Merge compose.desktop.application plugin with compose plugin

This change removes `org.jetbrains.compose.desktop.application` plugin id
in favor of doing everything in `org.jetbrains.compose`.
The change simplifies configuring Compose Desktop projects.
Now, just one plugin dependency is needed.

To avoid task name conflicts with common task names such as `package` and `run`,
the plugin creates tasks lazily only if `application` block/property is used in a script.

examples/imageviewer/build.gradle.kts

@@ -1,5 +1,8 @@
 buildscript {
     repositories {
+        mavenLocal().mavenContent {
+            includeModule("org.jetbrains.compose", "compose-gradle-plugin")
+        }
         google()
         jcenter()
         maven("https://maven.pkg.jetbrains.space/public/p/compose/dev")
@@ -7,7 +10,6 @@ buildscript {
 
     dependencies {
         classpath("org.jetbrains.compose:compose-gradle-plugin:0.1.0-m1-build57")
-        classpath("org.jetbrains.compose:compose-desktop-application-gradle-plugin:0.1.0-m1-build57")
         classpath("com.android.tools.build:gradle:4.0.1")
         classpath(kotlin("gradle-plugin", version = "1.4.0"))
     }

examples/imageviewer/desktop/build.gradle.kts

@@ -4,7 +4,6 @@ import org.jetbrains.compose.desktop.application.dsl.TargetFormat
 plugins {
     kotlin("multiplatform") // kotlin("jvm") doesn't work well in IDEA/AndroidStudio (https://github.com/JetBrains/compose-jb/issues/22)
     id("org.jetbrains.compose")
-    id("org.jetbrains.compose.desktop.application")
 }
 
 kotlin {

gradle-plugins/compose-desktop-application/build.gradle.kts

@@ -1,47 +0,0 @@
-import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
-
-plugins {
-    kotlin("jvm")
-    id("com.gradle.plugin-publish")
-    id("java-gradle-plugin")
-    id("maven-publish")
-    id("com.github.johnrengelman.shadow") version "6.1.0"
-}
-
-gradlePluginConfig {
-    pluginId = "org.jetbrains.compose.desktop.application"
-    artifactId = "compose-desktop-application-gradle-plugin"
-    displayName = "JetBrains Compose Desktop Application Plugin"
-    description = "Plugin for creating native distributions and run configurations"
-    implementationClass = "org.jetbrains.compose.desktop.application.ApplicationPlugin"
-}
-
-val embedded by configurations.creating
-
-dependencies {
-    fun embeddedCompileOnly(dep: String) {
-        compileOnly(dep)
-        embedded(dep)
-    }
-
-    compileOnly(gradleApi())
-    compileOnly(kotlin("gradle-plugin-api"))
-    compileOnly(kotlin("gradle-plugin"))
-    // include relocated download task to avoid potential runtime conflicts
-    embeddedCompileOnly("de.undercouch:gradle-download-task:4.1.1")
-}
-
-val shadow = tasks.named<ShadowJar>("shadowJar") {
-    val fromPackage = "de.undercouch"
-    val toPackage = "org.jetbrains.compose.$fromPackage"
-    relocate(fromPackage, toPackage)
-    archiveClassifier.set("shadow")
-    configurations = listOf(embedded)
-    exclude("META-INF/gradle-plugins/de.undercouch.download.properties")
-}
-
-val jar = tasks.named<Jar>("jar") {
-    dependsOn(shadow)
-    from(zipTree(shadow.get().archiveFile))
-    this.duplicatesStrategy = DuplicatesStrategy.INCLUDE
-}

gradle-plugins/compose-desktop-application/src/main/kotlin/org/jetbrains/compose/ComposeBasePlugin.kt

