Direct Settlement

app/src/main/java/net/helcel/cowspent/android/bill_edit/EditBillScreen.kt

@@ -1,11 +1,14 @@
 package net.helcel.cowspent.android.bill_edit
 
 import android.annotation.SuppressLint
+import android.os.Build
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
+import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.foundation.interaction.MutableInteractionSource
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.text.BasicTextField
 import androidx.compose.foundation.text.KeyboardActions
 import androidx.compose.foundation.text.KeyboardOptions
@@ -19,18 +22,24 @@ import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.draw.drawBehind
+import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.draw.scale
 import androidx.compose.ui.focus.FocusDirection
 import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.focus.onFocusChanged
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.SolidColor
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalFocusManager
+import androidx.compose.ui.res.colorResource
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.TextRange
 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 androidx.compose.ui.tooling.preview.Preview
@@ -62,6 +71,8 @@ fun EditBillScreen(
     val canEdit = accessLevel == DBProject.ACCESS_LEVEL_UNKNOWN || accessLevel >= DBProject.ACCESS_LEVEL_PARTICIPANT
     val context = LocalContext.current
     val focusRequester = remember { FocusRequester() }
+    var amountFocused by remember { mutableStateOf(false) }
+    var amountSelection by remember { mutableStateOf(TextRange(viewModel.amount.length)) }
 
     // The activity reads the project off the main thread and only then reports whether this is a
     // new bill, so the flag arrives after the first composition. Keying on it rather than on Unit
@@ -118,16 +129,21 @@ fun EditBillScreen(
                 val errorOwers = stringResource(R.string.error_invalid_bill_owers)
                 val errorInvalidForm = stringResource(R.string.error_generic)
 
-                FloatingActionButton(onClick = {
-                    val validationError = viewModel.getValidationError(
-                        errorWhat, errorDate, errorPayer, errorOwers, errorInvalidForm
-                    )
-                    if (validationError == null) {
-                        onSave()
-                    } else {
-                        showToast(context, validationError)
-                    }
-                }) {
+                FloatingActionButton(
+                    // Keep the button clear of the operator row pinned above the keyboard.
+                    modifier = Modifier.padding(
+                        bottom = if (amountFocused) MathOperatorRowHeight else 0.dp
+                    ),
+                    onClick = {
+                        val validationError = viewModel.getValidationError(
+                            errorWhat, errorDate, errorPayer, errorOwers, errorInvalidForm
+                        )
+                        if (validationError == null) {
+                            onSave()
+                        } else {
+                            showToast(context, validationError)
+                        }
+                    }) {
                     Icon(
                         Icons.Default.Done,
                         contentDescription = stringResource(R.string.action_save)
@@ -141,42 +157,138 @@ fun EditBillScreen(
             modifier = Modifier
                 .padding(padding)
                 .imePadding()
-                .padding(16.dp)
                 .fillMaxSize()
-                .verticalScroll(scrollState)
         ) {
-            BillBasicInfoSection(
-                viewModel = viewModel,
-                canEdit = canEdit,
-                onDateClick = onDateClick,
-                onTimeClick = onTimeClick,
-                amountFocusRequester = focusRequester
-            )
+            Column(
+                modifier = Modifier
+                    .weight(1f)
+                    .padding(16.dp)
+                    .verticalScroll(scrollState)
+            ) {
+                BillBasicInfoSection(
+                    viewModel = viewModel,
+                    canEdit = canEdit,
+                    onDateClick = onDateClick,
+                    onTimeClick = onTimeClick,
+                    amountFocusRequester = focusRequester,
+                    amountSelection = amountSelection,
+                    onAmountSelectionChange = { amountSelection = it },
+                    onAmountFocusChange = { amountFocused = it }
+                )
 
-            Spacer(modifier = Modifier.height(8.dp))
+                Spacer(modifier = Modifier.height(8.dp))
 
-            PayerSection(
-                viewModel = viewModel,
-                canEdit = canEdit
-            )
+                PayerSection(
+                    viewModel = viewModel,
+                    canEdit = canEdit
+                )
 
-            Spacer(modifier = Modifier.height(8.dp))
+                Spacer(modifier = Modifier.height(8.dp))
 
-            OwerSelectionSection(
-                viewModel = viewModel,
-                canEdit = canEdit
-            )
+                OwerSelectionSection(
+                    viewModel = viewModel,
+                    canEdit = canEdit
+                )
 
-            Spacer(modifier = Modifier.height(8.dp))
+                Spacer(modifier = Modifier.height(8.dp))
 
-            BillAdditionalDetailsSection(
-                viewModel = viewModel,
-                categories = categories,
-                paymentModes = paymentModes,
-                canEdit = canEdit
-            )
+                BillAdditionalDetailsSection(
+                    viewModel = viewModel,
+                    categories = categories,
+                    paymentModes = paymentModes,
+                    canEdit = canEdit
+                )
 
