[NPW|Assets] fix: generate sources on a background thread under modal progress

Issues: IDEA-349863, IDEA-341180

GitOrigin-RevId: 06c621f3d98cd15231b5b083fba3884626e06b1d

java/idea-ui/src/com/intellij/ide/projectWizard/generators/AssetsNewProjectWizardStep.kt

@@ -14,14 +14,19 @@ import com.intellij.ide.wizard.NewProjectWizardBaseData.Companion.baseData
 import com.intellij.ide.wizard.NewProjectWizardStep
 import com.intellij.ide.wizard.setupProjectSafe
 import com.intellij.ide.wizard.whenProjectCreated
+import com.intellij.openapi.application.invokeAndWaitIfNeeded
 import com.intellij.openapi.fileEditor.FileEditorManager
+import com.intellij.openapi.progress.blockingContext
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.openapi.vfs.isFile
 import com.intellij.openapi.vfs.refreshAndFindVirtualFile
 import com.intellij.openapi.vfs.refreshAndFindVirtualFileOrDirectory
+import com.intellij.platform.ide.progress.runWithModalProgressBlocking
 import com.intellij.psi.PsiManager
 import com.intellij.ui.UIBundle
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
 import org.jetbrains.annotations.ApiStatus
 import java.net.URL
 import java.nio.file.Path
@@ -93,8 +98,11 @@ abstract class AssetsNewProjectWizardStep(parent: NewProjectWizardStep) : Abstra
       val outputDirectory = resolveOutputDirectory()
       val filesToOpen = resolveFilesToOpen(outputDirectory)
 
-      val assetsProcessor = AssetsProcessor.getInstance()
+      val generatedFiles = invokeAndWaitIfNeeded {
-      val generatedFiles = assetsProcessor.generateSources(outputDirectory, assets, templateProperties)
+        runWithModalProgressBlocking(project, UIBundle.message("label.project.wizard.new.assets.step.generate.sources.progress", project.name)) {
+          generateSources(outputDirectory)
+        }
+      }
 
       whenProjectCreated(project) { //IDEA-244863
         reformatCode(project, generatedFiles.mapNotNull { it.refreshAndFindVirtualFileOrDirectory() }.filter { it.isFile })
@@ -121,6 +129,15 @@ abstract class AssetsNewProjectWizardStep(parent: NewProjectWizardStep) : Abstra
     return filesToOpen.map { outputDirectory.resolve(it).normalize() }
   }
 
+  private suspend fun generateSources(outputDirectory: Path): List<Path> {
+    return withContext(Dispatchers.IO) {
+      blockingContext {
+        val assetsProcessor = AssetsProcessor.getInstance()
+        assetsProcessor.generateSources(outputDirectory, assets, templateProperties)
+      }
+    }
+  }
+
   private fun reformatCode(project: Project, files: List<VirtualFile>) {
     val psiManager = PsiManager.getInstance(project)
     val psiFiles = files.mapNotNull { psiManager.findFile(it) }

platform/platform-api/resources/messages/UIBundle.properties

@@ -313,6 +313,7 @@ label.project.wizard.new.module.name.exists.error=Module ''{0}'' already exists
 label.project.wizard.new.module.directory.already.taken.error=Module {0} already exists in this location
 label.project.wizard.empty.project.generator.name=Empty Project
 label.project.wizard.empty.project.generator.full.description=A basic project with free structure.
+label.project.wizard.new.assets.step.generate.sources.progress=Generating project {0} sources\u2026
 
 error.project.wizard.new.project.title=New {0,choice,0#Module|1#Project} Wizard Error
 error.project.wizard.new.project.sample.code=Unable to generate {0,choice,0#module|1#project} sources