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Common constants

Content​

This is a set of constants which are useful throughout the development process, rather than creating them every time, they are being created once and stored and exported from commonConstants.ts

Platform dependant​

Rather than always importing Device or Platform and checking whether it's iOS or Android or some versions, it's easier to have this checks

  • isIos
  • isIphoneX
  • isIpad
  • isTablet
  • isAndroid
  • isAndroidLollipop
  • isAndroid11AndHigher
  • hasNotch
  • hasDynamicIsland

Dimensions dependant​

Most of the time the apps are made for smartphones and orientation is almost always locked to portrait, so instead of checking dimensions all the time it's easier to use next constants:

  • windowWidth
  • windowHeight - on Android it also subtracts StatusBar.currentHeight from height

In cases when it comes to tablets where all the orientations are unlocked or in other cases where orientation is not locked, there are next two constants:

  • maxWindowDimension
  • minWindowDimension

They basically compare (max/min) windowHeight and windowWidth on start so that you could use them rather than always calling Dimensions.

Hit slops​

Some basic predefined hit slops, you can change them for your needs:

  • hitSlop
  • hitSlopBig

Time dependant​

  • minimalLegalAge - subtracts 16 years from current time
  • maximalAge - subtracts 100 years from current time

Other​

  • hairlineWidth - contains the result of StyleSheet.hairlineWidth
  • pixelRatio - contains the result of PixelRatio.get()
  • perfectSize - pixel perfect size calculation across devices (e.g. perfectSize(10))