Body Mass calculator refactor

- Added normal weight info
- Added link to help
- Added tests

core/base/src/main/res/values/strings.xml

@@ -10,6 +10,9 @@
     <string name="body_mass_imperial">Imperial</string>
     <string name="body_mass_metric">Metric</string>
     <string name="body_mass_normal">Normal weight</string>
+
+    <!-- Will be a text followed by a number like so: "Normal weight for your height - 60" -->
+    <string name="body_mass_normal_weight">Normal weight for your height</string>
     <string name="body_mass_obese_1">Obese (Class 1)</string>
     <string name="body_mass_obese_2">Obese (Class 2)</string>
     <string name="body_mass_obese_3">Obese (Class 3)</string>

core/ui/src/main/java/com/sadellie/unitto/core/ui/LocalWindowSize.kt

@@ -37,7 +37,7 @@ import androidx.window.layout.WindowMetricsCalculator
 
 val LocalWindowSize: ProvidableCompositionLocal<WindowSizeClass> = compositionLocalOf {
     WindowSizeClass.calculateFromSize(
-        size = Size.Unspecified,
+        size = Size.Zero,
         density = defaultDensity
     )
 }

feature/bodymass/src/main/java/com/sadellie/unitto/feature/bodymass/BodyMassScreen.kt

@@ -18,7 +18,6 @@
 
 package com.sadellie.unitto.feature.bodymass
 
-import androidx.annotation.StringRes
 import androidx.compose.animation.AnimatedContent
 import androidx.compose.animation.Crossfade
 import androidx.compose.animation.SizeTransform
@@ -32,33 +31,25 @@ import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.foundation.text.KeyboardActions
-import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.ElevatedButton
 import androidx.compose.material3.MaterialTheme
-import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.Immutable
-import androidx.compose.runtime.Stable
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.clip
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
-import androidx.compose.ui.platform.LocalFocusManager
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.input.ImeAction
-import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.text.input.TextFieldValue
-import androidx.compose.ui.text.input.VisualTransformation
+import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.hilt.navigation.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
-import com.sadellie.unitto.core.base.OutputFormat
 import com.sadellie.unitto.core.base.R
-import com.sadellie.unitto.core.base.Token
 import com.sadellie.unitto.core.ui.common.MenuButton
 import com.sadellie.unitto.core.ui.common.SegmentedButton
 import com.sadellie.unitto.core.ui.common.SegmentedButtonsRow
@@ -66,10 +57,11 @@ import com.sadellie.unitto.core.ui.common.SettingsButton
 import com.sadellie.unitto.core.ui.common.UnittoEmptyScreen
 import com.sadellie.unitto.core.ui.common.UnittoScreenWithTopBar
 import com.sadellie.unitto.core.ui.common.textfield.ExpressionTransformer
-import com.sadellie.unitto.core.ui.common.textfield.formatExpression
-import com.sadellie.unitto.data.common.format
+import com.sadellie.unitto.core.ui.common.textfield.FormatterSymbols
+import com.sadellie.unitto.core.ui.openLink
 import com.sadellie.unitto.data.common.isEqualTo
-import com.sadellie.unitto.data.common.isLessThan
+import com.sadellie.unitto.feature.bodymass.components.BodyMassResult
+import com.sadellie.unitto.feature.bodymass.components.BodyMassTextField
 import java.math.BigDecimal
 
 @Composable
@@ -106,15 +98,10 @@ private fun BodyMassScreen(
     val expressionTransformer = remember(uiState.formatterSymbols) {
         ExpressionTransformer(uiState.formatterSymbols)
     }
-    val weightLabel = remember(uiState.isMetric) {
-        val s1 = mContext.resources.getString(R.string.body_mass_weight)
-        val s2 = if (uiState.isMetric) {
-            mContext.resources.getString(R.string.unit_kilogram_short)
-        } else {
-            mContext.resources.getString(R.string.unit_pound_short)
-        }
-
-        "$s1, $s2"
+    val weightShortLabel = remember(uiState.isMetric) {
+        mContext.resources.getString(
+            if (uiState.isMetric) R.string.unit_kilogram_short else R.string.unit_pound_short
+        )
     }
 
