FontScaleConverter

Kotlin |Java

interface FontScaleConverter

android.content.res.FontScaleConverter

A converter for non-linear font scaling. Converts font sizes given in "sp" dimensions to a "dp" dimension according to a non-linear curve.

This is meant to improve readability at larger font scales: larger fonts will scale up more slowly than smaller fonts, so we don't get ridiculously huge fonts that don't fit on the screen.

The thinking here is that large fonts are already big enough to read, but we still want to scale them slightly to preserve the visual hierarchy when compared to smaller fonts.

Summary

Public methods
abstract Float	`convertDpToSp(dp: Float)` Converts a dimension in "dp" back to "sp".
abstract Float	`convertSpToDp(sp: Float)` Converts a dimension in "sp" to "dp".
open static FontScaleConverter?	`forScale(fontScale: Float)` Finds a matching FontScaleConverter for the given fontScale factor.
open static Boolean	`isNonLinearFontScalingActive(fontScale: Float)` Returns true if non-linear font scaling curves would be in effect for the given scale, false if the scaling would follow a linear curve or for no scaling.

Public methods

convertDpToSp

Added in API level 35

abstract fun convertDpToSp(dp: Float): Float

Converts a dimension in "dp" back to "sp".

convertSpToDp

Added in API level 35

abstract fun convertSpToDp(sp: Float): Float

Converts a dimension in "sp" to "dp".

forScale

Added in API level 35

open static fun forScale(fontScale: Float): FontScaleConverter?

Finds a matching FontScaleConverter for the given fontScale factor. Generally you shouldn't need this; you can use android.util.TypedValue#applyDimension(int, float, DisplayMetrics) directly and it will do the scaling conversion for you. Dimens and resources loaded from XML will also be automatically converted. But for UI frameworks or other situations where you need to do the conversion without an Android Context, you can use this method.
This method is safe to call from any thread.

Parameters
`fontScale`	Float: the scale factor, usually from `Configuration#fontScale`.

Return
`FontScaleConverter?`	a converter for the given scale, or null if non-linear scaling should not be used.

isNonLinearFontScalingActive

Added in API level 35

open static fun isNonLinearFontScalingActive(fontScale: Float): Boolean

Returns true if non-linear font scaling curves would be in effect for the given scale, false if the scaling would follow a linear curve or for no scaling.

Example usage: isNonLinearFontScalingActive(getResources().getConfiguration().fontScale)
This method is safe to call from any thread.