            }
          }
 
          if (DataEditingAddr == addr) {
            // Display text input on current byte
            bool data_write = false;
            ImGui::PushID((void*)addr);
            if (DataEditingTakeFocus) {
              ImGui::SetKeyboardFocusHere(0);
              sprintf(AddrInputBuf, format_data, s.AddrDigitsCount,
                      base_display_addr + addr);
              sprintf(DataInputBuf, format_byte,
                      ReadFn ? ReadFn(mem_data, addr) : mem_data[addr]);
            }
            struct UserData {
              // FIXME: We should have a way to retrieve the text edit cursor
              // position more easily in the API, this is rather tedious. This
              // is such a ugly mess we may be better off not using InputText()
              // at all here.
              static int Callback(ImGuiInputTextCallbackData* data) {
                UserData* user_data = (UserData*)data->UserData;
                if (!data->HasSelection())
                  user_data->CursorPos = data->CursorPos;
                if (data->SelectionStart == 0 &&
                    data->SelectionEnd == data->BufTextLen) {
                  // When not editing a byte, always refresh its InputText
                  // content pulled from underlying memory data (this is a bit
                  // tricky, since InputText technically "owns" the master copy
                  // of the buffer we edit it in there)
                  data->DeleteChars(0, data->BufTextLen);
                  data->InsertChars(0, user_data->CurrentBufOverwrite);
                  data->SelectionStart = 0;
                  data->SelectionEnd = 2;
                  data->CursorPos = 0;
                }
                return 0;
              }
              char CurrentBufOverwrite[3];  // Input
              int CursorPos;                // Output
            };
            UserData user_data;
            user_data.CursorPos = -1;
            sprintf(user_data.CurrentBufOverwrite, format_byte,
                    ReadFn ? ReadFn(mem_data, addr) : mem_data[addr]);
            ImGuiInputTextFlags flags = ImGuiInputTextFlags_CharsHexadecimal |
                                        ImGuiInputTextFlags_EnterReturnsTrue |
                                        ImGuiInputTextFlags_AutoSelectAll |
                                        ImGuiInputTextFlags_NoHorizontalScroll |
                                        ImGuiInputTextFlags_CallbackAlways;
#if IMGUI_VERSION_NUM >= 18104
            flags |= ImGuiInputTextFlags_AlwaysOverwrite;
#else
            flags |= ImGuiInputTextFlags_AlwaysInsertMode;
#endif
            ImGui::SetNextItemWidth(s.GlyphWidth * 2);
            if (ImGui::InputText("##data", DataInputBuf,
                                 IM_ARRAYSIZE(DataInputBuf), flags,
                                 UserData::Callback, &user_data))
              data_write = data_next = true;
            else if (!DataEditingTakeFocus && !ImGui::IsItemActive())
              DataEditingAddr = data_editing_addr_next = (size_t)-1;
            DataEditingTakeFocus = false;
            if (user_data.CursorPos >= 2)
              data_write = data_next = true;
            if (data_editing_addr_next != (size_t)-1)
              data_write = data_next = false;
            unsigned int data_input_value = 0;
            if (data_write &&
                sscanf(DataInputBuf, "%X", &data_input_value) == 1) {
              if (WriteFn)
                WriteFn(mem_data, addr, (ImU8)data_input_value);
              else
                mem_data[addr] = (ImU8)data_input_value;
            }
            ImGui::PopID();
          } else {
            // NB: The trailing space is not visible but ensure there's no gap
            // that the mouse cannot click on.
            ImU8 b = ReadFn ? ReadFn(mem_data, addr) : mem_data[addr];
 
            if (OptShowHexII) {
              if ((b >= 32 && b < 128))
                ImGui::Text(".%c ", b);
              else if (b == 0xFF && OptGreyOutZeroes)
                ImGui::TextDisabled("## ");
              else if (b == 0x00)
                ImGui::Text("   ");
              else
                ImGui::Text(format_byte_space, b);
            } else {
              if (b == 0 && OptGreyOutZeroes)
                ImGui::TextDisabled("00 ");
              else
                ImGui::Text(format_byte_space, b);
            }
            if (!ReadOnly && ImGui::IsItemHovered() &&
                ImGui::IsMouseClicked(0)) {
              DataEditingTakeFocus = true;
              data_editing_addr_next = addr;
            }
          }
        }
 
