Use a ProjectConfigurator extension to configure Gradle projects

Previously, the plugin listened to a Gradle project's settings being
refreshed to apply its settings to the project. This only worked if
the plugin had been previously activated by one of its other
extensions (m2e or code formatting). In situations where the plugin
had not already been activated, the refresh would be missed and the
plugin's settings were not applied to the project.

This commit switches from the listener-based approach to using a
ProjectConfigurator extension. Buildship automatically calls the
extension when a Gradle project is being configured, either because
it's being imported into the workspace for the first time or because
its settings are being refreshed. The use of an extension means that
the plugin is automatically activated if needed when Buildship
calls the extension.

Closes gh-123

Author: wilkinsona

spring-javaformat-eclipse/io.spring.javaformat.eclipse/plugin.xml

@@ -11,7 +11,7 @@
  <extension
        point="org.eclipse.m2e.core.projectConfigurators">
     <configurator
-          class="io.spring.javaformat.eclipse.m2e.ProjectSettingsConfigurator"
+          class="io.spring.javaformat.eclipse.m2e.MavenProjectSettingsConfigurator"
           id="io.spring.javaformat.eclipse.m2e.configurator"
           runsAfter="org.eclipse.m2e.jdt.javaConfigurator">
     </configurator>
@@ -31,4 +31,11 @@
           name="Spring Built-in Checks">
     </check-configuration>
  </extension>
+ <extension
+       point="org.eclipse.buildship.core.projectconfigurators">
+       <configurator
+             id="io.spring.javaformat.eclipse.gradle.ProjectSettingsConfigurator"
+             class="io.spring.javaformat.eclipse.gradle.GradleProjectSettingsConfigurator">
+       </configurator>
+ </extension>
 </plugin>

spring-javaformat-eclipse/io.spring.javaformat.eclipse/src/io/spring/javaformat/eclipse/Activator.java

@@ -19,8 +19,6 @@
 import org.eclipse.ui.plugin.AbstractUIPlugin;
 import org.osgi.framework.BundleContext;
 
-import io.spring.javaformat.eclipse.gradle.RefreshProjectSettingsListeners;
-
 /**
  * The activator class controls the plug-in life cycle.
  *
@@ -41,7 +39,6 @@ public Activator() {
 	@Override
 	public void start(BundleContext context) throws Exception {
 		super.start(context);
-		RefreshProjectSettingsListeners.attach();
 		plugin = this;
 	}
 

spring-javaformat-eclipse/io.spring.javaformat.eclipse/src/io/spring/javaformat/eclipse/gradle/RefreshProjectsSettingsJob.java renamed to spring-javaformat-eclipse/io.spring.javaformat.eclipse/src/io/spring/javaformat/eclipse/gradle/GradleProjectSettingsConfigurator.java

@@ -18,95 +18,71 @@
 
 import java.io.File;
 import java.io.IOException;
-import java.util.Arrays;
-import java.util.Collection;
 import java.util.LinkedHashSet;
 import java.util.Optional;
 import java.util.Set;
 
 import org.eclipse.buildship.core.GradleBuild;
+import org.eclipse.buildship.core.InitializationContext;
+import org.eclipse.buildship.core.ProjectConfigurator;
+import org.eclipse.buildship.core.ProjectContext;
 import org.eclipse.buildship.core.internal.CorePlugin;
 import org.eclipse.buildship.core.internal.workspace.FetchStrategy;
 import org.eclipse.buildship.core.internal.workspace.InternalGradleBuild;
 import org.eclipse.buildship.core.internal.workspace.InternalGradleWorkspace;
 import org.eclipse.buildship.core.internal.workspace.ModelProviderUtil;
 import org.eclipse.core.resources.IProject;
-import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
-import org.eclipse.core.runtime.IStatus;
-import org.eclipse.core.runtime.Status;
-import org.eclipse.core.runtime.jobs.Job;
 import org.gradle.tooling.CancellationTokenSource;
 import org.gradle.tooling.GradleConnector;
 import org.gradle.tooling.model.GradleTask;
 import org.gradle.tooling.model.eclipse.EclipseProject;
 
-import io.spring.javaformat.eclipse.Executor;
-import io.spring.javaformat.eclipse.Messages;
 import io.spring.javaformat.eclipse.projectsettings.ProjectSettingsFilesLocator;
 
