2019-05-25 具有历史记录功能的基本计算器

.gitignore

@@ -0,0 +1,17 @@
+*.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
+
+.idea
+app/build
+app/*.iml

app/.gitignore

@@ -0,0 +1 @@
+/build

app/build.gradle

@@ -0,0 +1,28 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 28
+    defaultConfig {
+        applicationId "club.lzlbog.calculator"
+        minSdkVersion 15
+        targetSdkVersion 28
+        versionCode 1
+        versionName "1.0"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation 'com.android.support:appcompat-v7:28.0.0-rc02'
+    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation 'com.android.support.test:runner:1.0.2'
+    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
+}

app/proguard-rules.pro

@@ -0,0 +1,21 @@
+# 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

app/src/androidTest/java/club/lzlbog/calculator/ExampleInstrumentedTest.java

@@ -0,0 +1,26 @@
+package club.lzlbog.calculator;
+
+import android.content.Context;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getTargetContext();
+
+        assertEquals("club.lzlbog.calculator", appContext.getPackageName());
+    }
+}

app/src/main/AndroidManifest.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="club.lzlbog.calculator">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
+        <activity android:name=".MainActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>

app/src/main/java/club/lzlbog/calculator/ExpressionCache.java

@@ -0,0 +1,40 @@
+package club.lzlbog.calculator;
+
+import java.util.HashMap;
+import java.util.LinkedList;
+
+public class ExpressionCache extends LinkedList<String> {
+    private int capacity;
+    private HashMap<String, String> result;
+
+    ExpressionCache(int capacity) {
+        this.capacity = capacity;
+        this.result = new HashMap<>();
+    }
+
+    public String getResult(String exp) {
+        if (result.containsKey(exp)) {
+            return result.get(exp);
+        }
+        return "";
+    }
+
+    public void putResult(String exp, String res) {
+        result.put(exp, res);
+    }
+
+    @Override
+    public void addFirst(String s) {
+        if (size() >= capacity) {
+            String last = removeLast();
+            result.remove(last);
+        }
+        super.addFirst(s);
+    }
+
+    @Override
+    public void clear() {
+        super.clear();
+        result.clear();
+    }
+}