perating system
will likely place system UI, such as the keyboard, that fully obscures
any content.</p>
<p>When this changes, <a href="dart-ui/Window/onMetricsChanged.html">onMetricsChanged</a> is called.</p>
<p>See also:</p><ul><li><code>WidgetsBindingObserver</code>, for a mechanism at the widgets layer to
observe when this value changes.</li><li><code>MediaQuery.of</code>, a simpler mechanism for the same.</li><li><code>Scaffold</code>, which automatically applies the view insets in material
design appli