Method DebugRenderKeyboardPreview

src/imgui/imgui.cpp:15847–15894

Draw an arbitrary US keyboard layout to visualize translated keys

// Draw an arbitrary US keyboard layout to visualize translated keys
void ImGui::DebugRenderKeyboardPreview(ImDrawList* draw_list)
{
    const float scale = ImGui::GetFontSize() / 13.0f;
    const ImVec2 key_size = ImVec2(35.0f, 35.0f) * scale;
    const float  key_rounding = 3.0f * scale;
    const ImVec2 key_face_size = ImVec2(25.0f, 25.0f) * scale;
    const ImVec2 key_face_pos = ImVec2(5.0f, 3.0f) * scale;
    const float  key_face_rounding = 2.0f * scale;
    const ImVec2 key_label_pos = ImVec2(7.0f, 4.0f) * scale;
    const ImVec2 key_step = ImVec2(key_size.x - 1.0f, key_size.y - 1.0f);
    const float  key_row_offset = 9.0f * scale;

    ImVec2 board_min = GetCursorScreenPos();
    ImVec2 board_max = ImVec2(board_min.x + 3 * key_step.x + 2 * key_row_offset + 10.0f, board_min.y + 3 * key_step.y + 10.0f);
    ImVec2 start_pos = ImVec2(board_min.x + 5.0f - key_step.x, board_min.y);

    struct KeyLayoutData { int Row, Col; const char* Label; ImGuiKey Key; };
    const KeyLayoutData keys_to_display[] =
    {
        { 0, 0, "", ImGuiKey_Tab },      { 0, 1, "Q", ImGuiKey_Q }, { 0, 2, "W", ImGuiKey_W }, { 0, 3, "E", ImGuiKey_E }, { 0, 4, "R", ImGuiKey_R },
        { 1, 0, "", ImGuiKey_CapsLock }, { 1, 1, "A", ImGuiKey_A }, { 1, 2, "S", ImGuiKey_S }, { 1, 3, "D", ImGuiKey_D }, { 1, 4, "F", ImGuiKey_F },
        { 2, 0, "", ImGuiKey_LeftShift },{ 2, 1, "Z", ImGuiKey_Z }, { 2, 2, "X", ImGuiKey_X }, { 2, 3, "C", ImGuiKey_C }, { 2, 4, "V", ImGuiKey_V }
    };

    // Elements rendered manually via ImDrawList API are not clipped automatically.
    // While not strictly necessary, here IsItemVisible() is used to avoid rendering these shapes when they are out of view.
    Dummy(board_max - board_min);
    if (!IsItemVisible())
        return;
    draw_list->PushClipRect(board_min, board_max, true);
    for (int n = 0; n < IM_ARRAYSIZE(keys_to_display); n++)
    {
        const KeyLayoutData* key_data = &keys_to_display[n];
        ImVec2 key_min = ImVec2(start_pos.x + key_data->Col * key_step.x + key_data->Row * key_row_offset, start_pos.y + key_data->Row * key_step.y);
        ImVec2 key_max = key_min + key_size;
        draw_list->AddRectFilled(key_min, key_max, IM_COL32(204, 204, 204, 255), key_rounding);
        draw_list->AddRect(key_min, key_max, IM_COL32(24, 24, 24, 255), key_rounding);
        ImVec2 face_min = ImVec2(key_min.x + key_face_pos.x, key_min.y + key_face_pos.y);
        ImVec2 face_max = ImVec2(face_min.x + key_face_size.x, face_min.y + key_face_size.y);
        draw_list->AddRect(face_min, face_max, IM_COL32(193, 193, 193, 255), key_face_rounding, ImDrawFlags_None, 2.0f);
        draw_list->AddRectFilled(face_min, face_max, IM_COL32(252, 252, 252, 255), key_face_rounding);
        ImVec2 label_min = ImVec2(key_min.x + key_label_pos.x, key_min.y + key_label_pos.y);
        draw_list->AddText(label_min, IM_COL32(64, 64, 64, 255), key_data->Label);
        if (IsKeyDown(key_data->Key))
            draw_list->AddRectFilled(key_min, key_max, IM_COL32(255, 0, 0, 128), key_rounding);
    }
    draw_list->PopClipRect();
}

// Helper tool to diagnose between text encoding issues and font loading issues. Pass your UTF-8 string and verify that there are correct.
void ImGui::DebugTextEncoding(const char* str)