IDEA-CR-20931 address 'his is a non-transparent assumption, I'd argue noone except of the author of MessageBusUtil#subscribe knows about it'

Make code more maintainable and clear

platform/lang-impl/src/com/intellij/ide/script/IdeStartupScripts.java

@@ -17,23 +17,19 @@ package com.intellij.ide.script;
 
 import com.intellij.ide.extensionResources.ExtensionsRootType;
 import com.intellij.ide.plugins.PluginManagerCore;
-import com.intellij.openapi.Disposable;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.components.ApplicationComponent;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.extensions.PluginId;
 import com.intellij.openapi.progress.ProcessCanceledException;
 import com.intellij.openapi.project.Project;
-import com.intellij.openapi.project.ProjectManager;
-import com.intellij.openapi.project.ProjectManagerListener;
+import com.intellij.openapi.project.ProjectUtil;
 import com.intellij.openapi.startup.StartupManager;
 import com.intellij.openapi.util.Condition;
-import com.intellij.openapi.util.Disposer;
 import com.intellij.openapi.util.Pair;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.VfsUtilCore;
 import com.intellij.openapi.vfs.VirtualFile;
-import com.intellij.util.MessageBusUtil;
 import com.intellij.util.ObjectUtils;
 import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
@@ -50,6 +46,7 @@ import java.util.List;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
 class IdeStartupScripts implements ApplicationComponent {
@@ -69,7 +66,7 @@ class IdeStartupScripts implements ApplicationComponent {
     LOG.info(scripts.size() + " startup script(s) found");
     if (scripts.isEmpty()) return;
 
-    MessageBusUtil.subscribe(ProjectManager.TOPIC, new MyProjectManagerListener(prepareScriptEnginesAsync(scripts)));
+    ProjectUtil.runWhenProjectOpened(project -> new MyProjectOpenedHandler(prepareScriptEnginesAsync(scripts)));
   }
 
   @NotNull
@@ -132,21 +129,20 @@ class IdeStartupScripts implements ApplicationComponent {
     return ExtensionsRootType.getInstance().findResourceDirectory(corePlugin, SCRIPT_DIR, false);
   }
 
-  private static class MyProjectManagerListener implements ProjectManagerListener, Disposable {
+  private static class MyProjectOpenedHandler implements Consumer<Project> {
     final AtomicBoolean myScriptsExecutionStarted;
     private final Future<List<Pair<VirtualFile, IdeScriptEngine>>> myScriptsAndEnginesFuture;
 
-    public MyProjectManagerListener(@NotNull Future<List<Pair<VirtualFile, IdeScriptEngine>>> scriptsAndEnginesFuture) {
+    public MyProjectOpenedHandler(@NotNull Future<List<Pair<VirtualFile, IdeScriptEngine>>> scriptsAndEnginesFuture) {
       myScriptsAndEnginesFuture = scriptsAndEnginesFuture;
       myScriptsExecutionStarted = new AtomicBoolean();
     }
 
     @Override
-    public void projectOpened(final Project project) {
+    public void accept(@NotNull Project project) {
       StartupManager.getInstance(project).runWhenProjectIsInitialized(() -> {
         if (project.isDisposed()) return;
         if (!myScriptsExecutionStarted.compareAndSet(false, true)) return;
-        Disposer.dispose(this);
         runAllScriptsImpl(project);
       });
     }
@@ -177,9 +173,5 @@ class IdeStartupScripts implements ApplicationComponent {
         LOG.error(e);
       }
     }
-
-    @Override
-    public void dispose() {
-    }
   }
 }

platform/platform-api/src/com/intellij/openapi/project/ProjectUtil.kt

@@ -19,6 +19,7 @@ package com.intellij.openapi.project
 import com.intellij.ide.DataManager
 import com.intellij.ide.highlighter.ProjectFileType
 import com.intellij.openapi.actionSystem.CommonDataKeys
+import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.application.appSystemDir
 import com.intellij.openapi.application.runWriteAction
 import com.intellij.openapi.fileEditor.UniqueVFilePathBuilder
@@ -39,6 +40,7 @@ import java.nio.file.InvalidPathException
 import java.nio.file.Path
 import java.nio.file.Paths
 import java.util.*
+import java.util.function.Consumer
 import javax.swing.JComponent
 