        if (OptShowAscii) {
          // Draw ASCII values
          ImGui::SameLine(s.PosAsciiStart);
          ImVec2 pos = ImGui::GetCursorScreenPos();
          addr = line_i * Cols;
          ImGui::PushID(line_i);
          if (ImGui::InvisibleButton(
                  "ascii",
                  ImVec2(s.PosAsciiEnd - s.PosAsciiStart, s.LineHeight))) {
            DataEditingAddr = DataPreviewAddr =
                addr +
                (size_t)((ImGui::GetIO().MousePos.x - pos.x) / s.GlyphWidth);
            DataEditingTakeFocus = true;
          }
          ImGui::PopID();
          for (int n = 0; n < Cols && addr < mem_size; n++, addr++) {
            if (addr == DataEditingAddr) {
              draw_list->AddRectFilled(
                  pos, ImVec2(pos.x + s.GlyphWidth, pos.y + s.LineHeight),
                  ImGui::GetColorU32(ImGuiCol_FrameBg));
              draw_list->AddRectFilled(
                  pos, ImVec2(pos.x + s.GlyphWidth, pos.y + s.LineHeight),
                  ImGui::GetColorU32(ImGuiCol_TextSelectedBg));
            }
            unsigned char c = ReadFn ? ReadFn(mem_data, addr) : mem_data[addr];
            char display_c = (c < 32 || c >= 128) ? '.' : c;
            draw_list->AddText(pos,
                               (display_c == c) ? color_text : color_disabled,
                               &display_c, &display_c + 1);
            pos.x += s.GlyphWidth;
          }
        }
      }
    ImGui::PopStyleVar(2);
    ImGui::EndChild();
 
    // Notify the main window of our ideal child content size (FIXME: we are
    // missing an API to get the contents size from the child)
    ImGui::SetCursorPosX(s.WindowWidth);
 
    if (data_next && DataEditingAddr + 1 < mem_size) {
      DataEditingAddr = DataPreviewAddr = DataEditingAddr + 1;
      DataEditingTakeFocus = true;
    } else if (data_editing_addr_next != (size_t)-1) {
      DataEditingAddr = DataPreviewAddr = data_editing_addr_next;
      DataEditingTakeFocus = true;
    }
 
    const bool lock_show_data_preview = OptShowDataPreview;
    if (OptShowOptions) {
      ImGui::Separator();
      DrawOptionsLine(s, mem_data, mem_size, base_display_addr);
    }
 
    if (lock_show_data_preview) {
      ImGui::Separator();
      DrawPreviewLine(s, mem_data, mem_size, base_display_addr);
    }
  }
 
  void DrawOptionsLine(const Sizes& s, void* mem_data, size_t mem_size,
                       size_t base_display_addr) {
    IM_UNUSED(mem_data);
    ImGuiStyle& style = ImGui::GetStyle();
    const char* format_range =
        OptUpperCaseHex ? "Range %0*" _PRISizeT "X..%0*" _PRISizeT "X"
                        : "Range %0*" _PRISizeT "x..%0*" _PRISizeT "x";
 
    // Options menu
    if (ImGui::Button(ICON_MD_SETTINGS " Options"))
      ImGui::OpenPopup("context");
    if (ImGui::BeginPopup("context")) {
      ImGui::SetNextItemWidth(s.GlyphWidth * 7 + style.FramePadding.x * 2.0f);
      if (ImGui::DragInt(ICON_MD_VIEW_COLUMN " ##cols", &Cols, 0.2f, 4, 32, "%d cols")) {
        ContentsWidthChanged = true;
        if (Cols < 1)
          Cols = 1;
      }
      ImGui::Checkbox(ICON_MD_PREVIEW " Show Data Preview", &OptShowDataPreview);
      ImGui::Checkbox(ICON_MD_HEXAGON " Show HexII", &OptShowHexII);
      if (ImGui::Checkbox(ICON_MD_ABC " Show Ascii", &OptShowAscii)) {
        ContentsWidthChanged = true;
      }
      ImGui::Checkbox(ICON_MD_FORMAT_COLOR_RESET " Grey out zeroes", &OptGreyOutZeroes);
      ImGui::Checkbox(ICON_MD_KEYBOARD_CAPSLOCK " Uppercase Hex", &OptUpperCaseHex);
 
