Finish Exercise 4

E04SumCalculator/.gitignore

+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.cxx
+local.properties

E04SumCalculator/.idea/.gitignore

+# Default ignored files
+/shelf/
+/workspace.xml

E04SumCalculator/.idea/.name

+E04 Sum Calculator
\ No newline at end of file

E04SumCalculator/.idea/compiler.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CompilerConfiguration">
+    <bytecodeTargetLevel target="17" />
+  </component>
+</project>
\ No newline at end of file

E04SumCalculator/.idea/deploymentTargetDropDown.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="deploymentTargetDropDown">
+    <value>
+      <entry key="app">
+        <State />
+      </entry>
+    </value>
+  </component>
+</project>
\ No newline at end of file

E04SumCalculator/.idea/gradle.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
+  <component name="GradleSettings">
+    <option name="linkedExternalProjectsSettings">
+      <GradleProjectSettings>
+        <option name="externalProjectPath" value="$PROJECT_DIR$" />
+        <option name="gradleJvm" value="#GRADLE_LOCAL_JAVA_HOME" />
+        <option name="modules">
+          <set>
+            <option value="$PROJECT_DIR$" />
+            <option value="$PROJECT_DIR$/app" />
+          </set>
+        </option>
+        <option name="resolveExternalAnnotations" value="false" />
+      </GradleProjectSettings>
+    </option>
+  </component>
+</project>
\ No newline at end of file

E04SumCalculator/.idea/kotlinc.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="KotlinJpsPluginSettings">
+    <option name="version" value="1.9.0" />
+  </component>
+</project>
\ No newline at end of file

E04SumCalculator/.idea/migrations.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectMigrations">
+    <option name="MigrateToGradleLocalJavaHome">
+      <set>
+        <option value="$PROJECT_DIR$" />
+      </set>
+    </option>
+  </component>
+</project>
\ No newline at end of file

E04SumCalculator/.idea/misc.xml

+<project version="4">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="jbr-17" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/build/classes" />
+  </component>
+  <component name="ProjectType">
+    <option name="id" value="Android" />
+  </component>
+</project>
\ No newline at end of file

E04SumCalculator/.idea/vcs.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/.." vcs="Git" />
+  </component>
+</project>
\ No newline at end of file

E04SumCalculator/app/.gitignore

+/build
\ No newline at end of file

E04SumCalculator/app/build.gradle.kts

+plugins {
+    id("com.android.application")
+    id("org.jetbrains.kotlin.android")
+}
+
+android {
+    namespace = "com.example.e04sumcalculator"
+    compileSdk = 34
+
+    defaultConfig {
+        applicationId = "com.example.e04sumcalculator"
+        minSdk = 30
+        targetSdk = 34
+        versionCode = 1
+        versionName = "1.0"
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+        vectorDrawables {
+            useSupportLibrary = true
+        }
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+    }
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_1_8
+        targetCompatibility = JavaVersion.VERSION_1_8
+    }
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+    buildFeatures {
+        compose = true
+    }
+    composeOptions {
+        kotlinCompilerExtensionVersion = "1.5.1"
+    }
+    packaging {
+        resources {
+            excludes += "/META-INF/{AL2.0,LGPL2.1}"
+        }
+    }
+}
+
+dependencies {
+    implementation("androidx.core:core-ktx:1.12.0")
+    implementation("androidx.lifecycle:lifecycle-runtime-ktx:2.6.2")
+    implementation("androidx.activity:activity-compose:1.8.1")
+    implementation(platform("androidx.compose:compose-bom:2023.08.00"))
+    implementation("androidx.compose.ui:ui")
+    implementation("androidx.compose.ui:ui-graphics")
+    implementation("androidx.compose.ui:ui-tooling-preview")
+    implementation("androidx.compose.material3:material3")
+    implementation("androidx.compose.material3:material3-window-size-class")
+    testImplementation("junit:junit:4.13.2")
+    androidTestImplementation("androidx.test.ext:junit:1.1.5")
+    androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")
+    androidTestImplementation(platform("androidx.compose:compose-bom:2023.08.00"))
+    androidTestImplementation("androidx.compose.ui:ui-test-junit4")
+    debugImplementation("androidx.compose.ui:ui-tooling")
+    debugImplementation("androidx.compose.ui:ui-test-manifest")
+
+    // extra dependencies
+    implementation("androidx.lifecycle:lifecycle-viewmodel-compose:{latest_version}")
+
+    // Third party libraries
+    implementation("com.notkamui.libs:keval:0.9.0")
+}
\ No newline at end of file

