Window

Programmatic window controls from JavaScript and an opt-in CSS-driven window drag listener.

Config key	window
JS namespace	Window
Core	No
Phases	Bindable · WebviewInject
Hard deps	—
Platforms	macOS · Linux · Windows

The Window plugin exposes runtime window controls to JavaScript — minimize, maximize, center, resize, retitle — and a CSS-driven drag listener for custom title bars. For initial window size, title, and macOS chrome options, see Window Configuration.

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JavaScript API

import { lune } from "../lunejs/runtime/runtime.js";

await lune.Window.minimize();
await lune.Window.maximize();
await lune.Window.center();

await lune.Window.setTitle({ title: "My App — Unsaved" });
await lune.Window.setSize({ width: 1440, height: 900 });

Method	Signature	Returns
minimize	minimize()	Promise<void>
maximize	maximize()	Promise<void>
center	center()	Promise<void>
setTitle	setTitle({ title })	Promise<void>
setSize	setSize({ width, height })	Promise<void>

lune.Window.startDrag is also exposed but is invoked by the auto-injected mousedown listener — application code rarely calls it directly.

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Window drag (macOS + Windows)

Tag DOM elements with a CSS custom property and mousedown on them initiates a native window drag. Essential when using a custom title bar without the OS chrome.

Lune.run(app) do |opts|
  opts.window.drag_zone = "--lune-draggable"
end

Option	Type	Default	Description
drag_zone	String	""	Inline CSS custom property that marks drag handles or excludes subtrees. Empty disables dragging.
drag_exclude	String	Interactive elements (below)	CSS selector for elements whose entire subtree must keep pointer interaction. Override for custom widgets; "" disables selector exclusions.

Mark an element as a drag handle with an inline style. Non-empty values enable dragging, except false, 0, and no-drag, which exclude a subtree. Write true for clarity:

<div style="--lune-draggable: true">Title bar</div>

Inline style required. Detection reads style.getPropertyValue directly. The event's composed path is checked, including ancestors across shadow roots. Exclusions always win, even over a nested drag handle.

You can mark the entire app draggable and opt custom interaction areas out:

<div style="--lune-draggable: true">
  <h1>Drag from this heading or the background</h1>
  <button>Buttons remain clickable automatically</button>
  <div style="--lune-draggable: false">Selectable text or a custom widget</div>
  <div data-lune-no-drag>Another custom interaction area</div>
</div>

By default, drag_exclude includes links, buttons, inputs, selects, textareas, labels, summaries, editable regions, elements with tabindex, ARIA buttons/links/sliders/checkboxes/switches/tabs/menuitems/comboboxes, HTML drag sources, [data-lune-no-drag], dialogs, SVG, and canvas. Their descendants are excluded too. Disabled controls also remain excluded. The data-lune-no-drag attribute is part of this default selector; inline false/0/no-drag exclusions always apply, even with a custom selector.

For custom selectors, assign opts.window.drag_exclude (this replaces the default selector). Unmodified primary-button presses initiate dragging; secondary buttons, modifier clicks, already-cancelled events, and native scrollbar presses retain their normal behavior. Text in draggable regions cannot be selected by dragging; mark selectable content as no-drag.

When drag_zone is empty (the default), no mousedown listener is installed and the start_drag binding is unused — the plugin behaves exactly like before the drag feature existed. To "disable" drag, leave drag_zone unset.

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Notes

• setSize sets the content area in logical pixels (independent of screen DPI).
• For initial size and position constraints (min_width, max_width, etc.) use the Window Configuration options.

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Platform notes

• macOS — Verified. Programmatic controls + drag both work.
• Linux — Untested. Programmatic controls only — drag_zone has no effect (drag needs _NET_WM_MOVERESIZE; tracked in ROADMAP.md).
• Windows — Verified. Programmatic controls + drag_zone (mousedown → ReleaseCapture + SendMessage(WM_NCLBUTTONDOWN, HTCAPTION, 0)). Window state opt-in via remember_frame = true (live GetWindowRect tracker since HWND is destroyed before save). Chrome opts are macOS-only.

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Disabling

plugins:
  disabled:
    - window

This turns off everything — the JS bindings AND the drag listener. To keep the programmatic controls but turn off drag, leave opts.window.drag_zone empty (the default).