blockly > IFocusableTree > onTreeFocus

IFocusableTree.onTreeFocus() method

Called when a node of this tree has received active focus.

Note that a null previousTree does not necessarily indicate that this is the first time Blockly is receiving focus. In fact, few assumptions can be made about previous focus state as a previous null tree simply indicates that Blockly did not hold active focus prior to this tree becoming focused (which can happen due to focus exiting the Blockly injection div, or for other cases like ephemeral focus).

See IFocusableNode.onNodeFocus() as implementations have the same restrictions as with that method.

Signature:

onTreeFocus(node: IFocusableNode, previousTree: IFocusableTree | null): void;

Parameters

Parameter	Type	Description
node	IFocusableNode	The node receiving active focus.
previousTree	IFocusableTree | null	The previous tree that held active focus, or null if none.

Returns:

void