E04SumCalculator/app/proguard-rules.pro

+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile
\ No newline at end of file

E04SumCalculator/app/src/androidTest/java/com/example/e04sumcalculator/ExampleInstrumentedTest.kt

+package com.example.e04sumcalculator
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("com.example.e04sumcalculator", appContext.packageName)
+    }
+}
\ No newline at end of file

E04SumCalculator/app/src/main/AndroidManifest.xml

+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
+
+    <application
+        android:allowBackup="true"
+        android:dataExtractionRules="@xml/data_extraction_rules"
+        android:fullBackupContent="@xml/backup_rules"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.E04SumCalculator"
+        tools:targetApi="31">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:label="@string/app_name"
+            android:theme="@style/Theme.E04SumCalculator">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>
\ No newline at end of file

E04SumCalculator/app/src/main/java/com/example/e04sumcalculator/CalculatorViewModel.kt

+package com.example.e04sumcalculator
+
+
+import androidx.lifecycle.ViewModel
+import com.notkamui.keval.keval
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import java.math.RoundingMode
+
+
+data class MathExpression(
+    val expression: String,
+    val result: String
+)
+
+const val EXAMPLE_EXPRESSION = "(e*PI)^2 * ((10-2.5+3)/2)^2"
+
+data class CalculatorState(
+    val previousExpressions: MutableList<MathExpression> = mutableListOf(
+        MathExpression(
+            EXAMPLE_EXPRESSION,
+            EXAMPLE_EXPRESSION.keval().toBigDecimal().setScale(2, RoundingMode.HALF_EVEN).toString()
+        )
+    ),
+    val currentExpression: MathExpression = MathExpression("", "")
+)
+
+class CalculatorViewModel : ViewModel() {
+    private val _state = MutableStateFlow(CalculatorState())
+    val state: StateFlow<CalculatorState> = _state.asStateFlow()
+    private val validDigits = setOf("0", "1", "2", "3", "4", "5", "6", "7", "8", "9", ".")
+    private val validKevalOperators = setOf("+", "-", "*", "/", "%", "^", "neg", "PI", "e", "(", ")")
+    private val validActions = setOf("C", "<=", "=")
+
+    fun onKeyPressed(data: String) {
+        val expr = _state.value.currentExpression.expression
+        if (isValidDigit(data) || isValidOperator(data)) {
+            concatCurrentExpression(data)
+        } else if (isValidAction(data)) {
+            when (data) {
+                "C" -> clearCurrentExpression()
+                "=" -> evaluateCurrentExpression()
+                "<=" -> eraseLastCharacter()
+            }
+        } else {
+            println("Have no idea what you are doing.")
+        }
+    }
+
+    private fun evaluateCurrentExpression() {
+        val expr = _state.value.currentExpression.expression
+        if (expr.isEmpty()) return
+        var exprRes = "Error"
+        try {
+            exprRes = expr
+                .keval()
+                .toBigDecimal()
+                .setScale(2, RoundingMode.HALF_EVEN)
+                .toString()
+        } catch (error: Exception) {
+            println("Error curred")
+        }
+        _state.update {
+            var prevExpressions = it.previousExpressions
+            prevExpressions.add(MathExpression(expr, exprRes))
+            CalculatorState(
+                previousExpressions = prevExpressions,
+                currentExpression = MathExpression("", "")
+            )
+        }
+    }
+
+    private fun eraseLastCharacter() {
+        val expr = state.value.currentExpression.expression
+        if (expr.isNotEmpty()) {
+            _state.update {
+                it.copy(currentExpression = MathExpression(expr.dropLast(1), ""))
+            }
+        } else if (_state.value.previousExpressions.size > 0) {
+            _state.update {
+                var prevExpressions = it.previousExpressions
+                var lastExpr = prevExpressions.removeLast()
+                it.copy(previousExpressions = prevExpressions, currentExpression = lastExpr)
+            }
+        }
+    }
+
+    private fun clearCurrentExpression() {
+        _state.update {
+            it.copy(currentExpression = MathExpression("", ""))
+        }
+    }
+
+    private fun concatCurrentExpression(str: String) {
+        _state.update {
+            it.copy(currentExpression = MathExpression(it.currentExpression.expression + str, ""))
+        }
+    }
+
+    private fun isValidDigit(str: String): Boolean {
+        return validDigits.contains(str)
+    }
+
+    private fun isValidOperator(str: String): Boolean {
+        return validKevalOperators.contains(str)
+    }
+
+    private fun isValidAction(str: String): Boolean {
+        return validActions.contains(str)
+    }
+}

