Fix IDEA project open hang (#8903)

Fixes #8845.

Follows up on #8846
which I reverted before the last release because it was causing new
projects to prompt the user to open twice (at least in my environment).
The change I made since then is to not reload after setting up the
modules.

The risk of not reloading is that there could be things that don't
recognize the new module identity e.g., tool windows or DAS may not
start properly. I checked that those two things aren't an issue, so I
feel like this is reasonable and better than being prompted twice to
open a new project.

Author: helin24

CHANGELOG.md

@@ -7,6 +7,8 @@
 ### Removed
 
 ### Fixed
+- Silent failure when opening Flutter projects without `.idea` directory in IntelliJ IDEA, by removing `FlutterProjectOpenProcessor` and
+  migrating configuration logic to `FlutterInitializer`. (#8903)
 
 ## 91.0.0
 

resources/META-INF/plugin.xml

@@ -335,8 +335,6 @@
     <!-- See https://github.com/flutter/flutter-intellij/issues/8029 -->
     <projectService serviceImplementation="io.flutter.view.InspectorView" overrides="false"/>
 
-    <projectOpenProcessor id="flutter" implementation="io.flutter.project.FlutterProjectOpenProcessor" order="first"/>
-
     <editorNotificationProvider implementation="io.flutter.editor.FlutterPubspecNotificationProvider"/>
     <editorNotificationProvider implementation="io.flutter.inspections.SdkConfigurationNotificationProvider"/>
     <editorNotificationProvider implementation="io.flutter.editor.NativeEditorNotificationProvider"/>

src/io/flutter/FlutterInitializer.java

@@ -67,8 +67,6 @@
  * Runs actions after the project has started up and the index is up to date.
  *
  * @see ProjectOpenActivity for actions that run earlier.
- * @see io.flutter.project.FlutterProjectOpenProcessor for additional actions that
- * may run when a project is being imported.
  */
 public class FlutterInitializer extends FlutterProjectActivity {
   private boolean toolWindowsInitialized = false;
@@ -115,8 +113,19 @@ public void executeProjectStartup(@NotNull Project project) {
       }
 
       log().info("Flutter module has been found for project: " + project.getName());
-      // Ensure SDKs are configured; needed for clean module import.
-      FlutterModuleUtils.enableDartSDK(module);
+
+      // Ensure Flutter project configuration is applied for projects that may have been
+      // opened without a .idea directory. Previously this was handled by FlutterProjectOpenProcessor,
+      // but that processor silently failed when no delegate processor could open the project.
+      // Instead, we let the platform open the project normally and apply our configuration here.
+      // See https://github.com/flutter/flutter-intellij/issues/8661 (Android Studio equivalent)
+      if (!FlutterModuleUtils.isFlutterModule(module)) {
+        log().info("Fixing Flutter module configuration for " + module.getName());
+        FlutterModuleUtils.setFlutterModuleWithoutReload(module, project);
+      } else {
+        // Ensure SDKs are configured; needed for clean module import.
+        FlutterModuleUtils.enableDartSDK(module);
+      }
 
       for (PubRoot root : PubRoots.forModule(module)) {
         // Set Android SDK.

src/io/flutter/project/FlutterProjectOpenProcessor.kt

@@ -373,15 +373,14 @@ public static void setFlutterModuleType(@NotNull Module module) {
     module.setModuleType(getModuleTypeIDForFlutter());
   }
 
-  public static void setFlutterModuleAndReload(@NotNull Module module, @NotNull Project project) {
+  public static void setFlutterModuleWithoutReload(@NotNull Module module, @NotNull Project project) {
     if (project.isDisposed()) return;
     ApplicationManager.getApplication().invokeLater(() -> {
       ApplicationManager.getApplication().runWriteAction(() -> setFlutterModuleType(module));
       enableDartSDK(module);
       project.save();
 
       EditorNotifications.getInstance(project).updateAllNotifications();
-      ProjectManager.getInstance().reloadProject(project);
     });
   }