Package ch.bailu.gtk.glib

Class Variant

java.lang.Object
ch.bailu.gtk.type.Type
ch.bailu.gtk.type.Pointer
ch.bailu.gtk.type.Record
ch.bailu.gtk.glib.Variant
All Implemented Interfaces:
PointerInterface
public class Variant extends Record
#GVariant is a variant datatype; it can contain one or more values
along with information about the type of the values.

A #GVariant may contain simple types, like an integer, or a boolean value;
or complex types, like an array of two strings, or a dictionary of key
value pairs. A #GVariant is also immutable: once it's been created neither
its type nor its content can be modified further.

GVariant is useful whenever data needs to be serialized, for example when
sending method parameters in D-Bus, or when saving settings using GSettings.

When creating a new #GVariant, you pass the data you want to store in it
along with a string representing the type of data you wish to pass to it.

For instance, if you want to create a #GVariant holding an integer value you
can use: 
<!-- language="C" -->
   GVariant *v = g_variant_new ("u", 40);


The string "u" in the first argument tells #GVariant that the data passed to
the constructor (40) is going to be an unsigned integer.

More advanced examples of #GVariant in use can be found in documentation for
[GVariant format strings][gvariant-format-strings-pointers].

The range of possible values is determined by the type.

The type system used by #GVariant is #GVariantType.

#GVariant instances always have a type and a value (which are given
at construction time). The type and value of a #GVariant instance
can never change other than by the #GVariant itself being
destroyed. A #GVariant cannot contain a pointer.

#GVariant is reference counted using g_variant_ref() and
g_variant_unref(). #GVariant also has floating reference counts --
see g_variant_ref_sink().

#GVariant is completely threadsafe. A #GVariant instance can be
concurrently accessed in any way from any number of threads without
problems.

#GVariant is heavily optimised for dealing with data in serialized
form. It works particularly well with data located in memory-mapped
files. It can perform nearly all deserialization operations in a
small constant time, usually touching only a single memory page.
Serialized #GVariant data can also be sent over the network.

#GVariant is largely compatible with D-Bus. Almost all types of
#GVariant instances can be sent over D-Bus. See #GVariantType for
exceptions. (However, #GVariant's serialization format is not the same
as the serialization format of a D-Bus message body: use #GDBusMessage,
in the gio library, for those.)

For space-efficiency, the #GVariant serialization format does not
automatically include the variant's length, type or endianness,
which must either be implied from context (such as knowledge that a
particular file format always contains a little-endian
%G_VARIANT_TYPE_VARIANT which occupies the whole length of the file)
or supplied out-of-band (for instance, a length, type and/or endianness
indicator could be placed at the beginning of a file, network message
or network stream).

A #GVariant's size is limited mainly by any lower level operating
system constraints, such as the number of bits in #gsize. For
example, it is reasonable to have a 2GB file mapped into memory
with #GMappedFile, and call g_variant_new_from_data() on it.

For convenience to C programmers, #GVariant features powerful
varargs-based value construction and destruction. This feature is
designed to be embedded in other libraries.

There is a Python-inspired text language for describing #GVariant
values. #GVariant includes a printer for this language and a parser
with type inferencing.

## Memory Use

#GVariant tries to be quite efficient with respect to memory use.
This section gives a rough idea of how much memory is used by the
current implementation. The information here is subject to change
in the future.

The memory allocated by #GVariant can be grouped into 4 broad
purposes: memory for serialized data, memory for the type
information cache, buffer management memory and memory for the
#GVariant structure itself.

## Serialized Data Memory

This is the memory that is used for storing GVariant data in
serialized form. This is what would be sent over the network or
what would end up on disk, not counting any indicator of the
endianness, or of the length or type of the top-level variant.

The amount of memory required to store a boolean is 1 byte. 16,
32 and 64 bit integers and double precision floating point numbers
use their "natural" size. Strings (including object path and
signature strings) are stored with a nul terminator, and as such
use the length of the string plus 1 byte.

Maybe types use no space at all to represent the null value and
use the same amount of space (sometimes plus one byte) as the
equivalent non-maybe-typed value to represent the non-null case.

Arrays use the amount of space required to store each of their
members, concatenated. Additionally, if the items stored in an
array are not of a fixed-size (ie: strings, other arrays, etc)
then an additional framing offset is stored for each item. The
size of this offset is either 1, 2 or 4 bytes depending on the
overall size of the container. Additionally, extra padding bytes
are added as required for alignment of child values.

Tuples (including dictionary entries) use the amount of space
required to store each of their members, concatenated, plus one
framing offset (as per arrays) for each non-fixed-sized item in
the tuple, except for the last one. Additionally, extra padding
bytes are added as required for alignment of child values.

Variants use the same amount of space as the item inside of the
variant, plus 1 byte, plus the length of the type string for the
item inside the variant.

As an example, consider a dictionary mapping strings to variants.
In the case that the dictionary is empty, 0 bytes are required for
the serialization.

If we add an item "width" that maps to the int32 value of 500 then
we will use 4 byte to store the int32 (so 6 for the variant
containing it) and 6 bytes for the string. The variant must be
aligned to 8 after the 6 bytes of the string, so that's 2 extra
bytes. 6 (string) + 2 (padding) + 6 (variant) is 14 bytes used
for the dictionary entry. An additional 1 byte is added to the
array as a framing offset making a total of 15 bytes.

If we add another entry, "title" that maps to a nullable string
that happens to have a value of null, then we use 0 bytes for the
null value (and 3 bytes for the variant to contain it along with
its type string) plus 6 bytes for the string. Again, we need 2
padding bytes. That makes a total of 6 + 2 + 3 = 11 bytes.

We now require extra padding between the two items in the array.
After the 14 bytes of the first item, that's 2 bytes required.
We now require 2 framing offsets for an extra two
bytes. 14 + 2 + 11 + 2 = 29 bytes to encode the entire two-item
dictionary.

## Type Information Cache

For each GVariant type that currently exists in the program a type
information structure is kept in the type information cache. The
type information structure is required for rapid deserialization.

Continuing with the above example, if a #GVariant exists with the
type "a{sv}" then a type information struct will exist for
"a{sv}", "{sv}", "s", and "v". Multiple uses of the same type
will share the same type information. Additionally, all
single-digit types are stored in read-only static memory and do
not contribute to the writable memory footprint of a program using
#GVariant.

Aside from the type information structures stored in read-only
memory, there are two forms of type information. One is used for
container types where there is a single element type: arrays and
maybe types. The other is used for container types where there
are multiple element types: tuples and dictionary entries.

Array type info structures are 6 * sizeof (void *), plus the
memory required to store the type string itself. This means that
on 32-bit systems, the cache entry for "a{sv}" would require 30
bytes of memory (plus malloc overhead).

Tuple type info structures are 6 * sizeof (void *), plus 4 *
sizeof (void *) for each item in the tuple, plus the memory
required to store the type string itself. A 2-item tuple, for
example, would have a type information structure that consumed
writable memory in the size of 14 * sizeof (void *) (plus type
string) This means that on 32-bit systems, the cache entry for
"{sv}" would require 61 bytes of memory (plus malloc overhead).

