TreeView

#include "toolkit/tree_view.hpp"

A scrollable, expandable/collapsible tree bound to a TreeModel, with single/multi selection. Inherits ScrollableWidget.

macOS

Material

Windows 11

Windows 95

Plasma 6

GNOME

TreeModel

struct TreeNode {
    std::string text;
    std::vector<TreeNode> children;
    bool expanded = false;
    int parent_index = -1;
    int depth = 0;
};

class TreeModel {
  public:
    virtual int root_count() const = 0;
    virtual TreeNode const &root_at(int index) const = 0;
    std::function<void()> on_data_changed;
};

SimpleTreeModel is a ready-made TreeModel over std::vector<TreeNode> (set_roots(), clear()). FileTreeModel is another built-in implementation, backed by the filesystem.

Example

auto model = std::make_shared<toolkit::SimpleTreeModel>(build_tree());
auto tree = std::make_unique<toolkit::TreeView>(model);

Construction

explicit TreeView(std::shared_ptr<TreeModel> model);

API

Member	Description
set_model(std::shared_ptr<TreeModel>) / model()	Data source
expand(int node_index) / collapse(int node_index) / toggle(int node_index)	Expansion state
set_selected_node(int) / selected_node()	Single-selection cursor
set_selection(std::set<int>) / selection()	Full selection set
clear_selection() / is_selected(int)	Manage selection
set_multi_select(bool) / multi_select()	Allow selecting multiple nodes
set_alternating_row_colors(bool) / alternating_row_colors()	Zebra-striped rows

Node indices are into the view's internal flattened (visible) node list, not the model's tree structure directly.

Callbacks

Callback	Description
on_selection_changed — std::function<void(int node_index)>	Fired when selection changes
on_node_expanded — std::function<void(int node_index)>	Fired when a node is expanded/collapsed