Gbp-Dch: ignore

The Description assumed that all packages that depend on gi-docgen will
vendor a copy, but libportal does not (which will have a higher regression
risk until gi-docgen is stable).

Update to upstream version '2021.8+ds1'
with Debian dir 2c5100f52f2a1a691096e584987a38b1a37a3cc3

We now have "descendants" and "implementations" sections in the class
and interface indices, respectively.

Classes implement interfaces.

Resolve class descendants and interface implementations

Closes #104 and #105

See merge request GNOME/gi-docgen!113

We show the list of direct descendants, collapsed by default as it could
be arbitrarily long.

Fixes: #105

Store the direct descendants of each class when resolving the namespace,
so we can display them later.

The annotations are incomplete, so running mypy shouldn't really be a
blocker.

The interface page should list the implementations available in a class.

The list can be arbitrarily long, so let's collapse the section by
default.

Fixes: #104

We want to know the classes that implement an interface within the
current namespace.

gir: Identify type/gpointer types

Closes #110

See merge request GNOME/gi-docgen!112

When using out/in-out arguments in signals, the C type assigned is
derived from G_TYPE_POINTER (so: gpointer), but the type name is
typically overridden via a (type) annotation. This produces type
definitions like:

    <type name="gint" c:type="gpointer"/>

Since the C type is gpointer, we use the type name when looking up the
ast.Type in the GIR parser, and that usually ends up giving use a type
for the integral type, instead of a proper pointer type.

To avoid that, we check if the type definition takes a generic pointer
as the C type, and the type name is an integral type, and tweak the
query parameters for the types LUT.

Fixes: #110

generate: Parse attribute for property defaults

See merge request GNOME/gi-docgen!111

We already provide the symbol name with `()`.

Restrict the function escape regular expression

See merge request GNOME/gi-docgen!110

Introspection data does not have a default value for properties, so we
should allow library authors to define the default through an attribute.

We only want to match function names followed by `()`, but there are too
many cases in which we end up messing it up.

generate: Fix the threshold for inherited methods

See merge request GNOME/gi-docgen!109

The threshold on the methods still applies, but now we're going to show
the name and summary for all inherited methods, properties, and signals
even across namespaces.

We should not add methods until we hit the threshold: we should check
the number of (visible) methods in ancestors and interfaces, and then
decide whether or not to add the methods.

gir: Parse new property attributes

See merge request GNOME/gi-docgen!108

Starting from gobject-introspection 1.70, the GIR data now contains
annotations that replace the special gi-docgen attributes when it comes
to linking properties and their accessors.

These new attributes are validated by the introspection generator, so we
can simplify the code that generates the links.

Starting from gobject-introspection 1.70, the introspection data now
contains new attributes for the method elements:

 - glib:set-property="name"
 - glib:get-property="name"

Starting from gobject-introspection 1.70, we're going to get new
introspection annotations for property elements, namely:

 - setter="method_name"
 - getter="method_name"

We need to parse them and apply them to the ast.Property class.

Fixes for deep type resolution

Closes #107

See merge request GNOME/gi-docgen!107

When finding a type for a cross-link, we need to pass all components,
including the namespace; otherwise, the type lookup will just find the
first type matching the name in the various dependencies, generating
collisions or weird results.

Fixes: #107

Types like "gint", "gboolean", or "gdouble" should be marked as such, so
we can detect them when traversing the AST.

Makes it easier to visually distinguish functions from types.

generate: Use the C type name for callback types

See merge request GNOME/gi-docgen!106

Use the C type in the results.

Global callbacks are types, and they should have a C type in the index.

We use the identifier for function pointer fields inside structures, but
for callbacks that have a C type, we should use the type name instead.