 val Module.rootManager: ModuleRootManager
@@ -164,4 +166,30 @@ fun Project.getProjectCachePath(cacheName: String, forceNameUse: Boolean = false
 @JvmOverloads
 fun Project.getProjectCachePath(baseDir: Path, forceNameUse: Boolean = false, hashSeparator: String = "."): Path {
   return baseDir.resolve(getProjectCacheFileName(forceNameUse, hashSeparator))
+}
+
+/**
+ * Add one-time projectOpened listener.
+ */
+fun Project.runWhenProjectOpened(handler: Runnable) = runWhenProjectOpened(this) { handler.run() }
+
+/**
+ * Add one-time first projectOpened listener.
+ */
+@JvmOverloads
+fun runWhenProjectOpened(project: Project? = null, handler: Consumer<Project>) = runWhenProjectOpened(project) { handler.accept(it) }
+
+/**
+ * Add one-time projectOpened listener.
+ */
+inline fun runWhenProjectOpened(project: Project? = null, crossinline handler: (project: Project) -> Unit) {
+  val connection = (project ?: ApplicationManager.getApplication()).messageBus.connect()
+  connection.subscribe(ProjectManager.TOPIC, object : ProjectManagerListener {
+    override fun projectOpened(eventProject: Project) {
+      if (project == null || project === eventProject) {
+        connection.disconnect()
+        handler(eventProject)
+      }
+    }
+  })
 }

platform/platform-impl/src/com/intellij/designer/LightToolWindowManager.java

@@ -26,8 +26,7 @@ import com.intellij.openapi.fileEditor.FileEditorManagerEvent;
 import com.intellij.openapi.fileEditor.FileEditorManagerListener;
 import com.intellij.openapi.project.DumbAwareRunnable;
 import com.intellij.openapi.project.Project;
-import com.intellij.openapi.project.ProjectManager;
-import com.intellij.openapi.project.ProjectManagerListener;
+import com.intellij.openapi.project.ProjectUtil;
 import com.intellij.openapi.startup.StartupManager;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.openapi.wm.ToolWindow;
@@ -66,16 +65,7 @@ public abstract class LightToolWindowManager implements Disposable {
     myPropertiesComponent = PropertiesComponent.getInstance(myProject);
     myEditorModeKey = EDITOR_MODE + getComponentName() + ".STATE";
 
-    MessageBusConnection connection = myProject.getMessageBus().connect();
-    connection.subscribe(ProjectManager.TOPIC, new ProjectManagerListener() {
-      @Override
-      public void projectOpened(Project project) {
-        if (myProject == project) {
-          connection.disconnect();
-          LightToolWindowManager.this.projectOpened();
-        }
-      }
-    });
+    ProjectUtil.runWhenProjectOpened(project, () -> projectOpened());
   }
 
   protected void projectOpened() {

platform/platform-impl/src/com/intellij/openapi/ui/playback/util/ProjectPlaybackCall.java

@@ -16,17 +16,13 @@
 package com.intellij.openapi.ui.playback.util;
 
 import com.intellij.ide.RecentProjectsManager;
-import com.intellij.openapi.Disposable;
 import com.intellij.openapi.project.DumbService;
-import com.intellij.openapi.project.Project;
 import com.intellij.openapi.project.ProjectManager;
-import com.intellij.openapi.project.ProjectManagerListener;
+import com.intellij.openapi.project.ProjectUtil;
 import com.intellij.openapi.startup.StartupManager;
 import com.intellij.openapi.ui.playback.PlaybackContext;
 import com.intellij.openapi.util.AsyncResult;
-import com.intellij.openapi.util.Disposer;
 import com.intellij.openapi.util.io.FileUtil;
-import com.intellij.util.MessageBusUtil;
 import com.intellij.util.ui.UIUtil;
 
