Method TreeSetAllInOpenNodes

extern/ImGui/imgui_demo.cpp:3085–3092

                }

                static void TreeSetAllInOpenNodes(ExampleTreeNode* node, ImGuiSelectionBasicStorage* selection, bool selected)
                {
                    if (node->Parent != NULL) // Root node isn't visible nor selectable in our scheme
                        selection->SetItemSelected((ImGuiID)node->UID, selected);
                    if (node->Parent == NULL || TreeNodeGetOpen(node))
                        for (ExampleTreeNode* child : node->Childs)
                            TreeSetAllInOpenNodes(child, selection, selected);
                }

                // Interpolate in *user-visible order* AND only *over opened nodes*.
                // If you have a sequential mapping tables (e.g. generated after a filter/search pass) this would be simpler.