      ImGui::EndPopup();
    }
 
    ImGui::SameLine();
    ImGui::Text(ICON_MD_ZOOM_OUT_MAP);
    ImGui::SameLine();
    ImGui::Text(format_range, s.AddrDigitsCount, base_display_addr,
                s.AddrDigitsCount, base_display_addr + mem_size - 1);
    ImGui::SameLine();
    ImGui::SetNextItemWidth((s.AddrDigitsCount + 1) * s.GlyphWidth +
                            style.FramePadding.x * 2.0f);
    if (ImGui::InputText("##addr", AddrInputBuf, IM_ARRAYSIZE(AddrInputBuf),
                         ImGuiInputTextFlags_CharsHexadecimal |
                             ImGuiInputTextFlags_EnterReturnsTrue)) {
      size_t goto_addr;
      if (sscanf(AddrInputBuf, "%" _PRISizeT "X", &goto_addr) == 1) {
        GotoAddr = goto_addr - base_display_addr;
        HighlightMin = HighlightMax = (size_t)-1;
      }
    }
    ImGui::SameLine();
    ImGui::Text(ICON_MD_LOCATION_ON);
 
    if (GotoAddr != (size_t)-1) {
      if (GotoAddr < mem_size) {
        ImGui::BeginChild("##scrolling");
        ImGui::SetScrollFromPosY(ImGui::GetCursorStartPos().y +
                                 (GotoAddr / Cols) *
                                     ImGui::GetTextLineHeight());
        ImGui::EndChild();
        DataEditingAddr = DataPreviewAddr = GotoAddr;
        DataEditingTakeFocus = true;
      }
      GotoAddr = (size_t)-1;
    }
  }
 
  void DrawPreviewLine(const Sizes& s, void* mem_data_void, size_t mem_size,
                       size_t base_display_addr) {
    IM_UNUSED(base_display_addr);
    ImU8* mem_data = (ImU8*)mem_data_void;
    ImGuiStyle& style = ImGui::GetStyle();
    ImGui::AlignTextToFramePadding();
    ImGui::Text(ICON_MD_SEARCH " Preview as:");
    ImGui::SameLine();
    ImGui::SetNextItemWidth((s.GlyphWidth * 10.0f) +
                            style.FramePadding.x * 2.0f +
                            style.ItemInnerSpacing.x);
    if (ImGui::BeginCombo("##combo_type", DataTypeGetDesc(PreviewDataType),
                          ImGuiComboFlags_HeightLargest)) {
      for (int n = 0; n < ImGuiDataType_COUNT; n++)
        if (ImGui::Selectable(DataTypeGetDesc((ImGuiDataType)n),
                              PreviewDataType == n))
          PreviewDataType = (ImGuiDataType)n;
      ImGui::EndCombo();
    }
    ImGui::SameLine();
    ImGui::SetNextItemWidth((s.GlyphWidth * 6.0f) +
                            style.FramePadding.x * 2.0f +
                            style.ItemInnerSpacing.x);
    ImGui::Combo("##combo_endianess", &PreviewEndianess, "LE\0BE\0\0");
 
    char buf[128] = "";
    float x = s.GlyphWidth * 6.0f;
    bool has_value = DataPreviewAddr != (size_t)-1;
    if (has_value)
      DrawPreviewData(DataPreviewAddr, mem_data, mem_size, PreviewDataType,
                      DataFormat_Dec, buf, (size_t)IM_ARRAYSIZE(buf));
    ImGui::Text(ICON_MD_NUMBERS " Dec");
    ImGui::SameLine(x);
    ImGui::TextUnformatted(has_value ? buf : "N/A");
    if (has_value)
      DrawPreviewData(DataPreviewAddr, mem_data, mem_size, PreviewDataType,
                      DataFormat_Hex, buf, (size_t)IM_ARRAYSIZE(buf));
    ImGui::Text(ICON_MD_HEXAGON " Hex");
    ImGui::SameLine(x);
    ImGui::TextUnformatted(has_value ? buf : "N/A");
    if (has_value)
      DrawPreviewData(DataPreviewAddr, mem_data, mem_size, PreviewDataType,
                      DataFormat_Bin, buf, (size_t)IM_ARRAYSIZE(buf));
    buf[IM_ARRAYSIZE(buf) - 1] = 0;
    ImGui::Text(ICON_MD_DATA_ARRAY " Bin");
    ImGui::SameLine(x);
    ImGui::TextUnformatted(has_value ? buf : "N/A");
  }
 
