Filtering

Filtering is an optional feature. It allows to filter the preferences and render the result as a flat list or just filters and still keeps the hierarchy intact.

Setup#

You just have to define a filter mode...

val filterModes = listOf(
    DefaultPreferenceFilter.Mode.ContainsText,
    DefaultPreferenceFilter.Mode.AllWords(false),
    DefaultPreferenceFilter.Mode.AnyWord(false)
)

... then create a filter setup ...

val filter = rememberDefaultPreferenceFilter(
    highlightSpan = SpanStyle(color = Color.Red),
    mode = filterModes[0]
)

... and finally pass on the filter to the screen:

PreferenceScreen(
    modifier = Modifier.weight(1f).fillMaxWidth(),
    settings = settings,
    filter = filter,
    state = state
)

Filter#

Afterwards simple adjust the filter.search state in your TextField or wherever you want and the screen will automatically update the list of preferences based on your filter settings.

TextField(
    value = filter.search.value,
    onValueChange = { filter.search.value = it }
)

Other customisations#

Additionally the filter object does provide some states to make more adjustments if desired.

/**
 * Remember a DefaultPreferenceFilter with the given parameters.
 *
 * @param search the search string to filter by
 * @param flattenResult Whether to flatten the result of the filter
 * @param mode the mode to use for the filter
 * @param ignoreCase whether to ignore the case of the search string
 * @param highlightSpan the SpanStyle to use for highlighting the search string
 */
class DefaultPreferenceFilter internal constructor(
    override val search: MutableState<String>,
    override val flattenResult: MutableState<Boolean>,
    val mode: MutableState<Mode>,
    private val ignoreCase: MutableState<Boolean>,
    private val highlightSpan: SpanStyle
) : PreferenceFilter

Custom filter#

If desired, you can implement a full custom implementation of the PreferenceFilter interface. Just check out the DefaultPreferenceFilter to find an example on how this is done.