Struct gtk4::SignalListItemFactory[][src]

pub struct SignalListItemFactory(_);
Expand description

SignalListItemFactory is a ListItemFactory that emits signals to to manage listitems.

Signals are emitted for every listitem in the same order:

  1. signal::SignalListItemFactory::setup is emitted to set up permanent things on the listitem. This usually means constructing the widgets used in the row and adding them to the listitem.

  2. signal::SignalListItemFactory::bind is emitted to bind the item passed via property::ListItem::item to the widgets that have been created in step 1 or to add item-specific widgets. Signals are connected to listen to changes - both to changes in the item to update the widgets or to changes in the widgets to update the item. After this signal has been called, the listitem may be shown in a list widget.

  3. signal::SignalListItemFactory::unbind is emitted to undo everything done in step 2. Usually this means disconnecting signal handlers. Once this signal has been called, the listitem will no longer be used in a list widget.

  4. signal::SignalListItemFactory::bind and signal::SignalListItemFactory::unbind may be emitted multiple times again to bind the listitem for use with new items. By reusing listitems, potentially costly setup can be avoided. However, it means code needs to make sure to properly clean up the listitem in step 3 so that no information from the previous use leaks into the next use.

  5. signal::SignalListItemFactory::teardown is emitted to allow undoing the effects of signal::SignalListItemFactory::setup. After this signal was emitted on a listitem, the listitem will be destroyed and not be used again.

Note that during the signal emissions, changing properties on the GtkListItems passed will not trigger notify signals as the listitem’s notifications are frozen. See g_object_freeze_notify() for details.

For tracking changes in other properties in the ListItem, the ::notify signal is recommended. The signal can be connected in the signal::SignalListItemFactory::setup signal and removed again during signal::SignalListItemFactory::teardown.

Implements

[ListItemFactoryExt][trait@crate::prelude::ListItemFactoryExt], glib::ObjectExt

Implementations

Creates a new SignalListItemFactory.

You need to connect signal handlers before you use it.

Returns

a new SignalListItemFactory

Emitted when a new property::ListItem::item has been set on the listitem and should be bound for use.

After this signal was emitted, the listitem might be shown in a ListView or other list widget.

The signal::SignalListItemFactory::unbind signal is the opposite of this signal and can be used to undo everything done in this signal.

listitem

The ListItem to bind

Emitted when a new listitem has been created and needs to be setup for use.

It is the first signal emitted for every listitem.

The signal::SignalListItemFactory::teardown signal is the opposite of this signal and can be used to undo everything done in this signal.

listitem

The ListItem to set up

Emitted when a listitem is about to be destroyed.

It is the last signal ever emitted for this listitem.

This signal is the opposite of the signal::SignalListItemFactory::setup signal and should be used to undo everything done in that signal.

listitem

The ListItem to teardown

Emitted when a listitem has been removed from use in a list widget and its new property::ListItem::item is about to be unset.

This signal is the opposite of the signal::SignalListItemFactory::bind signal and should be used to undo everything done in that signal.

listitem

The ListItem to unbind

Trait Implementations

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This method tests for self and other values to be equal, and is used by ==. Read more

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This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

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This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

Returns the type identifier of Self.

Auto Trait Implementations

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Same as connect but takes a SignalId instead of a signal name.

Same as connect_local but takes a SignalId instead of a signal name.

Same as connect_unsafe but takes a SignalId instead of a signal name.

Emit signal by signal id.

Same as emit but takes Value for the arguments.

Emit signal by its name.

Same as emit_by_name but takes Value for the arguments.

Emit signal with details by signal id.

Same as emit_with_details but takes Value for the arguments.

The resulting type after obtaining ownership.

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The type returned in the event of a conversion error.

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The type returned in the event of a conversion error.

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