  // Utilities for Data Preview
  const char* DataTypeGetDesc(ImGuiDataType data_type) const {
    const char* descs[] = {"Int8",   "Uint8", "Int16",  "Uint16", "Int32",
                           "Uint32", "Int64", "Uint64", "Float",  "Double"};
    IM_ASSERT(data_type >= 0 && data_type < ImGuiDataType_COUNT);
    return descs[data_type];
  }
 
  size_t DataTypeGetSize(ImGuiDataType data_type) const {
    const size_t sizes[] = {
        1, 1, 2, 2, 4, 4, 8, 8, sizeof(float), sizeof(double)};
    IM_ASSERT(data_type >= 0 && data_type < ImGuiDataType_COUNT);
    return sizes[data_type];
  }
 
  const char* DataFormatGetDesc(DataFormat data_format) const {
    const char* descs[] = {"Bin", "Dec", "Hex"};
    IM_ASSERT(data_format >= 0 && data_format < DataFormat_COUNT);
    return descs[data_format];
  }
 
  bool IsBigEndian() const {
    uint16_t x = 1;
    char c[2];
    memcpy(c, &x, 2);
    return c[0] != 0;
  }
 
  static void* EndianessCopyBigEndian(void* _dst, void* _src, size_t s,
                                      int is_little_endian) {
    if (is_little_endian) {
      uint8_t* dst = (uint8_t*)_dst;
      uint8_t* src = (uint8_t*)_src + s - 1;
      for (int i = 0, n = (int)s; i < n; ++i)
        memcpy(dst++, src--, 1);
      return _dst;
    } else {
      return memcpy(_dst, _src, s);
    }
  }
 
  static void* EndianessCopyLittleEndian(void* _dst, void* _src, size_t s,
                                         int is_little_endian) {
    if (is_little_endian) {
      return memcpy(_dst, _src, s);
    } else {
      uint8_t* dst = (uint8_t*)_dst;
      uint8_t* src = (uint8_t*)_src + s - 1;
      for (int i = 0, n = (int)s; i < n; ++i)
        memcpy(dst++, src--, 1);
      return _dst;
    }
  }
 
  void* EndianessCopy(void* dst, void* src, size_t size) const {
    static void* (*fp)(void*, void*, size_t, int) = nullptr;
    if (fp == nullptr)
      fp = IsBigEndian() ? EndianessCopyBigEndian : EndianessCopyLittleEndian;
    return fp(dst, src, size, PreviewEndianess);
  }
 
  const char* FormatBinary(const uint8_t* buf, int width) const {
    IM_ASSERT(width <= 64);
    size_t out_n = 0;
    static char out_buf[64 + 8 + 1];
    int n = width / 8;
    for (int j = n - 1; j >= 0; --j) {
      for (int i = 0; i < 8; ++i)
        out_buf[out_n++] = (buf[j] & (1 << (7 - i))) ? '1' : '0';
      out_buf[out_n++] = ' ';
    }
    IM_ASSERT(out_n < IM_ARRAYSIZE(out_buf));
    out_buf[out_n] = 0;
    return out_buf;
  }
 
  // [Internal]
  void DrawPreviewData(size_t addr, const ImU8* mem_data, size_t mem_size,
                       ImGuiDataType data_type, DataFormat data_format,
                       char* out_buf, size_t out_buf_size) const {
    uint8_t buf[8];
    size_t elem_size = DataTypeGetSize(data_type);
    size_t size = addr + elem_size > mem_size ? mem_size - addr : elem_size;
    if (ReadFn)
      for (int i = 0, n = (int)size; i < n; ++i)
        buf[i] = ReadFn(mem_data, addr + i);
    else
      memcpy(buf, mem_data + addr, size);
 
    if (data_format == DataFormat_Bin) {
      uint8_t binbuf[8];
      EndianessCopy(binbuf, buf, size);
      ImSnprintf(out_buf, out_buf_size, "%s",
                 FormatBinary(binbuf, (int)size * 8));
      return;
    }
 