This means that in total, for our "a{sv}" example, 91 bytes of
type information would be allocated.

The type information cache, additionally, uses a #GHashTable to
store and look up the cached items and stores a pointer to this
hash table in static storage. The hash table is freed when there
are zero items in the type cache.

Although these sizes may seem large it is important to remember
that a program will probably only have a very small number of
different types of values in it and that only one type information
structure is required for many different values of the same type.

## Buffer Management Memory

#GVariant uses an internal buffer management structure to deal
with the various different possible sources of serialized data
that it uses. The buffer is responsible for ensuring that the
correct call is made when the data is no longer in use by
#GVariant. This may involve a g_free() or a g_slice_free() or
even g_mapped_file_unref().

One buffer management structure is used for each chunk of
serialized data. The size of the buffer management structure
is 4 * (void *). On 32-bit systems, that's 16 bytes.

## GVariant structure

The size of a #GVariant structure is 6 * (void *). On 32-bit
systems, that's 24 bytes.

#GVariant structures only exist if they are explicitly created
with API calls. For example, if a #GVariant is constructed out of
serialized data for the example given above (with the dictionary)
then although there are 9 individual values that comprise the
entire dictionary (two keys, two values, two variants containing
the values, two dictionary entries, plus the dictionary itself),
only 1 #GVariant instance exists -- the one referring to the
dictionary.

If calls are made to start accessing the other values then
#GVariant instances will exist for those values only for as long
as they are in use (ie: until you call g_variant_unref()). The
type information is shared. The serialized data and the buffer
management structure for that serialized data is shared by the
child.

## Summary

To put the entire example together, for our dictionary mapping
strings to variants (with two entries, as given above), we are
using 91 bytes of memory for type information, 29 bytes of memory
for the serialized data, 16 bytes for buffer management and 24
bytes for the #GVariant instance, or a total of 160 bytes, plus
malloc overhead. If we were to use g_variant_get_child_value() to
access the two dictionary entries, we would use an additional 48
bytes. If we were to have other dictionaries of the same type, we
would use more memory for the serialized data and buffer
management for those dictionaries, but the type information would
be shared.

https://docs.gtk.org/glib/struct.Variant.html

  • Constructor Details

    • Variant

      public Variant(PointerContainer pointer)

    • Variant

      public Variant(@Nonnull Str format_string, Object... _elipse)
      Creates a new #GVariant instance.

      Think of this function as an analogue to g_strdup_printf().

      The type of the created instance and the arguments that are expected
      by this function are determined by @format_string. See the section on
      [GVariant format strings][gvariant-format-strings]. Please note that
      the syntax of the format string is very likely to be extended in the
      future.

      The first character of the format string must not be '*' '?' '@' or
      'r'; in essence, a new #GVariant must always be constructed by this
      function (and not merely passed through it unmodified).

      Note that the arguments must be of the correct width for their types
      specified in @format_string. This can be achieved by casting them. See
      the [GVariant varargs documentation][gvariant-varargs]. 
      <!-- language="C" -->
 MyFlags some_flags = FLAG_ONE | FLAG_TWO;
 const gchar *some_strings[] = { "a", "b", "c", NULL };
 GVariant *new_variant;
 
 new_variant = g_variant_new ("(t^as)",
                              // This cast is required.
                              (guint64) some_flags,
                              some_strings);
      Parameters:
      format_string - a #GVariant format string
      _elipse - arguments, as per @format_string

    • Variant

      public Variant(String format_string, Object... _elipse)
      Creates a new #GVariant instance.

      Think of this function as an analogue to g_strdup_printf().

      The type of the created instance and the arguments that are expected
      by this function are determined by @format_string. See the section on
      [GVariant format strings][gvariant-format-strings]. Please note that
      the syntax of the format string is very likely to be extended in the
      future.

      The first character of the format string must not be '*' '?' '@' or
      'r'; in essence, a new #GVariant must always be constructed by this
      function (and not merely passed through it unmodified).

      Note that the arguments must be of the correct width for their types
      specified in @format_string. This can be achieved by casting them. See
      the [GVariant varargs documentation][gvariant-varargs]. 
      <!-- language="C" -->
 MyFlags some_flags = FLAG_ONE | FLAG_TWO;
 const gchar *some_strings[] = { "a", "b", "c", NULL };
 GVariant *new_variant;
 
 new_variant = g_variant_new ("(t^as)",
                              // This cast is required.
                              (guint64) some_flags,
                              some_strings);
      Parameters:
      format_string - a #GVariant format string
      _elipse - arguments, as per @format_string

  • Method Details

    • getClassHandler

      public static ClassHandler getClassHandler()

    • newBooleanVariant

      public static Variant newBooleanVariant(boolean value)
      Creates a new boolean #GVariant instance -- either %TRUE or %FALSE.
      Parameters:
      value - a #gboolean value
      Returns:
      a floating reference to a new boolean #GVariant instance

    • newByteVariant

      public static Variant newByteVariant(int value)
      Creates a new byte #GVariant instance.
      Parameters:
      value - a #guint8 value
      Returns:
      a floating reference to a new byte #GVariant instance

    • newBytestringVariant

      public static Variant newBytestringVariant(@Nonnull Str string)
      Creates an array-of-bytes #GVariant with the contents of @string.
      This function is just like g_variant_new_string() except that the
      string need not be valid UTF-8.

      The nul terminator character at the end of the string is stored in
      the array.
      Parameters:
      string - a normal nul-terminated string in no particular encoding
      Returns:
      a floating reference to a new bytestring #GVariant instance

    • newBytestringVariant

      public static Variant newBytestringVariant(String string)
      Creates an array-of-bytes #GVariant with the contents of @string.
      This function is just like g_variant_new_string() except that the
      string need not be valid UTF-8.

      The nul terminator character at the end of the string is stored in
      the array.
      Parameters:
      string - a normal nul-terminated string in no particular encoding
      Returns:
      a floating reference to a new bytestring #GVariant instance

    • newDictEntryVariant

      public static Variant newDictEntryVariant(@Nonnull Variant key, @Nonnull Variant value)
      Creates a new dictionary entry #GVariant. @key and @value must be
      non-%NULL. @key must be a value of a basic type (ie: not a container).

      If the @key or @value are floating references (see g_variant_ref_sink()),
      the new instance takes ownership of them as if via g_variant_ref_sink().
      Parameters:
      key - a basic #GVariant, the key
      value - a #GVariant, the value
      Returns:
      a floating reference to a new dictionary entry #GVariant

    • newDoubleVariant

      public static Variant newDoubleVariant(double value)
      Creates a new double #GVariant instance.
      Parameters:
      value - a #gdouble floating point value
      Returns:
      a floating reference to a new double #GVariant instance

    • newFixedArrayVariant

      public static Variant newFixedArrayVariant(@Nonnull VariantType element_type, @Nullable Pointer elements, long n_elements, long element_size)
      Constructs a new array #GVariant instance, where the elements are
      of @element_type type.

