The size of the media in logical pixels (e.g, the size of the screen).
Logical pixels are roughly the same visual size across devices. Physical pixels are the size of the actual hardware pixels on the device. The number of physical pixels per logical pixel is described by the devicePixelRatio.
It is considered bad practice to cache and later use the size returned by
MediaQuery.sizeOf(context). It will make the application non-responsive
and might lead to unexpected behaviors.
For instance, during startup, especially in release mode, the first returned size might be Size.zero. The size will be updated when the native platform reports the actual resolution. Using MediaQuery.sizeOf will ensure that when the size changes, any widgets depending on the size are automatically rebuilt.
See the article on Creating responsive and adaptive apps for an introduction.
final Size size;