 /**
- * Job to trigger refresh of project specific settings when the gradle plugin is used.
+ * {@link ProjectConfigurator} to apply project-specific settings to Gradle projects.
  *
+ * @author Andy Wilkinson
  * @author Phillip Webb
  */
 @SuppressWarnings("restriction")
-public class RefreshProjectsSettingsJob extends Job {
+public class GradleProjectSettingsConfigurator implements ProjectConfigurator {
 
 	private static final Object TASK_NAME = "checkFormatMain";
 
-	private final CancellationTokenSource tokenSource;
+	private CancellationTokenSource tokenSource;
 
-	private final Set<IProject> projects;
-
-	public RefreshProjectsSettingsJob() {
-		this(null);
-	}
-
-	public RefreshProjectsSettingsJob(Set<IProject> projects) {
-		super("Refresh spring-javaformat project settings");
+	@Override
+	public void init(InitializationContext context, IProgressMonitor monitor) {
 		this.tokenSource = GradleConnector.newCancellationTokenSource();
-		this.projects = projects;
+
 	}
 
 	@Override
-	protected IStatus run(IProgressMonitor monitor) {
+	public void configure(ProjectContext context, IProgressMonitor monitor) {
 		try {
-			new Executor(Messages.springFormatSettingsImportError).run(() -> {
-				configureProjects(monitor);
-			});
+			configureProject(context.getProject(), monitor);
 		}
-		catch (CoreException ex) {
-			return ex.getStatus();
+		catch (Exception ex) {
+			context.error("Failed to apply project settings", ex);
 		}
-		return Status.OK_STATUS;
 	}
 
-	private void configureProjects(IProgressMonitor monitor) throws CoreException, IOException {
+	private void configureProject(IProject project, IProgressMonitor monitor) throws CoreException, IOException {
 		InternalGradleWorkspace workspace = CorePlugin.internalGradleWorkspace();
-		Collection<IProject> projects = this.projects;
-		if (projects == null) {
-			projects = Arrays.asList(ResourcesPlugin.getWorkspace().getRoot().getProjects());
-		}
-		for (IProject project : projects) {
-			Optional<GradleBuild> build = workspace.getBuild(project);
-			if (build.isPresent()) {
-				configureProject(project, (InternalGradleBuild) build.get(), monitor);
+		Optional<GradleBuild> build = workspace.getBuild(project);
+		if (build.isPresent()) {
+			Set<EclipseProject> projects = ModelProviderUtil.fetchAllEclipseProjects((InternalGradleBuild) build.get(),
+					this.tokenSource, FetchStrategy.FORCE_RELOAD, monitor);
+			if (hasSpringFormatPlugin(projects)) {
+				ProjectSettingsFilesLocator locator = new ProjectSettingsFilesLocator(getSearchFolders(projects));
+				locator.locateSettingsFiles().applyToProject(project, monitor);
 			}
 		}
 	}
 
-	private void configureProject(IProject project, InternalGradleBuild build, IProgressMonitor monitor)
-			throws CoreException, IOException {
-		Set<EclipseProject> projects = ModelProviderUtil.fetchAllEclipseProjects(build, this.tokenSource,
-				FetchStrategy.FORCE_RELOAD, monitor);
-		if (hasSpringFormatPlugin(projects)) {
-			ProjectSettingsFilesLocator locator = new ProjectSettingsFilesLocator(getSearchFolders(projects));
-			locator.locateSettingsFiles().applyToProject(project, monitor);
-		}
-	}
-
 	private boolean hasSpringFormatPlugin(Set<EclipseProject> projects) {
 		for (EclipseProject project : projects) {
 			for (GradleTask task : project.getGradleProject().getTasks()) {
@@ -133,4 +109,8 @@ private Set<File> getSearchFolders(Set<EclipseProject> projects) {
 		return searchFolders;
 	}
 
+	@Override
+	public void unconfigure(ProjectContext context, IProgressMonitor monitor) {
+	}
+
 }

spring-javaformat-eclipse/io.spring.javaformat.eclipse/src/io/spring/javaformat/eclipse/gradle/RefreshProjectSettingsListeners.java

@@ -32,11 +32,11 @@
 import io.spring.javaformat.eclipse.projectsettings.ProjectSettingsFilesLocator;
 
 /**
- * Configurator to apply project specific settings.
+ * Configurator to apply project-specific settings to Maven projects.
  *
  * @author Phillip Webb
  */
-public class ProjectSettingsConfigurator extends AbstractProjectConfigurator {
+public class MavenProjectSettingsConfigurator extends AbstractProjectConfigurator {
 
 	@Override
 	public void configure(ProjectConfigurationRequest request, IProgressMonitor monitor) throws CoreException {