support Java Platform Module System (JPMS) (issue #1)

.travis.yml

@@ -24,5 +24,5 @@ deploy:
   skip_cleanup: true # to upload artifacts created during the build
   on:
     branch: master
-    jdk: openjdk8
+    jdk: openjdk11
     tags: true

CHANGELOG.md

@@ -1,6 +1,12 @@
 FlatLaf Change Log
 ==================
 
+## Unreleased
+
+- Added Java 9 module descriptor `module-info.class` to `flatlaf.jar` (in
+  `META-INF/versions/9`). But FlatLaf remains Java 8 compatible. (issue #1)
+
+
 ## 0.9
 
 - Initial release

flatlaf-core/build.gradle.kts

@@ -26,7 +26,20 @@ repositories {
 	jcenter()
 }
 
+if( JavaVersion.current() >= JavaVersion.VERSION_1_9 ) {
+	sourceSets {
+		create( "main9" ) {
+			java {
+				setSrcDirs( listOf( "src/main9/java" ) )
+			}
+		}
+	}
+}
+
 dependencies {
+	if( JavaVersion.current() >= JavaVersion.VERSION_1_9 )
+		"main9Implementation"( files( sourceSets["main"].output.classesDirs ).builtBy( "compileJava" ) )
+
 	testImplementation( "com.miglayout:miglayout-swing:5.2" )
 	testImplementation( "com.jgoodies:jgoodies-forms:1.9.0" )
 }
@@ -37,8 +50,30 @@ java {
 }
 
 tasks {
+	if( JavaVersion.current() >= JavaVersion.VERSION_1_9 ) {
+		named<JavaCompile>( "compileMain9Java" ) {
+			doFirst {
+				options.compilerArgs = listOf(
+					"--release", "9",
+					"--patch-module", "com.formdev.flatlaf=" + classpath.asPath
+				)
+				classpath = files()
+			}
+		}
+	}
+	
 	jar {
 		archiveBaseName.set( "flatlaf" )
+
+		if( JavaVersion.current() >= JavaVersion.VERSION_1_9 ) {
+			manifest.attributes(
+				"Multi-Release" to "true"
+			)
+
+			into( "META-INF/versions/9" ) {
+				from( sourceSets["main9"].output )
+			}
+		}
 	}
 
 	javadoc {

flatlaf-core/src/main9/java/module-info.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * 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
+ *
+ *     http://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.
+ */
+
+/**
+ * @author Karl Tauber
+ */
+module com.formdev.flatlaf {
+	requires java.desktop;
+
+	exports com.formdev.flatlaf;
+	exports com.formdev.flatlaf.icons;
+	exports com.formdev.flatlaf.ui;
+	exports com.formdev.flatlaf.util;
+}

flatlaf-demo/build.gradle.kts

@@ -42,6 +42,8 @@ tasks {
 			attributes( "Main-Class" to "com.formdev.flatlaf.demo.FlatLafDemo" )
 		}
 
+		exclude( "META-INF/versions/**" )
+
 		// include all dependencies in jar
 		from( {
 			configurations.runtimeClasspath.get().filter { it.name.endsWith( "jar" ) }.map { zipTree( it ) }