Replace DateTimeInterpreter with lambdas (alamkanak#149)

* Replace DateTimeInterpreter with setDateFormatter and setTimeFormatter

* Remove DefaultDateTimeInterpreterTest

Author: thellmund

core/src/main/java/com/alamkanak/weekview/CalendarExtensions.kt

@@ -250,18 +250,15 @@ internal fun Calendar.isAtStartOfNextDay(startDate: Calendar): Boolean {
     }
 }
 
-internal fun getDefaultDateFormat(numberOfDays: Int): SimpleDateFormat {
-    return when (numberOfDays) {
-        1 -> SimpleDateFormat("EEEE M/dd", Locale.getDefault()) // full weekday
-        in 2..6 -> SimpleDateFormat("EEE M/dd", Locale.getDefault()) // first three characters
-        else -> SimpleDateFormat("EEEEE M/dd", Locale.getDefault()) // first character
-    }
+internal fun defaultDateFormatter(
+    numberOfDays: Int
+): SimpleDateFormat = when (numberOfDays) {
+    1 -> SimpleDateFormat("EEEE M/dd", Locale.getDefault()) // full weekday
+    in 2..6 -> SimpleDateFormat("EEE M/dd", Locale.getDefault()) // first three characters
+    else -> SimpleDateFormat("EEEEE M/dd", Locale.getDefault()) // first character
 }
 
-internal fun getDefaultTimeFormat(is24HourFormat: Boolean): SimpleDateFormat {
-    val format = if (is24HourFormat) "HH:mm" else "hh a"
-    return SimpleDateFormat(format, Locale.getDefault())
-}
+internal fun defaultTimeFormatter(): SimpleDateFormat = SimpleDateFormat("hh a", Locale.getDefault())
 
 internal fun Calendar.format(
     format: Int = java.text.DateFormat.MEDIUM

core/src/main/java/com/alamkanak/weekview/DateTimeInterpreter.kt

@@ -1,9 +1,6 @@
 package com.alamkanak.weekview
 
-import android.content.Context
-import android.text.format.DateFormat
 import java.util.Calendar
-import java.util.Locale
 
 interface DateTimeInterpreter {
     fun onSetNumberOfDays(days: Int) {
@@ -12,41 +9,3 @@ interface DateTimeInterpreter {
     fun interpretDate(date: Calendar): String
     fun interpretTime(hour: Int): String
 }
-
-internal class DefaultDateTimeInterpreter(
-    dateFormatProvider: DateFormatProvider,
-    numberOfDays: Int
-) : DateTimeInterpreter {
-
-    private var sdfDate = getDefaultDateFormat(numberOfDays)
-    private val sdfTime = getDefaultTimeFormat(dateFormatProvider.is24HourFormat)
-
-    // This calendar is only used for interpreting the time. To avoid issues with time changes,
-    // we always use the first day of the year
-    private val calendar = firstDayOfYear()
-
-    override fun onSetNumberOfDays(days: Int) {
-        sdfDate = getDefaultDateFormat(days)
-    }
-
-    override fun interpretDate(date: Calendar): String {
-        return sdfDate.format(date.time).toUpperCase(Locale.getDefault())
-    }
-
-    override fun interpretTime(hour: Int): String {
-        val time = calendar.withTime(hour, minutes = 0)
-        return sdfTime.format(time.time)
-    }
-}
-
-internal interface DateFormatProvider {
-    val is24HourFormat: Boolean
-}
-
-internal class RealDateFormatProvider(
-    private val context: Context
-) : DateFormatProvider {
-
-    override val is24HourFormat: Boolean
-        get() = DateFormat.is24HourFormat(context)
-}

core/src/main/java/com/alamkanak/weekview/DayLabelDrawer.kt

@@ -51,7 +51,7 @@ internal class DayLabelDrawer<T>(
     }
 
     private fun provideAndCacheDayLabel(key: Int, day: Calendar): String {
-        return config.dateTimeInterpreter.interpretDate(day).also {
+        return config.dateFormatter(day).also {
             cache.dayLabelCache.put(key, it)
         }
     }