      @elements must be an array with fixed-sized elements. Numeric types are
      fixed-size as are tuples containing only other fixed-sized types.

      @element_size must be the size of a single element in the array.
      For example, if calling this function for an array of 32-bit integers,
      you might say sizeof(gint32). This value isn't used except for the purpose
      of a double-check that the form of the serialized data matches the caller's
      expectation.

      @n_elements must be the length of the @elements array.
      Parameters:
      element_type - the #GVariantType of each element
      elements - a pointer to the fixed array of contiguous elements
      n_elements - the number of elements
      element_size - the size of each element
      Returns:
      a floating reference to a new array #GVariant instance

    • newFromBytesVariant

      public static Variant newFromBytesVariant(@Nonnull VariantType type, @Nonnull Bytes bytes, boolean trusted)
      Constructs a new serialized-mode #GVariant instance. This is the
      inner interface for creation of new serialized values that gets
      called from various functions in gvariant.c.

      A reference is taken on @bytes.

      The data in @bytes must be aligned appropriately for the @type being loaded.
      Otherwise this function will internally create a copy of the memory (since
      GLib 2.60) or (in older versions) fail and exit the process.
      Parameters:
      type - a #GVariantType
      bytes - a #GBytes
      trusted - if the contents of @bytes are trusted
      Returns:
      a new #GVariant with a floating reference

    • newFromDataVariant

      public static Variant newFromDataVariant(@Nonnull VariantType type, @Nonnull Pointer data, long size, boolean trusted, Variant.OnDestroyNotify notify, @Nullable Pointer user_data)
      Creates a new #GVariant instance from serialized data.

      @type is the type of #GVariant instance that will be constructed.
      The interpretation of @data depends on knowing the type.

      @data is not modified by this function and must remain valid with an
      unchanging value until such a time as @notify is called with
      @user_data. If the contents of @data change before that time then
      the result is undefined.

      If @data is trusted to be serialized data in normal form then
      @trusted should be %TRUE. This applies to serialized data created
      within this process or read from a trusted location on the disk (such
      as a file installed in /usr/lib alongside your application). You
      should set trusted to %FALSE if @data is read from the network, a
      file in the user's home directory, etc.

      If @data was not stored in this machine's native endianness, any multi-byte
      numeric values in the returned variant will also be in non-native
      endianness. g_variant_byteswap() can be used to recover the original values.

      @notify will be called with @user_data when @data is no longer
      needed. The exact time of this call is unspecified and might even be
      before this function returns.

      Note: @data must be backed by memory that is aligned appropriately for the
      @type being loaded. Otherwise this function will internally create a copy of
      the memory (since GLib 2.60) or (in older versions) fail and exit the
      process.
      Parameters:
      type - a definite #GVariantType
      data - the serialized data
      size - the size of @data
      trusted - %TRUE if @data is definitely in normal form
      notify - function to call when @data is no longer needed
      user_data - data for @notify
      Returns:
      a new floating #GVariant of type @type

    • newHandleVariant

      public static Variant newHandleVariant(int value)
      Creates a new handle #GVariant instance.

      By convention, handles are indexes into an array of file descriptors
      that are sent alongside a D-Bus message. If you're not interacting
      with D-Bus, you probably don't need them.
      Parameters:
      value - a #gint32 value
      Returns:
      a floating reference to a new handle #GVariant instance

    • newInt16Variant

      public static Variant newInt16Variant(int value)
      Creates a new int16 #GVariant instance.
      Parameters:
      value - a #gint16 value
      Returns:
      a floating reference to a new int16 #GVariant instance

    • newInt32Variant

      public static Variant newInt32Variant(int value)
      Creates a new int32 #GVariant instance.
      Parameters:
      value - a #gint32 value
      Returns:
      a floating reference to a new int32 #GVariant instance

    • newInt64Variant

      public static Variant newInt64Variant(long value)
      Creates a new int64 #GVariant instance.
      Parameters:
      value - a #gint64 value
      Returns:
      a floating reference to a new int64 #GVariant instance

    • newMaybeVariant

      public static Variant newMaybeVariant(@Nullable VariantType child_type, @Nullable Variant child)
      Depending on if @child is %NULL, either wraps @child inside of a
      maybe container or creates a Nothing instance for the given @type.

      At least one of @child_type and @child must be non-%NULL.
      If @child_type is non-%NULL then it must be a definite type.
      If they are both non-%NULL then @child_type must be the type
      of @child.

      If @child is a floating reference (see g_variant_ref_sink()), the new
      instance takes ownership of @child.
      Parameters:
      child_type - the #GVariantType of the child, or %NULL
      child - the child value, or %NULL
      Returns:
      a floating reference to a new #GVariant maybe instance

    • newObjectPathVariant

      public static Variant newObjectPathVariant(@Nonnull Str object_path)
      Creates a D-Bus object path #GVariant with the contents of @string.
      @string must be a valid D-Bus object path. Use
      g_variant_is_object_path() if you're not sure.
      Parameters:
      object_path - a normal C nul-terminated string
      Returns:
      a floating reference to a new object path #GVariant instance

    • newObjectPathVariant

      public static Variant newObjectPathVariant(String object_path)
      Creates a D-Bus object path #GVariant with the contents of @string.
      @string must be a valid D-Bus object path. Use
      g_variant_is_object_path() if you're not sure.
      Parameters:
      object_path - a normal C nul-terminated string
      Returns:
      a floating reference to a new object path #GVariant instance

    • newParsedVariant

      public static Variant newParsedVariant(@Nonnull Str format, Object... _elipse)
      Parses @format and returns the result.

      @format must be a text format #GVariant with one extension: at any
      point that a value may appear in the text, a '%' character followed
      by a GVariant format string (as per g_variant_new()) may appear. In
      that case, the same arguments are collected from the argument list as
      g_variant_new() would have collected.

      Note that the arguments must be of the correct width for their types
      specified in @format. This can be achieved by casting them. See
      the [GVariant varargs documentation][gvariant-varargs].

      Consider this simple example: 
      <!-- language="C" -->
  g_variant_new_parsed ("[('one', 1), ('two', %i), (%s, 3)]", 2, "three");


      In the example, the variable argument parameters are collected and
      filled in as if they were part of the original string to produce the
      result of 
      <!-- language="C" -->
 [('one', 1), ('two', 2), ('three', 3)]


      This function is intended only to be used with @format as a string
      literal. Any parse error is fatal to the calling process. If you
      want to parse data from untrusted sources, use g_variant_parse().

      You may not use this function to return, unmodified, a single
      #GVariant pointer from the argument list. ie: @format may not solely
      be anything along the lines of "%*", "%?", "\%r", or anything starting
      with "%@".
      Parameters:
      format - a text format #GVariant
      _elipse - arguments as per @format
      Returns:
      a new floating #GVariant instance

    • newParsedVariant

      public static Variant newParsedVariant(String format, Object... _elipse)
      Parses @format and returns the result.

