UI stops updating (selection / preview / 2nd face) — root causes found, fixes tested and working

[moomoolien-ops]

Hi! First off — thanks for maintaining this add-in, it's a lifesaver for CNC work.

Full disclosure: I'm a game designer, not a programmer. I ran into several UI-update bugs while using the add-in, and debugged/fixed them through AI-assisted coding (Claude), verifying each fix in Fusion on a real model. Sharing the findings here in case they're useful — happy to open a PR if there's interest.

## Symptoms I hit (master, 2026-07)

1. **Face selection doesn't register on click** — I had to toggle a checkbox (detection/preview) before clicks started working.
2. **Preview randomly freezes** — sometimes it updates, sometimes only toggling the Preview checkbox brings it back.
3. **Selecting a 2nd face does nothing** — edge count doesn't increase, no preview for the added face.

## Root causes found

1. **Normal clicks are gated off by the ctrl-click mechanism.** With Preview enabled (the default), `onFaceSelect` blocks plain-click selection entirely (`previewActive and previewEnabled` gate in `DogboneUi.py`). That's why selection only "wakes up" after toggling checkboxes.

2. **Any keypress kills the preview.** `onKeyUp` sets `previewActive = False` for *every* non-Ctrl key release — so just typing a tool diameter freezes preview updates until the Preview checkbox is toggled (the only code path that resets the flag). This makes bug 2 look random, but it's deterministic: it happens right after you use the keyboard.

3. **All of this fails silently** because every event handler exception is swallowed by the blanket `try/except` in `lib/utils/decorators.py`, and the default log level is `Notset`. Once I made the handler log tracebacks, the remaining bug became obvious:

4. **The preview recompute invalidates cached `BRepFace` proxies, and nothing revalidates them.** After `onExecutePreview` builds the dogbone bodies, the model recomputes and the stored `BRepFace` references for already-selected faces go stale. Hovering/selecting a 2nd face then throws
   `RuntimeError: 2 : InternalValidationError : face` (257 times in a single session log!) in `onFaceSelect`, and a `KeyError` in `onInputChanged` — so the 2nd face never gets registered. Interestingly, `DbFace.revalidate()` already exists in the codebase but is never called from anywhere.

   (Bonus, unrelated: `commands/refreshMfgCommand/main.py` references an undefined `g._design`, so the Manufacturing "Dogbone Refresh" command crashes 100% — also invisible due to #3.)

## What I changed (all verified in Fusion)

- Removed the ctrl-click / `previewActive` key-tracking mechanism (plain click now selects; tooltips updated to match)
- Made `DbFace.face` a self-healing property: revalidates the proxy from the stored point when it goes stale (finally putting `revalidate()` to work)
- Hardened the FACE_SELECT add/remove logic in `onInputChanged` (None guard, directional set difference instead of symmetric difference)
- Fixed an attribute-order bug in `DbFace`/`DbEdge.__init__` (attributes referenced before assignment on the re-select path)
- Handler exceptions still don't propagate, but they now always log the full traceback

After these changes: click-to-select works immediately, preview survives keyboard input and slider drags, and adding a 2nd/3rd face detects edges and updates the preview as expected.

The fixes live here (7 commits, 3 files, +134/−54):
- Branch: https://github.com/moomoolien-ops/Dogbone/tree/fix/ui-update-bugs
- Full diff vs master: https://github.com/DVE2000/Dogbone/compare/master...moomoolien-ops:Dogbone:fix/ui-update-bugs

Again — vibe-coded fixes by a non-programmer, so please treat the diff with healthy suspicion. But every symptom above was reproducible before and gone after, verified on a real CAM model. Happy to open a PR or provide the session logs if useful.

[pludikar]

Hi, Many thanks, I guess I caused confusion more than anything else when I tried to be clever 🙁, but at the same time I did try to make it easier from a programming perspective. One of the main motivations behind the ctrl-click is that selecting and deselecting an edge, for example, can only be done simply when preview mode is deactivated, at least after the 1st face is selected. The preview mode effectively creates a whole new set of edge and face Ids, which then make it difficult to correlate the faces/edges the addin has registered, but if you and Claude have solved that, then I'm a happy man 🙂. F360 allows you to select features by clicking on them, but if you want to select a bunch of features you have to press ctrl in addition to click to add the extras. In my infinite wisdom I thought it would be simpler just to keep ctrl down whenever you select anything regardless of whether it was the first or anything more, but clearly my definition of "infinite" isn't greatd either. I did throw up a message to say "use ctrl-click to select", but if users aren't expecting it then it doesn't get seen. I guess that I made it inconsistent with the rest of how f360 behaves. I was contemplating reverting it, but it looks like you may have beaten me to it. So, yes I'd love to incorporate your changes, after I've tried it myself, but I'm reasonably confident, based on your breakdown, that it'll do what it is supposed to. A couple of years ago I accidently merged someone's changes before testing it and it ended up breaking the addon, and left the contributor frustrated and unhappy, because I had to unceremoniously rewind the repository, which put everything out of sync with his own work. I'll try not to do that again. I really do appreciate all contributions and help. Regards Peter

