Method BeginTableEx

extern/imgui/imgui_tables.cpp:310–562

}

bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImGuiTableFlags flags, const ImVec2& outer_size, float inner_width)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* outer_window = GetCurrentWindow();
    if (outer_window->SkipItems) // Consistent with other tables + beneficial side effect that assert on miscalling EndTable() will be more visible.
        return false;

    // Sanity checks
    IM_ASSERT(columns_count > 0 && columns_count <= IMGUI_TABLE_MAX_COLUMNS && "Only 1..64 columns allowed!");
    if (flags & ImGuiTableFlags_ScrollX)
        IM_ASSERT(inner_width >= 0.0f);

    // If an outer size is specified ahead we will be able to early out when not visible. Exact clipping rules may evolve.
    const bool use_child_window = (flags & (ImGuiTableFlags_ScrollX | ImGuiTableFlags_ScrollY)) != 0;
    const ImVec2 avail_size = GetContentRegionAvail();
    ImVec2 actual_outer_size = CalcItemSize(outer_size, ImMax(avail_size.x, 1.0f), use_child_window ? ImMax(avail_size.y, 1.0f) : 0.0f);
    ImRect outer_rect(outer_window->DC.CursorPos, outer_window->DC.CursorPos + actual_outer_size);
    if (use_child_window && IsClippedEx(outer_rect, 0))
    {
        ItemSize(outer_rect);
        return false;
    }

    // Acquire storage for the table
    ImGuiTable* table = g.Tables.GetOrAddByKey(id);
    const int instance_no = (table->LastFrameActive != g.FrameCount) ? 0 : table->InstanceCurrent + 1;
    const ImGuiID instance_id = id + instance_no;
    const ImGuiTableFlags table_last_flags = table->Flags;
    if (instance_no > 0)
        IM_ASSERT(table->ColumnsCount == columns_count && "BeginTable(): Cannot change columns count mid-frame while preserving same ID");

    // Acquire temporary buffers
    const int table_idx = g.Tables.GetIndex(table);
    if (++g.TablesTempDataStacked > g.TablesTempData.Size)
        g.TablesTempData.resize(g.TablesTempDataStacked, ImGuiTableTempData());
    ImGuiTableTempData* temp_data = table->TempData = &g.TablesTempData[g.TablesTempDataStacked - 1];
    temp_data->TableIndex = table_idx;
    table->DrawSplitter = &table->TempData->DrawSplitter;
    table->DrawSplitter->Clear();

    // Fix flags
    table->IsDefaultSizingPolicy = (flags & ImGuiTableFlags_SizingMask_) == 0;
    flags = TableFixFlags(flags, outer_window);

    // Initialize
    table->ID = id;
    table->Flags = flags;
    table->InstanceCurrent = (ImS16)instance_no;
    table->LastFrameActive = g.FrameCount;
    table->OuterWindow = table->InnerWindow = outer_window;
    table->ColumnsCount = columns_count;
    table->IsLayoutLocked = false;
    table->InnerWidth = inner_width;
    temp_data->UserOuterSize = outer_size;
    if (instance_no > 0 && table->InstanceDataExtra.Size < instance_no)
        table->InstanceDataExtra.push_back(ImGuiTableInstanceData());

    // When not using a child window, WorkRect.Max will grow as we append contents.