lattice/docs/components.md

Components

Element

Element<T> is the self-typed base class: children, layout state, visibility, focus, hover/press state, listeners, and fluent configuration (every setter returns T). Subclasses implement onRender(mouseX, mouseY).

Input listeners (fluent):

element
    .onClick { event -> true }        // return true to consume
    .onRelease { event -> true }
    .onScroll { event -> true }
    .onMouseEnter { }
    .onMouseExit { }
    .onMouseMove { }
    .onCharType { event -> true }     // needs focus, or ignoreFocus()
    .onValueChange { value -> }       // widgets push their new value here

Tree management: childOf(parent), addChild(child), destroy() (recursive, detaches from parent, clears listeners). Attach roots to a Window (screens expose one as window).

Focus: clicking focuses an element and unfocuses the rest of the tree; setRequiresFocus() makes clicks elsewhere drop focus; ignoreFocus() lets an element receive key events without focus.

Debug: enableDebugRendering() draws hitboxes (cyan = idle, yellow = hovered, orange = focused), recursively.

Box

Box<T> adds padding and optional vertical scrolling (see layout). It is the base for anything that contains other elements.

Built-in components (ui.component)

• Container — invisible Box; pure layout/scroll region.
• Rectangle — Box that paints: background (solid or two-color gradient), border (solid or gradient), per-corner radii (borderRadiusVarying), hover/pressed background swap, dropShadow(), rotation/rotateTo().
• Text — single-line label; Auto size measures the string. Optional shadow. Ignores the mouse.
• SvgImage — rasterized SVG with tint (setSvgColor(argb)) and rotation; releases its GPU image on destroy().
• Tooltip — attach with element.addTooltip("text"); fades in/out on hover. Reposition with setPosition(TooltipPosition.Top/Bottom/Left/Right).

Window and UIScreen

Window is the root container: it drives rendering (draw()), routes input, and cleans up (cleanup() destroys the tree and stops animations).

UIScreen bridges a vanilla Screen to a Window: it renders through the RenderEvent.Gui NanoVG frame, translates vanilla input events, closes on ESC when nothing consumes the key, and calls afterInitialization() once. display() opens the screen on the next tick from any thread.