Request to add tree widget to GUI API

Description

Contributor guide

Tech stack

cpp

Domain

desktopapi

Issue type

feature

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

4

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

over 1 week

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

stale

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

mostly clear

Prerequisites

C++ knowledgedlib GUI API familiarity

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

15

Research direction

Examine existing dlib GUI widgets (e.g., in dlib/gui widgets) to understand the API pattern. Review any prior discussions or examples of custom widgets. The issue requests a tree widget with multiple columns, so research tree data structures and typical GUI tree implementations (e.g., wxWidgets tree control). Consider proposing a design that integrates with dlib's event system and drawing primitives.