Fix ToolWindow's NPE when reopening the project

src/main/java/ee/carlrobert/codegpt/ide/action/AskAction.java

@@ -19,7 +19,7 @@ public class AskAction extends AnAction {
     var project = event.getProject();
     if (project != null) {
       ConversationsState.getInstance().startConversation();
-      ContentManagerService.getInstance(project).displayChatTab();
+      project.getService(ContentManagerService.class).displayChatTab();
       var chatToolWindow = project.getService(ToolWindowService.class).getChatToolWindow();
       chatToolWindow.show();
       chatToolWindow.displayLandingView();

src/main/java/ee/carlrobert/codegpt/ide/action/BaseAction.java

@@ -5,13 +5,23 @@ import com.intellij.openapi.actionSystem.AnActionEvent;
 import com.intellij.openapi.actionSystem.PlatformDataKeys;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.NlsActions;
 import ee.carlrobert.codegpt.ide.conversations.ConversationsState;
 import ee.carlrobert.codegpt.ide.toolwindow.ContentManagerService;
 import ee.carlrobert.codegpt.ide.toolwindow.ToolWindowService;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public abstract class BaseAction extends AnAction {
 
+  public BaseAction() {
+    super();
+  }
+
+  public BaseAction(@Nullable @NlsActions.ActionText String text) {
+    super(text);
+  }
+
   protected abstract void actionPerformed(Project project, Editor editor, String selectedText);
 
   public void actionPerformed(@NotNull AnActionEvent event) {
@@ -34,7 +44,7 @@ public abstract class BaseAction extends AnAction {
 
   protected void sendMessage(@NotNull Project project, String prompt) {
     ConversationsState.getInstance().startConversation();
-    ContentManagerService.getInstance(project).displayChatTab();
+    project.getService(ContentManagerService.class).displayChatTab();
 
     var toolWindowService = project.getService(ToolWindowService.class);
     var chatToolWindow = toolWindowService.getChatToolWindow();

src/main/java/ee/carlrobert/codegpt/ide/toolwindow/ChatGptToolWindow.java

@@ -216,5 +216,6 @@ public class ChatGptToolWindow {
     scrollablePanel.setLayout(new BoxLayout(scrollablePanel, BoxLayout.Y_AXIS));
     scrollPane = new ScrollPane(scrollablePanel);
     generateButton = new GenerateButton();
+    displayLandingView();
   }
 }

src/main/java/ee/carlrobert/codegpt/ide/toolwindow/ContentManagerService.java

@@ -2,9 +2,7 @@ package ee.carlrobert.codegpt.ide.toolwindow;
 
 import static java.util.Objects.requireNonNull;
 
-import com.intellij.openapi.application.ApplicationManager;
-import com.intellij.openapi.project.Project;
-import com.intellij.openapi.wm.ToolWindowManager;
+import com.intellij.openapi.wm.ToolWindow;
 import com.intellij.ui.content.Content;
 import com.intellij.ui.content.ContentFactory;
 import com.intellij.ui.content.ContentManager;
@@ -15,42 +13,39 @@ import org.jetbrains.annotations.NotNull;
 
 public class ContentManagerService {
 
-  private static ContentManagerService instance;
-  private final ContentManager contentManager;
+  private ToolWindow toolWindow;
 
-  private ContentManagerService(Project project) {
-    this.contentManager = requireNonNull(ToolWindowManager.getInstance(project).getToolWindow("CodeGPT")).getContentManager();
+  public void setToolWindow(@NotNull ToolWindow toolWindow) {
+    this.toolWindow = toolWindow;
   }
 
-  public static ContentManagerService getInstance(@NotNull Project project) {
-    if (instance == null) {
-      instance = new ContentManagerService(project);
-    }
-    return instance;
-  }
-
-  public void addContent(JPanel content, String displayName) {
-    contentManager.addContent(ApplicationManager.getApplication()
-        .getService(ContentFactory.class)
-        .createContent(content, displayName, false));
+  public void addContent(JPanel panel, String displayName) {
+    ContentFactory contentFactory = ContentFactory.SERVICE.getInstance();
+    Content content = contentFactory.createContent(panel, displayName, false);
+    toolWindow.getContentManager().addContent(content);
   }
 
   public void displayChatTab() {
+    var contentManager = getContentManager();
     tryFindChatTabContent().ifPresentOrElse(
         contentManager::setSelectedContent,
-        () -> contentManager.setSelectedContent(requireNonNull(contentManager.getContent(0)))
+        () -> contentManager.setSelectedContent(requireNonNull(getContentManager().getContent(0)))
     );
   }
 
   public Optional<Content> tryFindChatTabContent() {
-    return Arrays.stream(contentManager.getContents())
+    return Arrays.stream(getContentManager().getContents())
         .filter(content -> "Chat".equals(content.getTabName()))
         .findFirst();
   }
 
   public boolean isChatTabSelected() {
     return tryFindChatTabContent()
-        .filter(contentManager::isSelected)
+        .filter(content -> getContentManager().isSelected(content))
         .isPresent();
   }
+
+  private ContentManager getContentManager() {
+    return toolWindow.getContentManager();
+  }
 }

src/main/java/ee/carlrobert/codegpt/ide/toolwindow/ProjectToolWindowFactory.java

@@ -18,7 +18,8 @@ public class ProjectToolWindowFactory implements ToolWindowFactory, DumbAware {
     var conversationsToolWindow = new ConversationsToolWindow(project);
     toolWindowService.setChatToolWindow(chatToolWindow);
 
-    var contentManagerService = ContentManagerService.getInstance(project);
+    var contentManagerService = project.getService(ContentManagerService.class);
+    contentManagerService.setToolWindow(toolWindow);
     contentManagerService.addContent(chatToolWindow.getContent(), "Chat");
     contentManagerService.addContent(conversationsToolWindow.getContent(), "Conversation History");
     toolWindow.addContentManagerListener(new ContentManagerListener() {

src/main/java/ee/carlrobert/codegpt/ide/toolwindow/conversations/ConversationsToolWindow.java

@@ -46,7 +46,7 @@ public class ConversationsToolWindow {
     var mainPanel = new RootConversationPanel(() -> {
       ConversationsState.getInstance().setCurrentConversation(conversation);
       changeSettings(conversation);
-      ContentManagerService.getInstance(project).displayChatTab();
+      project.getService(ContentManagerService.class).displayChatTab();
       project.getService(ToolWindowService.class)
           .getChatToolWindow()
           .displayConversation(conversation);

src/main/resources/META-INF/plugin.xml

@@ -93,8 +93,7 @@
     <change-notes>
         <![CDATA[
       <ul>
-        <li>Replace model on conversation change</li>
-        <li>Start new conversation on model change</li>
+        <li>Fix ToolWindow's NPE when reopening the project</li>
       </ul>
     ]]>
     </change-notes>
@@ -113,6 +112,7 @@
         <applicationService serviceImplementation="ee.carlrobert.codegpt.ide.settings.SettingsState"/>
         <applicationService serviceImplementation="ee.carlrobert.codegpt.ide.conversations.ConversationsState"/>
         <projectService serviceImplementation="ee.carlrobert.codegpt.ide.toolwindow.ToolWindowService"/>
+        <projectService serviceImplementation="ee.carlrobert.codegpt.ide.toolwindow.ContentManagerService"/>
         <toolWindow id="CodeGPT" icon="Icons.ToolWindowIcon" anchor="right"
             factoryClass="ee.carlrobert.codegpt.ide.toolwindow.ProjectToolWindowFactory"/>
     </extensions>