Add shared multiplatform module

build.gradle

@@ -60,6 +60,7 @@ plugins {
     id "com.ncorti.ktfmt.gradle" version "0.11.0"
     id "com.google.dagger.hilt.android" version "$hiltVersion" apply false
     id "io.gitlab.arturbosch.detekt" version "1.23.0"
+    id "org.jetbrains.kotlin.multiplatform" version "1.9.22" apply false
 }
 
 allprojects {

settings.gradle

@@ -2,5 +2,5 @@ plugins {
     id 'org.gradle.toolchains.foojay-resolver-convention' version '0.4.0'
 }
 
-include ':ground', ':sharedTest'
+include ':shared', ':ground', ':sharedTest'
 

shared/build.gradle.kts

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+plugins {
+  kotlin("multiplatform")
+  id("com.android.library")
+}
+
+kotlin {
+  androidTarget { compilations.all { kotlinOptions { jvmTarget = "1.8" } } }
+
+  js(IR) { nodejs() }
+
+  sourceSets {
+    commonMain.dependencies {
+      // put your multiplatform dependencies here
+    }
+    //        commonTest.dependencies {
+    //            implementation(libs.kotlin.test)
+    //        }
+  }
+}
+
+android {
+  namespace = "com.google.ground.shared"
+  compileSdk = 34
+  defaultConfig { minSdk = 24 }
+}

shared/src/androidMain/kotlin/com/google/ground/shared/Platform.android.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.ground.shared
+
+class AndroidPlatform : Platform {
+    override val name: String = "Android ${android.os.Build.VERSION.SDK_INT}"
+}
+
+actual fun getPlatform(): Platform = AndroidPlatform()

shared/src/commonMain/kotlin/com/google/ground/shared/Greeting.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.ground.shared
+
+class Greeting {
+    private val platform: Platform = getPlatform()
+
+    fun greet(): String {
+        return "Hello, ${platform.name}!"
+    }
+}

shared/src/commonMain/kotlin/com/google/ground/shared/Platform.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.ground.shared
+
+interface Platform {
+    val name: String
+}
+
+expect fun getPlatform(): Platform

shared/src/iosMain/kotlin/com/google/ground/shared/Platform.ios.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.ground.shared
+
+import platform.UIKit.UIDevice
+
+class IOSPlatform: Platform {
+    override val name: String = UIDevice.currentDevice.systemName() + " " + UIDevice.currentDevice.systemVersion
+}
+
+actual fun getPlatform(): Platform = IOSPlatform()