完成标准计算器所有运算

Author: equationl

app/build.gradle

@@ -57,7 +57,10 @@ dependencies {
     implementation "androidx.compose.material:material:$compose_version"
     implementation "androidx.compose.ui:ui-tooling-preview:$compose_version"
     implementation "androidx.compose.material:material-icons-extended:$compose_version"
-    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.5.1'
+    implementation "androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle_version"
+    implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version"
+    implementation "androidx.lifecycle:lifecycle-viewmodel-compose:$lifecycle_version"
+    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
     implementation 'androidx.activity:activity-compose:1.4.0'
 
     testImplementation 'junit:junit:4.13.2'

app/src/main/java/com/equationl/calculator_compose/MainActivity.kt

@@ -7,7 +7,10 @@ import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.material.MaterialTheme
 import androidx.compose.material.Surface
 import androidx.compose.ui.Modifier
+import androidx.lifecycle.viewmodel.compose.viewModel
 import com.equationl.calculator_compose.ui.theme.CalculatorComposeTheme
+import com.equationl.calculator_compose.view.StandardScreen
+import com.equationl.calculator_compose.viewModel.StandardViewModel
 
 class MainActivity : ComponentActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -19,7 +22,8 @@ class MainActivity : ComponentActivity() {
                     modifier = Modifier.fillMaxSize(),
                     color = MaterialTheme.colors.background
                 ) {
-
+                    val viewModel: StandardViewModel = viewModel()
+                    StandardScreen(viewModel)
                 }
             }
         }

app/src/main/java/com/equationl/calculator_compose/dataModel/KeyBoardData.kt

@@ -10,15 +10,15 @@ val EqualColor = Color.Cyan
 
 val StandardKeyBoardBtn = listOf(
     listOf(
-        KeyBoardData("%", FunctionColor, KeyBoardBtnSize.Standard, 0),
+        KeyBoardData("%", FunctionColor, KeyBoardBtnSize.Standard, 19),
         KeyBoardData("CE", FunctionColor, KeyBoardBtnSize.Standard, 1001),
         KeyBoardData("C", FunctionColor, KeyBoardBtnSize.Standard, 1002),
         KeyBoardData("←", FunctionColor, KeyBoardBtnSize.Standard, 1003),
     ),
     listOf(
-        KeyBoardData("1/x", FunctionColor, KeyBoardBtnSize.Standard, 4),
-        KeyBoardData("x²", FunctionColor, KeyBoardBtnSize.Standard, 5),
-        KeyBoardData("√x", FunctionColor, KeyBoardBtnSize.Standard, 6),
+        KeyBoardData("1/x", FunctionColor, KeyBoardBtnSize.Standard, 16),
+        KeyBoardData("x²", FunctionColor, KeyBoardBtnSize.Standard, 17),
+        KeyBoardData("√x", FunctionColor, KeyBoardBtnSize.Standard, 18),
         KeyBoardData(Operator.Divide.showText, FunctionColor, KeyBoardBtnSize.Standard, 13),
     ),
     listOf(
@@ -64,5 +64,7 @@ enum class Operator(val showText: String) {
     MINUS("-"),
     MULTIPLY("×"),
     Divide("÷"),
+    SQRT("√"),
+    POW2("²"),
     NUll("")
 }

app/src/main/java/com/equationl/calculator_compose/utils/Utils.kt

@@ -3,6 +3,7 @@ package com.equationl.calculator_compose.utils
 import androidx.core.text.isDigitsOnly
 import com.equationl.calculator_compose.dataModel.Operator
 import java.math.BigDecimal
+import java.math.RoundingMode
 
 /**
  * BigDecimal 的开平方
@@ -25,9 +26,9 @@ fun BigDecimal.sqrt(scale: Int): BigDecimal {
 /**
  * 格式化数字（添加逗号分隔符）
  * */
-fun String.formatNumber(): String {
+fun String.formatNumber(formatDecimal: Boolean = false, formatInteger: Boolean = true): String {
     // 如果不是合法数字则不做处理
-    if (this.substring(0, 1) != "-" && !this.isDigitsOnly()) return this
+    if (this.substring(0, 1) != "-" && !this.replace(".", "").isDigitsOnly()) return this
 
     val stringBuilder = StringBuilder(this)
 
@@ -48,11 +49,25 @@ fun String.formatNumber(): String {
         decimal.insert(0, '.')
     }
 
-    // 添加逗号分隔符
-    if (integer.length > 3) {
-        val end = if (integer[0] == '-') 2 else 1 // 判断是否有前导符号
-        for (i in integer.length-3 downTo end step 3) {
-            integer.insert(i, ",")
+    if (formatInteger) {
+        // 给整数部分添加逗号分隔符
+        if (integer.length > 3) {
+            val end = if (integer[0] == '-') 2 else 1 // 判断是否有前导符号
+            for (i in integer.length-3 downTo end step 3) {
+                integer.insert(i, ",")
+            }
+        }
+    }
+
+    if (formatDecimal) {
+        // 移除小数部分末尾占位的 0
+        if (decimal.isNotEmpty()) {
+            while (decimal.last() == '0') {
+                decimal.deleteAt(decimal.lastIndex)
+            }
+            if (decimal.length == 1) { // 上面我们给小数部分首位添加了点号 ”.“ ，所以如果长度为 1 则表示不存在有效小数，则将点号也删除掉
+                decimal.deleteAt(0)
+            }
         }
     }
 
@@ -78,8 +93,16 @@ fun calculate(leftValue: String, rightValue: String, operator: Operator): Result
             if (right.signum() == 0) {
                 return Result.failure(ArithmeticException("除数不能为零"))
             }
-            left.setScale(16)
-            return  Result.success(left.divide(right))
+            return  Result.success(left.divide(right, 16, RoundingMode.HALF_UP))
+        }
+        Operator.SQRT -> {
+            if (left.signum() == -1) {
+                return Result.failure(ArithmeticException("无效输入"))
+            }
+            return Result.success(left.sqrt(16))
+        }
+        Operator.POW2 -> {
+            return Result.success(left.pow(2))
         }
         Operator.NUll -> {
             return  Result.success(left)

app/src/main/java/com/equationl/calculator_compose/view/StandardScreen.kt

@@ -38,8 +38,8 @@ fun StandardScreen(viewModel: StandardViewModel) {
             Modifier
                 .fillMaxWidth()
                 .height(150.dp), horizontalAlignment = Alignment.End, verticalArrangement = Arrangement.Center) {
-            Text(text = "${viewState.showValueLeft}${viewState.inputOperator.showText}${viewState.showValueRight}", modifier = Modifier.padding(8.dp), fontSize = 24.sp)
-            Text(text = viewState.inputValue.formatNumber(), modifier = Modifier.padding(8.dp), fontSize = 32.sp, fontWeight = FontWeight.Bold)
+            Text(text = viewState.showText, modifier = Modifier.padding(8.dp), fontSize = 24.sp)
+            Text(text = viewState.inputValue.formatNumber(viewState.isFinalResult), modifier = Modifier.padding(8.dp), fontSize = 32.sp, fontWeight = FontWeight.Bold)
         }
 
         StandardKeyBoard(viewModel)