30 lines
1.3 KiB
Kotlin
30 lines
1.3 KiB
Kotlin
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package co.electriccoin.zcash.preference.model.entry
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import co.electriccoin.zcash.preference.api.PreferenceProvider
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/**
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* An entry represents a key and a default value for a preference. By using a Default object,
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* multiple parts of the code can fetch the same preference without duplication or accidental
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* variation in default value. Clients define the key and default value together, rather than just
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* the key.
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*/
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/*
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* API note: the default value is not available through the public interface in order to prevent
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* clients from accidentally using the default value instead of the preference value.
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*
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* Implementation note: although primitives would be nice, Objects don't increase memory usage much.
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* The autoboxing cache solves Booleans, and Strings are already objects, so that just leaves Integers.
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* Overall the number of Integer preference entries is expected to be low compared to Booleans,
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* and perhaps many Integer values will also fit within the autoboxing cache.
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*/
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interface PreferenceDefault<T> {
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val key: Key
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/**
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* @param preferenceProvider Provides actual preference values
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* @return The value in the preference, or the default value if no preference exists.
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*/
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suspend fun getValue(preferenceProvider: PreferenceProvider): T
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}
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