     UnittoScreenWithTopBar(
@@ -124,10 +111,12 @@ private fun BodyMassScreen(
     ) { paddingValues ->
         Column(
             modifier = Modifier
+                .verticalScroll(rememberScrollState())
                 .padding(paddingValues)
                 .padding(16.dp)
                 .fillMaxSize(),
-            verticalArrangement = Arrangement.spacedBy(16.dp)
+            verticalArrangement = Arrangement.spacedBy(16.dp),
+            horizontalAlignment = Alignment.CenterHorizontally
         ) {
             SegmentedButtonsRow(
                 modifier = Modifier.fillMaxWidth()
@@ -193,7 +182,7 @@ private fun BodyMassScreen(
                     modifier = Modifier.fillMaxWidth(),
                     value = uiState.weight,
                     onValueChange = updateWeight,
-                    label = weightLabel,
+                    label = "${stringResource(R.string.body_mass_weight)}, $weightShortLabel",
                     expressionFormatter = expressionTransformer,
                     imeAction = ImeAction.Done
                 )
@@ -208,112 +197,44 @@ private fun BodyMassScreen(
             ) { targetState ->
                 if (targetState.isEqualTo(BigDecimal.ZERO)) return@AnimatedContent
 
-                val value = remember(targetState) {
-                    targetState
-                        .format(3, OutputFormat.PLAIN)
-                        .formatExpression(uiState.formatterSymbols)
-                }
+                BodyMassResult(
+                    value = targetState,
+                    range = uiState.normalWeightRange,
+                    rangeSuffix = weightShortLabel,
+                    formatterSymbols = uiState.formatterSymbols
+                )
+            }
 
-                val classification = remember(targetState) {
-                    getBodyMassData(targetState)
-                }
-
-                Column(
-                    modifier = Modifier
-                        .clip(RoundedCornerShape(32.dp))
-                        .background(classification.color)
-                        .padding(16.dp, 32.dp)
-                        .fillMaxWidth(),
-                    horizontalAlignment = Alignment.CenterHorizontally,
-                    verticalArrangement = Arrangement.Center
-                ) {
-                    // TODO Link to web
-
-                    Text(
-                        text = stringResource(classification.classification),
-                        style = MaterialTheme.typography.displaySmall,
-                    )
-                    Text(
-                        text = value,
-                        style = MaterialTheme.typography.bodyLarge
-                    )
+            ElevatedButton(
+                onClick = {
+                    openLink(mContext, "https://sadellie.github.io/unitto/help#body-mass-index")
                 }
+            ) {
+                Text(text = stringResource(R.string.time_zone_no_results_button)) // TODO Rename
             }
         }
     }
 }
 
