Method TreeNodeBehavior

src-core/imgui/imgui_widgets.cpp:6147–6343

}

bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* label, const char* label_end)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;
    const bool display_frame = (flags & ImGuiTreeNodeFlags_Framed) != 0;
    const ImVec2 padding = (display_frame || (flags & ImGuiTreeNodeFlags_FramePadding)) ? style.FramePadding : ImVec2(style.FramePadding.x, ImMin(window->DC.CurrLineTextBaseOffset, style.FramePadding.y));

    if (!label_end)
        label_end = FindRenderedTextEnd(label);
    const ImVec2 label_size = CalcTextSize(label, label_end, false);

    // We vertically grow up to current line height up the typical widget height.
    const float frame_height = ImMax(ImMin(window->DC.CurrLineSize.y, g.FontSize + style.FramePadding.y * 2), label_size.y + padding.y * 2);
    ImRect frame_bb;
    frame_bb.Min.x = (flags & ImGuiTreeNodeFlags_SpanFullWidth) ? window->WorkRect.Min.x : window->DC.CursorPos.x;
    frame_bb.Min.y = window->DC.CursorPos.y;
    frame_bb.Max.x = window->WorkRect.Max.x;
    frame_bb.Max.y = window->DC.CursorPos.y + frame_height;
    if (display_frame)
    {
        // Framed header expand a little outside the default padding, to the edge of InnerClipRect
        // (FIXME: May remove this at some point and make InnerClipRect align with WindowPadding.x instead of WindowPadding.x*0.5f)
        frame_bb.Min.x -= IM_TRUNC(window->WindowPadding.x * 0.5f - 1.0f);
        frame_bb.Max.x += IM_TRUNC(window->WindowPadding.x * 0.5f);
    }

    const float text_offset_x = g.FontSize + (display_frame ? padding.x * 3 : padding.x * 2);           // Collapser arrow width + Spacing
    const float text_offset_y = ImMax(padding.y, window->DC.CurrLineTextBaseOffset);                    // Latch before ItemSize changes it
    const float text_width = g.FontSize + (label_size.x > 0.0f ? label_size.x + padding.x * 2 : 0.0f);  // Include collapser
    ImVec2 text_pos(window->DC.CursorPos.x + text_offset_x, window->DC.CursorPos.y + text_offset_y);
    ItemSize(ImVec2(text_width, frame_height), padding.y);

    // For regular tree nodes, we arbitrary allow to click past 2 worth of ItemSpacing
    ImRect interact_bb = frame_bb;
    if (!display_frame && (flags & (ImGuiTreeNodeFlags_SpanAvailWidth | ImGuiTreeNodeFlags_SpanFullWidth)) == 0)
        interact_bb.Max.x = frame_bb.Min.x + text_width + style.ItemSpacing.x * 2.0f;

    // Compute open and multi-select states before ItemAdd() as it clear NextItem data.
    bool is_open = TreeNodeUpdateNextOpen(id, flags);
    bool item_add = ItemAdd(interact_bb, id);
    g.LastItemData.StatusFlags |= ImGuiItemStatusFlags_HasDisplayRect;
    g.LastItemData.DisplayRect = frame_bb;

    // If a NavLeft request is happening and ImGuiTreeNodeFlags_NavLeftJumpsBackHere enabled:
    // Store data for the current depth to allow returning to this node from any child item.
    // For this purpose we essentially compare if g.NavIdIsAlive went from 0 to 1 between TreeNode() and TreePop().
    // It will become tempting to enable ImGuiTreeNodeFlags_NavLeftJumpsBackHere by default or move it to ImGuiStyle.
    // Currently only supports 32 level deep and we are fine with (1 << Depth) overflowing into a zero, easy to increase.
    if (is_open && !g.NavIdIsAlive && (flags & ImGuiTreeNodeFlags_NavLeftJumpsBackHere) && !(flags & ImGuiTreeNodeFlags_NoTreePushOnOpen))
        if (g.NavMoveDir == ImGuiDir_Left && g.NavWindow == window && NavMoveRequestButNoResultYet())
        {
            g.NavTreeNodeStack.resize(g.NavTreeNodeStack.Size + 1);
            ImGuiNavTreeNodeData* nav_tree_node_data = &g.NavTreeNodeStack.back();
            nav_tree_node_data->ID = id;