core/src/main/java/com/alamkanak/weekview/MultiLineDayLabelHeightUpdater.kt

@@ -64,7 +64,7 @@ internal class MultiLineDayLabelHeightUpdater<T>(
     }
 
     private fun provideAndCacheDayLabel(key: Int, day: Calendar): String {
-        return config.dateTimeInterpreter.interpretDate(day).also {
+        return config.dateFormatter(day).also {
             cache.dayLabelCache.put(key, it)
         }
     }

core/src/main/java/com/alamkanak/weekview/TimeColumnDrawer.kt

@@ -16,7 +16,7 @@ internal class TimeColumnDrawer(
 
     private fun cacheTimeLabels() = with(config) {
         for (hour in timeRange step timeColumnHoursInterval) {
-            timeLabelCache.put(hour, dateTimeInterpreter.interpretTime(hour))
+            timeLabelCache.put(hour, timeFormatter(hour))
         }
     }
 

core/src/main/java/com/alamkanak/weekview/WeekView.kt

@@ -1418,13 +1418,28 @@ class WeekView<T : Any> @JvmOverloads constructor(
     }
 
     @PublicApi
+    @Deprecated("Use setDateFormatter() and setTimeFormatter() instead.")
     var dateTimeInterpreter: DateTimeInterpreter
-        get() = configWrapper.dateTimeInterpreter
+        get() = object : DateTimeInterpreter {
+            override fun interpretDate(date: Calendar): String = configWrapper.dateFormatter(date)
+            override fun interpretTime(hour: Int): String = configWrapper.timeFormatter(hour)
+        }
         set(value) {
-            configWrapper.dateTimeInterpreter = value
+            setDateFormatter { value.interpretDate(it) }
+            setTimeFormatter { value.interpretTime(it) }
             clearCaches()
         }
 
+    @PublicApi
+    fun setDateFormatter(formatter: (Calendar) -> String) {
+        configWrapper.dateFormatter = formatter
+    }
+
+    @PublicApi
+    fun setTimeFormatter(formatter: (Int) -> String) {
+        configWrapper.timeFormatter = formatter
+    }
+
     private fun clearCaches() {
         drawers
             .filterIsInstance(CachingDrawer::class.java)

core/src/main/java/com/alamkanak/weekview/WeekViewConfigWrapper.kt

@@ -11,13 +11,14 @@ import java.util.Calendar
 import kotlin.math.max
 import kotlin.math.min
 
+typealias DateFormatter = (Calendar) -> String
+typealias TimeFormatter = (Int) -> String
+
 internal class WeekViewConfigWrapper(
     private val view: WeekView<*>,
     private val config: WeekViewConfig
 ) {
 
-    private val context = view.context
-
     var timeTextPaint: Paint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
         textAlign = Paint.Align.RIGHT
         textSize = config.timeColumnTextSize.toFloat()
@@ -151,13 +152,19 @@ internal class WeekViewConfigWrapper(
     var minDate: Calendar? = null
     var maxDate: Calendar? = null
 
-    private var internalDateTimeInterpreter: DateTimeInterpreter =
-        DefaultDateTimeInterpreter(RealDateFormatProvider(context), numberOfVisibleDays)
+    var dateFormatter: DateFormatter = { date ->
+        defaultDateFormatter(numberOfDays = numberOfVisibleDays).format(date.time)
+    }
+
+    private var _timeFormatter: TimeFormatter = { hour ->
+        val date = now().withTime(hour = hour, minutes = 0)
+        defaultTimeFormatter().format(date.time)
+    }
 
-    var dateTimeInterpreter: DateTimeInterpreter
-        get() = internalDateTimeInterpreter
+    var timeFormatter: TimeFormatter
+        get() = _timeFormatter
         set(value) {
-            internalDateTimeInterpreter = value
+            _timeFormatter = value
             initTextTimeWidth()
         }
 
@@ -752,7 +759,7 @@ internal class WeekViewConfigWrapper(
      */
     private fun initTextTimeWidth() {
         timeTextWidth = (0 until hoursPerDay)
-            .map { dateTimeInterpreter.interpretTime(it) }
+            .map { _timeFormatter(it) }
             .map { timeTextPaint.measureText(it) }
             .max() ?: 0f
     }