feat: добавил визуальную индикацию ожидающей операции

2026-06-18 23:48:19 +00:00
parent 4ca53cf34e
commit babec55122
4 changed files with 96 additions and 22 deletions
--- a/app/src/main/java/com/heller/calculator/CalculatorScreen.kt
+++ b/app/src/main/java/com/heller/calculator/CalculatorScreen.kt
@@ -54,21 +54,41 @@ fun CalculatorScreen(viewModel: CalculatorViewModel) {
                    .padding(16.dp),
                verticalArrangement = Arrangement.SpaceBetween,
            ) {
-                DisplaySection(display = uiState.display)
-                ButtonGrid(viewModel = viewModel)
+                DisplaySection(
+                    display = uiState.display,
+                    pendingExpression = uiState.pendingExpression,
+                )
+                ButtonGrid(
+                    viewModel = viewModel,
+                    pendingOperation = uiState.pendingOperation,
+                )
            }
        }
    }
 }

@Composable
-private fun DisplaySection(display: String) {
+private fun DisplaySection(
+    display: String,
+    pendingExpression: String?,
+) {
    Column(
        modifier = Modifier
            .fillMaxWidth()
            .padding(vertical = 24.dp),
        horizontalAlignment = Alignment.End,
    ) {
+        if (pendingExpression != null) {
+            Text(
+                text = pendingExpression,
+                style = MaterialTheme.typography.titleMedium,
+                color = MaterialTheme.colorScheme.onBackground.copy(alpha = 0.6f),
+                textAlign = TextAlign.End,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+                modifier = Modifier.fillMaxWidth(),
+            )
+        }
        Text(
            text = display,
            style = MaterialTheme.typography.headlineLarge,
@@ -82,7 +102,10 @@ private fun DisplaySection(display: String) {
 }

@Composable
-private fun ButtonGrid(viewModel: CalculatorViewModel) {
+private fun ButtonGrid(
+    viewModel: CalculatorViewModel,
+    pendingOperation: CalculatorOperation?,
+) {
    val rows = listOf(
        listOf("C" to CalculatorButtonType.Clear, "÷" to CalculatorButtonType.Operator),
        listOf("7" to CalculatorButtonType.Digit, "8" to CalculatorButtonType.Digit, "9" to CalculatorButtonType.Digit, "×" to CalculatorButtonType.Operator),
@@ -111,6 +134,7 @@ private fun ButtonGrid(viewModel: CalculatorViewModel) {
                label = "÷",
                type = CalculatorButtonType.Operator,
                onClick = { viewModel.onOperation(CalculatorOperation.Divide) },
+                isSelected = pendingOperation == CalculatorOperation.Divide,
                modifier = Modifier
                    .weight(1f)
                    .aspectRatio(1f),
@@ -128,6 +152,7 @@ private fun ButtonGrid(viewModel: CalculatorViewModel) {
                        label = label,
                        type = type,
                        onClick = { handleButtonClick(label, viewModel) },
+                        isSelected = labelToOperation(label) == pendingOperation,
                        modifier = Modifier
                            .weight(weight)
                            .aspectRatio(if (label == "0") 2.15f else 1f),
@@ -139,6 +164,14 @@ private fun ButtonGrid(viewModel: CalculatorViewModel) {
    }
 }

+private fun labelToOperation(label: String): CalculatorOperation? = when (label) {
+    "+" -> CalculatorOperation.Add
+    "−" -> CalculatorOperation.Subtract
+    "×" -> CalculatorOperation.Multiply
+    "÷" -> CalculatorOperation.Divide
+    else -> null
+}
+
 private fun handleButtonClick(label: String, viewModel: CalculatorViewModel) {
    when (label) {
        "C" -> viewModel.onClear()
--- a/app/src/main/java/com/heller/calculator/CalculatorState.kt
+++ b/app/src/main/java/com/heller/calculator/CalculatorState.kt
@@ -1,10 +1,10 @@
 package com.heller.calculator