      @format must be a text format #GVariant with one extension: at any
      point that a value may appear in the text, a '%' character followed
      by a GVariant format string (as per g_variant_new()) may appear. In
      that case, the same arguments are collected from the argument list as
      g_variant_new() would have collected.

      Note that the arguments must be of the correct width for their types
      specified in @format. This can be achieved by casting them. See
      the [GVariant varargs documentation][gvariant-varargs].

      Consider this simple example: 
      <!-- language="C" -->
  g_variant_new_parsed ("[('one', 1), ('two', %i), (%s, 3)]", 2, "three");


      In the example, the variable argument parameters are collected and
      filled in as if they were part of the original string to produce the
      result of 
      <!-- language="C" -->
 [('one', 1), ('two', 2), ('three', 3)]


      This function is intended only to be used with @format as a string
      literal. Any parse error is fatal to the calling process. If you
      want to parse data from untrusted sources, use g_variant_parse().

      You may not use this function to return, unmodified, a single
      #GVariant pointer from the argument list. ie: @format may not solely
      be anything along the lines of "%*", "%?", "\%r", or anything starting
      with "%@".
      Parameters:
      format - a text format #GVariant
      _elipse - arguments as per @format
      Returns:
      a new floating #GVariant instance

    • newPrintfVariant

      public static Variant newPrintfVariant(@Nonnull Str format_string, Object... _elipse)
      Creates a string-type GVariant using printf formatting.

      This is similar to calling g_strdup_printf() and then
      g_variant_new_string() but it saves a temporary variable and an
      unnecessary copy.
      Parameters:
      format_string - a printf-style format string
      _elipse - arguments for @format_string
      Returns:
      a floating reference to a new string #GVariant instance

    • newPrintfVariant

      public static Variant newPrintfVariant(String format_string, Object... _elipse)
      Creates a string-type GVariant using printf formatting.

      This is similar to calling g_strdup_printf() and then
      g_variant_new_string() but it saves a temporary variable and an
      unnecessary copy.
      Parameters:
      format_string - a printf-style format string
      _elipse - arguments for @format_string
      Returns:
      a floating reference to a new string #GVariant instance

    • newSignatureVariant

      public static Variant newSignatureVariant(@Nonnull Str signature)
      Creates a D-Bus type signature #GVariant with the contents of
      @string. @string must be a valid D-Bus type signature. Use
      g_variant_is_signature() if you're not sure.
      Parameters:
      signature - a normal C nul-terminated string
      Returns:
      a floating reference to a new signature #GVariant instance

    • newSignatureVariant

      public static Variant newSignatureVariant(String signature)
      Creates a D-Bus type signature #GVariant with the contents of
      @string. @string must be a valid D-Bus type signature. Use
      g_variant_is_signature() if you're not sure.
      Parameters:
      signature - a normal C nul-terminated string
      Returns:
      a floating reference to a new signature #GVariant instance

    • newStringVariant

      public static Variant newStringVariant(@Nonnull Str string)
      Creates a string #GVariant with the contents of @string.

      @string must be valid UTF-8, and must not be %NULL. To encode
      potentially-%NULL strings, use g_variant_new() with `ms` as the
      [format string][gvariant-format-strings-maybe-types].
      Parameters:
      string - a normal UTF-8 nul-terminated string
      Returns:
      a floating reference to a new string #GVariant instance

    • newStringVariant

      public static Variant newStringVariant(String string)
      Creates a string #GVariant with the contents of @string.

      @string must be valid UTF-8, and must not be %NULL. To encode
      potentially-%NULL strings, use g_variant_new() with `ms` as the
      [format string][gvariant-format-strings-maybe-types].
      Parameters:
      string - a normal UTF-8 nul-terminated string
      Returns:
      a floating reference to a new string #GVariant instance

    • newTakeStringVariant

      public static Variant newTakeStringVariant(@Nonnull Str string)
      Creates a string #GVariant with the contents of @string.

      @string must be valid UTF-8, and must not be %NULL. To encode
      potentially-%NULL strings, use this with g_variant_new_maybe().

      This function consumes @string. g_free() will be called on @string
      when it is no longer required.

      You must not modify or access @string in any other way after passing
      it to this function. It is even possible that @string is immediately
      freed.
      Parameters:
      string - a normal UTF-8 nul-terminated string
      Returns:
      a floating reference to a new string #GVariant instance

    • newUint16Variant

      public static Variant newUint16Variant(int value)
      Creates a new uint16 #GVariant instance.
      Parameters:
      value - a #guint16 value
      Returns:
      a floating reference to a new uint16 #GVariant instance

    • newUint32Variant

      public static Variant newUint32Variant(int value)
      Creates a new uint32 #GVariant instance.
      Parameters:
      value - a #guint32 value
      Returns:
      a floating reference to a new uint32 #GVariant instance

    • newUint64Variant

      public static Variant newUint64Variant(long value)
      Creates a new uint64 #GVariant instance.
      Parameters:
      value - a #guint64 value
      Returns:
      a floating reference to a new uint64 #GVariant instance

    • newVariantVariant

      public static Variant newVariantVariant(@Nonnull Variant value)
      Boxes @value. The result is a #GVariant instance representing a
      variant containing the original value.

      If @child is a floating reference (see g_variant_ref_sink()), the new
      instance takes ownership of @child.
      Parameters:
      value - a #GVariant instance
      Returns:
      a floating reference to a new variant #GVariant instance

    • byteswap

      public Variant byteswap()
      Performs a byteswapping operation on the contents of @value. The
      result is that all multi-byte numeric data contained in @value is
      byteswapped. That includes 16, 32, and 64bit signed and unsigned
      integers as well as file handles and double precision floating point
      values.

      This function is an identity mapping on any value that does not
      contain multi-byte numeric data. That include strings, booleans,
      bytes and containers containing only these things (recursively).

      The returned value is always in normal form and is marked as trusted.
      Returns:
      the byteswapped form of @value

    • checkFormatString

      public boolean checkFormatString(@Nonnull Str format_string, boolean copy_only)
      Checks if calling g_variant_get() with @format_string on @value would
      be valid from a type-compatibility standpoint. @format_string is
      assumed to be a valid format string (from a syntactic standpoint).

      If @copy_only is %TRUE then this function additionally checks that it
      would be safe to call g_variant_unref() on @value immediately after
      the call to g_variant_get() without invalidating the result. This is
      only possible if deep copies are made (ie: there are no pointers to
      the data inside of the soon-to-be-freed #GVariant instance). If this
      check fails then a g_critical() is printed and %FALSE is returned.

      This function is meant to be used by functions that wish to provide
      varargs accessors to #GVariant values of uncertain values (eg:
      g_variant_lookup() or g_menu_model_get_item_attribute()).
      Parameters:
      format_string - a valid #GVariant format string
      copy_only - %TRUE to ensure the format string makes deep copies
      Returns:
      %TRUE if @format_string is safe to use

    • checkFormatString

      public boolean checkFormatString(String format_string, boolean copy_only)
      Checks if calling g_variant_get() with @format_string on @value would
      be valid from a type-compatibility standpoint. @format_string is
      assumed to be a valid format string (from a syntactic standpoint).