+@Preview
 @Composable
-private fun BodyMassTextField(
-    modifier: Modifier,
-    value: TextFieldValue,
-    onValueChange: (TextFieldValue) -> Unit,
-    label: String,
-    expressionFormatter: VisualTransformation,
-    imeAction: ImeAction
-) {
-    val focusManager = LocalFocusManager.current
-    OutlinedTextField(
-        modifier = modifier,
-        value = value,
-        onValueChange = {
-            val cleanText = it.text
-                .replace(",", ".")
-                .filter { char ->
-                    Token.Digit.allWithDot.contains(char.toString())
-                }
-            onValueChange(it.copy(cleanText))
-        },
-        label = { AnimatedContent(label) { Text(it) } },
-        singleLine = true,
-        visualTransformation = expressionFormatter,
-        keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal, imeAction = imeAction),
-        keyboardActions = KeyboardActions(onDone = { focusManager.clearFocus() })
+fun PreviewBodyMassScreen() {
+    BodyMassScreen(
+        uiState = UIState.Ready(
+            isMetric = false,
+            height1 = TextFieldValue(),
+            height2 = TextFieldValue(),
+            weight = TextFieldValue(),
+            normalWeightRange = BigDecimal(30) to BigDecimal(50),
+            result = BigDecimal(18.5),
+            allowVibration = false,
+            formatterSymbols = FormatterSymbols.Spaces
+        ),
+        updateHeight1 = {},
+        updateHeight2 = {},
+        updateWeight = {},
+        updateIsMetric = {},
+        openDrawer = {},
+        navigateToSettings = {}
     )
 }
-
-@Immutable
-private data class BodyMassData(
-    val color: Color,
-    @StringRes val classification: Int
-)
-
-@Stable
-private fun getBodyMassData(value: BigDecimal): BodyMassData = when {
-    value.isLessThan(BigDecimal("18.5")) -> {
-        BodyMassData(
-            color = Color(0x800EACDD),
-            classification = R.string.body_mass_underweight
-        )
-    }
-    value.isLessThan(BigDecimal("25")) -> {
-        BodyMassData(
-            color = Color(0x805BF724),
-            classification = R.string.body_mass_normal
-        )
-    }
-    value.isLessThan(BigDecimal("30")) -> {
-        BodyMassData(
-            color = Color(0x80DBEC18),
-            classification = R.string.body_mass_overweight
-        )
-    }
-    value.isLessThan(BigDecimal("35")) -> {
-        BodyMassData(
-            color = Color(0x80FF9634),
-            classification = R.string.body_mass_obese_1
-        )
-    }
-    value.isLessThan(BigDecimal("40")) -> {
-        BodyMassData(
-            color = Color(0x80F85F31),
-            classification = R.string.body_mass_obese_2
-        )
-    }
-    else -> {
-        BodyMassData(
-            color = Color(0x80FF2323),
-            classification = R.string.body_mass_obese_3
-        )
-    }
-}

feature/bodymass/src/main/java/com/sadellie/unitto/feature/bodymass/BodyMassUtils.kt

@@ -0,0 +1,112 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2024 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.bodymass
+
+import com.sadellie.unitto.core.base.MAX_PRECISION
+import java.math.BigDecimal
+import java.math.RoundingMode
+
+/**
+ * Calculates BMI value for metric system.
+ *
+ * @param heightCm Height in centimeters.
+ * @param weightKg Weight in kilograms.
+ * @return BMI Value with [MAX_PRECISION].
+ */
+internal fun calculateMetric(
+    heightCm: BigDecimal,
+    weightKg: BigDecimal,
+): BigDecimal {
+    val heightMeters = heightCm
+        .divide(cmToMFactor, MAX_PRECISION, RoundingMode.HALF_EVEN)
+
+    return weightKg
+        .divide(heightMeters.pow(2), MAX_PRECISION, RoundingMode.HALF_EVEN)
+}
+
+/**
+ * Calculates BMI value for imperial system.
+ *
+ * @param heightFt Height in feet.
+ * @param heightIn Height in inches.
+ * @param weightLbs Weight in pounds.
+ * @return BMI Value with [MAX_PRECISION].
+ */
+internal fun calculateImperial(
+    heightFt: BigDecimal,
+    heightIn: BigDecimal,
+    weightLbs: BigDecimal
+): BigDecimal {
+    val heightInches = heightFt
+        .multiply(footToInchFactor)
+        .plus(heightIn)
+
+    return weightLbs
+        .divide(heightInches.pow(2), MAX_PRECISION, RoundingMode.HALF_EVEN)
+        .multiply(metricToImperialFactor) // Approximate lbs/inch^2 to kg/m^2
+}
+
+/**
+ * Calculates weight (kilograms) range for normal BMI values.
+ *
+ * @param heightCm Height in centimeters.
+ * @return [Pair] of [BigDecimal]. First value is lowest weight. Second value is highest value.
+ */
+internal fun calculateNormalWeightMetric(
+    heightCm: BigDecimal
+): Pair<BigDecimal, BigDecimal> {
+    val heightMetres2 = heightCm
+        .divide(cmToMFactor, MAX_PRECISION, RoundingMode.HALF_EVEN)
+        .pow(2)
+
+    val lowest = lowestNormalIndex.multiply(heightMetres2)
+    val highest = highestNormalIndex.multiply(heightMetres2)
+
+    return lowest to highest
+}
+
+/**
+ * Calculates weight (pounds) range for normal BMI values.
+ *
+ * @param heightFt Height in feet.
+ * @param heightIn Height in inches.
+ * @return [Pair] of [BigDecimal]. First value is lowest weight. Second value is highest value.
+ */
+internal fun calculateNormalWeightImperial(
+    heightFt: BigDecimal,
+    heightIn: BigDecimal,
+): Pair<BigDecimal, BigDecimal> {
+    val heightInches2 = heightFt
+        .multiply(footToInchFactor)
+        .plus(heightIn)
+        .pow(2)
+        .divide(metricToImperialFactor, MAX_PRECISION, RoundingMode.HALF_EVEN)
+
+    val lowest = lowestNormalIndex.multiply(heightInches2)
+    val highest = highestNormalIndex.multiply(heightInches2)
+
+    return lowest to highest
+}
+
+private val cmToMFactor = BigDecimal("100")
+private val footToInchFactor = BigDecimal("12")
+private val metricToImperialFactor = BigDecimal("703")
+
+private val lowestNormalIndex = BigDecimal("18.5")
+private val highestNormalIndex = BigDecimal("25")

