maven: code clean-up, notnulls

plugins/maven/src/main/java/org/jetbrains/idea/maven/navigator/actions/MavenProjectsNavigatorAction.java

@@ -16,6 +16,7 @@
 package org.jetbrains.idea.maven.navigator.actions;
 
 import com.intellij.openapi.actionSystem.AnActionEvent;
+import com.intellij.openapi.project.Project;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.idea.maven.navigator.MavenProjectsNavigator;
@@ -39,7 +40,8 @@ public abstract class MavenProjectsNavigatorAction extends MavenToggleAction {
 
   @Nullable
   private static MavenProjectsNavigator getNavigator(AnActionEvent e) {
-    return MavenProjectsNavigator.getInstance(MavenActionUtil.getProject(e.getDataContext()));
+    final Project project = MavenActionUtil.getProject(e.getDataContext());
+    return project != null ? MavenProjectsNavigator.getInstance(project) : null;
   }
 
   protected abstract boolean isSelected(@NotNull MavenProjectsNavigator navigator);

plugins/maven/src/main/java/org/jetbrains/idea/maven/project/actions/DownloadAllSourcesAndDocsAction.java

@@ -15,6 +15,7 @@
  */
 package org.jetbrains.idea.maven.project.actions;
 
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.idea.maven.project.MavenProjectsManager;
 
 public class DownloadAllSourcesAndDocsAction extends MavenProjectsManagerAction {
@@ -32,7 +33,7 @@ public class DownloadAllSourcesAndDocsAction extends MavenProjectsManagerAction
   }
 
   @Override
-  protected void perform(MavenProjectsManager manager) {
+  protected void perform(@NotNull MavenProjectsManager manager) {
     manager.scheduleArtifactsDownloading(manager.getProjects(), null, mySources, myDocs, null);
   }
 }

plugins/maven/src/main/java/org/jetbrains/idea/maven/project/actions/MavenProjectsManagerAction.java

@@ -24,7 +24,10 @@ import org.jetbrains.idea.maven.utils.actions.MavenActionUtil;
 public abstract class MavenProjectsManagerAction extends MavenAction {
   @Override
   public void actionPerformed(@NotNull AnActionEvent e) {
-    perform(MavenActionUtil.getProjectsManager(e.getDataContext()));
+    final MavenProjectsManager projectsManager = MavenActionUtil.getProjectsManager(e.getDataContext());
+    if (projectsManager != null) {
+      perform(projectsManager);
+    }
   }
 
   @Override
@@ -34,5 +37,5 @@ public abstract class MavenProjectsManagerAction extends MavenAction {
     return projectsManager != null && projectsManager.isMavenizedProject();
   }
 
-  protected abstract void perform(MavenProjectsManager manager);
+  protected abstract void perform(@NotNull MavenProjectsManager manager);
 }

plugins/maven/src/main/java/org/jetbrains/idea/maven/project/actions/ReimportAction.java

@@ -16,6 +16,7 @@
 package org.jetbrains.idea.maven.project.actions;
 
 import com.intellij.openapi.actionSystem.AnActionEvent;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.idea.maven.project.MavenProjectsManager;
 import org.jetbrains.idea.maven.utils.actions.MavenActionUtil;
 
@@ -26,7 +27,7 @@ public class ReimportAction extends MavenProjectsManagerAction {
   }
 
   @Override
-  protected void perform(MavenProjectsManager manager) {
+  protected void perform(@NotNull MavenProjectsManager manager) {
     manager.forceUpdateAllProjectsOrFindAllAvailablePomFiles();
   }
 }

plugins/maven/src/main/java/org/jetbrains/idea/maven/project/actions/UpdateFoldersAction.java

@@ -15,11 +15,12 @@
  */
 package org.jetbrains.idea.maven.project.actions;
 
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.idea.maven.project.MavenProjectsManager;
 
 public class UpdateFoldersAction extends MavenProjectsManagerAction {
   @Override
-  protected void perform(MavenProjectsManager manager) {
+  protected void perform(@NotNull MavenProjectsManager manager) {
     manager.scheduleFoldersResolveForAllProjects();
   }
 }