-            Spacer(modifier = Modifier.height(8.dp))
+                Spacer(modifier = Modifier.height(8.dp))
+            }
+
+            if (amountFocused && canEdit) {
+                MathOperatorRow(onInsert = { op ->
+                    val text = viewModel.amount
+                    val start = amountSelection.min.coerceIn(0, text.length)
+                    val end = amountSelection.max.coerceIn(0, text.length)
+                    viewModel.amount = text.replaceRange(start, end, op)
+                    amountSelection = TextRange(start + op.length)
+                    viewModel.updateSplits()
+                })
+            }
+        }
+    }
+}
+
+private val MathOperatorRowHeight = 54.dp
+
+private data class KeyboardColors(val tray: Color, val edge: Color, val key: Color, val label: Color)
+
+@Composable
+private fun keyboardColors(): KeyboardColors {
+    val dark = isSystemInDarkTheme()
+    return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+        val (tray, edge) = when {
+            Build.VERSION.SDK_INT >= Build.VERSION_CODES.UPSIDE_DOWN_CAKE -> if (dark) {
+                colorResource(android.R.color.system_surface_container_dark) to
+                    colorResource(android.R.color.system_surface_container_high_dark)
+            } else {
+                colorResource(android.R.color.system_surface_container_light) to
+                    colorResource(android.R.color.system_surface_container_high_light)
+            }
+
+            else -> if (dark) {
+                colorResource(android.R.color.system_neutral1_900) to
+                    colorResource(android.R.color.system_neutral1_800)
+            } else {
+                colorResource(android.R.color.system_neutral1_50) to
+                    colorResource(android.R.color.system_neutral1_100)
+            }
+        }
+        if (dark) KeyboardColors(
+            tray = tray,
+            edge = edge,
+            key = colorResource(android.R.color.system_accent2_700),
+            label = colorResource(android.R.color.system_neutral1_50)
+        ) else KeyboardColors(
+            tray = tray,
+            edge = edge,
+            key = colorResource(android.R.color.system_accent2_100),
+            label = colorResource(android.R.color.system_neutral1_900)
+        )
+    } else {
+        if (dark) KeyboardColors(Color(0xFF1B1B1F), Color(0xFF2B2B2F), Color(0xFF43474E), Color(0xFFE3E2E6))
+        else KeyboardColors(Color(0xFFEEEDF6), Color(0xFFE7E7F0), Color(0xFFDDE2F9), Color(0xFF1B1B1F))
+    }
+}
+
+/** Operator keys shown above the numeric keypad, which has no room for them itself. */
+@Composable
+fun MathOperatorRow(onInsert: (String) -> Unit) {
+    val colors = keyboardColors()
+    Surface(color = colors.tray) {
+        // Flat pill-shaped keys, styled like the keyboard's own function keys (e.g. its minus).
+        val keyShape = RoundedCornerShape(percent = 50)
+        Row(
+            modifier = Modifier
+                .fillMaxWidth()
+                .height(MathOperatorRowHeight)
+                .drawBehind {
+                    // A thin edge in the same tone the keyboard uses for its own top border.
+                    drawLine(colors.edge, Offset(0f, 0f), Offset(size.width, 0f), 1.dp.toPx())
+                }
+                .padding(horizontal = 3.dp, vertical = 5.dp)
+        ) {
+            listOf("(" to "(", ")" to ")", "+" to "+", "−" to "-", "×" to "*", "÷" to "/").forEach { (label, op) ->
+                Box(
+                    modifier = Modifier
+                        .weight(1f)
+                        .fillMaxHeight()
+                        .padding(horizontal = 3.dp)
+                        .clip(keyShape)
+                        .background(colors.key)
+                        .clickable { onInsert(op) },
+                    contentAlignment = Alignment.Center
+                ) {
+                    Text(label, fontSize = 24.sp, color = colors.label)
+                }
+            }
         }
     }
 }
@@ -187,7 +299,10 @@ fun BillBasicInfoSection(
     canEdit: Boolean,
     onDateClick: () -> Unit,
     onTimeClick: () -> Unit,
-    amountFocusRequester: FocusRequester
+    amountFocusRequester: FocusRequester,
+    amountSelection: TextRange = TextRange(viewModel.amount.length),
+    onAmountSelectionChange: (TextRange) -> Unit = {},
+    onAmountFocusChange: (Boolean) -> Unit = {}
 ) {
     Text(
         text = "GENERAL",
@@ -203,15 +318,29 @@ fun BillBasicInfoSection(
         stringResource(R.string.currency_dialog_title, viewModel.mainCurrencyName)
 
