padding property

The number of physical pixels on each side of the display rectangle into which the view can render, but which may be partially obscured by system UI (such as the system notification area), or physical intrusions in the display (e.g. overscan regions on television screens or phone sensor housings).

This value is calculated by taking max(0.0, FlutterView.viewPadding - FlutterView.viewInsets). This will treat a system IME that increases the bottom inset as consuming that much of the bottom padding. For example, on an iPhone X, EdgeInsets.bottom of FlutterView.padding is the same as EdgeInsets.bottom of FlutterView.viewPadding when the soft keyboard is not drawn (to account for the bottom soft button area), but will be 0.0 when the soft keyboard is visible.

When this changes, PlatformDispatcher.onMetricsChanged is called. When using the Flutter framework, using MediaQuery.of to obtain the padding (via MediaQueryData.padding), instead of directly obtaining the padding from a FlutterView, will automatically cause any widgets dependent on the padding to rebuild when it changes, without having to listen to PlatformDispatcher.onMetricsChanged.

The relationship between this viewInsets, viewPadding, and padding are described in more detail in the documentation for FlutterView.

See also:

• WidgetsBindingObserver, for a mechanism at the widgets layer to observe when this value changes.
• MediaQuery.of, a simpler mechanism for the same.
• Scaffold, which automatically applies the padding in material design applications.