Memory Editor
Source
// Mini memory editor for ImGui (to embed in your game/tools)
// v0.10
//
// You can adjust the keyboard repeat delay/rate in ImGuiIO.
// The code assume a mono-space font for simplicity! If you don't use the default font, use ImGui::PushFont()/PopFont() to switch to a mono-space font before caling this.
//
// Usage:
// static MemoryEditor memory_editor; // save your state somewhere
// memory_editor.Draw("Memory Editor", mem_block, mem_block_size, (size_t)mem_block); // run
//
// TODO: better resizing policy (ImGui doesn't have flexible window resizing constraints yet)
struct MemoryEditor
{
bool Open;
bool AllowEdits;
int Rows;
int DataEditingAddr;
bool DataEditingTakeFocus;
char DataInput[32];
char AddrInput[32];
MemoryEditor()
{
Open = true;
Rows = 16;
DataEditingAddr = -1;
DataEditingTakeFocus = false;
strcpy(DataInput, "");
strcpy(AddrInput, "");
AllowEdits = true;
}
void Draw(const char* title, unsigned char* mem_data, int mem_size, size_t base_display_addr = 0)
{
if (ImGui::Begin(title, &Open))
{
ImGui::BeginChild("##scrolling", ImVec2(0, -ImGui::GetItemsLineHeightWithSpacing()));
ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0,0));
ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(0,0));
int addr_digits_count = 0;
for (int n = base_display_addr + mem_size - 1; n > 0; n >>= 4)
addr_digits_count++;
float glyph_width = ImGui::CalcTextSize("F").x;
float cell_width = glyph_width * 3; // "FF " we include trailing space in the width to easily catch clicks everywhere
float line_height = ImGui::GetTextLineHeight();
int line_total_count = (int)((mem_size + Rows-1) / Rows);
ImGuiListClipper clipper(line_total_count, line_height);
int visible_start_addr = clipper.DisplayStart * Rows;
int visible_end_addr = clipper.DisplayEnd * Rows;
bool data_next = false;
if (!AllowEdits || DataEditingAddr >= mem_size)
DataEditingAddr = -1;
int data_editing_addr_backup = DataEditingAddr;
if (DataEditingAddr != -1)
{
if (ImGui::IsKeyPressed(ImGui::GetKeyIndex(ImGuiKey_UpArrow)) && DataEditingAddr >= Rows) { DataEditingAddr -= Rows; DataEditingTakeFocus = true; }
else if (ImGui::IsKeyPressed(ImGui::GetKeyIndex(ImGuiKey_DownArrow)) && DataEditingAddr < mem_size - Rows) { DataEditingAddr += Rows; DataEditingTakeFocus = true; }
else if (ImGui::IsKeyPressed(ImGui::GetKeyIndex(ImGuiKey_LeftArrow)) && DataEditingAddr > 0) { DataEditingAddr -= 1; DataEditingTakeFocus = true; }
else if (ImGui::IsKeyPressed(ImGui::GetKeyIndex(ImGuiKey_RightArrow)) && DataEditingAddr < mem_size - 1) { DataEditingAddr += 1; DataEditingTakeFocus = true; }
}
if ((DataEditingAddr / Rows) != (data_editing_addr_backup / Rows))
{
// Track cursor movements
float scroll_offset = ((DataEditingAddr / Rows) - (data_editing_addr_backup / Rows)) * line_height;
bool scroll_desired = (scroll_offset < 0.0f && DataEditingAddr < visible_start_addr + Rows*2) || (scroll_offset > 0.0f && DataEditingAddr > visible_end_addr - Rows*2);
if (scroll_desired)
ImGui::SetScrollY(ImGui::GetScrollY() + scroll_offset);
}
bool draw_separator = true;
for (int line_i = clipper.DisplayStart; line_i < clipper.DisplayEnd; line_i++) // display only visible items
{
int addr = line_i * Rows;
ImGui::Text("%0*X: ", addr_digits_count, base_display_addr+addr);
ImGui::SameLine();
// Draw Hexadecimal
float line_start_x = ImGui::GetCursorPosX();
for (int n = 0; n < Rows && addr < mem_size; n++, addr++)
{
ImGui::SameLine(line_start_x + cell_width * n);
if (DataEditingAddr == addr)
{
// Display text input on current byte
ImGui::PushID(addr);
struct FuncHolder
{
// FIXME: We should have a way to retrieve the text edit cursor position more easily in the API, this is rather tedious.