feature/bodymass/src/main/java/com/sadellie/unitto/feature/bodymass/BodyMassViewModel.kt

@@ -24,7 +24,6 @@ import android.os.Build
 import androidx.compose.ui.text.input.TextFieldValue
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
-import com.sadellie.unitto.core.base.MAX_PRECISION
 import com.sadellie.unitto.core.ui.common.textfield.AllFormatterSymbols
 import com.sadellie.unitto.data.common.combine
 import com.sadellie.unitto.data.common.stateIn
@@ -36,7 +35,6 @@ import kotlinx.coroutines.flow.mapLatest
 import kotlinx.coroutines.flow.update
 import kotlinx.coroutines.withContext
 import java.math.BigDecimal
-import java.math.RoundingMode
 import javax.inject.Inject
 
 @HiltViewModel
@@ -48,9 +46,7 @@ internal class BodyMassViewModel @Inject constructor(
     private val _height2 = MutableStateFlow(TextFieldValue())
     private val _weight = MutableStateFlow(TextFieldValue())
     private val _result = MutableStateFlow<BigDecimal>(BigDecimal.ZERO)
-    private val cmToMFactor = BigDecimal("10000")
-    private val footToInchFactor = BigDecimal("12")
-    private val metricToImperialFactor = BigDecimal("703")
+    private val _normalWeightRange = MutableStateFlow<Pair<BigDecimal, BigDecimal>>(BigDecimal.ZERO to BigDecimal.ZERO)
 
     val uiState = combine(
         userPreferencesRepository.bodyMassPrefs,
@@ -58,35 +54,41 @@ internal class BodyMassViewModel @Inject constructor(
         _height1,
         _height2,
         _weight,
-        _result
-    ) { userPrefs, isMetric, height1, height2, weight, result ->
+        _result,
+        _normalWeightRange
+    ) { userPrefs, isMetric, height1, height2, weight, result, normalWeightRange ->
         UIState.Ready(
             isMetric = isMetric,
             height1 = height1,
             height2 = height2,
             weight = weight,
             result = result,
+            normalWeightRange = normalWeightRange,
             allowVibration = userPrefs.enableVibrations,
             formatterSymbols = AllFormatterSymbols.getById(userPrefs.separator)
         )
     }
         .mapLatest { ui ->
-            val newResult: BigDecimal = try {
-                val height1 = BigDecimal(ui.height1.text.ifEmpty { "0" })
-                val weight = BigDecimal(ui.weight.text.ifEmpty { "0" })
+            withContext(Dispatchers.Default) {
+                try {
+                    val height1 = BigDecimal(ui.height1.text.ifEmpty { "0" })
+                    val weight = BigDecimal(ui.weight.text.ifEmpty { "0" })
 