     OutlinedTextField(
-        value = viewModel.amount,
+        value = TextFieldValue(
+            text = viewModel.amount,
+            selection = TextRange(
+                amountSelection.start.coerceIn(0, viewModel.amount.length),
+                amountSelection.end.coerceIn(0, viewModel.amount.length)
+            )
+        ),
         onValueChange = { nv ->
-            val filteredValue = nv.filter { it in "0123456789.+-*/" }
-            viewModel.amount = filteredValue
-            viewModel.updateSplits()
+            val filteredValue = nv.text.filter { it in "0123456789.,+-*/()" }
+            onAmountSelectionChange(
+                if (filteredValue == nv.text) nv.selection else TextRange(filteredValue.length)
+            )
+            if (filteredValue != viewModel.amount) {
+                viewModel.amount = filteredValue
+                viewModel.updateSplits()
+            }
         },
         enabled = canEdit,
         placeholder = { Text("0") },
-        modifier = Modifier.fillMaxWidth().focusRequester(amountFocusRequester),
+        modifier = Modifier
+            .fillMaxWidth()
+            .focusRequester(amountFocusRequester)
+            .onFocusChanged { onAmountFocusChange(it.isFocused) },
         leadingIcon = {
             val currencyToShow = viewModel.selectedCurrencyName.ifEmpty {
                 viewModel.mainCurrencyName.ifEmpty { "$" }
@@ -245,7 +374,7 @@ fun BillBasicInfoSection(
                 Icon(Icons.Default.SwapHoriz, contentDescription = "Change Currency")
             }
         },
-        keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Phone, imeAction = ImeAction.Next),
+        keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal, imeAction = ImeAction.Next),
         keyboardActions = KeyboardActions(onNext = { focusManager.moveFocus(FocusDirection.Next) })
     )
 
@@ -473,7 +602,7 @@ fun OwerSelectionSection(
                 BasicTextField(
                     value = value,
                     onValueChange = { nv ->
-                        val filteredValue = nv.filter { it in "0123456789.+-*/" }
+                        val filteredValue = nv.filter { it in "0123456789,.+-*/" }
                         if (viewModel.splitMode == SplitMode.PERCENT) {
                             viewModel.owersPercentSplit[member.id] = filteredValue
                         } else {

app/src/main/java/net/helcel/cowspent/android/bill_edit/EditBillViewModel.kt

@@ -48,7 +48,7 @@ class EditBillViewModel : ViewModel() {
         if (input.isBlank()) return 0.0
         val sanitized = input.replace(',', '.')
         // If it contains any math operator, try evalMath first
-        if (sanitized.any { it in "+-*/" }) {
+        if (sanitized.any { it in "+-*/()" }) {
             try {
                 val result = evalMath(sanitized)
                 if (result != 0.0) return SupportUtil.round2(result)

app/src/main/java/net/helcel/cowspent/android/project/settle/ProjectSettlementScreen.kt

@@ -48,8 +48,10 @@ import net.helcel.cowspent.model.Transaction
 import net.helcel.cowspent.model.UserItem
 import net.helcel.cowspent.persistence.CowspentSQLiteOpenHelper
 import net.helcel.cowspent.util.SupportUtil
+import net.helcel.cowspent.util.SupportUtil.SETTLE_DIRECT
 import net.helcel.cowspent.util.SupportUtil.SETTLE_OPTIMAL
 import net.helcel.cowspent.util.SupportUtil.settleBills
+import net.helcel.cowspent.util.SupportUtil.settleBillsDirect
 
 @Composable
 fun ProjectSettlementDialogContent(
@@ -60,10 +62,12 @@ fun ProjectSettlementDialogContent(
     onDismiss: () -> Unit
 ) {
     val centerNoneStr = stringResource(R.string.center_none)
+    val centerDirectStr = stringResource(R.string.center_none_direct)
     val memberList = remember(proj.id) { db.getMembersOfProject(proj.id, null) }
-    val userList = remember(memberList, centerNoneStr) {
+    val userList = remember(memberList, centerNoneStr, centerDirectStr) {
         buildList {
             add(UserItem(SETTLE_OPTIMAL, centerNoneStr))
+            add(UserItem(SETTLE_DIRECT, centerDirectStr))
             addAll(memberList.map { UserItem(it.id, it.name) })
         }
     }
@@ -91,7 +95,11 @@ fun ProjectSettlementDialogContent(
     }
 
     val transactions = remember(selectedMemberId, membersBalance, membersSortedByName) {
-        settleBills(membersSortedByName, membersBalance, selectedMemberId)
+        if (selectedMemberId == SETTLE_DIRECT) {
+            settleBillsDirect(membersSortedByName, db.getBillsOfProject(proj.id))
+        } else {
+            settleBills(membersSortedByName, membersBalance, selectedMemberId)
+        }
     }
 
