spacr.qt.dnd_handlers

Per-module drop handlers.

Each pipeline app has different expectations for what a “source” means. This module encodes those policies as DropHandler subclasses that the AppScreen wires up at construction time.

Handler map (also read by get_handler):

App

Accepts

mask measure external_masks annotate classify make_masks map_barcodes umap ml_analyze regression recruitment activation analyze_plaques train_cellpose cellpose_masks cellpose_all other modules

folder w/ images (auto-parses regex + preview) folder named merged OR one containing merged/ mixed image/label files or folders; assignment table folder with measurements/measurements.db folder with data/ or measurements/ folder with images + optional masks/ folder with FASTQ; also a raw .fastq.gz drop folder with measurements/measurements.db ditto ditto + scores.csv folder with per-well recruitment CSVs folder with saved activation maps or the CV model dir folder with plaque images folder with image+mask pairs folder with images ditto an existing source folder or supported data file

Every handler falls back to CSV settings-import via spacr.qt.dnd so users can also drop a settings CSV on any screen to load it.

Attributes

LOG
NO_DROP_TARGET

Classes

AlignDropHandler	Use a dropped image folder (or one tile) as Align & Stitch input.
AnnotateDropHandler	Accept a plate folder with measurements/measurements.db or
BatchDropHandler	Load queue files or add dropped settings snapshots as jobs.
ClassifyDropHandler	Accept a plate folder with measurements/measurements.db or
CoefficientsDropHandler	Prediction Profiler: the regression coefficients under results/.
ConvertDropHandler	Use a dropped microscopy container or folder as converter input.
DataManagerDropHandler	Data Manager: set the project, then measure it.
DatabaseDropHandler	Open a dropped measurements database in the Database Browser.
EvaluationBundleDropHandler	Classifier Evaluation: the run folder holding the evaluation bundle.
ExternalMasksDropHandler	Append mixed intensity images and external label masks to the mapper.
ForeignProjectDropHandler	Populate Import Project from image folders, tables and mapping files.
ImageFieldsDropHandler	Image-folder input shared by Model Compare.
LabelMaskDropHandler	Curate and Napari Bridge: one label mask, from wherever you drop.
LayerStackDropHandler	Layer Viewer: the dropped array, added as an image or as labels.
LayoutDropHandler	Drop policy for a screen that names what it wants, not where it is.
LineageDropHandler	Lineage: a database path field and one load.
MakeMasksDropHandler	Accept a folder with images (or image+mask pairs).
MapBarcodesDropHandler	Accept a FASTQ file (.fastq/.fastq.gz) or a folder
MaskDropHandler	Accept a folder of raw microscopy images and preview its filename
MeasureDropHandler	Accept the merged folder produced by the mask module, or a
MeasurementsDropHandler	Accept a database, its measurements folder, or its plate folder.
MethodsSourcesDropHandler	Methods & Results: fill whichever of its four source fields fits.
ModelZooDropHandler	Scan checkpoints, or use image-only folders as benchmark fields.
PlateQueueDropHandler	Queue plate folders that carry spaCR settings snapshots.
ProjectFolderDropHandler	A screen that takes a whole project, wherever inside it you drop.
ProjectRootsDropHandler	Project Browser: several folders at once, each becoming a root.
ReportDropHandler	Accept a completed spaCR run folder and scan its report inputs.
ResultsDatabaseDropHandler	Database input for Plate Viewer and Annotator Agreement.
ResultsFolderDropHandler	Hit List: the results/ folder a regression wrote.
RunHistoryDropHandler	Run History: select the run a dropped run folder belongs to.
ScatterTableDropHandler	Image Scatter: a path field, a table picker, then the read.
SourceDropHandler	General source-path policy for modules without a narrower contract.
SubmissionSettingsDropHandler	Distributed Jobs: a settings snapshot to submit, or the plate with one.
TableDropHandler	A screen that reads one table: the explorers, the plotters, the gates.
TrainingRunsDropHandler	Accept a directory and asynchronously scan it for training runs.

Functions

active_scan_jobs(→ int)	How many folder-scan threads screen still owns.
get_handler(→ spacr.qt.dnd.DropHandler)	Return a fresh DropHandler for app_key.
scan_folder_structure(→ Dict[str, Any])	Walk a dropped folder ONCE and return the folder-metadata report.
scan_is_busy(→ bool)	True while a dropped folder is still being walked for screen.
scan_mask_folder(→ Dict[str, Any])	List the top level of a dropped folder once. Worker-safe.
table_names(→ List[str])	Return the tables in a SQLite file, or [] for anything else.

