Use dots to indicate pages

core/ui/src/main/java/com/sadellie/unitto/core/ui/common/PagedIsland.kt

@@ -0,0 +1,108 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2023 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.core.ui.common
+
+import androidx.annotation.IntRange
+import androidx.compose.animation.AnimatedContent
+import androidx.compose.foundation.Canvas
+import androidx.compose.foundation.background
+import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ColumnScope
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.contentColorFor
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+
+@Composable
+fun PagedIsland(
+    modifier: Modifier = Modifier,
+    @IntRange(from = 1) pagesCount: Int,
+    onPageChange: (currentPage: Int) -> Unit = {},
+    backgroundColor: Color = MaterialTheme.colorScheme.secondaryContainer,
+    pageContent: @Composable ColumnScope.(currentPage: Int) -> Unit,
+) {
+    var currentPage: Int by remember { mutableIntStateOf(0) }
+    val contentColor = MaterialTheme.colorScheme.contentColorFor(backgroundColor)
+    val disabledContentColor = contentColor.copy(alpha = 0.5f)
+
+    AnimatedContent(
+        modifier = modifier
+            .squashable(
+                onClick = {
+                    if (currentPage == pagesCount - 1) currentPage = 0 else currentPage++
+                    onPageChange(currentPage)
+                },
+                cornerRadiusRange = 8.dp..32.dp,
+                interactionSource = remember { MutableInteractionSource() }
+            )
+            .background(backgroundColor),
+        targetState = currentPage
+    ) { state ->
+        ProvideColor(color = contentColor) {
+            Column(
+                modifier = Modifier.padding(16.dp)
+            ) {
+                Row(
+                    modifier = Modifier
+                        .padding(8.dp),
+                    horizontalArrangement = Arrangement.spacedBy(8.dp)
+                ) {
+                    repeat(pagesCount) {
+                        ADot(color = if (it == state) contentColor else disabledContentColor)
+                    }
+                }
+                pageContent(state)
+            }
+        }
+    }
+}
+
+@Composable
+private fun ADot(
+    color: Color,
+) {
+    Canvas(modifier = Modifier.size(4.dp)) {
+        drawCircle(color)
+    }
+}
+
+@Preview
+@Composable
+private fun PreviewPagedIsland() {
+    PagedIsland(pagesCount = 5) { currentPage ->
+        Text("Current page: $currentPage")
+
+        if (currentPage == 3) {
+            Text("Middle in: $currentPage")
+        }
+    }
+}

feature/settings/src/main/java/com/sadellie/unitto/feature/settings/formatting/FormattingScreen.kt

@@ -18,11 +18,8 @@
 
 package com.sadellie.unitto.feature.settings.formatting
 
-import androidx.compose.foundation.background
 import androidx.compose.foundation.horizontalScroll
-import androidx.compose.foundation.interaction.MutableInteractionSource
 import androidx.compose.foundation.layout.Arrangement
-import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
@@ -55,15 +52,18 @@ import com.sadellie.unitto.core.base.OutputFormat
 import com.sadellie.unitto.core.base.R
 import com.sadellie.unitto.core.base.Separator
 import com.sadellie.unitto.core.ui.common.NavigateUpButton
+import com.sadellie.unitto.core.ui.common.PagedIsland
 import com.sadellie.unitto.core.ui.common.SegmentedButton
 import com.sadellie.unitto.core.ui.common.SegmentedButtonsRow
 import com.sadellie.unitto.core.ui.common.UnittoEmptyScreen
 import com.sadellie.unitto.core.ui.common.UnittoListItem
 import com.sadellie.unitto.core.ui.common.UnittoScreenWithLargeTopBar
 import com.sadellie.unitto.core.ui.common.UnittoSlider
-import com.sadellie.unitto.core.ui.common.squashable
+import com.sadellie.unitto.core.ui.common.textfield.FormatterSymbols
 import com.sadellie.unitto.core.ui.common.textfield.formatExpression
 import com.sadellie.unitto.core.ui.theme.NumberTypographyUnitto
+import com.sadellie.unitto.data.common.format
+import kotlin.math.ceil
 import kotlin.math.roundToInt
 