…

________________________________ From: moomoolien-ops ***@***.***> Sent: July 6, 2026 7:26 AM To: DVE2000/Dogbone ***@***.***> Cc: Subscribed ***@***.***> Subject: [DVE2000/Dogbone] UI stops updating (selection / preview / 2nd face) — root causes found, fixes tested and working (Issue #69) [https://avatars.githubusercontent.com/u/240120963?s=20&v=4]moomoolien-ops created an issue (DVE2000/Dogbone#69)<#69> Hi! First off — thanks for maintaining this add-in, it's a lifesaver for CNC work. Full disclosure: I'm a game designer, not a programmer. I ran into several UI-update bugs while using the add-in, and debugged/fixed them through AI-assisted coding (Claude), verifying each fix in Fusion on a real model. Sharing the findings here in case they're useful — happy to open a PR if there's interest. ## Symptoms I hit (master, 2026-07) 1. **Face selection doesn't register on click** — I had to toggle a checkbox (detection/preview) before clicks started working. 2. **Preview randomly freezes** — sometimes it updates, sometimes only toggling the Preview checkbox brings it back. 3. **Selecting a 2nd face does nothing** — edge count doesn't increase, no preview for the added face. ## Root causes found 1. **Normal clicks are gated off by the ctrl-click mechanism.** With Preview enabled (the default), `onFaceSelect` blocks plain-click selection entirely (`previewActive and previewEnabled` gate in `DogboneUi.py`). That's why selection only "wakes up" after toggling checkboxes. 2. **Any keypress kills the preview.** `onKeyUp` sets `previewActive = False` for *every* non-Ctrl key release — so just typing a tool diameter freezes preview updates until the Preview checkbox is toggled (the only code path that resets the flag). This makes bug 2 look random, but it's deterministic: it happens right after you use the keyboard. 3. **All of this fails silently** because every event handler exception is swallowed by the blanket `try/except` in `lib/utils/decorators.py`, and the default log level is `Notset`. Once I made the handler log tracebacks, the remaining bug became obvious: 4. **The preview recompute invalidates cached `BRepFace` proxies, and nothing revalidates them.** After `onExecutePreview` builds the dogbone bodies, the model recomputes and the stored `BRepFace` references for already-selected faces go stale. Hovering/selecting a 2nd face then throws `RuntimeError: 2 : InternalValidationError : face` (257 times in a single session log!) in `onFaceSelect`, and a `KeyError` in `onInputChanged` — so the 2nd face never gets registered. Interestingly, `DbFace.revalidate()` already exists in the codebase but is never called from anywhere. (Bonus, unrelated: `commands/refreshMfgCommand/main.py` references an undefined `g._design`, so the Manufacturing "Dogbone Refresh" command crashes 100% — also invisible due to #3.) ## What I changed (all verified in Fusion) - Removed the ctrl-click / `previewActive` key-tracking mechanism (plain click now selects; tooltips updated to match) - Made `DbFace.face` a self-healing property: revalidates the proxy from the stored point when it goes stale (finally putting `revalidate()` to work) - Hardened the FACE_SELECT add/remove logic in `onInputChanged` (None guard, directional set difference instead of symmetric difference) - Fixed an attribute-order bug in `DbFace`/`DbEdge.__init__` (attributes referenced before assignment on the re-select path) - Handler exceptions still don't propagate, but they now always log the full traceback After these changes: click-to-select works immediately, preview survives keyboard input and slider drags, and adding a 2nd/3rd face detects edges and updates the preview as expected. The fixes live here (7 commits, 3 files, +134/−54): - Branch: https://github.com/moomoolien-ops/Dogbone/tree/fix/ui-update-bugs - Full diff vs master: master...moomoolien-ops:Dogbone:fix/ui-update-bugs Again — vibe-coded fixes by a non-programmer, so please treat the diff with healthy suspicion. But every symptom above was reproducible before and gone after, verified on a real CAM model. Happy to open a PR or provide the session logs if useful. — Reply to this email directly, view it on GitHub<#69?email_source=notifications&email_token=ABBJGTGFPDVVGPDWTCTIZ735DOEGFA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBYGE4DMNBXG43DRJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ABBJGTD5D4NDEYFBNEIAEMT5DOEGFAVCNFSNUABEKJSXA33TNF2G64TZHMZTINBZGE2DQMR3JFZXG5LFHM2DQMJYGY2DONZWHCQXMAQ>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS<https://github.com/notifications/mobile/ios/ABBJGTCSXDK726TRUIN27D35DOEGFA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBYGE4DMNBXG43DRJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2KUZTPN52GK4S7NFXXG> and Android<https://github.com/notifications/mobile/android/ABBJGTDQWTBLNFOS56NW6BD5DOEGFA5CNFSL4Z3JMQ5C6L3HNF2C22DVMIXUS43TOVSS6NBYGE4DMNBXG43DRJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2K4ZTPN52GK4S7MFXGI4TPNFSA>. Download it today! You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[pludikar]

Hi again,

I have a model that allows me to test various face/edge selection scenarios here: https://a360.co/4vOUN0C

I've tried to make it as comprehensive as I could, and I suspect many scenarios may never be used, but it's better to be ready for it. I tested your version and unfortunately it's not very happy. I suspect it's because the preview mode breaks the corelation between the registered entities and the displayed ones.

If you try selecting different faces on the same component/body, you'll see that the preview breaks, as does the corelation between the edges and the faces. for example, if you unselect a face on a body/component that has multiple faces selected, then the edges associated with that face should also deselect, but unfortunately all edges on the body become deselected - this may be inconsistent, and appears to depend on whether the face has edges associated with it or not.

The dogbone edge selection in the dialog also becomes active after selecting a face - edge selection is something that you typically do on occasion, rather than all the time. You use it to deselect an edge if you have, say a mortice and you want to later apply a different type of dogbone. For > 90% of the cases you probably won't need to touch the dogbone edge selection box.

Anyway that just a quick check on your version. I would suggest, if you're willing, that you keep the bulk of the UI as it is, but what would be really useful is to allow the 1st face to be selected as you've done, but allow subsequent faces to be added using the ctrl-click approach - this would be consistent with the way F360 does it. The ctrl button, primarily deactivates the preview, exposing the original edges and faces to selection.

Happy to chat if you need or want to.

regards
Peter

[tponviji1005-oss]

Someone is already working on this.