Function: isFocusable(domElement, boolIncludingNegativeTabIndex)

Description: Determines if a DOM element is focusable.

Returns: True if yes, False otherwise.

Note: If only the first parameter is used, isFocusable will only return true if the referenced element is in the native tab order. If the second parameter is set to true, it will also return true if the element is programmatically focusable using tabindex="-1". The isFocusable() function always returns a Boolean value, even when chained.

Example:

// Is an element in the native focus order, such as tabbing back or forward.
var isNativelyFocusable = $A.isFocusable(domElement);

// Is an element in the native tab order, or can it also receive focus using domElement.focus().
var canReceiveFocus = $A.isFocusable(domElement, true);

// Or the same using chaining

// Is an element in the native focus order, such as tabbing back or forward.
var isNativelyFocusable = $A(domElement).isFocusable();

// Is an element in the native tab order, or can it also receive focus using domElement.focus().
var canReceiveFocus = $A(domElement).isFocusable(true);