Module Contents

class spacr.qt.dnd_handlers.AlignDropHandler

Bases: spacr.qt.dnd.DropHandler

Use a dropped image folder (or one tile) as Align & Stitch input.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.AnnotateDropHandler

Bases: spacr.qt.dnd.DropHandler

Accept a plate folder with measurements/measurements.db or the .db file itself.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.BatchDropHandler

Bases: spacr.qt.dnd.DropHandler

Load queue files or add dropped settings snapshots as jobs.

accepts_multiple() → bool

Return True to be called per-folder on multi-item drops.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.ClassifyDropHandler

Bases: spacr.qt.dnd.DropHandler

Accept a plate folder with measurements/measurements.db or a folder produced by the annotate step.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.CoefficientsDropHandler(app_key: str = '')

Bases: LayoutDropHandler

Prediction Profiler: the regression coefficients under results/.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

kinds

suffixes = ('.csv',)

class spacr.qt.dnd_handlers.ConvertDropHandler

Bases: spacr.qt.dnd.DropHandler

Use a dropped microscopy container or folder as converter input.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.DataManagerDropHandler(app_key: str = '')

Bases: ProjectFolderDropHandler

Data Manager: set the project, then measure it.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

class spacr.qt.dnd_handlers.DatabaseDropHandler

Bases: spacr.qt.dnd.DropHandler

Open a dropped measurements database in the Database Browser.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.EvaluationBundleDropHandler(app_key: str = '')

Bases: LayoutDropHandler

Classifier Evaluation: the run folder holding the evaluation bundle.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

form = 'root'

kinds

suffixes = ('.json', '.csv')

class spacr.qt.dnd_handlers.ExternalMasksDropHandler

Bases: spacr.qt.dnd.DropHandler

Append mixed intensity images and external label masks to the mapper.

accepts_multiple() → bool

Return True to be called per-folder on multi-item drops.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.ForeignProjectDropHandler

Bases: spacr.qt.dnd.DropHandler

Populate Import Project from image folders, tables and mapping files.

accepts_multiple() → bool

Return True to be called per-folder on multi-item drops.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.ImageFieldsDropHandler

Bases: spacr.qt.dnd.DropHandler

Image-folder input shared by Model Compare.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.LabelMaskDropHandler(app_key: str = '')

Bases: LayoutDropHandler

Curate and Napari Bridge: one label mask, from wherever you drop.

Dropping the project resolves masks/; a folder of masks is not one mask, so the file is asked for rather than guessed at.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

kinds

suffixes = ('.tif', '.tiff', '.png', '.npy')

class spacr.qt.dnd_handlers.LayerStackDropHandler(app_key: str = '')

Bases: LabelMaskDropHandler

Layer Viewer: the dropped array, added as an image or as labels.

A viewer stacks layers, so a multi-drop of an image and its mask lands as two layers rather than as the first one.

accepts_multiple() → bool

Return True to be called per-folder on multi-item drops.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

suffixes = ('.tif', '.tiff', '.png', '.jpg', '.jpeg', '.npy', '.npz')

class spacr.qt.dnd_handlers.LayoutDropHandler(app_key: str = '')

Bases: spacr.qt.dnd.DropHandler

Drop policy for a screen that names what it wants, not where it is.

A subclass says two things: the vocabulary terms it consumes (kinds, from spacr.ports.ALL_KINDS) and what to do with the answer (deliver()). Everything between — climbing from the dropped path to the project root, asking the registry, falling back to the declared layout, noticing that the answer is ambiguous — is spacr.chaining.resolve_drop().

Ambiguity is routed through the machinery spacr.qt.dnd already has: an ambiguous drop reports can_accept() is False and returns the candidates from suggest_alternatives(), so the user gets the “did you mean…” chooser and apply() is called again with their answer. A drop that resolves to nothing reports spacr.chaining.DropResolution.reason, which is spacr.ports.check_ready()’s own sentence about what is missing.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

abstract deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

resolve(path: pathlib.Path)

Return the spacr.chaining.DropResolution for path.

suggest_alternatives(path: pathlib.Path) → List[pathlib.Path]

When can_accept returns False, return sibling/child folders that WOULD be accepted so the UI can prompt “did you mean…”.

