class: ListModelItemschangedCallback

[252:7] extends: object

Generated low-level callback wrapper for GIR callback items-changed.

Members

callbackObj
userFn
userData
hasUserData

Methods

ListModelItemschangedCallback (callback Fn, UserData = null)

Creates one native callback wrapper. The wrapper owns a trampoline that converts native pointers into generated wrapper objects before invoking Fn.
- @p Fn is the Aussom callback implementation.
- @p UserData is retained and passed through to Fn on each invocation when provided.
trampoline (nativeSelf, position, removed, added, nativeUserData)

Internal trampoline. Converts native pointer arguments into generated wrapper instances, then invokes the user's callback.
callback ()

Returns the wrapped NativeCallback.
handle ()

Returns the callback as a NativeHandle.
close ()

Closes the underlying NativeCallback.
isClosed ()

Returns true when the callback has been closed.

class: ListModelMeta

[322:14] static extends: object

Generated metadata helpers for ListModel interface surfaces.

Methods

signals ()

Returns signal metadata for ListModel.
- @r A list.

class: ListModel

[54:7] extends: object

GListModel is an interface that represents a mutable list of [class@GObject.Object]. Its main intention is as a model for various widgets in user interfaces, such as list views, but it can also be used as a convenient method of returning lists of data, with support for updates. Each object in the list may also report changes in itself via some mechanism (normally the [signal@GObject.Object::notify] signal). Taken together with the [signal@Gio.ListModel::items-changed] signal, this provides for a list that can change its membership, and in which the members can change their individual properties. A good example would be the list of visible wireless network access points, where each access point can report dynamic properties such as signal strength. It is important to note that the GListModel itself does not report changes to the individual items. It only reports changes to the list membership. If you want to observe changes to the objects themselves then you need to connect signals to the objects that you are interested in. All items in a GListModel are of (or derived from) the same type. [method@Gio.ListModel.get_item_type] returns that type. The type may be an interface, in which case all objects in the list must implement it. The semantics are close to that of an array: [method@Gio.ListModel.get_n_items] returns the number of items in the list and [method@Gio.ListModel.get_item] returns an item at a (0-based) position. In order to allow implementations to calculate the list length lazily, you can also iterate over items: starting from 0, repeatedly call [method@Gio.ListModel.get_item] until it returns NULL. An implementation may create objects lazily, but must take care to return the same object for a given position until all references to it are gone. On the other side, a consumer is expected only to hold references on objects that are currently ‘user visible’, in order to facilitate the maximum level of laziness in the implementation of the list and to reduce the required number of signal connections at a given time. This interface is intended only to be used from a single thread. The thread in which it is appropriate to use it depends on the particular implementation, but typically it will be from the thread that owns the thread-default main context (see [method@GLib.MainContext.push_thread_default]) in effect at the time that the model was created. Over time, it has established itself as good practice for list model implementations to provide properties item-type and n-items to ease working with them. While it is not required, it is recommended that implementations provide these two properties. They should return the values of [method@Gio.ListModel.get_item_type] and [method@Gio.ListModel.get_n_items] respectively and be defined as such: c properties[PROP_ITEM_TYPE] = g_param_spec_gtype ("item-type", NULL, NULL, G_TYPE_OBJECT, G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS); properties[PROP_N_ITEMS] = g_param_spec_uint ("n-items", NULL, NULL, 0, G_MAXUINT, 0, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);

Members

handleObj
lib
retainedCallbacks
signalHandlerNames
signalSetterHandlers

Methods

ListModel (Handle = null)

Creates a new ListModel 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.
connectSignal (string Name, CallbackObj)

Connects one generated callback wrapper to a named signal.
- @p Name is the signal name.
- @p CallbackObj is the generated callback wrapper to connect.
- @r The connected handler id.
disconnectSignalHandler (int HandlerId)

Disconnects one retained signal handler id.
- @p HandlerId is the signal handler id to disconnect.
- @r None.
setOnItemschanged (callback Fn, UserData = null)

This signal is emitted whenever items were added to or removed from
- @list. At @position, @removed items were removed and @added items were added in their place. Note: If removed != added, the positions of all later items in the model change.
- @p Fn is the Aussom callback.
- @p Fn is called with (ListModel Self, int Position, int Removed, int Added).
- @p UserData is retained and passed through to the generated callback wrapper when provided.
- @r The connected handler id.
get_item (int position)

Get the item at @position. If @position is greater than the number of items in @list, %NULL is returned. %NULL is never returned for an index that is smaller than the length of the list. See also: g_list_model_get_n_items()
- @p position is the position of the item to fetch.
get_n_items ()

Gets the number of items in @list. Depending on the model implementation, calling this function may be less efficient than iterating the list with increasing values for @position until g_list_model_get_item() returns %NULL.
get_object (int position)

Get the item at @position. If @position is greater than the number of items in @list, %NULL is returned. %NULL is never returned for an index that is smaller than the length of the list. This function is meant to be used by language bindings in place of g_list_model_get_item(). See also: g_list_model_get_n_items()
- @p position is the position of the item to fetch.
items_changed (int position, int removed, int added)

Emits the #GListModel::items-changed signal on @list. This function should only be called by classes implementing #GListModel. It has to be called after the internal representation of @list has been updated, because handlers connected to this signal might query the new state of the list. Implementations must only make changes to the model (as visible to its consumer) in places that will not cause problems for that consumer. For models that are driven directly by a write API (such as #GListStore), changes can be reported in response to uses of that API. For models that represent remote data, changes should only be made from a fresh mainloop dispatch. It is particularly not permitted to make changes in response to a call to the #GListModel consumer API. Stated another way: in general, it is assumed that code making a series of accesses to the model via the API, without returning to the mainloop, and without calling other code, will continue to view the same contents of the model.
- @p position is the position at which @list changed.
- @p removed is the number of items removed.
- @p added is the number of items added.
- @r None.