package information passing back to gradle build via plugin extensions.

.classpath

 <?xml version="1.0" encoding="UTF-8"?>
 <classpath>
+	<classpathentry kind="src" path="src/main/groovy"/>
 	<classpathentry kind="lib" path="gradle/wrapper/gradle-wrapper.jar"/>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
 	<classpathentry kind="output" path="bin"/>

src/main/groovy/com/github/rosjava/rosjava_gradle_plugins/CatkinPlugin.groovy

@@ -5,21 +5,97 @@ import org.gradle.api.Plugin;
 import org.gradle.api.Task;
 import org.gradle.api.*;
 
+/*
+ * Provides catkin information to the gradle build, defining properties for
+ * use by the project:
+ *
+ * - project.catkin.rosPackagePath
+ * - project.catkin.packages
+ *
+ * The latter can be iterated over for information:
+ *
+ * project.catkin.packages.each { pair ->
+ *     pkg = pair.value
+ *     println pkg.name
+ *     println pkg.version
+ *     pkg.dependencies.each { d ->
+ *         println d
+ *     }
+ * }
+ * 
+ * Use this only once in the root of a multi-project gradle build - it will
+ * only generate the properties once and share them this way.
+ */
 class CatkinPlugin implements Plugin<Project> {
+    /* 
+     * Possibly should check for existence of these properties and 
+     * be lazy if they're already defined.
+     */
 	def void apply(Project project) {
-	    project.ext.ROS_PACKAGE_PATH = "$System.env.ROS_PACKAGE_PATH".split(":")
-        project.ext.ROS_PACKAGE_TREES = [] 
-	    project.ext.ROS_PACKAGE_PATH.each { rosPackageRoot ->
-	        println("Ros Package Root: " + rosPackageRoot)
+	    project.extensions.create("catkin", CatkinPluginExtension)
+	    project.catkin.packages = [:]
+	    project.catkin.rosPackagePath = []
+	    project.catkin.rosPackagePath = "$System.env.ROS_PACKAGE_PATH".split(":")
+	    project.catkin.rosPackagePath.each { rosPackageRoot ->
+	        println("RosPackageRoot.........${rosPackageRoot}")
             def manifestTree = project.fileTree(dir: rosPackageRoot, include: '**/package.xml')
             manifestTree.each { file -> 
-                println("File: " + file)
+                def pkg = new CatkinPackage(file)
+                project.catkin.packages.put(pkg.name, pkg)
             }
 	    }
-        println("We are happy, you should be too.")
-        project.task('happy') << {
+        println("CatkinPlugin is happy, you should be too.")
+        project.task('catkinPackageInfo') << {
             println "I'll teach your grandmother to suck eggs!"
-            println("ROS_PACKAGE_PATH........." + project.ROS_PACKAGE_PATH)
+            println("rosPackagePath........." + project.catkin.rosPackagePath)
+            println("Catkin Packages")
+            project.catkin.packages.each { pkg ->
+                print pkg.value.toString()
             }
         }
     }
+}
+
+class CatkinPluginExtension {
+    Map<String, CatkinPackage> packages
+    List<String> rosPackagePath
+}
+
+/*
+ * Use this to establish methods that can be used by the project.
+ * Currently don't have any.
+ */
+class CatkinPluginConvention {
+    private Project project
+    public CatkinPluginConvention(Project project) {
+        this.project = project
+    }
+}
+
+class CatkinPackage {
+    def name
+    def version
+    def dependencies
+    
+    def CatkinPackage(File packageXmlFilename) {
+        def packageXml = new XmlParser().parse(packageXmlFilename)
+        name = packageXml.name.text()
+        version = packageXml.version.text()
+        dependencies = []
+        packageXml.build_depend.each { d ->
+            dependencies.add(d.text())
+        }
+    }
+    def String toString() {
+        def out = new String()
+        out += name + "\n"
+        out += "  version: " + version + "\n"
+        out += "  dependencies:" + "\n"
+        dependencies.each { d ->
+            out += "    " + d + "\n"
+        }
+        return out
+    
+    }
+}
+