Penyesuaian Warna ketika Tema Terang dan Penambahan Fitur Validasi Input

app/src/main/java/com/example/bmicalculator/MainActivity.kt

@@ -95,6 +95,7 @@ fun BMICalculatorLayout() {
         var heightInput by remember { mutableStateOf("") }
         var weightInput by remember { mutableStateOf("") }
         var unitUSC     by remember { mutableStateOf(false) }
+        var errorMessage by remember { mutableStateOf("") }
 
         // State baru untuk mengontrol kapan output ditampilkan
         var showResult by remember { mutableStateOf(false) }
@@ -104,6 +105,7 @@ fun BMICalculatorLayout() {
             heightInput = ""
             weightInput = ""
             showResult = false
+            errorMessage = ""
         }
 
         val bmiHeight = heightInput.toDoubleOrNull() ?: 0.0
@@ -179,6 +181,57 @@ fun BMICalculatorLayout() {
 
                 Button(
                     onClick = {
+                        // Validasi angka
+                        if (bmiHeight == 0.0 || bmiWeight == 0.0) {
+                            errorMessage = "Input harus berupa angka yang valid."
+                            showResult = false
+                            return@Button
+                        }
+
+                        // Validasi untuk SI Units
+                        if (!unitUSC) {
+                            if (bmiHeight !in 50.0..300.0 && bmiWeight !in 20.0..500.0) {
+                                errorMessage =
+                                    "Masukkan Tinggi Badan pada rentang 50-300 cm \ndan\n Berat Badan pada rentang 20-500 kg"
+                                showResult = false
+                                return@Button
+                            }
+                            else if (bmiHeight !in 50.0..300.0) {
+                                errorMessage = "Tinggi harus berada pada rentang 50–300 cm."
+                                showResult = false
+                                return@Button
+                            }
+                            else if (bmiWeight !in 20.0..500.0) {
+                                errorMessage = "Berat harus berada pada rentang 20–500 kg."
+                                showResult = false
+                                return@Button
+                            }
+
+                        }
+
+                        // Validasi untuk USC Units
+                        if (unitUSC) {
+                            if (bmiHeight !in 20.0..120.0 && bmiWeight !in 44.0..1100.0){
+                                errorMessage =
+                                    "Masukkan Tinggi Badan pada rentang 20-120 in dan\n Berat Badan pada rentang 44-110 kg"
+                                showResult = false
+                                return@Button
+                            }
+                            else if (bmiHeight !in 20.0..120.0) {
+                                errorMessage = "Tinggi harus berada pada rentang 20–120 in."
+                                showResult = false
+                                return@Button
+                            }
+                            else if (bmiWeight !in 44.0..1100.0) {
+                                errorMessage = "Berat harus berada pada rentang 44–1100 lbs."
+                                showResult = false
+                                return@Button
+                            }
+
+                        }
+
+                        // Jika valid
+                        errorMessage = ""
                         showResult = true
                     },
                     modifier = Modifier.weight(1f)
@@ -193,6 +246,7 @@ fun BMICalculatorLayout() {
                         heightInput = ""
                         weightInput = ""
                         showResult = false
+                        errorMessage = ""
                     },
                     modifier = Modifier.weight(1f)
                 ) {
@@ -202,6 +256,22 @@ fun BMICalculatorLayout() {
 
             Spacer(modifier = Modifier.height(32.dp))
 
+            // Pesan Error
+            if (errorMessage.isNotEmpty()) {
+                Text(
+                    text = errorMessage,
+                    color = MaterialTheme.colorScheme.error,
+                    fontWeight = FontWeight.SemiBold,
+                    modifier = Modifier
+                        .padding(top = 16.dp)
+                        .fillMaxWidth(),
+                    textAlign = TextAlign.Center
+                )
+            }
+
+            Spacer(modifier = Modifier.height(32.dp))
+
+            // Output BMI
             if (showResult) {
                 Text(
                     text = "BMI: $bmi",

app/src/main/java/com/example/bmicalculator/ui/theme/Color.kt

@@ -17,8 +17,8 @@ package com.example.bmicalculator.ui.theme
 
 import androidx.compose.ui.graphics.Color
 
-val md_theme_light_primary = Color(0xFFE3E2DE)
+val md_theme_light_primary = Color(0xFF1351AA) // Button
-val md_theme_light_onPrimary = Color(0xFF1351AA)
+val md_theme_light_onPrimary = Color(0xFFE3E2DE)
 val md_theme_light_primaryContainer = Color(0xFFE3E2DE)
 val md_theme_light_onPrimaryContainer = Color(0xFF1351AA)
 val md_theme_light_secondary = Color(0xFFE3E2DE)