requestFocus method
- FocusNode? node
Requests the primary focus for this node, or for a supplied node
, which
will also give focus to its ancestors.
If called without a node, request focus for this node. If the node hasn't been added to the focus tree yet, then defer the focus request until it is, allowing newly created widgets to request focus as soon as they are added.
If the given node
is not yet a part of the focus tree, then this method
will add the node
as a child of this node before requesting focus.
If the given node
is a FocusScopeNode and that focus scope node has a
non-null FocusScopeNode.focusedChild, then request the focus for the
focused child. This process is recursive and continues until it encounters
either a focus scope node with a null focused child or an ordinary
(non-scope) FocusNode is found.
The node is notified that it has received the primary focus in a microtask, so notification may lag the request by up to one frame.
Implementation
void requestFocus([FocusNode? node]) {
if (node != null) {
if (node._parent == null) {
_reparent(node);
}
assert(node.ancestors.contains(this), 'Focus was requested for a node that is not a descendant of the scope from which it was requested.');
node._doRequestFocus(findFirstFocus: true);
return;
}
_doRequestFocus(findFirstFocus: true);
}