feat: stage explorer part 3

[fdrgsp]

Third part of the stage explore widget (#400 ) after #420.

Here we add a stage marker to track the position of the microscope stage.

TODO:

• add tests

[codecov]

Codecov Report

Attention: Patch coverage is 87.93103% with 21 lines in your changes missing coverage. Please review.

Project coverage is 90.52%. Comparing base (9a7248f) to head (923b0eb).
Report is 16 commits behind head on main.

Files with missing lines	Patch %	Lines
...widgets/control/_stage_explorer/_stage_explorer.py	86.27%	21 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #422      +/-   ##
==========================================
- Coverage   90.59%   90.52%   -0.08%     
==========================================
  Files          88       89       +1     
  Lines        9644     9791     +147     
==========================================
+ Hits         8737     8863     +126     
- Misses        907      928      +21     

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[tlambert03]

just keeps getting better!

the position outline is awesome. I tried to make it "hard" by decreasing the velocity of the demo cam and it works great. But found a small inconsistency: when you double click on a position, it does not poll as it moves, but when you click the stage widget it does. This probably indicates something deeper about how we deal with threading in the two scenarios (and may harken back to #410 ... and indicate that we need more conveniences around slow stage moves), but see what happens here:

Untitled.mov

also, definitely related to #410: if you have snap-on-click selected you no longer see the stage move

[tlambert03]

another feature request that might as well go in here: I can imagine wanting the position indicator to have 4 possible states:

1. no outline/indicator at all
2. outline corresponding to field of view (as done here)
3. crosshair only marking the stage position (but no outline)
4. a combination of 2 and 3: crosshairs as well as outline

[tlambert03]

I'm thinking that this widget might eventually gain so many configurations, that might be worth having a whole ExplorerConfig class:

class ExplorerConfig:
    auto_zoom_to_fit: bool = False
    snap_on_double_click: bool = False
    show_position: Literal[None, 'outline', 'crosshairs', 'crosshairs-with-outline']
    clims: tuple | None
    colormap

(but just thinking out loud... not entirely sure yet)

[fdrgsp]

This probably indicates something deeper about how we deal with threading...

Yes, exactly...is related to #410 and is because we need to call self._mmc.waitForDevice(self._mmc.getXYStageDevice()) here before taking an image. Otherwise, the image will be snapped as soon as we double-click, not at the position we double-click on.

Screen.Recording.2025-05-03.at.8.52.50.PM.mov

[fdrgsp]

another feature request that might as well go in here: I can imagine wanting the position indicator to have 4 possible states...

That’s a great idea! I attempted to implement something along those lines:

Screen.Recording.2025-05-04.at.12.52.47.AM.mov

And I agree, it would be good to have an ExplorerConfig once we understand all the options that the widget can have!

[tlambert03]

this is just lovely. :) i pushed a few small organizational updates in dc07ae3. will keep looking

[tlambert03]

ok, i just merged it in. we can undo 58ebde9 (or parts of it) if you find issues with it.

[tlambert03]

i also got rid of _is_stage_marker_out_of_view ... I'm not sure it's necessary? same goes for _is_visual_within_view ... are you attempting to avoid costly performance stuff?

[tlambert03]

...and, if you're happy with it, go ahead and merge (not worried about the last little bit of test coverage)