@@ -1,10 +0,0 @@
-package org.jetbrains.compose
-
-import org.gradle.api.Plugin
-import org.gradle.api.Project
-
-open class ComposeBasePlugin : Plugin<Project> {
-    override fun apply(project: Project) {
-        project.extensions.create("compose", ComposeExtension::class.java)
-    }
-}

gradle-plugins/compose-desktop-application/src/main/kotlin/org/jetbrains/compose/desktop/DesktopBasePlugin.kt

@@ -1,14 +0,0 @@
-package org.jetbrains.compose.desktop
-
-import org.gradle.api.Plugin
-import org.gradle.api.Project
-import org.jetbrains.compose.ComposeBasePlugin
-import org.jetbrains.compose.ComposeExtension
-
-open class DesktopBasePlugin : Plugin<Project> {
-    override fun apply(project: Project) {
-        project.plugins.apply(ComposeBasePlugin::class.java)
-        val composeExt = project.extensions.getByType(ComposeExtension::class.java)
-        composeExt.extensions.create("desktop", DesktopExtension::class.java)
-    }
-}

gradle-plugins/compose-desktop-application/src/main/kotlin/org/jetbrains/compose/desktop/DesktopExtension.kt

@@ -1,5 +0,0 @@
-package org.jetbrains.compose.desktop
-
-import org.gradle.api.plugins.ExtensionAware
-
-abstract class DesktopExtension : ExtensionAware

gradle-plugins/compose/build.gradle.kts

@@ -1,9 +1,12 @@
+import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
+
 plugins {
     kotlin("jvm")
     id("de.fuerstenau.buildconfig")
     id("com.gradle.plugin-publish")
     id("java-gradle-plugin")
     id("maven-publish")
+    id("com.github.johnrengelman.shadow") version "6.1.0"
 }
 
 gradlePluginConfig {
@@ -20,9 +23,34 @@ buildConfig {
     buildConfigField("String", "composeVersion", BuildProperties.composeVersion)
 }
 
+val embedded by configurations.creating
+
 dependencies {
     compileOnly(gradleApi())
     compileOnly(localGroovy())
-    compileOnly("org.jetbrains.kotlin:kotlin-gradle-plugin")
+    compileOnly(kotlin("gradle-plugin-api"))
+    compileOnly(kotlin("gradle-plugin"))
     testImplementation(gradleTestKit())
+
+    fun embeddedCompileOnly(dep: String) {
+        compileOnly(dep)
+        embedded(dep)
+    }
+    // include relocated download task to avoid potential runtime conflicts
+    embeddedCompileOnly("de.undercouch:gradle-download-task:4.1.1")
+}
+
+val shadow = tasks.named<ShadowJar>("shadowJar") {
+    val fromPackage = "de.undercouch"
+    val toPackage = "org.jetbrains.compose.$fromPackage"
+    relocate(fromPackage, toPackage)
+    archiveClassifier.set("shadow")
+    configurations = listOf(embedded)
+    exclude("META-INF/gradle-plugins/de.undercouch.download.properties")
+}
+
+val jar = tasks.named<Jar>("jar") {
+    dependsOn(shadow)
+    from(zipTree(shadow.get().archiveFile))
+    this.duplicatesStrategy = DuplicatesStrategy.INCLUDE
 }

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/ComposePlugin.kt

@@ -5,6 +5,8 @@ package org.jetbrains.compose
 import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.api.artifacts.dsl.DependencyHandler
+import org.jetbrains.compose.desktop.DesktopExtension
+import org.jetbrains.compose.desktop.application.internal.configureApplicationImpl
 import org.jetbrains.kotlin.gradle.plugin.KotlinDependencyHandler
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
@@ -12,7 +14,16 @@ private val composeVersion get() = ComposeBuildConfig.composeVersion
 
 class ComposePlugin : Plugin<Project> {
     override fun apply(project: Project) {
+        val composeExtension = project.extensions.create("compose", ComposeExtension::class.java)
+        val desktopExtension = composeExtension.extensions.create("desktop", DesktopExtension::class.java)
+
         project.afterEvaluate {
+            if (desktopExtension._isApplicationInitialized) {
+                // If application object was not accessed in a script,
+                // we want to avoid creating tasks like package, run, etc. to avoid conflicts with other plugins
+                configureApplicationImpl(project, desktopExtension.application)
+            }
+
             project.dependencies.add(
                     "kotlinCompilerPluginClasspath",
                     "org.jetbrains.compose.compiler:compiler:$composeVersion"

