docs: Move the GType SECTION

Move the contents to the new types.md files.

Helps: #3037

docs/reference/gobject/gobject.toml.in

@@ -44,6 +44,7 @@ urlmap_file = "urlmap.js"
 content_files = [
   "concepts.md",
   "tutorial.md",
+  "types.md",
   "floating-refs.md",
   "boxed.md",
   "enum-types.md",

docs/reference/gobject/meson.build

@@ -72,6 +72,7 @@ expand_content_files = [
   'floating-refs.md',
   'gvalue.md',
   'tutorial.md',
+  'types.md',
 ]
 
 gobject_gir = meson.current_source_dir() / 'GObject-2.0.gir'

docs/reference/gobject/types.md

@@ -0,0 +1,64 @@
+Title: Types
+SPDX-License-Identifier: LGPL-2.1-or-later
+SPDX-FileCopyrightText: 2001, 2003 Owen Taylor
+SPDX-FileCopyrightText: 2002, 2003, 2004, 2005 Matthias Clasen
+SPDX-FileCopyrightText: 2003, 2006 Josh Parsons
+SPDX-FileCopyrightText: 2005 Stefan Kost
+SPDX-FileCopyrightText: 2015 Collabora, Ltd.
+SPDX-FileCopyrightText: 2021 Emmanuele Bassi
+SPDX-FileCopyrightText: 2023 Endless OS Foundation, LLC
+
+# Types
+
+The GType API is the foundation of the GObject system. It provides the
+facilities for registering and managing all fundamental data types,
+user-defined object and interface types.
+
+For type creation and registration purposes, all types fall into one of
+two categories: static or dynamic. Static types are never loaded or
+unloaded at run-time as dynamic types may be.  Static types are created
+with [func@GObject.type_register_static] that gets type specific
+information passed in via a `GTypeInfo` structure.
+
+Dynamic types are created with [func@GObject.type_register_dynamic],
+which takes a `GTypePlugin` structure instead. The remaining type information
+(the `GTypeInfo` structure) is retrieved during runtime through `GTypePlugin`
+and the `g_type_plugin_*()` API.
+
+These registration functions are usually called only once from a
+function whose only purpose is to return the type identifier for a
+specific class. Once the type (or class or interface) is registered,
+it may be instantiated, inherited, or implemented depending on exactly
+what sort of type it is.
+
+There is also a third registration function for registering fundamental
+types called [func@GObject.type_register_fundamental], which requires
+both a `GTypeInfo` structure and a `GTypeFundamentalInfo` structure, but it
+is rarely used since most fundamental types are predefined rather than user-defined.
+
+Type instance and class structs are limited to a total of 64 KiB,
+including all parent types. Similarly, type instances' private data
+(as created by `G_ADD_PRIVATE()`) are limited to a total of
+64 KiB. If a type instance needs a large static buffer, allocate it
+separately (typically by using [`struct@GLib.Array`] or [`struct@GLib.PtrArray`])
+and put a pointer to the buffer in the structure.
+
+As mentioned in the [GType conventions](concepts.html#conventions), type names must
+be at least three characters long. There is no upper length limit. The first
+character must be a letter (a–z or A–Z) or an underscore (‘\_’). Subsequent
+characters can be letters, numbers or any of ‘-\_+’.
+
+# Runtime Debugging
+
+When `G_ENABLE_DEBUG` is defined during compilation, the GObject library
+supports an environment variable `GOBJECT_DEBUG` that can be set to a
+combination of flags to trigger debugging messages about
+object bookkeeping and signal emissions during runtime.
+
+The currently supported flags are:
+
+ - `objects`: Tracks all `GObject` instances in a global hash table called
+   `debug_objects_ht`, and prints the still-alive objects on exit.
+ - `instance-count`: Tracks the number of instances of every `GType` and makes
+   it available via the [func@GObject.type_get_instance_count] function.
+ - `signals`: Currently unused.