4d Capture Gif

4D window → animated GIF

Record a 4D form in motion (slides, transitions, bursts, spinners) to a GIF. FORM SCREENSHOT / the 4d-form-screenshot skill only give a still frame and do not run On Load; this skill runs the real app and films the window.

The engine is scripts/capture_demo.py. It:

1. Launches /Applications/4D.app with --startup-method=<method> --dataless --skip-onstartup — a real window. (Headless tool4d shows nothing, so it cannot be used here.)
2. Finds the form window via CGWindowListCopyWindowInfo (owner 4D, layer 0). When a --click is given, the form is read so the window whose size matches the form wins — an incidental 4D IDE window can't be mistaken for the demo.
3. Clicks (optional): a button is located by its label in the .4DForm, its centre mapped to screen coordinates (title-bar and border insets derived from frame − form content, no magic numbers), 4D is brought to the front, and a HID click is posted. Clicks are scheduled, so several can be staged.
4. Records with CGWindowListCreateImage in-process — this is essential: the screencapture CLI fails from a subprocess (wrong TCC attribution), whereas in-process capture runs under the host app's Screen Recording grant.
5. Kills 4D and writes the GIF (frames down-scaled off the Retina buffer, with their real inter-frame timings).

Requirements (once)

• macOS with /Applications/4D.app.

• Python deps — install into a venv:

  python3 -m venv .venv && ./.venv/bin/pip install -r "$SKILL_DIR/scripts/requirements.txt"
  

• Screen Recording permission for the app that runs the script (the terminal / the Claude app / …). Without it every frame is black. Check and, if needed, prompt for it:

  import Quartz
  print(Quartz.CGPreflightScreenCaptureAccess())   # True == granted
  Quartz.CGRequestScreenCaptureAccess()            # shows the system prompt
  

  If it is off, the user grants it in System Settings ▸ Privacy & Security ▸ Screen Recording and restarts that app (a fresh grant needs a relaunch). This is a security setting — you cannot toggle it for them.

Usage

python "$SKILL_DIR/scripts/capture_demo.py" \
    --project /path/to/<Name>/Project/<Name>.4DProject \
    --method  PLAY_<Name> \
    --out     /path/to/<Name>/Documentation/<name>.gif \
    [--click "Label@1.2" ...] [--duration 4] [--fps 18] [--width 520] [--colors 128]

--method is the startup method that opens the form window (for these demos, PLAY_<Name>, which the base's On Startup normally calls).

No click — it animates on load

python "$SKILL_DIR/scripts/capture_demo.py" --project …/MatrixRain.4DProject \
    --method PLAY_MatrixRain --duration 4 --out MatrixRain/Documentation/matrixrain.gif

One click

python "$SKILL_DIR/scripts/capture_demo.py" --project …/Confetti.4DProject \
    --method PLAY_Confetti --click Celebrate --duration 4.5 \
    --out Confetti/Documentation/confetti.gif

Several clicks, staged (Label@seconds)

# three toasts stacking; then a segmented control's pill gliding across
--click "Success@0.5" --click "Info@1.2" --click "Error@1.9"
--click "Week@0.6" --click "Month@1.3" --click "Year@2.0" --click "Day@2.7"

A click target is a label looked up in the form (a button, or any object with that text — e.g. a segment's text label sitting over a transparent click button), or literal form-point coordinates x,y. Without an explicit @time, clicks are spaced by --click-gap starting at --click-delay.

Key options

Tips

• File size. Scenes with constant motion (rain, spinners) can't dedup static frames, so their GIFs are larger — trim with --colors 48 --fps 14 --width 440. Scenes that settle (a toast that stops, a list that lands) stay small on their own.
• Odd form path. If the demo form is not Forms/Demo/form.4DForm, pass --form (e.g. MatrixRain's is Forms/Rain/form.4DForm).
• Focus race. The script brings 4D to the front before clicking; if a GIF ever comes out with no effect (the click was swallowed by window focus), just re-run.
• Verify. Read a few frames back to confirm motion before shipping: Image.open(gif); g.seek(i); g.convert("RGB").