E04SumCalculator/app/src/main/java/com/example/e04sumcalculator/ui/theme/Color.kt

+package com.example.e04sumcalculator.ui.theme
+
+import androidx.compose.ui.graphics.Color
+
+val Purple80 = Color(0xFFD0BCFF)
+val PurpleGrey80 = Color(0xFFCCC2DC)
+val Pink80 = Color(0xFFEFB8C8)
+
+val Purple40 = Color(0xFF6650a4)
+val PurpleGrey40 = Color(0xFF625b71)
+val Pink40 = Color(0xFF7D5260)
\ No newline at end of file

E04SumCalculator/app/src/main/java/com/example/e04sumcalculator/ui/theme/Theme.kt

+package com.example.e04sumcalculator.ui.theme
+
+import android.app.Activity
+import android.os.Build
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.darkColorScheme
+import androidx.compose.material3.dynamicDarkColorScheme
+import androidx.compose.material3.dynamicLightColorScheme
+import androidx.compose.material3.lightColorScheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.SideEffect
+import androidx.compose.ui.graphics.toArgb
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.platform.LocalView
+import androidx.core.view.WindowCompat
+
+private val DarkColorScheme = darkColorScheme(
+    primary = Purple80,
+    secondary = PurpleGrey80,
+    tertiary = Pink80
+)
+
+private val LightColorScheme = lightColorScheme(
+    primary = Purple40,
+    secondary = PurpleGrey40,
+    tertiary = Pink40
+
+    /* Other default colors to override
+    background = Color(0xFFFFFBFE),
+    surface = Color(0xFFFFFBFE),
+    onPrimary = Color.White,
+    onSecondary = Color.White,
+    onTertiary = Color.White,
+    onBackground = Color(0xFF1C1B1F),
+    onSurface = Color(0xFF1C1B1F),
+    */
+)
+
+@Composable
+fun E04SumCalculatorTheme(
+    darkTheme: Boolean = isSystemInDarkTheme(),
+    // Dynamic color is available on Android 12+
+    dynamicColor: Boolean = true,
+    content: @Composable () -> Unit
+) {
+    val colorScheme = when {
+        dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {
+            val context = LocalContext.current
+            if (darkTheme) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context)
+        }
+
+        darkTheme -> DarkColorScheme
+        else -> LightColorScheme
+    }
+    val view = LocalView.current
+    if (!view.isInEditMode) {
+        SideEffect {
+            val window = (view.context as Activity).window
+            window.statusBarColor = colorScheme.primary.toArgb()
+            WindowCompat.getInsetsController(window, view).isAppearanceLightStatusBars = darkTheme
+        }
+    }
+
+    MaterialTheme(
+        colorScheme = colorScheme,
+        typography = Typography,
+        content = content
+    )
+}
\ No newline at end of file

E04SumCalculator/app/src/main/java/com/example/e04sumcalculator/ui/theme/Type.kt

+package com.example.e04sumcalculator.ui.theme
+
+import androidx.compose.material3.Typography
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.sp
+
+// Set of Material typography styles to start with
+val Typography = Typography(
+    bodyLarge = TextStyle(
+        fontFamily = FontFamily.Default,
+        fontWeight = FontWeight.Normal,
+        fontSize = 16.sp,
+        lineHeight = 24.sp,
+        letterSpacing = 0.5.sp
+    )
+    /* Other default text styles to override
+    titleLarge = TextStyle(
+        fontFamily = FontFamily.Default,
+        fontWeight = FontWeight.Normal,
+        fontSize = 22.sp,
+        lineHeight = 28.sp,
+        letterSpacing = 0.sp
+    ),
+    labelSmall = TextStyle(
+        fontFamily = FontFamily.Default,
+        fontWeight = FontWeight.Medium,
+        fontSize = 11.sp,
+        lineHeight = 16.sp,
+        letterSpacing = 0.5.sp
+    )
+    */
+)
\ No newline at end of file