      If @copy_only is %TRUE then this function additionally checks that it
      would be safe to call g_variant_unref() on @value immediately after
      the call to g_variant_get() without invalidating the result. This is
      only possible if deep copies are made (ie: there are no pointers to
      the data inside of the soon-to-be-freed #GVariant instance). If this
      check fails then a g_critical() is printed and %FALSE is returned.

      This function is meant to be used by functions that wish to provide
      varargs accessors to #GVariant values of uncertain values (eg:
      g_variant_lookup() or g_menu_model_get_item_attribute()).
      Parameters:
      format_string - a valid #GVariant format string
      copy_only - %TRUE to ensure the format string makes deep copies
      Returns:
      %TRUE if @format_string is safe to use

    • classify

      public int classify()
      Classifies @value according to its top-level type.
      Returns:
      the #GVariantClass of @value

    • compare

      public int compare(@Nonnull Pointer two)
      Compares @one and @two.

      The types of @one and @two are #gconstpointer only to allow use of
      this function with #GTree, #GPtrArray, etc. They must each be a
      #GVariant.

      Comparison is only defined for basic types (ie: booleans, numbers,
      strings). For booleans, %FALSE is less than %TRUE. Numbers are
      ordered in the usual way. Strings are in ASCII lexographical order.

      It is a programmer error to attempt to compare container values or
      two values that have types that are not exactly equal. For example,
      you cannot compare a 32-bit signed integer with a 32-bit unsigned
      integer. Also note that this function is not particularly
      well-behaved when it comes to comparison of doubles; in particular,
      the handling of incomparable values (ie: NaN) is undefined.

      If you only require an equality comparison, g_variant_equal() is more
      general.
      Parameters:
      two - a #GVariant instance of the same type
      Returns:
      negative value if a < b; zero if a = b; positive value if a > b.

    • dupBytestring

      public Str dupBytestring(@Nullable Int64 length)
      Similar to g_variant_get_bytestring() except that instead of
      returning a constant string, the string is duplicated.

      The return value must be freed using g_free().
      Parameters:
      length - a pointer to a #gsize, to store the length (not including the nul terminator)
      Returns:
      a newly allocated string

    • dupString

      public Str dupString(@Nonnull Int64 length)
      Similar to g_variant_get_string() except that instead of returning
      a constant string, the string is duplicated.

      The string will always be UTF-8 encoded.

      The return value must be freed using g_free().
      Parameters:
      length - a pointer to a #gsize, to store the length
      Returns:
      a newly allocated string, UTF-8 encoded

    • equal

      public boolean equal(@Nonnull Pointer two)
      Checks if @one and @two have the same type and value.

      The types of @one and @two are #gconstpointer only to allow use of
      this function with #GHashTable. They must each be a #GVariant.
      Parameters:
      two - a #GVariant instance
      Returns:
      %TRUE if @one and @two are equal

    • get

      public void get(@Nonnull Str format_string, Object... _elipse)
      Deconstructs a #GVariant instance.

      Think of this function as an analogue to scanf().

      The arguments that are expected by this function are entirely
      determined by @format_string. @format_string also restricts the
      permissible types of @value. It is an error to give a value with
      an incompatible type. See the section on
      [GVariant format strings][gvariant-format-strings].
      Please note that the syntax of the format string is very likely to be
      extended in the future.

      @format_string determines the C types that are used for unpacking
      the values and also determines if the values are copied or borrowed,
      see the section on
      [GVariant format strings][gvariant-format-strings-pointers].
      Parameters:
      format_string - a #GVariant format string
      _elipse - arguments, as per @format_string

    • get

      public void get(String format_string, Object... _elipse)
      Deconstructs a #GVariant instance.

      Think of this function as an analogue to scanf().

      The arguments that are expected by this function are entirely
      determined by @format_string. @format_string also restricts the
      permissible types of @value. It is an error to give a value with
      an incompatible type. See the section on
      [GVariant format strings][gvariant-format-strings].
      Please note that the syntax of the format string is very likely to be
      extended in the future.

      @format_string determines the C types that are used for unpacking
      the values and also determines if the values are copied or borrowed,
      see the section on
      [GVariant format strings][gvariant-format-strings-pointers].
      Parameters:
      format_string - a #GVariant format string
      _elipse - arguments, as per @format_string

    • getBoolean

      public boolean getBoolean()
      Returns the boolean value of @value.

      It is an error to call this function with a @value of any type
      other than %G_VARIANT_TYPE_BOOLEAN.
      Returns:
      %TRUE or %FALSE

    • getByte

      public int getByte()
      Returns the byte value of @value.

      It is an error to call this function with a @value of any type
      other than %G_VARIANT_TYPE_BYTE.
      Returns:
      a #guint8

    • getBytestring

      public Str getBytestring()
      Returns the string value of a #GVariant instance with an
      array-of-bytes type. The string has no particular encoding.

      If the array does not end with a nul terminator character, the empty
      string is returned. For this reason, you can always trust that a
      non-%NULL nul-terminated string will be returned by this function.

      If the array contains a nul terminator character somewhere other than
      the last byte then the returned string is the string, up to the first
      such nul character.

      g_variant_get_fixed_array() should be used instead if the array contains
      arbitrary data that could not be nul-terminated or could contain nul bytes.

      It is an error to call this function with a @value that is not an
      array of bytes.

      The return value remains valid as long as @value exists.
      Returns:
      the constant string

    • getChild

      public void getChild(long index_, @Nonnull Str format_string, Object... _elipse)
      Reads a child item out of a container #GVariant instance and
      deconstructs it according to @format_string. This call is
      essentially a combination of g_variant_get_child_value() and
      g_variant_get().

      @format_string determines the C types that are used for unpacking
      the values and also determines if the values are copied or borrowed,
      see the section on
      [GVariant format strings][gvariant-format-strings-pointers].
      Parameters:
      index_ - the index of the child to deconstruct
      format_string - a #GVariant format string
      _elipse - arguments, as per @format_string

    • getChild

      public void getChild(long index_, String format_string, Object... _elipse)
      Reads a child item out of a container #GVariant instance and
      deconstructs it according to @format_string. This call is
      essentially a combination of g_variant_get_child_value() and
      g_variant_get().

      @format_string determines the C types that are used for unpacking
      the values and also determines if the values are copied or borrowed,
      see the section on
      [GVariant format strings][gvariant-format-strings-pointers].
      Parameters:
      index_ - the index of the child to deconstruct
      format_string - a #GVariant format string
      _elipse - arguments, as per @format_string

    • getChildValue

      public Variant getChildValue(long index_)
      Reads a child item out of a container #GVariant instance. This
      includes variants, maybes, arrays, tuples and dictionary
      entries. It is an error to call this function on any other type of
      #GVariant.

      It is an error if @index_ is greater than the number of child items
      in the container. See g_variant_n_children().