 @Composable
@@ -80,7 +80,6 @@ fun FormattingRoute(
                 onPrecisionChange = viewModel::updatePrecision,
                 onSeparatorChange = viewModel::updateSeparator,
                 onOutputFormatChange = viewModel::updateOutputFormat,
-                togglePreview = viewModel::togglePreview
             )
         }
     }
@@ -93,7 +92,6 @@ fun FormattingScreen(
     onPrecisionChange: (Int) -> Unit,
     onSeparatorChange: (Int) -> Unit,
     onOutputFormatChange: (Int) -> Unit,
-    togglePreview: () -> Unit,
     precisions: ClosedFloatingPointRange<Float> = 0f..16f, // 16th is a MAX_PRECISION (1000)
 ) {
     val resources = LocalContext.current.resources
@@ -120,25 +118,24 @@ fun FormattingScreen(
                 .padding(paddingValues)
         ) {
             item("preview") {
-                Column(
-                    Modifier
-                        .padding(16.dp)
-                        .squashable(
-                            onClick = togglePreview,
-                            cornerRadiusRange = 8.dp..32.dp,
-                            interactionSource = remember { MutableInteractionSource() }
-                        )
-                        .background(MaterialTheme.colorScheme.secondaryContainer)
+                PagedIsland(
+                    modifier = Modifier
                         .fillMaxWidth()
-                        .padding(16.dp)
-                ) {
+                        .padding(16.dp),
+                    pagesCount = 2,
+                ) { currentPage ->
+                    val preview = when (currentPage) {
+                        0 -> "123456.${"789123456".repeat(ceil(uiState.precision.toDouble() / 9.0).toInt())}"
+                        1 -> "0.${"1".padStart(uiState.precision, '0')}"
+                        else -> ""
+                    }
+                        .toBigDecimalOrNull()
+                        ?.format(uiState.precision, uiState.outputFormat)
+                        ?.formatExpression(uiState.formatterSymbols)
+                        ?: ""
+
                     Text(
-                        text = stringResource(R.string.settings_formatting_preview),
-                        style = MaterialTheme.typography.labelMedium,
-                        color = MaterialTheme.colorScheme.onSecondaryContainer
-                    )
-                    Text(
-                        text = uiState.preview,
+                        text = preview,
                         style = NumberTypographyUnitto.displayMedium,
                         maxLines = 1,
                         modifier = Modifier
@@ -153,7 +150,10 @@ fun FormattingScreen(
             item("precision_label") {
                 UnittoListItem(
                     leadingContent = {
-                        Icon(Icons.Default.Architecture, stringResource(R.string.settings_precision))
+                        Icon(
+                            Icons.Default.Architecture,
+                            stringResource(R.string.settings_precision)
+                        )
                     },
                     headlineContent = {
                         Row(
@@ -265,15 +265,14 @@ private fun PreviewFormattingScreen() {
 
     FormattingScreen(
         uiState = FormattingUIState(
-            preview = "123456.789",
             precision = 16,
             separator = Separator.SPACE,
-            outputFormat = OutputFormat.PLAIN
+            outputFormat = OutputFormat.PLAIN,
+            formatterSymbols = FormatterSymbols.Spaces
         ),
         onPrecisionChange = { currentPrecision = it },
         onSeparatorChange = { currentSeparator = it },
         onOutputFormatChange = { currentOutputFormat = it },
         navigateUpAction = {},
-        togglePreview = {}
     )
 }

feature/settings/src/main/java/com/sadellie/unitto/feature/settings/formatting/FormattingUIState.kt

@@ -21,9 +21,8 @@ package com.sadellie.unitto.feature.settings.formatting
 import com.sadellie.unitto.core.ui.common.textfield.FormatterSymbols
 
 data class FormattingUIState(
-    val preview: String = "",
-    val precision: Int = 0,
-    val separator: Int? = null,
-    val outputFormat: Int? = null,
-    val formatterSymbols: FormatterSymbols = FormatterSymbols.Spaces
+    val precision: Int,
+    val separator: Int,
+    val outputFormat: Int,
+    val formatterSymbols: FormatterSymbols,
 )

feature/settings/src/main/java/com/sadellie/unitto/feature/settings/formatting/FormattingViewModel.kt

@@ -22,64 +22,29 @@ 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.core.ui.common.textfield.FormatterSymbols
-import com.sadellie.unitto.core.ui.common.textfield.formatExpression
-import com.sadellie.unitto.data.common.format
 import com.sadellie.unitto.data.common.stateIn
 import com.sadellie.unitto.data.model.repository.UserPreferencesRepository
 import dagger.hilt.android.lifecycle.HiltViewModel
-import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.combine
-import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
-import java.math.BigDecimal
 import javax.inject.Inject
-import kotlin.math.ceil
 
 @HiltViewModel
 class FormattingViewModel @Inject constructor(
     private val userPreferencesRepository: UserPreferencesRepository
 ) : ViewModel() {
     private val _prefs = userPreferencesRepository.formattingPrefs
-    private val _fractional = MutableStateFlow(false)
 
-    val uiState = combine(_prefs, _fractional) { mainPrefs, fractional ->
-        val formatterSymbols = AllFormatterSymbols.getById(mainPrefs.separator)
-
-        return@combine FormattingUIState(
-            preview = updatePreview(
-                fractional = fractional,
-                precision = mainPrefs.digitsPrecision,
-                outputFormat = mainPrefs.outputFormat,
-                formatterSymbols = formatterSymbols
-            ),
+    val uiState = _prefs.map { mainPrefs ->
+        FormattingUIState(
             precision = mainPrefs.digitsPrecision,
             separator = mainPrefs.separator,
             outputFormat = mainPrefs.outputFormat,
-            formatterSymbols = formatterSymbols
+            formatterSymbols = AllFormatterSymbols.getById(mainPrefs.separator)
         )
     }
         .stateIn(viewModelScope, null)
 
-    fun togglePreview() = _fractional.update { !it }
-
-    private fun updatePreview(
-        fractional: Boolean,
-        precision: Int,
-        outputFormat: Int,
-        formatterSymbols: FormatterSymbols
-    ): String {
-        val bigD = when {
-            fractional -> "0.${"1".padStart(precision, '0')}"
-            precision > 0 -> "123456.${"789123456".repeat(ceil(precision.toDouble() / 9.0).toInt())}"
-            else -> "123456"
-        }
-
-        return BigDecimal(bigD)
-            .format(precision, outputFormat)
-            .formatExpression(formatterSymbols)
-    }
-
     /**
      * @see UserPreferencesRepository.updateDigitsPrecision
      */