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/DesktopExtension.kt

@@ -0,0 +1,20 @@
+package org.jetbrains.compose.desktop
+
+import org.gradle.api.model.ObjectFactory
+import org.gradle.api.plugins.ExtensionAware
+import org.jetbrains.compose.desktop.application.dsl.Application
+import javax.inject.Inject
+
+abstract class DesktopExtension @Inject constructor(private val objectFactory: ObjectFactory) : ExtensionAware {
+    internal var _isApplicationInitialized = false
+        private set
+
+    val application: Application by lazy {
+        _isApplicationInitialized = true
+        objectFactory.newInstance(Application::class.java, "main")
+    }
+
+    fun application(fn: Application.() -> Unit) {
+        application.fn()
+    }
+}

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/dsl/Application.kt

@@ -16,6 +16,9 @@ open class Application @Inject constructor(
     objects: ObjectFactory
 ) {
     internal var _configurationSource: ConfigurationSource? = null
+        private set
+    internal var _isDefaultConfigurationEnabled = true
+        private set
     internal val _fromFiles = objects.fileCollection()
     internal val _dependenciesTaskNames = ArrayList<String>()
 
@@ -28,7 +31,7 @@ open class Application @Inject constructor(
         _configurationSource = ConfigurationSource.KotlinMppTarget(from)
     }
     fun disableDefaultConfiguration() {
-        _configurationSource = null
+        _isDefaultConfigurationEnabled = false
     }
 
     fun fromFiles(vararg files: Any) {

gradle-plugins/compose/src/main/kotlin/org/jetbrains/compose/desktop/application/internal/configureApplication.kt

@@ -1,51 +1,35 @@
-package org.jetbrains.compose.desktop.application
+package org.jetbrains.compose.desktop.application.internal
 
 import org.gradle.api.*
 import org.gradle.api.plugins.JavaPluginConvention
 import org.gradle.api.tasks.JavaExec
 import org.gradle.api.tasks.TaskContainer
 import org.gradle.api.tasks.TaskProvider
-import org.jetbrains.compose.ComposeExtension
-import org.jetbrains.compose.desktop.DesktopBasePlugin
-import org.jetbrains.compose.desktop.DesktopExtension
 import org.jetbrains.compose.desktop.application.dsl.Application
 import org.jetbrains.compose.desktop.application.dsl.TargetFormat
-import org.jetbrains.compose.desktop.application.internal.OS
-import org.jetbrains.compose.desktop.application.internal.configureWix
-import org.jetbrains.compose.desktop.application.internal.currentOS
-import org.jetbrains.compose.desktop.application.internal.provider
 import org.jetbrains.compose.desktop.application.tasks.AbstractJPackageTask
 import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
 import org.jetbrains.kotlin.gradle.plugin.KotlinPlatformType
 import java.io.File
 import java.util.*
 