 import java.io.File;
@@ -54,12 +50,12 @@ public class ProjectPlaybackCall {
 
   public static AsyncResult<String> openProject(final PlaybackContext context, final String path) {
     final AsyncResult<String> result = new AsyncResult<>();
-    final ProjectManager projectManager = ProjectManager.getInstance();
-    MessageBusUtil.subscribe(ProjectManager.TOPIC, new MyProjectManagerListener(result));
-
+    ProjectUtil.runWhenProjectOpened(project -> StartupManager.getInstance(project).registerPostStartupActivity(() -> {
+      DumbService.getInstance(project).runWhenSmart(() -> result.setDone("Opened successfully: " + project.getPresentableUrl()));
+    }));
     UIUtil.invokeLaterIfNeeded(() -> {
       try {
-        projectManager.loadAndOpenProject(path);
+        ProjectManager.getInstance().loadAndOpenProject(path);
       }
       catch (Exception e) {
         context.error(e.getMessage(), context.getCurrentLine());
@@ -69,24 +65,4 @@ public class ProjectPlaybackCall {
 
     return result;
   }
-
-  private static class MyProjectManagerListener implements ProjectManagerListener, Disposable {
-    private final AsyncResult<String> myResult;
-
-    public MyProjectManagerListener(AsyncResult<String> result) {
-      myResult = result;
-    }
-
-    @Override
-    public void projectOpened(final Project project) {
-      StartupManager.getInstance(project).registerPostStartupActivity(() -> {
-        Disposer.dispose(this);
-        DumbService.getInstance(project).runWhenSmart(() -> myResult.setDone("Opened successfully: " + project.getPresentableUrl()));
-      });
-    }
-
-    @Override
-    public void dispose() {
-    }
-  }
 }

platform/platform-impl/src/com/intellij/openapi/vfs/encoding/EncodingProjectManagerImpl.java

@@ -27,8 +27,7 @@ import com.intellij.openapi.fileEditor.FileDocumentManager;
 import com.intellij.openapi.fileTypes.StdFileTypes;
 import com.intellij.openapi.progress.ProgressManager;
 import com.intellij.openapi.project.Project;
-import com.intellij.openapi.project.ProjectManager;
-import com.intellij.openapi.project.ProjectManagerListener;
+import com.intellij.openapi.project.ProjectUtil;
 import com.intellij.openapi.roots.ProjectFileIndex;
 import com.intellij.openapi.roots.ProjectRootManager;
 import com.intellij.openapi.startup.StartupManager;
@@ -67,14 +66,7 @@ public class EncodingProjectManagerImpl extends EncodingProjectManager implement
   public EncodingProjectManagerImpl(Project project, EncodingManager ideEncodingManager) {
     myProject = project;
     myIdeEncodingManager = (EncodingManagerImpl)ideEncodingManager;
-    project.getMessageBus().connect().subscribe(ProjectManager.TOPIC, new ProjectManagerListener() {
-      @Override
-      public void projectOpened(Project project) {
-        if (project == myProject) {
-          StartupManager.getInstance(project).runWhenProjectIsInitialized(EncodingProjectManagerImpl.this::reloadAlreadyLoadedDocuments);
-        }
-      }
-    });
+    ProjectUtil.runWhenProjectOpened(project, () -> StartupManager.getInstance(project).runWhenProjectIsInitialized(this::reloadAlreadyLoadedDocuments));
   }
 
   private final Map<VirtualFile, Charset> myMapping = ContainerUtil.newConcurrentMap();

platform/platform-impl/src/com/intellij/util/MessageBusUtil.java

@@ -51,12 +51,4 @@ public class MessageBusUtil {
       }
     };
   }
-
-  public static <L> void subscribe(@NotNull Topic<L> topic, @NotNull L handler) {
-    subscribe(ApplicationManager.getApplication().getMessageBus(), topic, handler);
-  }
-
-  public static <L> void subscribe(@NotNull MessageBus messageBus, @NotNull Topic<L> topic, @NotNull L handler) {
-    (handler instanceof Disposable ? messageBus.connect((Disposable)handler) : messageBus.connect()).subscribe(topic, handler);
-  }
 }

platform/testGuiFramework/src/com/intellij/testGuiFramework/framework/GuiTestUtil.java