      The returned value is never floating. You should free it with
      g_variant_unref() when you're done with it.

      Note that values borrowed from the returned child are not guaranteed to
      still be valid after the child is freed even if you still hold a reference
      to @value, if @value has not been serialized at the time this function is
      called. To avoid this, you can serialize @value by calling
      g_variant_get_data() and optionally ignoring the return value.

      There may be implementation specific restrictions on deeply nested values,
      which would result in the unit tuple being returned as the child value,
      instead of further nested children. #GVariant is guaranteed to handle
      nesting up to at least 64 levels.

      This function is O(1).
      Parameters:
      index_ - the index of the child to fetch
      Returns:
      the child at the specified index

    • getData

      public Pointer getData()
      Returns a pointer to the serialized form of a #GVariant instance.
      The returned data may not be in fully-normalised form if read from an
      untrusted source. The returned data must not be freed; it remains
      valid for as long as @value exists.

      If @value is a fixed-sized value that was deserialized from a
      corrupted serialized container then %NULL may be returned. In this
      case, the proper thing to do is typically to use the appropriate
      number of nul bytes in place of @value. If @value is not fixed-sized
      then %NULL is never returned.

      In the case that @value is already in serialized form, this function
      is O(1). If the value is not already in serialized form,
      serialization occurs implicitly and is approximately O(n) in the size
      of the result.

      To deserialize the data returned by this function, in addition to the
      serialized data, you must know the type of the #GVariant, and (if the
      machine might be different) the endianness of the machine that stored
      it. As a result, file formats or network messages that incorporate
      serialized #GVariants must include this information either
      implicitly (for instance "the file always contains a
      %G_VARIANT_TYPE_VARIANT and it is always in little-endian order") or
      explicitly (by storing the type and/or endianness in addition to the
      serialized data).
      Returns:
      the serialized form of @value, or %NULL

    • getDataAsBytes

      public Bytes getDataAsBytes()
      Returns a pointer to the serialized form of a #GVariant instance.
      The semantics of this function are exactly the same as
      g_variant_get_data(), except that the returned #GBytes holds
      a reference to the variant data.
      Returns:
      A new #GBytes representing the variant data

    • getDouble

      public double getDouble()
      Returns the double precision floating point value of @value.

      It is an error to call this function with a @value of any type
      other than %G_VARIANT_TYPE_DOUBLE.
      Returns:
      a #gdouble

    • getFixedArray

      public Pointer getFixedArray(@Nonnull Int64 n_elements, long element_size)
      Provides access to the serialized data for an array of fixed-sized
      items.

      @value must be an array with fixed-sized elements. Numeric types are
      fixed-size, as are tuples containing only other fixed-sized types.

      @element_size must be the size of a single element in the array,
      as given by the section on
      [serialized data memory][gvariant-serialized-data-memory].

      In particular, arrays of these fixed-sized types can be interpreted
      as an array of the given C type, with @element_size set to the size
      the appropriate type:
      - %G_VARIANT_TYPE_INT16 (etc.): #gint16 (etc.)
      - %G_VARIANT_TYPE_BOOLEAN: #guchar (not #gboolean!)
      - %G_VARIANT_TYPE_BYTE: #guint8
      - %G_VARIANT_TYPE_HANDLE: #guint32
      - %G_VARIANT_TYPE_DOUBLE: #gdouble

      For example, if calling this function for an array of 32-bit integers,
      you might say `sizeof(gint32)`. This value isn't used except for the purpose
      of a double-check that the form of the serialized data matches the caller's
      expectation.

      @n_elements, which must be non-%NULL, is set equal to the number of
      items in the array.
      Parameters:
      n_elements - a pointer to the location to store the number of items
      element_size - the size of each element
      Returns:
      a pointer to the fixed array

    • getHandle

      public int getHandle()
      Returns the 32-bit signed integer value of @value.

      It is an error to call this function with a @value of any type other
      than %G_VARIANT_TYPE_HANDLE.

      By convention, handles are indexes into an array of file descriptors
      that are sent alongside a D-Bus message. If you're not interacting
      with D-Bus, you probably don't need them.
      Returns:
      a #gint32

    • getInt16

      public int getInt16()
      Returns the 16-bit signed integer value of @value.

      It is an error to call this function with a @value of any type
      other than %G_VARIANT_TYPE_INT16.
      Returns:
      a #gint16

    • getInt32

      public int getInt32()
      Returns the 32-bit signed integer value of @value.

      It is an error to call this function with a @value of any type
      other than %G_VARIANT_TYPE_INT32.
      Returns:
      a #gint32

    • getInt64

      public long getInt64()
      Returns the 64-bit signed integer value of @value.

      It is an error to call this function with a @value of any type
      other than %G_VARIANT_TYPE_INT64.
      Returns:
      a #gint64

    • getMaybe

      public Variant getMaybe()
      Given a maybe-typed #GVariant instance, extract its value. If the
      value is Nothing, then this function returns %NULL.
      Returns:
      the contents of @value, or %NULL

    • getNormalForm

      public Variant getNormalForm()
      Gets a #GVariant instance that has the same value as @value and is
      trusted to be in normal form.

      If @value is already trusted to be in normal form then a new
      reference to @value is returned.

      If @value is not already trusted, then it is scanned to check if it
      is in normal form. If it is found to be in normal form then it is
      marked as trusted and a new reference to it is returned.

      If @value is found not to be in normal form then a new trusted
      #GVariant is created with the same value as @value.

      It makes sense to call this function if you've received #GVariant
      data from untrusted sources and you want to ensure your serialized
      output is definitely in normal form.

      If @value is already in normal form, a new reference will be returned
      (which will be floating if @value is floating). If it is not in normal form,
      the newly created #GVariant will be returned with a single non-floating
      reference. Typically, g_variant_take_ref() should be called on the return
      value from this function to guarantee ownership of a single non-floating
      reference to it.
      Returns:
      a trusted #GVariant

    • getSize

      public long getSize()
      Determines the number of bytes that would be required to store @value
      with g_variant_store().

      If @value has a fixed-sized type then this function always returned
      that fixed size.

      In the case that @value is already in serialized form or the size has
      already been calculated (ie: this function has been called before)
      then this function is O(1). Otherwise, the size is calculated, an
      operation which is approximately O(n) in the number of values
      involved.
      Returns:
      the serialized size of @value

    • getString

      public Str getString(@Nullable Int64 length)
      Returns the string value of a #GVariant instance with a string
      type. This includes the types %G_VARIANT_TYPE_STRING,
      %G_VARIANT_TYPE_OBJECT_PATH and %G_VARIANT_TYPE_SIGNATURE.

      The string will always be UTF-8 encoded, will never be %NULL, and will never
      contain nul bytes.

      If @length is non-%NULL then the length of the string (in bytes) is
      returned there. For trusted values, this information is already
      known. Untrusted values will be validated and, if valid, a strlen() will be
      performed. If invalid, a default value will be returned — for
      %G_VARIANT_TYPE_OBJECT_PATH, this is `"/"`, and for other types it is the
      empty string.

