Signed-off-by: Sam Maxwell <[email protected]>
Signed-off-by: Benjamin Gilbert <[email protected]>

Signed-off-by: Sam Maxwell <[email protected]>

Signed-off-by: Benjamin Gilbert <[email protected]>

Signed-off-by: Benjamin Gilbert <[email protected]>

AbstractSlide subclasses will always return their specific type from
this method.  Ensure the type system knows this.

Signed-off-by: Benjamin Gilbert <[email protected]>

bytes will not work in at least one case (the OpenSlide initializer), are
not documented to work, and the type annotations are currently
inconsistent about accepting it.  For now, forbid it everywhere for
consistency.

Signed-off-by: Benjamin Gilbert <[email protected]>

open_slide() can't return any possible AbstractSlide subclass, only the
two that it's documented to return.  Make that explicit in the type hint.

Signed-off-by: Benjamin Gilbert <[email protected]>

Avoid overcommitting to internal implementation details in the types being
returned.  It's sufficient to say that the property and associated image
maps implement Mapping.

Signed-off-by: Benjamin Gilbert <[email protected]>

We don't want to encourage library users to duck-type a replacement for
OpenSlideCache, since any replacement would inherently need to make
assumptions about our implementation details.

Signed-off-by: Benjamin Gilbert <[email protected]>

When an operation is performed on a closed ImageSlide, we've historically
raised an AttributeError upon dereferencing None.  Add proper checks so
the type system understands what we're doing, raising ValueError as
lowlevel does.  This is not an API change because it only affects invalid
caller behavior.

Signed-off-by: Benjamin Gilbert <[email protected]>

We don't need to avoid generator expressions to keep the type checker
happy; we can just assert that the resulting tuples have the correct
length.  This lets us avoid carrying redundant unrolled code.

Signed-off-by: Benjamin Gilbert <[email protected]>

level_dimensions is always a tuple of 2-tuples.  Prove this to the type
checker.

Signed-off-by: Benjamin Gilbert <[email protected]>

Keep the type checker happy by asserting the correct tuple lengths rather
than unrolling generator expressions.

Signed-off-by: Benjamin Gilbert <[email protected]>

__init__() methods don't need a return type hint unless they take no
arguments.

Signed-off-by: Benjamin Gilbert <[email protected]>

ImageSlide is hardcoded to a single level, and the level_count property
and get_best_level_for_downsample() return types already reflect this.
Reduce the level_dimensions() and level_downsamples() return types to
1-tuples.  In the latter case we can't reduce to a Literal because literal
floats are disallowed.

Signed-off-by: Benjamin Gilbert <[email protected]>