Lantr

A narrative-first presentation editor for Android and Windows, built with Kotlin and Compose Multiplatform.

Retired product, maintained source archive. Lantr explored a presentation workflow that begins with the speaker's argument and narrative arc rather than an empty slide. This repository preserves the Android and Windows app, its cross-platform engineering, and the experiments that shaped it.

Why Lantr existed

Most presentation tools begin with a rectangle. Lantr began with the story: who is listening, what should change for them, and how should the argument unfold?

The editor connects two working modes:

• Arc mode structures the presentation as rhetorical sections and story blocks.
• Slide mode turns those blocks into visual moments with text, images, themes, alignment, and direct manipulation.

The result is a document editor where slides belong to a narrative instead of living in a flat list.

What is here

• composeApp — the Compose Multiplatform application for Android and desktop JVM.
• Experiments/DirectorService — a testable Azure agent prototype that turns a brain dump into a proposed narrative arc.
• Docs/Architecture — subsystem notes for the model, canvas, drag and drop, document format, and platform boundaries.
• Docs/CaseStudies — engineering retrospectives, including what failed and what should change.
• Docs/Experiments — smaller design and technology studies.
• Media — project-owned brand and demonstration material.

Architecture

flowchart TD
    P[Presentation] --> A[Arc]
    A --> SB[Story blocks]
    SB --> S[Slides]
    S --> CB[Text and image blocks]
    VM[Presentation / Arc / Slide view models] --> P
    UI[Compose UI] --> VM
    UI --> PB[Platform boundaries]
    PB --> Android[Android documents and intents]
    PB --> JVM[Desktop windows and file associations]

Loading

Shared code owns the domain model, editor state, canvas behavior, themes, and most UI. Small platform boundaries handle documents, native image loading, drag and drop, window behavior, and .ltrn file integration.

Read the architecture index or start with the building Lantr case study.

Requirements

• JDK 17
• Android Studio with an Android SDK for Android builds
• Windows, macOS, or Linux for desktop JVM development

# Desktop app
.\gradlew :composeApp:run

# Desktop tests
.\gradlew :composeApp:jvmTest

# Android debug build
.\gradlew :composeApp:assembleDebug

The desktop distribution is configured for MSI, DMG, and DEB packaging. Windows is the maintained desktop target represented by this archive.

Experiments

The archive separates experiments from shipped editor code. Each experiment must build independently, carry no bundled credential, and document its question and failure modes.

The first preserved experiment is Director Service: an Azure-backed prototype for mapping raw ideas into typed arc sections. Its HTTP boundary can be tested entirely offline.

Sister project

Dave Retegan's Apple-platform Lantr archive preserves the native Swift product and Live Presenter speech-to-slides experiment. The repositories are separate implementations from the same wider product effort.

History and people

Matei Ursache designed and built the Kotlin/Compose application represented here. Raul Boanca contributed to the wider Lantr effort and the original Director service prototype. David Retegan built the separate Apple-platform application and contributed to the shared product direction.

See PROVENANCE.md for the import boundary and THIRD_PARTY_NOTICES.md for dependency and asset attribution.

Archive status

This is a portfolio and learning archive, not a hosted service. Focused fixes, documentation improvements, tests, and platform-compatibility updates are welcome. No Lantr account, production backend, or cloud credential is required to build the editor.

The project-owned source is MIT licensed unless a dependency or bundled asset states otherwise.