didChangeMetrics method

@override @mustCallSuper void didChangeMetrics()

Called when the application's dimensions change. For example, when a phone is rotated.

Implementation

@override
@mustCallSuper
void didChangeMetrics() {
  /// In general, this is not overridden often as the layout system takes care of
  /// automatically recomputing the application geometry when the application
  /// size changes
  ///
  /// This method exposes notifications from [Window.onMetricsChanged].
  /// See sample code below. No need to call super if you override.
  ///   @override
  ///   void didChangeMetrics() {
  ///     setState(() { _lastSize = ui.window.physicalSize; });
  ///   }

  // A triggered system event
  _hadSystemEvent = true;

  // Don't if the State object is defunct.
  if (!mounted) {
    return;
  }

  /// No 'setState()' functions are allowed to fully function at this point.
  _setStateAllowed = false;

  for (final con in controllerList) {
    con.didChangeMetrics();
  }

  _setStateAllowed = true;

  if (_setStateRequested) {
    _setStateRequested = false;
    // Only the latest State is rebuilt
    if (isLastState) {
      /// Perform a 'rebuild' if requested.
      setState(() {});
    }
  }

  // Record the triggered event
  assert(() {
    if (_printEvents) {
      debugPrint('============ Event: didChangeMetrics() in $this');
    }
    return true;
  }());
}