-                if (ui.isMetric) {
-                    calculateMetric(height1, weight)
-                } else {
-                    val height2 = BigDecimal(ui.height2.text.ifEmpty { "0" })
-                    calculateImperial(height1, height2, weight)
+                    if (ui.isMetric) {
+                        _result.update { calculateMetric(height1, weight) }
+                        _normalWeightRange.update { calculateNormalWeightMetric(height1) }
+                    } else {
+                        val height2 = BigDecimal(ui.height2.text.ifEmpty { "0" })
+
+                        _result.update { calculateImperial(height1, height2, weight) }
+                        _normalWeightRange.update { calculateNormalWeightImperial(height1, height2) }
+                    }
+                } catch (e: Exception) {
+                    _result.update { BigDecimal.ZERO }
+                    _normalWeightRange.update { BigDecimal.ZERO to BigDecimal.ZERO }
                 }
-            } catch (e: Exception) {
-                BigDecimal.ZERO
             }
 
-            _result.update { newResult }
-
             ui
         }
         .stateIn(viewModelScope, UIState.Loading)
@@ -96,29 +98,6 @@ internal class BodyMassViewModel @Inject constructor(
     fun updateWeight(textFieldValue: TextFieldValue) = _weight.update { textFieldValue }
     fun updateIsMetric(isMetric: Boolean) = _isMetric.update { isMetric }
 
-    private suspend  fun calculateMetric(
-        height: BigDecimal,
-        weight: BigDecimal,
-    ) = withContext(Dispatchers.Default) {
-        return@withContext weight
-            .divide(height.pow(2), MAX_PRECISION, RoundingMode.HALF_EVEN)
-            .multiply(cmToMFactor)
-    }
-
-    private suspend fun calculateImperial(
-        height1: BigDecimal,
-        height2: BigDecimal,
-        weight: BigDecimal
-    ) = withContext(Dispatchers.Default) {
-        val height = height1
-            .multiply(footToInchFactor)
-            .plus(height2)
-
-        return@withContext weight
-            .divide(height.pow(2), MAX_PRECISION, RoundingMode.HALF_EVEN)
-            .multiply(metricToImperialFactor) // Approximate lbs/inch^2 to kg/m^2
-    }
-
     private fun getInitialIsMetric(): Boolean {
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) return true
         return LocaleData.getMeasurementSystem(ULocale.getDefault()) != LocaleData.MeasurementSystem.US

feature/bodymass/src/main/java/com/sadellie/unitto/feature/bodymass/UIState.kt

@@ -30,6 +30,7 @@ internal sealed class UIState {
         val height1: TextFieldValue,
         val height2: TextFieldValue,
         val weight: TextFieldValue,
+        val normalWeightRange: Pair<BigDecimal, BigDecimal>,
         val result: BigDecimal,
         val allowVibration: Boolean,
         val formatterSymbols: FormatterSymbols,

feature/bodymass/src/main/java/com/sadellie/unitto/feature/bodymass/components/BodyMassResult.kt

