initAttentionGuards method
void
initAttentionGuards()
Implementation
void initAttentionGuards() {
_docHasFocus = true;
_docVisible = (document.visibilityState == 'visible');
document.addEventListener(
'visibilitychange',
((Event _) =>
_docVisible = (document.visibilityState == 'visible')).toJS,
);
window.addEventListener(
'focus',
((Event _) => _docHasFocus = true).toJS,
);
window.addEventListener(
'blur',
((Event _) => _docHasFocus = false).toJS,
);
// Optional pointer hints (nice-to-have; not required)
document.addEventListener(
'pointerover',
((Event _) => _docHasFocus = true).toJS,
);
document.addEventListener(
'pointerleave',
((Event _) => _docHasFocus = false).toJS,
);
document.addEventListener(
'mouseleave',
((Event _) => _docHasFocus = false).toJS,
);
document.addEventListener(
'mouseenter',
((Event _) => _docHasFocus = true).toJS,
);
}