      It is an error to call this function with a @value of any type
      other than those three.

      The return value remains valid as long as @value exists.
      Parameters:
      length - a pointer to a #gsize, to store the length
      Returns:
      the constant string, UTF-8 encoded

    • getType

      public VariantType getType()
      Determines the type of @value.

      The return value is valid for the lifetime of @value and must not
      be freed.
      Returns:
      a #GVariantType

    • getTypeString

      public Str getTypeString()
      Returns the type string of @value. Unlike the result of calling
      g_variant_type_peek_string(), this string is nul-terminated. This
      string belongs to #GVariant and must not be freed.
      Returns:
      the type string for the type of @value

    • getUint16

      public int getUint16()
      Returns the 16-bit unsigned integer value of @value.

      It is an error to call this function with a @value of any type
      other than %G_VARIANT_TYPE_UINT16.
      Returns:
      a #guint16

    • getUint32

      public int getUint32()
      Returns the 32-bit unsigned integer value of @value.

      It is an error to call this function with a @value of any type
      other than %G_VARIANT_TYPE_UINT32.
      Returns:
      a #guint32

    • getUint64

      public long getUint64()
      Returns the 64-bit unsigned integer value of @value.

      It is an error to call this function with a @value of any type
      other than %G_VARIANT_TYPE_UINT64.
      Returns:
      a #guint64

    • getVariant

      public Variant getVariant()
      Unboxes @value. The result is the #GVariant instance that was
      contained in @value.
      Returns:
      the item contained in the variant

    • hash

      public int hash()
      Generates a hash value for a #GVariant instance.

      The output of this function is guaranteed to be the same for a given
      value only per-process. It may change between different processor
      architectures or even different versions of GLib. Do not use this
      function as a basis for building protocols or file formats.

      The type of @value is #gconstpointer only to allow use of this
      function with #GHashTable. @value must be a #GVariant.
      Returns:
      a hash value corresponding to @value

    • isContainer

      public boolean isContainer()
      Checks if @value is a container.
      Returns:
      %TRUE if @value is a container

    • isFloating

      public boolean isFloating()
      Checks whether @value has a floating reference count.

      This function should only ever be used to assert that a given variant
      is or is not floating, or for debug purposes. To acquire a reference
      to a variant that might be floating, always use g_variant_ref_sink()
      or g_variant_take_ref().

      See g_variant_ref_sink() for more information about floating reference
      counts.
      Returns:
      whether @value is floating

    • isNormalForm

      public boolean isNormalForm()
      Checks if @value is in normal form.

      The main reason to do this is to detect if a given chunk of
      serialized data is in normal form: load the data into a #GVariant
      using g_variant_new_from_data() and then use this function to
      check.

      If @value is found to be in normal form then it will be marked as
      being trusted. If the value was already marked as being trusted then
      this function will immediately return %TRUE.

      There may be implementation specific restrictions on deeply nested values.
      GVariant is guaranteed to handle nesting up to at least 64 levels.
      Returns:
      %TRUE if @value is in normal form

    • isOfType

      public boolean isOfType(@Nonnull VariantType type)
      Checks if a value has a type matching the provided type.
      Parameters:
      type - a #GVariantType
      Returns:
      %TRUE if the type of @value matches @type

    • iterNew

      public VariantIter iterNew()
      Creates a heap-allocated #GVariantIter for iterating over the items
      in @value.

      Use g_variant_iter_free() to free the return value when you no longer
      need it.

      A reference is taken to @value and will be released only when
      g_variant_iter_free() is called.
      Returns:
      a new heap-allocated #GVariantIter

    • lookup

      public boolean lookup(@Nonnull Str key, @Nonnull Str format_string, Object... _elipse)
      Looks up a value in a dictionary #GVariant.

      This function is a wrapper around g_variant_lookup_value() and
      g_variant_get(). In the case that %NULL would have been returned,
      this function returns %FALSE. Otherwise, it unpacks the returned
      value and returns %TRUE.

      @format_string determines the C types that are used for unpacking
      the values and also determines if the values are copied or borrowed,
      see the section on
      [GVariant format strings][gvariant-format-strings-pointers].

      This function is currently implemented with a linear scan. If you
      plan to do many lookups then #GVariantDict may be more efficient.
      Parameters:
      key - the key to look up in the dictionary
      format_string - a GVariant format string
      _elipse - the arguments to unpack the value into
      Returns:
      %TRUE if a value was unpacked

    • lookup

      public boolean lookup(String key, String format_string, Object... _elipse)
      Looks up a value in a dictionary #GVariant.

      This function is a wrapper around g_variant_lookup_value() and
      g_variant_get(). In the case that %NULL would have been returned,
      this function returns %FALSE. Otherwise, it unpacks the returned
      value and returns %TRUE.

      @format_string determines the C types that are used for unpacking
      the values and also determines if the values are copied or borrowed,
      see the section on
      [GVariant format strings][gvariant-format-strings-pointers].

      This function is currently implemented with a linear scan. If you
      plan to do many lookups then #GVariantDict may be more efficient.
      Parameters:
      key - the key to look up in the dictionary
      format_string - a GVariant format string
      _elipse - the arguments to unpack the value into
      Returns:
      %TRUE if a value was unpacked

    • lookupValue

      public Variant lookupValue(@Nonnull Str key, @Nullable VariantType expected_type)
      Looks up a value in a dictionary #GVariant.

      This function works with dictionaries of the type a{s*} (and equally
      well with type a{o*}, but we only further discuss the string case
      for sake of clarity).

      In the event that @dictionary has the type a{sv}, the @expected_type
      string specifies what type of value is expected to be inside of the
      variant. If the value inside the variant has a different type then
      %NULL is returned. In the event that @dictionary has a value type other
      than v then @expected_type must directly match the value type and it is
      used to unpack the value directly or an error occurs.

      In either case, if @key is not found in @dictionary, %NULL is returned.

      If the key is found and the value has the correct type, it is
      returned. If @expected_type was specified then any non-%NULL return
      value will have this type.

      This function is currently implemented with a linear scan. If you
      plan to do many lookups then #GVariantDict may be more efficient.
      Parameters:
      key - the key to look up in the dictionary
      expected_type - a #GVariantType, or %NULL
      Returns:
      the value of the dictionary key, or %NULL

    • lookupValue

      public Variant lookupValue(String key, @Nullable VariantType expected_type)
      Looks up a value in a dictionary #GVariant.

      This function works with dictionaries of the type a{s*} (and equally
      well with type a{o*}, but we only further discuss the string case
      for sake of clarity).

      In the event that @dictionary has the type a{sv}, the @expected_type
      string specifies what type of value is expected to be inside of the
      variant. If the value inside the variant has a different type then
      %NULL is returned. In the event that @dictionary has a value type other
      than v then @expected_type must directly match the value type and it is
      used to unpack the value directly or an error occurs.

      In either case, if @key is not found in @dictionary, %NULL is returned.