@@ -0,0 +1,176 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2024 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.bodymass.components
+
+import androidx.annotation.StringRes
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.Stable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import com.sadellie.unitto.core.base.OutputFormat
+import com.sadellie.unitto.core.base.R
+import com.sadellie.unitto.core.ui.common.textfield.FormatterSymbols
+import com.sadellie.unitto.core.ui.common.textfield.formatExpression
+import com.sadellie.unitto.data.common.format
+import java.math.BigDecimal
+
+@Composable
+internal fun BodyMassResult(
+    modifier: Modifier = Modifier,
+    value: BigDecimal,
+    range: Pair<BigDecimal, BigDecimal>,
+    rangeSuffix: String,
+    formatterSymbols: FormatterSymbols,
+) {
+    val formattedValue = remember(value, formatterSymbols) {
+        value
+            .format(3, OutputFormat.PLAIN)
+            .formatExpression(formatterSymbols)
+    }
+
+    val formattedRange = remember(range, formatterSymbols) {
+        val low = range.first
+            .format(0, OutputFormat.PLAIN)
+            .formatExpression(formatterSymbols)
+
+        val high = range.second
+            .format(0, OutputFormat.PLAIN)
+            .formatExpression(formatterSymbols)
+
+        "$low – $high $rangeSuffix"
+    }
+
+    val classification = remember(value) {
+        getBodyMassData(value)
+    }
+
+    Column(
+        modifier = modifier,
+        verticalArrangement = Arrangement.spacedBy(16.dp)
+    ) {
+        Column(
+            modifier = Modifier
+                .clip(RoundedCornerShape(32.dp))
+                .background(classification.color)
+                .padding(16.dp, 32.dp)
+                .fillMaxWidth(),
+        ) {
+            Text(
+                text = stringResource(classification.classification),
+                style = MaterialTheme.typography.displaySmall,
+                color = MaterialTheme.colorScheme.onSecondaryContainer
+            )
+            Text(
+                text = formattedValue,
+                style = MaterialTheme.typography.bodyLarge,
+                color = MaterialTheme.colorScheme.onSecondaryContainer
+            )
+        }
+
+        Column(
+            modifier = Modifier
+                .clip(RoundedCornerShape(32.dp))
+                .background(MaterialTheme.colorScheme.secondaryContainer)
+                .padding(16.dp, 32.dp)
+                .fillMaxWidth(),
+        ) {
+            Text(
+                text = formattedRange,
+                style = MaterialTheme.typography.displaySmall,
+                color = MaterialTheme.colorScheme.onSecondaryContainer
+            )
+            Text(
+                text = stringResource(R.string.body_mass_normal_weight),
+                style = MaterialTheme.typography.bodyLarge,
+                color = MaterialTheme.colorScheme.onSecondaryContainer
+            )
+        }
+    }
+}
+
+@Immutable
+private data class BodyMassData(
+    val minValue: BigDecimal,
+    val color: Color,
+    @StringRes val classification: Int
+)
+
+@Stable
+private fun getBodyMassData(value: BigDecimal): BodyMassData =
+    indexes.first { value >= it.minValue }
+
+private val indexes by lazy {
+    listOf(
+        BodyMassData(
+            minValue = BigDecimal("40"),
+            color = Color(0x80FF2323),
+            classification = R.string.body_mass_obese_3
+        ),
+        BodyMassData(
+            minValue = BigDecimal("35"),
+            color = Color(0x80F85F31),
+            classification = R.string.body_mass_obese_2
+        ),
+        BodyMassData(
+            minValue = BigDecimal("30"),
+            color = Color(0x80FF9634),
+            classification = R.string.body_mass_obese_1
+        ),
+        BodyMassData(
+            minValue = BigDecimal("25"),
+            color = Color(0x80DBEC18),
+            classification = R.string.body_mass_overweight
+        ),
+        BodyMassData(
+            minValue = BigDecimal("18.5"),
+            color = Color(0x805BF724),
+            classification = R.string.body_mass_normal
+        ),
+        BodyMassData(
+            minValue = BigDecimal("0"),
+            color = Color(0x800EACDD),
+            classification = R.string.body_mass_underweight
+        ),
+    )
+}
+
+@Preview
+@Composable
+fun PreviewBodyMassResult() {
+    BodyMassResult(
+        value = BigDecimal(18.5),
+        range = BigDecimal(50) to BigDecimal(80),
+        rangeSuffix = "kg",
+        formatterSymbols = FormatterSymbols.Spaces,
+    )
+}

feature/bodymass/src/main/java/com/sadellie/unitto/feature/bodymass/components/BodyMassTextField.kt

