class: GVariantIter

[28:7] extends: object

#GVariantIter is an opaque data structure and can only be accessed using the following functions.

Members

handleObj
lib
retainedCallbacks
signalHandlerNames
signalSetterHandlers

Methods

GVariantIter (Handle = null)

Creates a new VariantIter by wrapping a native handle or another wrapper.
- @p Handle is the native handle or another wrapper whose handle to adopt.
toNativeHandle (Source)

Normalizes a constructor argument into a raw pointer carrier. Accepts a raw NativeHandle, a raw NativeBuffer returned from fn.call(...), another generated wrapper exposing handle(), or null. Returns null when the argument carries no pointer.
- @p Source is the raw handle, raw buffer, wrapper, or null.
- @r A raw pointer carrier or null when no pointer is present.
getLib ()

Returns the opened native library for this generated wrapper.
- @r The opened native library.
handle ()

Returns the wrapped NativeHandle.
- @r The wrapped NativeHandle.
isNull ()

Returns true when the wrapped handle is null.
- @r A bool.
describe ()

Returns a small string for debugging generated wrappers.
- @r A string.
copy ()

Creates a new heap-allocated #GVariantIter to iterate over the container that was being iterated over by @iter. Iteration begins on the new iterator from the current position of the old iterator but the two copies are independent past that point. Use g_variant_iter_free() to free the return value when you no longer need it. A reference is taken to the container that @iter is iterating over and will be related only when g_variant_iter_free() is called.
- @r a new heap-allocated #GVariantIter.
free ()

Frees a heap-allocated #GVariantIter. Only call this function on iterators that were returned by g_variant_iter_new() or g_variant_iter_copy().
- @r None.
init (object value)

Initialises (without allocating) a #GVariantIter. @iter may be completely uninitialised prior to this call; its old value is ignored. The iterator remains valid for as long as @value exists, and need not be freed in any way.
- @p value is a container #GVariant.
- @r the number of items in @value.
loop (string format_string, list varargs)

Gets the next item in the container and unpacks it into the variable argument list according to @format_string, returning %TRUE. If no more items remain then %FALSE is returned. On the first call to this function, the pointers appearing on the variable argument list are assumed to point at uninitialised memory. On the second and later calls, it is assumed that the same pointers will be given and that they will point to the memory as set by the previous call to this function. This allows the previous values to be freed, as appropriate. This function is intended to be used with a while loop as demonstrated in the following example. This function can only be used when iterating over an array. It is only valid to call this function with a string constant for the format string and the same string constant must be used each time. Mixing calls to this function and g_variant_iter_next() or g_variant_iter_next_value() on the same iterator causes undefined behavior. If you break out of a such a while loop using g_variant_iter_loop() then you must free or unreference all the unpacked values as you would with g_variant_get(). Failure to do so will cause a memory leak. Here is an example for memory management with g_variant_iter_loop(): |[ // Iterates a dictionary of type 'a{sv}' void iterate_dictionary (GVariant *dictionary) { GVariantIter iter; GVariant *value; gchar *key; g_variant_iter_init (&iter, dictionary); while (g_variant_iter_loop (&iter, "{sv}", &key, &value)) { g_print ("Item '%s' has type '%s'\n", key, g_variant_get_type_string (value)); // no need to free 'key' and 'value' here // unless breaking out of this loop } } ]| For most cases you should use g_variant_iter_next(). This function is really only useful when unpacking into #GVariant or #GVariantIter in order to allow you to skip the call to g_variant_unref() or g_variant_iter_free(). For example, if you are only looping over simple integer and string types, g_variant_iter_next() is definitely preferred. For string types, use the '&' prefix to avoid allocating any memory at all (and thereby avoiding the need to free anything as well). @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.
- @p format_string is a GVariant format string.
- @p ... is the arguments to unpack the value into.
- @r %TRUE if a value was unpacked, or %FALSE if there was no value.
n_children ()

Queries the number of child items in the container that we are iterating over. This is the total number of items -- not the number of items remaining. This function might be useful for preallocation of arrays.
- @r the number of children in the container.
next (string format_string, list varargs)

Gets the next item in the container and unpacks it into the variable argument list according to @format_string, returning %TRUE. If no more items remain then %FALSE is returned. All of the pointers given on the variable arguments list of this function are assumed to point at uninitialised memory. It is the responsibility of the caller to free all of the values returned by the unpacking process. Here is an example for memory management with g_variant_iter_next(): |[ // Iterates a dictionary of type 'a{sv}' void iterate_dictionary (GVariant *dictionary) { GVariantIter iter; GVariant *value; gchar *key; g_variant_iter_init (&iter, dictionary); while (g_variant_iter_next (&iter, "{sv}", &key, &value)) { g_print ("Item '%s' has type '%s'\n", key, g_variant_get_type_string (value)); // must free data for ourselves g_variant_unref (value); g_free (key); } } ]| For a solution that is likely to be more convenient to C programmers when dealing with loops, see g_variant_iter_loop(). @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.
- @p format_string is a GVariant format string.
- @p ... is the arguments to unpack the value into.
- @r %TRUE if a value was unpacked, or %FALSE if there as no value.
next_value ()

Gets the next item in the container. If no more items remain then %NULL is returned. Use g_variant_unref() to drop your reference on the return value when you no longer need it. Here is an example for iterating with g_variant_iter_next_value(): |[ // recursively iterate a container void iterate_container_recursive (GVariant *container) { GVariantIter iter; GVariant *child; g_variant_iter_init (&iter, container); while ((child = g_variant_iter_next_value (&iter))) { g_print ("type '%s'\n", g_variant_get_type_string (child)); if (g_variant_is_container (child)) iterate_container_recursive (child); g_variant_unref (child); } } ]|
- @r a #GVariant, or %NULL.

class: GVariantIterLayout

[12:14] static extends: object

Generated struct layout helper for GIR record VariantIter.

Methods

layout ()

Returns the Panama struct layout for VariantIter.