    out_buf[0] = 0;
    switch (data_type) {
      case ImGuiDataType_S8: {
        int8_t int8 = 0;
        EndianessCopy(&int8, buf, size);
        if (data_format == DataFormat_Dec) {
          ImSnprintf(out_buf, out_buf_size, "%hhd", int8);
          return;
        }
        if (data_format == DataFormat_Hex) {
          ImSnprintf(out_buf, out_buf_size, "0x%02x", int8 & 0xFF);
          return;
        }
        break;
      }
      case ImGuiDataType_U8: {
        uint8_t uint8 = 0;
        EndianessCopy(&uint8, buf, size);
        if (data_format == DataFormat_Dec) {
          ImSnprintf(out_buf, out_buf_size, "%hhu", uint8);
          return;
        }
        if (data_format == DataFormat_Hex) {
          ImSnprintf(out_buf, out_buf_size, "0x%02x", uint8 & 0xFF);
          return;
        }
        break;
      }
      case ImGuiDataType_S16: {
        int16_t int16 = 0;
        EndianessCopy(&int16, buf, size);
        if (data_format == DataFormat_Dec) {
          ImSnprintf(out_buf, out_buf_size, "%hd", int16);
          return;
        }
        if (data_format == DataFormat_Hex) {
          ImSnprintf(out_buf, out_buf_size, "0x%04x", int16 & 0xFFFF);
          return;
        }
        break;
      }
      case ImGuiDataType_U16: {
        uint16_t uint16 = 0;
        EndianessCopy(&uint16, buf, size);
        if (data_format == DataFormat_Dec) {
          ImSnprintf(out_buf, out_buf_size, "%hu", uint16);
          return;
        }
        if (data_format == DataFormat_Hex) {
          ImSnprintf(out_buf, out_buf_size, "0x%04x", uint16 & 0xFFFF);
          return;
        }
        break;
      }
      case ImGuiDataType_S32: {
        int32_t int32 = 0;
        EndianessCopy(&int32, buf, size);
        if (data_format == DataFormat_Dec) {
          ImSnprintf(out_buf, out_buf_size, "%d", int32);
          return;
        }
        if (data_format == DataFormat_Hex) {
          ImSnprintf(out_buf, out_buf_size, "0x%08x", int32);
          return;
        }
        break;
      }
      case ImGuiDataType_U32: {
        uint32_t uint32 = 0;
        EndianessCopy(&uint32, buf, size);
        if (data_format == DataFormat_Dec) {
          ImSnprintf(out_buf, out_buf_size, "%u", uint32);
          return;
        }
        if (data_format == DataFormat_Hex) {
          ImSnprintf(out_buf, out_buf_size, "0x%08x", uint32);
          return;
        }
        break;
      }
      case ImGuiDataType_S64: {
        int64_t int64 = 0;
        EndianessCopy(&int64, buf, size);
        if (data_format == DataFormat_Dec) {
          ImSnprintf(out_buf, out_buf_size, "%lld", (long long)int64);
          return;
        }
        if (data_format == DataFormat_Hex) {
          ImSnprintf(out_buf, out_buf_size, "0x%016llx", (long long)int64);
          return;
        }
        break;
      }
      case ImGuiDataType_U64: {
        uint64_t uint64 = 0;
        EndianessCopy(&uint64, buf, size);
        if (data_format == DataFormat_Dec) {
          ImSnprintf(out_buf, out_buf_size, "%llu", (unsigned long long)uint64);
          return;
        }
        if (data_format == DataFormat_Hex) {
          ImSnprintf(out_buf, out_buf_size, "0x%016llx",
                     (unsigned long long)uint64);
          return;
        }
        break;
      }
      case ImGuiDataType_Float: {
        float float32 = 0.0f;
        EndianessCopy(&float32, buf, size);
        if (data_format == DataFormat_Dec) {
          ImSnprintf(out_buf, out_buf_size, "%f", float32);
          return;
        }
        if (data_format == DataFormat_Hex) {
          ImSnprintf(out_buf, out_buf_size, "%a", float32);
          return;
        }
        break;
      }
      case ImGuiDataType_Double: {
        double float64 = 0.0;
        EndianessCopy(&float64, buf, size);
        if (data_format == DataFormat_Dec) {
          ImSnprintf(out_buf, out_buf_size, "%f", float64);
          return;
        }
        if (data_format == DataFormat_Hex) {
          ImSnprintf(out_buf, out_buf_size, "%a", float64);
          return;
        }
        break;
      }
      case ImGuiDataType_COUNT:
        break;
    }  // Switch
  }
};
 
}  // namespace gui
}  // namespace yaze
 
#ifdef _MSC_VER
#pragma warning(pop)
#endif