@@ -0,0 +1,68 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2024 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.bodymass.components
+
+import androidx.compose.animation.AnimatedContent
+import androidx.compose.foundation.text.KeyboardActions
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material3.LocalTextStyle
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalFocusManager
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.input.TextFieldValue
+import androidx.compose.ui.text.input.VisualTransformation
+import androidx.compose.ui.text.style.TextAlign
+import com.sadellie.unitto.core.base.Token
+
+@Composable
+internal fun BodyMassTextField(
+    modifier: Modifier,
+    value: TextFieldValue,
+    onValueChange: (TextFieldValue) -> Unit,
+    label: String,
+    expressionFormatter: VisualTransformation,
+    imeAction: ImeAction
+) {
+    val focusManager = LocalFocusManager.current
+    OutlinedTextField(
+        modifier = modifier,
+        value = value,
+        onValueChange = {
+            val cleanText = it.text
+                .replace(",", ".")
+                .filter { char ->
+                    Token.Digit.allWithDot.contains(char.toString())
+                }
+            onValueChange(it.copy(cleanText))
+        },
+        label = { AnimatedContent(label) { Text(it) } },
+        singleLine = true,
+        visualTransformation = expressionFormatter,
+        keyboardOptions = KeyboardOptions(
+            keyboardType = KeyboardType.Decimal,
+            imeAction = imeAction
+        ),
+        textStyle = LocalTextStyle.current.copy(textAlign = TextAlign.End),
+        keyboardActions = KeyboardActions(onDone = { focusManager.clearFocus() })
+    )
+}

feature/bodymass/src/test/java/com/sadellie/unitto/feature/bodymass/BodyMassTest.kt

@@ -0,0 +1,72 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2024 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto.feature.bodymass
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import java.math.BigDecimal
+import java.math.RoundingMode
+
+class BodyMassTest {
+    @Test
+    fun testCalculateMetric() {
+        val height = BigDecimal("190")
+        val weight = BigDecimal("80")
+        val expected = BigDecimal("22.161").scaleDown()
+        val actual = calculateMetric(height, weight).scaleDown()
+
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun testCalculateImperial() {
+        val height1 = BigDecimal("6")
+        val height2 = BigDecimal("5")
+        val weight = BigDecimal("150")
+        val expected = BigDecimal("17.785")
+        val actual = calculateImperial(height1, height2, weight).scaleDown()
+
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun testCalculateNormalWeightMetric() {
+        val height = BigDecimal("190")
+        val expectedWeight1 = BigDecimal("66.785")
+        val expectedWeight2 = BigDecimal("90.250")
+        val actualWeight = calculateNormalWeightMetric(height)
+
+        assertEquals(expectedWeight1, actualWeight.first.scaleDown())
+        assertEquals(expectedWeight2, actualWeight.second.scaleDown())
+    }
+
+    @Test
+    fun testCalculateNormalWeightImperial() {
+        val heightFt = BigDecimal("6")
+        val heightIn = BigDecimal("5")
+        val expectedWeight1 = BigDecimal("156.026")
+        val expectedWeight2 = BigDecimal("210.846")
+        val actualWeight = calculateNormalWeightImperial(heightFt, heightIn)
+
+        assertEquals(expectedWeight1, actualWeight.first.scaleDown())
+        assertEquals(expectedWeight2, actualWeight.second.scaleDown())
+    }
+
+    private fun BigDecimal.scaleDown(): BigDecimal = setScale(3, RoundingMode.HALF_EVEN)
+}