-private const val PLUGIN_ID = "org.jetbrains.compose.desktop.application"
-
 // todo: multiple launchers
 // todo: file associations
 // todo: use workers
-@Suppress("unused") // Gradle plugin entry point
-open class ApplicationPlugin : Plugin<Project> {
-    override fun apply(project: Project) {
-        project.plugins.apply(DesktopBasePlugin::class.java)
-        val composeExt = project.extensions.getByType(ComposeExtension::class.java)
-        val desktopExt = composeExt.extensions.getByType(DesktopExtension::class.java)
-        val mainApplication = project.objects.newInstance(Application::class.java, "main")
-        desktopExt.extensions.add("application", mainApplication)
-        project.plugins.withId("org.jetbrains.kotlin.jvm") {
+fun configureApplicationImpl(project: Project, app: Application) {
+    project.afterEvaluate {
+        if (app._isDefaultConfigurationEnabled) {
+            if (project.plugins.hasPlugin("org.jetbrains.kotlin.multiplatform")) {
+                project.configureFromMppPlugin(app)
+            } else if (project.plugins.hasPlugin("org.jetbrains.kotlin.jvm")) {
                 val mainSourceSet = project.convention.getPlugin(JavaPluginConvention::class.java).sourceSets.getByName("main")
-            mainApplication.from(mainSourceSet)
+                app.from(mainSourceSet)
             }
-        project.plugins.withId("org.jetbrains.kotlin.multiplatform") {
-            project.configureFromMppPlugin(mainApplication)
         }
-        project.afterEvaluate {
-            project.configurePackagingTasks(listOf(mainApplication))
+        project.configurePackagingTasks(listOf(app))
         project.configureWix()
     }
 }
-}
 
 internal fun Project.configureFromMppPlugin(mainApplication: Application) {
     val kotlinExt = extensions.getByType(KotlinMultiplatformExtension::class.java)
@@ -56,7 +40,7 @@ internal fun Project.configureFromMppPlugin(mainApplication: Application) {
                 mainApplication.from(target)
                 isJvmTargetConfigured = true
             } else {
-                logger.error("w: Default configuration for '$PLUGIN_ID' is disabled: " +
+                logger.error("w: Default configuration for Compose Desktop Application is disabled: " +
                         "multiple Kotlin JVM targets definitions are detected. " +
                         "Specify, which target to use by using `compose.desktop.application.from(kotlinMppTarget)`")
                 mainApplication.disableDefaultConfiguration()

gradle-plugins/settings.gradle.kts

@@ -6,4 +6,3 @@ pluginManagement {
 }
 
 include(":compose")
-include(":compose-desktop-application")

tutorials/Native_distributions_and_local_execution/README.md

@@ -5,10 +5,9 @@
 In this tutorial, we'll show you how to create native distributions (installers/packages) for all the supported systems.
 We will also demonstrate how to run an application locally with the same settings as for distributions.
 
-## Desktop application Gradle plugin
+## Gradle plugin
 
-`org.jetbrains.compose.desktop.application` 
-simplifies the packaging of applications into native distributions and running an application locally.
+`org.jetbrains.compose` Gradle plugin simplifies the packaging of applications into native distributions and running an application locally.
 Currently, the plugin uses [jpackage](https://openjdk.java.net/jeps/343) for packaging self-contained applications.
 
 ## Basic usage
@@ -26,7 +25,6 @@ import org.jetbrains.compose.desktop.application.dsl.TargetFormat
 plugins {
     kotlin("jvm")
     id("org.jetbrains.compose")
-    id("org.jetbrains.compose.desktop.application")
 }
 
 dependencies {
@@ -54,6 +52,8 @@ aggregating all package tasks for an application.
 * `run` is used to run an app locally. You need to define a `mainClass` — an fq-name of a class, 
 containing the `main` function.
   
+Note, that the tasks are created only if the `application` block/property is used in a script.
+
 After a build, output binaries can be found in `${project.buildDir}/compose/binaries`.
 
 ## Available formats
@@ -144,7 +144,7 @@ If the default configuration is ambiguous or not sufficient, the plugin can be c
 ```kotlin
 plugins {
     kotlin("jvm")
-    id("org.jetbrains.compose.desktop.application")
+    id("org.jetbrains.compose")
 } 
 
 val customSourceSet = sourceSets.create("customSourceSet")
@@ -158,7 +158,7 @@ compose.desktop {
 ```kotlin
 plugins {
     kotlin("multiplatform")
-    id("org.jetbrains.compose.desktop.application")
+    id("org.jetbrains.compose")
 } 
 
 kotlin {