@@ -19,7 +19,6 @@ import com.intellij.diagnostic.AbstractMessage;
 import com.intellij.diagnostic.MessagePool;
 import com.intellij.ide.PrivacyPolicy;
 import com.intellij.ide.RecentProjectsManager;
-import com.intellij.openapi.Disposable;
 import com.intellij.openapi.actionSystem.ActionManager;
 import com.intellij.openapi.actionSystem.KeyboardShortcut;
 import com.intellij.openapi.application.ApplicationBundle;
@@ -33,8 +32,8 @@ import com.intellij.openapi.project.Project;
 import com.intellij.openapi.project.ProjectManager;
 import com.intellij.openapi.project.ProjectManagerListener;
 import com.intellij.openapi.ui.TextFieldWithBrowseButton;
-import com.intellij.openapi.util.Disposer;
 import com.intellij.openapi.util.Pair;
+import com.intellij.openapi.util.Ref;
 import com.intellij.openapi.util.SwitchBootJdkAction;
 import com.intellij.openapi.util.SystemInfo;
 import com.intellij.openapi.util.io.FileUtilRt;
@@ -50,8 +49,8 @@ import com.intellij.ui.components.JBList;
 import com.intellij.ui.popup.PopupFactoryImpl;
 import com.intellij.ui.popup.list.ListPopupModel;
 import com.intellij.util.JdkBundle;
-import com.intellij.util.MessageBusUtil;
 import com.intellij.util.Producer;
+import com.intellij.util.messages.MessageBusConnection;
 import com.intellij.util.ui.EdtInvocationManager;
 import org.fest.swing.core.*;
 import org.fest.swing.core.Robot;
@@ -207,20 +206,23 @@ GuiTestUtil {
     Robot robot = null;
     try {
       robot = BasicRobot.robotWithCurrentAwtHierarchy();
-      final MyProjectManagerListener listener = new MyProjectManagerListener();
 
       //[ACCEPT IntelliJ IDEA Privacy Policy Agreement]
       acceptAgreementIfNeeded(robot);
 
       if(isFirstStart) (new FirstStart(robot)).completeBefore();
 
+      final MyProjectManagerListener listener = new MyProjectManagerListener();
+      final Ref<MessageBusConnection> connection = new Ref<>();
+
       findFrame(new GenericTypeMatcher<Frame>(Frame.class) {
         @Override
         protected boolean isMatching(@NotNull Frame frame) {
           if (frame instanceof IdeFrame) {
             if (frame instanceof IdeFrameImpl) {
               listener.myActive = true;
-              MessageBusUtil.subscribe(ProjectManager.TOPIC, listener);
+              connection.set(ApplicationManager.getApplication().getMessageBus().connect());
+              connection.get().subscribe(ProjectManager.TOPIC, listener);
             }
             return true;
           }
@@ -253,7 +255,11 @@ GuiTestUtil {
                                !progressManager.hasProgressIndicator() &&
                                !progressManager.hasUnsafeProgressIndicator();
               if (isIdle) {
-                Disposer.dispose(listener);
+                MessageBusConnection busConnection = connection.get();
+                if (busConnection != null) {
+                  connection.set(null);
+                  busConnection.disconnect();
+                }
               }
               return isIdle;
             }
@@ -728,7 +734,7 @@ GuiTestUtil {
     return s == null ? System.getenv(name) : s;
   }
 
-  private static class MyProjectManagerListener implements ProjectManagerListener, Disposable {
+  private static class MyProjectManagerListener implements ProjectManagerListener {
     boolean myActive;
     boolean myNotified;
 
@@ -736,10 +742,6 @@ GuiTestUtil {
     public void projectOpened(Project project) {
       myNotified = true;
     }
-
-    @Override
-    public void dispose() {
-    }
   }
 
   private static class PrefixMatcher extends BaseMatcher<String> {