      If the key is found and the value has the correct type, it is
      returned. If @expected_type was specified then any non-%NULL return
      value will have this type.

      This function is currently implemented with a linear scan. If you
      plan to do many lookups then #GVariantDict may be more efficient.
      Parameters:
      key - the key to look up in the dictionary
      expected_type - a #GVariantType, or %NULL
      Returns:
      the value of the dictionary key, or %NULL

    • nChildren

      public long nChildren()
      Determines the number of children in a container #GVariant instance.
      This includes variants, maybes, arrays, tuples and dictionary
      entries. It is an error to call this function on any other type of
      #GVariant.

      For variants, the return value is always 1. For values with maybe
      types, it is always zero or one. For arrays, it is the length of the
      array. For tuples it is the number of tuple items (which depends
      only on the type). For dictionary entries, it is always 2

      This function is O(1).
      Returns:
      the number of children in the container

    • print

      public Str print(boolean type_annotate)
      Pretty-prints @value in the format understood by g_variant_parse().

      The format is described [here][gvariant-text].

      If @type_annotate is %TRUE, then type information is included in
      the output.
      Parameters:
      type_annotate - %TRUE if type information should be included in the output
      Returns:
      a newly-allocated string holding the result.

    • printString

      public GString printString(@Nullable GString string, boolean type_annotate)
      Behaves as g_variant_print(), but operates on a #GString.

      If @string is non-%NULL then it is appended to and returned. Else,
      a new empty #GString is allocated and it is returned.
      Parameters:
      string - a #GString, or %NULL
      type_annotate - %TRUE if type information should be included in the output
      Returns:
      a #GString containing the string

    • ref

      public Variant ref()
      Increases the reference count of @value.
      Returns:
      the same @value

    • refSink

      public Variant refSink()
      #GVariant uses a floating reference count system. All functions with
      names starting with `g_variant_new_` return floating
      references.

      Calling g_variant_ref_sink() on a #GVariant with a floating reference
      will convert the floating reference into a full reference. Calling
      g_variant_ref_sink() on a non-floating #GVariant results in an
      additional normal reference being added.

      In other words, if the @value is floating, then this call "assumes
      ownership" of the floating reference, converting it to a normal
      reference. If the @value is not floating, then this call adds a
      new normal reference increasing the reference count by one.

      All calls that result in a #GVariant instance being inserted into a
      container will call g_variant_ref_sink() on the instance. This means
      that if the value was just created (and has only its floating
      reference) then the container will assume sole ownership of the value
      at that point and the caller will not need to unreference it. This
      makes certain common styles of programming much easier while still
      maintaining normal refcounting semantics in situations where values
      are not floating.
      Returns:
      the same @value

    • store

      public void store(@Nonnull Pointer data)
      Stores the serialized form of @value at @data. @data should be
      large enough. See g_variant_get_size().

      The stored data is in machine native byte order but may not be in
      fully-normalised form if read from an untrusted source. See
      g_variant_get_normal_form() for a solution.

      As with g_variant_get_data(), to be able to deserialize the
      serialized variant successfully, its type and (if the destination
      machine might be different) its endianness must also be available.

      This function is approximately O(n) in the size of @data.
      Parameters:
      data - the location to store the serialized data at

    • takeRef

      public Variant takeRef()
      If @value is floating, sink it. Otherwise, do nothing.

      Typically you want to use g_variant_ref_sink() in order to
      automatically do the correct thing with respect to floating or
      non-floating references, but there is one specific scenario where
      this function is helpful.

      The situation where this function is helpful is when creating an API
      that allows the user to provide a callback function that returns a
      #GVariant. We certainly want to allow the user the flexibility to
      return a non-floating reference from this callback (for the case
      where the value that is being returned already exists).

      At the same time, the style of the #GVariant API makes it likely that
      for newly-created #GVariant instances, the user can be saved some
      typing if they are allowed to return a #GVariant with a floating
      reference.

      Using this function on the return value of the user's callback allows
      the user to do whichever is more convenient for them. The caller
      will always receives exactly one full reference to the value: either
      the one that was returned in the first place, or a floating reference
      that has been converted to a full reference.

      This function has an odd interaction when combined with
      g_variant_ref_sink() running at the same time in another thread on
      the same #GVariant instance. If g_variant_ref_sink() runs first then
      the result will be that the floating reference is converted to a hard
      reference. If g_variant_take_ref() runs first then the result will
      be that the floating reference is converted to a hard reference and
      an additional reference on top of that one is added. It is best to
      avoid this situation.
      Returns:
      the same @value

    • unref

      public void unref()
      Decreases the reference count of @value. When its reference count
      drops to 0, the memory used by the variant is freed.

    • isObjectPath

      public static boolean isObjectPath(@Nonnull Str string)
      Determines if a given string is a valid D-Bus object path. You
      should ensure that a string is a valid D-Bus object path before
      passing it to g_variant_new_object_path().

      A valid object path starts with `/` followed by zero or more
      sequences of characters separated by `/` characters. Each sequence
      must contain only the characters `[A-Z][a-z][0-9]_`. No sequence
      (including the one following the final `/` character) may be empty.
      Parameters:
      string - a normal C nul-terminated string
      Returns:
      %TRUE if @string is a D-Bus object path

    • isSignature

      public static boolean isSignature(@Nonnull Str string)
      Determines if a given string is a valid D-Bus type signature. You
      should ensure that a string is a valid D-Bus type signature before
      passing it to g_variant_new_signature().

      D-Bus type signatures consist of zero or more definite #GVariantType
      strings in sequence.
      Parameters:
      string - a normal C nul-terminated string
      Returns:
      %TRUE if @string is a D-Bus type signature

    • parseErrorPrintContext

      public static Str parseErrorPrintContext(@Nonnull Error error, @Nonnull Str source_str)
      Pretty-prints a message showing the context of a #GVariant parse
      error within the string for which parsing was attempted.

      The resulting string is suitable for output to the console or other
      monospace media where newlines are treated in the usual way.

      The message will typically look something like one of the following: 
       unterminated string constant:
   (1, 2, 3, 'abc
             ^^^^


      or 
       unable to find a common type:
   [1, 2, 3, 'str']
    ^        ^^^^^


      The format of the message may change in a future version.

      @error must have come from a failed attempt to g_variant_parse() and
      @source_str must be exactly the same string that caused the error.
      If @source_str was not nul-terminated when you passed it to
      g_variant_parse() then you must add nul termination before using this
      function.
      Parameters:
      error - a #GError from the #GVariantParseError domain
      source_str - the string that was given to the parser
      Returns:
      the printed message

    • parseErrorQuark

      public static int parseErrorQuark()
      Returns:

    • getTypeID

      public static long getTypeID()

    • getParentTypeID

      public static long getParentTypeID()

    • getTypeSize

      public static TypeSystem.TypeSize getTypeSize()

    • getParentTypeSize

      public static TypeSystem.TypeSize getParentTypeSize()

    • getInstanceSize

      public static int getInstanceSize()