Default: no suggestions.

app_key = 'LayoutDropHandler'

form: str = 'path'

kinds: tuple = ()

label: str = ''

suffixes: tuple = ()

class spacr.qt.dnd_handlers.LineageDropHandler(app_key: str = '')

Bases: TableDropHandler

Lineage: a database path field and one load.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

class spacr.qt.dnd_handlers.MakeMasksDropHandler

Bases: spacr.qt.dnd.DropHandler

Accept a folder with images (or image+mask pairs).

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

suggest_alternatives(path: pathlib.Path) → List[pathlib.Path]

When can_accept returns False, return sibling/child folders that WOULD be accepted so the UI can prompt “did you mean…”.

Default: no suggestions.

class spacr.qt.dnd_handlers.MapBarcodesDropHandler

Bases: spacr.qt.dnd.DropHandler

Accept a FASTQ file (.fastq/.fastq.gz) or a folder containing one.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.MaskDropHandler

Bases: spacr.qt.dnd.DropHandler

Accept a folder of raw microscopy images and preview its filename regex parse. Multi-drop is supported.

accepts_multiple() → bool

Return True to be called per-folder on multi-item drops.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

suggest_alternatives(path: pathlib.Path) → List[pathlib.Path]

When can_accept returns False, return sibling/child folders that WOULD be accepted so the UI can prompt “did you mean…”.

Default: no suggestions.

class spacr.qt.dnd_handlers.MeasureDropHandler

Bases: spacr.qt.dnd.DropHandler

Accept the merged folder produced by the mask module, or a parent folder that contains one.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

suggest_alternatives(path: pathlib.Path) → List[pathlib.Path]

When can_accept returns False, return sibling/child folders that WOULD be accepted so the UI can prompt “did you mean…”.

Default: no suggestions.

class spacr.qt.dnd_handlers.MeasurementsDropHandler

Bases: spacr.qt.dnd.DropHandler

Accept a database, its measurements folder, or its plate folder.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.MethodsSourcesDropHandler(app_key: str = '')

Bases: LayoutDropHandler

Methods & Results: fill whichever of its four source fields fits.

accepts_multiple() → bool

Return True to be called per-folder on multi-item drops.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

form = 'root'

class spacr.qt.dnd_handlers.ModelZooDropHandler

Bases: spacr.qt.dnd.DropHandler

Scan checkpoints, or use image-only folders as benchmark fields.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.PlateQueueDropHandler

Bases: spacr.qt.dnd.DropHandler

Queue plate folders that carry spaCR settings snapshots.

accepts_multiple() → bool

Return True to be called per-folder on multi-item drops.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.ProjectFolderDropHandler(app_key: str = '')

Bases: LayoutDropHandler

A screen that takes a whole project, wherever inside it you drop.

kinds is empty on purpose: there is no port for “the project”, and inventing one would put it in the module graph. The layout walk still happens — dropping <plate>/measurements/measurements.db on the pipeline graph opens <plate>.

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

form = 'root'

setters: tuple = ('load_project', 'set_project', 'set_source', 'add_root', 'set_src')

class spacr.qt.dnd_handlers.ProjectRootsDropHandler(app_key: str = '')

Bases: ProjectFolderDropHandler

Project Browser: several folders at once, each becoming a root.

accepts_multiple() → bool

Return True to be called per-folder on multi-item drops.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

setters = ('add_root',)

class spacr.qt.dnd_handlers.ReportDropHandler

Bases: spacr.qt.dnd.DropHandler

Accept a completed spaCR run folder and scan its report inputs.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.ResultsDatabaseDropHandler

Bases: DatabaseDropHandler

Database input for Plate Viewer and Annotator Agreement.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

class spacr.qt.dnd_handlers.ResultsFolderDropHandler(app_key: str = '')

Bases: LayoutDropHandler

Hit List: the results/ folder a regression wrote.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

kinds

suffixes = ()

class spacr.qt.dnd_handlers.RunHistoryDropHandler(app_key: str = '')

Bases: ProjectFolderDropHandler

Run History: select the run a dropped run folder belongs to.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

setters = ('select_run',)

class spacr.qt.dnd_handlers.ScatterTableDropHandler(app_key: str = '')

Bases: TableDropHandler

Image Scatter: a path field, a table picker, then the read.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

class spacr.qt.dnd_handlers.SourceDropHandler

Bases: spacr.qt.dnd.DropHandler

General source-path policy for modules without a narrower contract.

