Writing reels

A reel is a .reel file, one command per line, in three parts:

# 1. What it records: the first line (after any Import lines and comments).
Launch ~/Projects/musicbox/build/App/Musicbox.app

# 2. Setup: what to write and how. Nothing is recorded yet.
Output musicbox.mp4
Set Size 1440x900
Intro "Musicbox" "Chord progressions, sketched and heard"

# 3. Steps: recording starts at the first one.
Wait #lanes
Key space
Say "The chords lane drives the others."

• What it records. Launch an app, by bundle id or path, or Open a web page. Everything after is read knowing which, so a setting for the other kind (Set Viewport in an app reel, Set Size in a web reel) is refused at its line rather than ignored.
• Setup is Output, Set, Intro, Outro and Profile, before the first step. A reel needs at least one Output.
• Steps are everything else: Click, Type, Key, Say, Caption, Zoom, and the rest. See Commands.

# starts a comment at the start of a line, or after a space:

Set Size 1440x900
Click #play         # #play here is an identifier, not a comment

1. the window, in points

# straight after a word is part of it: #play is an element's identifier and #1d2b3a a colour.

• Durations: 500ms, 2s, 1.5s, 1m, or a bare number of seconds.
• Text in double quotes: Type "hello", Caption "Saved". \n is return, \" a quote.
• Options after @ on the command: Type@20ms "fast", Say@over "…", Zoom@ease-out,600ms #list, Intro@slide-up "Title".

reel reads the whole reel before it records anything, and an error names its line:

$ reel check demo.reel
Error: line 7: 'cmd+nope' is not a key; write a key name such as return or a, with modifiers: cmd+s

reel check reads a reel and says what it would do: what it launches, the narration, how many actions and captions, and every file it would write, for each profile.