static int Callback(ImGuiTextEditCallbackData* data)
{
int* p_cursor_pos = (int*)data->UserData;
if (!data->HasSelection())
*p_cursor_pos = data->CursorPos;
return 0;
}
};
int cursor_pos = -1;
bool data_write = false;
if (DataEditingTakeFocus)
{
ImGui::SetKeyboardFocusHere();
sprintf(AddrInput, "%0*X", addr_digits_count, base_display_addr+addr);
sprintf(DataInput, "%02X", mem_data[addr]);
}
ImGui::PushItemWidth(ImGui::CalcTextSize("FF").x);
ImGuiInputTextFlags flags = ImGuiInputTextFlags_CharsHexadecimal|ImGuiInputTextFlags_EnterReturnsTrue|ImGuiInputTextFlags_AutoSelectAll|ImGuiInputTextFlags_NoHorizontalScroll|ImGuiInputTextFlags_AlwaysInsertMode|ImGuiInputTextFlags_CallbackAlways;
if (ImGui::InputText("##data", DataInput, 32, flags, FuncHolder::Callback, &cursor_pos))
data_write = data_next = true;
else if (!DataEditingTakeFocus && !ImGui::IsItemActive())
DataEditingAddr = -1;
DataEditingTakeFocus = false;
ImGui::PopItemWidth();
if (cursor_pos >= 2)
data_write = data_next = true;
if (data_write)
{
int data;
if (sscanf(DataInput, "%X", &data) == 1)
mem_data[addr] = (unsigned char)data;
}
ImGui::PopID();
}
else
{
ImGui::Text("%02X ", mem_data[addr]);
if (AllowEdits && ImGui::IsItemHovered() && ImGui::IsMouseClicked(0))
{
DataEditingTakeFocus = true;
DataEditingAddr = addr;
}
}
}
ImGui::SameLine(line_start_x + cell_width * Rows + glyph_width * 2);
if (draw_separator)
{
ImVec2 screen_pos = ImGui::GetCursorScreenPos();
ImGui::GetWindowDrawList()->AddLine(ImVec2(screen_pos.x - glyph_width, screen_pos.y - 9999), ImVec2(screen_pos.x - glyph_width, screen_pos.y + 9999), ImColor(ImGui::GetStyle().Colors[ImGuiCol_Border]));
draw_separator = false;
}
// Draw ASCII values
addr = line_i * Rows;
for (int n = 0; n < Rows && addr < mem_size; n++, addr++)
{
if (n > 0) ImGui::SameLine();
int c = mem_data[addr];
ImGui::Text("%c", (c >= 32 && c < 128) ? c : '.');
}
}
clipper.End();
ImGui::PopStyleVar(2);
ImGui::EndChild();
if (data_next && DataEditingAddr < mem_size)
{
DataEditingAddr = DataEditingAddr + 1;
DataEditingTakeFocus = true;
}
ImGui::Separator();
ImGui::AlignFirstTextHeightToWidgets();
ImGui::PushItemWidth(50);
ImGui::PushAllowKeyboardFocus(false);
int rows_backup = Rows;
if (ImGui::DragInt("##rows", &Rows, 0.2f, 4, 32, "%.0f rows"))
{
ImVec2 new_window_size = ImGui::GetWindowSize();
new_window_size.x += (Rows - rows_backup) * (cell_width + glyph_width);
ImGui::SetWindowSize(new_window_size);
}
ImGui::PopAllowKeyboardFocus();
ImGui::PopItemWidth();
ImGui::SameLine();
ImGui::Text("Range %0*X..%0*X", addr_digits_count, (int)base_display_addr, addr_digits_count, (int)base_display_addr+mem_size-1);
ImGui::SameLine();
ImGui::PushItemWidth(70);
if (ImGui::InputText("##addr", AddrInput, 32, ImGuiInputTextFlags_CharsHexadecimal | ImGuiInputTextFlags_EnterReturnsTrue))
{
int goto_addr;
if (sscanf(AddrInput, "%X", &goto_addr) == 1)
{
goto_addr -= base_display_addr;
if (goto_addr >= 0 && goto_addr < mem_size)
{
ImGui::BeginChild("##scrolling");
ImGui::SetScrollFromPosY(ImGui::GetCursorStartPos().y + (goto_addr / Rows) * ImGui::GetTextLineHeight());
ImGui::EndChild();
DataEditingAddr = goto_addr;
DataEditingTakeFocus = true;
}
}
}
ImGui::PopItemWidth();
}
ImGui::End();
}
};