Every standard AppScreen has a src field. Accepting a real directory here gives newer and less-specialised modules drag-and-drop support automatically instead of requiring a registry edit for every screen. A dropped file is only accepted for known data extensions and is normalised to its containing directory.

Where the module declares ports, the value comes from spacr.chaining.resolve_drop() — the same answer auto-chaining would fill the field with — so dropping <plate>/measurements and letting the chain fill src cannot produce two different strings. A module with no declaration keeps the plain normalisation below, which is all there is to go on.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

class spacr.qt.dnd_handlers.SubmissionSettingsDropHandler(app_key: str = '')

Bases: LayoutDropHandler

Distributed Jobs: a settings snapshot to submit, or the plate with one.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

suffixes = ('.csv', '.json', '.yaml', '.yml')

class spacr.qt.dnd_handlers.TableDropHandler(app_key: str = '')

Bases: LayoutDropHandler

A screen that reads one table: the explorers, the plotters, the gates.

Drop the project and it finds measurements/measurements.db; drop the database and it uses it; drop a CSV and it reads that. When the database holds more than one table the table is asked rather than taken — load_path picks the first one silently, which is fine for a file dialog where the user chose the file and wrong for a drop where they chose a folder.

deliver(screen, value: str, target) → None

Put value into the screen. Runs on the GUI thread.

Parameters:

• screen – the screen the drop landed on.

• value – the resolved path.

• target – the spacr.chaining.DropTarget it came from, or None for a file the user dropped directly.

form = 'path'

kinds

suffixes = ('.db', '.sqlite', '.sqlite3', '.csv', '.tsv', '.parquet', '.txt')

class spacr.qt.dnd_handlers.TrainingRunsDropHandler

Bases: spacr.qt.dnd.DropHandler

Accept a directory and asynchronously scan it for training runs.

apply(path: pathlib.Path, screen) → None

Wire path into screen (set src, populate settings, etc.).

can_accept(path: pathlib.Path) → bool

Return True if path (folder OR file) is usable as-is.

error_message(path: pathlib.Path) → str

Human-friendly explanation for why path can’t be used.

spacr.qt.dnd_handlers.active_scan_jobs(screen) → int

How many folder-scan threads screen still owns.

spacr.qt.dnd_handlers.get_handler(app_key: str) → spacr.qt.dnd.DropHandler

Return a fresh DropHandler for app_key.

Falls back to SourceDropHandler so every conventional AppScreen can at least receive its source folder.

spacr.qt.dnd_handlers.scan_folder_structure(path) → Dict[str, Any]

Walk a dropped folder ONCE and return the folder-metadata report.

Worker-safe: plain data in, plain data out, nothing Qt. The single walk is the point. This replaced three walks of the same tree — detect_folder_metadata did one, plan_folder_extraction did another and called detect_folder_metadata again for a third — all on the GUI thread, all inside the drop event.

The probe is pulled off the same lazy generator the planner then drains, so a folder whose layout is not recognisable costs 30 files, not a traversal.

Returns:

{"labels": (...), "rows": [...], "error": ""}. Empty labels means no folder layout was recognised and there is nothing to report.

spacr.qt.dnd_handlers.scan_is_busy(screen) → bool

True while a dropped folder is still being walked for screen.

spacr.qt.dnd_handlers.scan_mask_folder(path, sample: int = 20) → Dict[str, Any]

List the top level of a dropped folder once. Worker-safe.

Returns the filenames the regex preview samples plus the total image count the report quotes. Both used to come from two separate listings of the same directory, taken on the GUI thread.

spacr.qt.dnd_handlers.table_names(path: pathlib.Path) → List[str]

Return the tables in a SQLite file, or [] for anything else.

One sqlite_master query; the table screens make the same one when they load. Kept here so the drop can ask which table rather than let load_path take the first one silently.

Opened read-only, and through a quoted URI: a folder with a ? or a # in its name would otherwise have everything after it read as query parameters, and the open would fail on a database that is perfectly fine.

spacr.qt.dnd_handlers.LOG

spacr.qt.dnd_handlers.NO_DROP_TARGET: Dict[str, str]