Guiderator

Drop exact ruler guides by typing a number — or a formula like 1920/2 — into a dockable panel, then click H or V.

Category: composition · Version: 2.0.0 · UI: PANEL (dockable palette)

What it does

Guiderator places precise ruler guides in the active composition without making you do the math first. Type a plain number or a simple arithmetic expression (1920/2, 1080*0.33) into the panel's field — the moment the field loses focus, the expression is evaluated and replaced with the computed result — then click H for a horizontal guide or V for a vertical one.

That built-in calculator is the point: "where's the exact center / third / quarter of my comp" becomes typing the formula and clicking once, instead of grabbing a calculator or eyeballing a guide into place. Because it's a dockable panel, it lives permanently in your workspace next to the Timeline rather than being a one-shot dialog.

A third button doubles as a guide-lock indicator and toggle: 🔐 when the active viewer's guides are locked, 🔓 when they're not; clicking flips the state. You can unlock guides to reposition them by hand, then re-lock — without hunting through the View menu.

Controls & options

Calculator examples

Usage

1. Make the target composition active and open/dock the Guiderator panel.
2. Type a number (540) or formula (1920/2) into the field.
3. Tab or click away — the field updates to the computed value (e.g. 960). Clicking H or V also triggers the evaluation first, since the click moves focus off the field.
4. Click H for a horizontal guide or V for a vertical guide at that position.
5. Optionally click the lock button to lock/unlock guides (🔐 = locked, 🔓 = unlocked).
6. Repeat as needed — the panel stays open between guides.

Notes

• Each guide is added inside its own "Add Guide" undo group, so a single undo removes one guide.
• The lock button reflects the real lock state at panel open and after each click of its own — but it does not update itself if you lock/unlock guides through AE's View menu while the panel is open.
• The field is evaluated with ExtendScript's eval(), so it technically accepts any ExtendScript — a deliberate trade-off for the formula convenience. Stick to arithmetic.
• Fully self-contained: no layers, effects, or expressions are touched. Its only footprint is addGuide() calls and the viewer's guide-lock flag.

Requirements & edge cases

• Needs an AE version with CompItem.addGuide() (CS6 or later); no explicit version check is made.
• An active composition is required — clicking H/V with a footage/folder item active alerts "Please select a composition." and does nothing.
• Empty field → "Please enter a value." Non-numeric text → "Please enter a valid number."
• If an un-evaluated expression somehow remains in the field when you click H/V, only its leading number is used (1920/2 → 1920). In normal use this can't happen, because clicking the button blurs the field and triggers evaluation first.
• The lock toggle is a silent no-op when there's no active viewer.

How it works

The whole script is one self-invoking block calling addGuideScript(this). buildUI() checks thisObj instanceof Panel to decide between a docked panel and a standalone Window("palette"), lays out the field and three 20×20 buttons in a row, and only calls .center()/.show() for the standalone window case (AE manages visibility for real docked panels).

The calculator wraps eval(input) in try/catch, rounding the result with Number(result.toFixed(2)); on any failure it returns the input untouched. It's wired to the field's onChange, which ScriptUI fires when the field loses focus — including when a button click steals focus, so the H/V handlers always see the evaluated text.

addGuide() trims the text with an ES3-safe regex, guards against empty/NaN input and non-comp active items, then calls comp.addGuide(0, value) for H (0 = horizontal in the AE API) or comp.addGuide(1, value) for V, wrapped in an undo group. The lock button reads and flips app.activeViewer.views[0].options.guidesLocked, updating its own label after each toggle.