Lysa UI  0.0
Lysa UI —UI components for the Lysa Engine
Lysa UI overview

Lysa UI is a user interface library for the Lysa Engine offering a hybrid system with retained-mode components drawn using an immediate-mode vector renderer.

Overview

Lysa UI provides a widget-based UI framework built on top of the Lysa Engine. It organizes interface elements into a hierarchy of typed widgets contained within virtual UI windows, all managed by a central WindowManager. Each widget participates in the engine's event system for input handling, focus management, and rendering callbacks.

Features

  • Alignment System: Powerful stacking and placement system via the Alignment enum — place children at corners, centers, edges, or fill their parent entirely.
  • Widget Hierarchy: Parent–child widget trees with padding, border, and overlap support.
    • create<T>() and add<T>() template helpers on both Widget and Window.
    • Recursive removeAll() and individual remove() for dynamic UI updates.
  • Widget Types:
    • Widget — transparent base widget; all other types derive from it.
    • Panel — rectangular widget with a background only.
    • Box — rectangular widget with a border and a background.
    • Frame — Box with an optional title string and configurable title color.
    • Button — clickable Box that fires UIEvent::OnClick.
    • ToggleButton — two-state (checked/unchecked) clickable button.
    • CheckWidget — abstract base for all two-state widgets.
    • Text — single-line text display with configurable color and font scale.
    • TextEdit — single-line editable text field with cursor and selection support.
    • Image — displays a lysa::Image resource with optional color tint and auto-sizing.
    • Line / HLine / VLine — horizontal or vertical divider lines.
    • ScrollBar / HScrollBar / VScrollBar — range-based scroll bars.
    • TreeView — hierarchical list widget with expand/collapse and scroll support.
    • ValueSelect — abstract base for range-bound numeric widgets (ScrollBar).
  • Window Management: WindowManager manages multiple virtual Window objects overlaid on a single RenderingWindow, with focus, resize, and z-ordering support.
  • Styling: Style base class with a built-in StyleClassic implementation providing a 3D raised/lowered/flat classic vector look. Custom styles can be added by subclassing Style.
  • Event System: All widget interactions are routed through the engine's EventManager using UIEvent signal constants (OnClick, OnTextChange, OnValueChange, and more).
  • Lua Scripting: All widget types expose their full API to Lua when compiled with LUA_BINDINGS=ON.

Architecture

Released under the MIT license.