     ProjectSettlementUI(

app/src/main/java/net/helcel/cowspent/util/SupportUtil.kt

@@ -141,7 +141,7 @@ object SupportUtil {
                 membersBalance[b.payerId] = balPayer + amount
                 val paid = membersPaid[b.payerId] ?: 0.0
                 membersPaid[b.payerId] = paid + amount
-                
+
                 var nbOwerShares = 0.0
                 for (bo in b.billOwers) {
                     nbOwerShares += membersWeight[bo.memberId] ?: 0.0
@@ -167,6 +167,39 @@ object SupportUtil {
     }
 
     const val SETTLE_OPTIMAL: Long = 0
+    const val SETTLE_DIRECT: Long = -1
+
+    @JvmStatic
+    fun settleBillsDirect(members: List<DBMember>, bills: List<DBBill>): List<Transaction> {
+        val membersWeight = members.associate { it.id to it.weight }
+        // owed[debtor][creditor] = total the debtor owes the creditor over all bills
+        val owed = HashMap<Long, HashMap<Long, Double>>()
+
+        for (b in bills) {
+            if (b.state == DBBill.STATE_DELETED) continue
+            val nbOwerShares = b.billOwers.sumOf { membersWeight[it.memberId] ?: 0.0 }
+            if (nbOwerShares <= 0.0) continue
+            for (bo in b.billOwers) {
+                if (bo.memberId == b.payerId) continue
+                val share = b.amount / nbOwerShares * (membersWeight[bo.memberId] ?: 0.0)
+                val row = owed.getOrPut(bo.memberId) { HashMap() }
+                row[b.payerId] = (row[b.payerId] ?: 0.0) + share
+            }
+        }
+
+        val results: MutableList<Transaction> = ArrayList()
+        for (debtor in members) {
+            for (creditor in members) {
+                if (debtor.id == creditor.id) continue
+                val net = (owed[debtor.id]?.get(creditor.id) ?: 0.0) -
+                        (owed[creditor.id]?.get(debtor.id) ?: 0.0)
+                if (round2(net) > 0.0) {
+                    results.add(Transaction(debtor.id, creditor.id, round2(net)))
+                }
+            }
+        }
+        return results
+    }
 
     @JvmStatic
     fun settleBills(
@@ -233,11 +266,11 @@ object SupportUtil {
                 if (cd1.balance < cd2.balance) 1 else -1
             }
         }
-        
+
         for (c in crediters) {
             Log.e(SupportUtil::class.java.simpleName, "* " + c.memberId + " : " + c.balance)
         }
-        
+
         debiters.sortWith { cd2, cd1 ->
             if (cd1.balance == cd2.balance) {
                 0

app/src/main/res/values-de-rDE/strings.xml

@@ -209,6 +209,7 @@
 
     <!-- Settlement -->
     <string name="center_none">Keine (optimal)</string>
+    <string name="center_none_direct">Keine (direkt)</string>
     <string name="settle_who">Wer zahlt</string>
     <string name="settle_to_whom">An wen</string>
     <string name="settle_how_much">Betrag</string>

app/src/main/res/values-es-rES/strings.xml

@@ -210,6 +210,7 @@
 
     <!-- Settlement -->
     <string name="center_none">Ninguno (óptimo)</string>
+    <string name="center_none_direct">Ninguno (directo)</string>
     <string name="settle_who">Quién paga</string>
     <string name="settle_to_whom">A quién</string>
     <string name="settle_how_much">Importe</string>

app/src/main/res/values-fr-rFR/strings.xml

@@ -213,6 +213,7 @@
 
     <!-- Settlement -->
     <string name="center_none">Aucun (optimal)</string>
+    <string name="center_none_direct">Aucun (direct)</string>
     <string name="settle_who">Qui paie</string>
     <string name="settle_to_whom">À qui</string>
     <string name="settle_how_much">Montant</string>

app/src/main/res/values-ru-rRU/strings.xml

@@ -209,6 +209,7 @@
 
     <!-- Settlement -->
     <string name="center_none">Нет (оптимально)</string>
+    <string name="center_none_direct">Нет (напрямую)</string>
     <string name="settle_who">Кто платит</string>
     <string name="settle_to_whom">Кому</string>
     <string name="settle_how_much">Сумма</string>

app/src/main/res/values/strings.xml

@@ -247,6 +247,7 @@
 
     <!-- Settlement -->
     <string name="center_none">None (Optimal)</string>
+    <string name="center_none_direct">None (Direct)</string>
     <string name="settle_who">Who pays</string>
     <string name="settle_to_whom">To whom</string>
     <string name="settle_how_much">Amount</string>