-enum class CalculatorOperation(val symbol: String) {
-    Add("+"),
-    Subtract("-"),
-    Multiply("*"),
-    Divide("/");
+enum class CalculatorOperation(val symbol: String, val displaySymbol: String) {
+    Add("+", "+"),
+    Subtract("-", "−"),
+    Multiply("*", "×"),
+    Divide("/", "÷");

    fun apply(a: Double, b: Double): Double = when (this) {
        Add -> a + b
@@ -17,4 +17,6 @@ enum class CalculatorOperation(val symbol: String) {
 data class CalculatorUiState(
    val display: String = "0",
    val error: String? = null,
+    val pendingOperation: CalculatorOperation? = null,
+    val pendingExpression: String? = null,
 )
--- a/app/src/main/java/com/heller/calculator/CalculatorViewModel.kt
+++ b/app/src/main/java/com/heller/calculator/CalculatorViewModel.kt
@@ -57,6 +57,7 @@ class CalculatorViewModel : ViewModel() {

        pendingOperation = operation
        waitingForOperand = true
+        syncUiState()
    }

    fun onEquals() {
@@ -69,7 +70,7 @@ class CalculatorViewModel : ViewModel() {
        storedValue = null
        pendingOperation = null
        waitingForOperand = true
-        updateDisplay(formatResult(result))
+        syncUiState(display = formatResult(result))
    }

    fun onClear() {
@@ -106,6 +107,33 @@ class CalculatorViewModel : ViewModel() {
    }

    private fun updateDisplay(display: String) {
-        _uiState.update { it.copy(display = display) }
+        syncUiState(display = display)
+    }
+
+    private fun syncUiState(
+        display: String? = null,
+        clearError: Boolean = false,
+        setError: String? = null,
+    ) {
+        _uiState.update { state ->
+            val newDisplay = display ?: state.display
+            val newError = when {
+                setError != null -> setError
+                clearError -> null
+                else -> state.error
+            }
+            val expression = if (pendingOperation != null && storedValue != null) {
+                "${formatResult(storedValue!!)} ${pendingOperation!!.displaySymbol}"
+            } else {
+                null
+            }
+
+            state.copy(
+                display = newDisplay,
+                error = newError,
+                pendingOperation = pendingOperation,
+                pendingExpression = expression,
+            )
+        }
    }
 }
--- a/app/src/main/java/com/heller/calculator/ui/components/CalculatorButton.kt
+++ b/app/src/main/java/com/heller/calculator/ui/components/CalculatorButton.kt
@@ -1,5 +1,6 @@
 package com.heller.calculator.ui.components

+import androidx.compose.foundation.BorderStroke
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.shape.RoundedCornerShape
@@ -26,19 +27,22 @@ fun CalculatorButton(
    type: CalculatorButtonType,
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
+    isSelected: Boolean = false,
 ) {
-    val containerColor = when (type) {
-        CalculatorButtonType.Digit -> MaterialTheme.colorScheme.surfaceVariant
-        CalculatorButtonType.Operator -> MaterialTheme.colorScheme.primaryContainer
-        CalculatorButtonType.Equals -> MaterialTheme.colorScheme.primary
-        CalculatorButtonType.Clear -> MaterialTheme.colorScheme.errorContainer
+    val containerColor = when {
+        isSelected -> MaterialTheme.colorScheme.primary
+        type == CalculatorButtonType.Digit -> MaterialTheme.colorScheme.surfaceVariant
+        type == CalculatorButtonType.Operator -> MaterialTheme.colorScheme.primaryContainer
+        type == CalculatorButtonType.Equals -> MaterialTheme.colorScheme.primary
+        else -> MaterialTheme.colorScheme.errorContainer
    }

-    val contentColor = when (type) {
-        CalculatorButtonType.Digit -> MaterialTheme.colorScheme.onSurfaceVariant
-        CalculatorButtonType.Operator -> MaterialTheme.colorScheme.onPrimaryContainer
-        CalculatorButtonType.Equals -> MaterialTheme.colorScheme.onPrimary
-        CalculatorButtonType.Clear -> MaterialTheme.colorScheme.onErrorContainer
+    val contentColor = when {
+        isSelected -> MaterialTheme.colorScheme.onPrimary
+        type == CalculatorButtonType.Digit -> MaterialTheme.colorScheme.onSurfaceVariant
+        type == CalculatorButtonType.Operator -> MaterialTheme.colorScheme.onPrimaryContainer
+        type == CalculatorButtonType.Equals -> MaterialTheme.colorScheme.onPrimary
+        else -> MaterialTheme.colorScheme.onErrorContainer
    }

    Button(
@@ -49,7 +53,14 @@ fun CalculatorButton(
            containerColor = containerColor,
            contentColor = contentColor,
        ),
-        elevation = ButtonDefaults.buttonElevation(defaultElevation = 2.dp),
+        border = if (isSelected) {
+            BorderStroke(2.dp, MaterialTheme.colorScheme.onPrimary)
+        } else {
+            null
+        },
+        elevation = ButtonDefaults.buttonElevation(
+            defaultElevation = if (isSelected) 6.dp else 2.dp,
+        ),
    ) {
        Box(
            modifier = Modifier.fillMaxSize(),