ion>
        
                <section class="desc markdown">
          <p>The system-reported text scale.</p>
<p>This establishes the text scaling factor to use when rendering text,
according to the user's platform preferences.</p>
<p>The <a href="dart-ui/Window/onTextScaleFactorChanged.html">onTextScaleFactorChanged</a> callback is called whenever this value
changes.</p>
<p>See also:</p>
<ul>
<li><code>WidgetsBindingObserver</code>, for a mechanism at the widgets layer to
observe when this value changes.<