code_samples/project_view_pane: Cleanup (#1093)

* code_samples/project_view_pane: Cleanup:

- fix bug with not refreshing "svg" files and add supporting "jpeg" extension
- fix not working "Folders Always on Top" switch
- fix extracting file extension
- change disposable from Project to ProjectViewPane
- use BulkFileListener instead of VirtualFileListener with Alarm for updating the tree for immediate updates
- use Application.invokeLater instead of SwingUtilities.invokeLater
- code cleanup

* code_samples/project_view_pane: Add project.getDisposed() condition to the Application.invokeLater() call

* code_samples/project_view_pane: Do not count non-project files

* code_samples/project_view_pane: Do not update UI too often

project_view_pane/src/main/java/org/intellij/sdk/view/pane/ImagesProjectNode.java

@@ -1,72 +1,86 @@
-// Copyright 2000-2022 JetBrains s.r.o. and other contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
-
 package org.intellij.sdk.view.pane;
 
 import com.intellij.icons.AllIcons;
 import com.intellij.ide.projectView.PresentationData;
 import com.intellij.ide.projectView.ProjectView;
+import com.intellij.ide.projectView.ProjectViewNode;
+import com.intellij.ide.projectView.ViewSettings;
+import com.intellij.ide.projectView.impl.GroupByTypeComparator;
 import com.intellij.ide.util.treeView.AbstractTreeNode;
+import com.intellij.openapi.Disposable;
+import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.application.ReadAction;
 import com.intellij.openapi.fileEditor.FileEditorManager;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.project.ProjectUtil;
-import com.intellij.openapi.util.Disposer;
+import com.intellij.openapi.roots.FileIndex;
+import com.intellij.openapi.roots.ProjectRootManager;
 import com.intellij.openapi.util.Key;
-import com.intellij.openapi.util.text.StringUtil;
-import com.intellij.openapi.vfs.LocalFileSystem;
 import com.intellij.openapi.vfs.VirtualFile;
-import com.intellij.openapi.vfs.VirtualFileEvent;
+import com.intellij.openapi.vfs.VirtualFileManager;
-import com.intellij.openapi.vfs.VirtualFileListener;
+import com.intellij.openapi.vfs.newvfs.BulkFileListener;
+import com.intellij.openapi.vfs.newvfs.events.VFileEvent;
 import com.intellij.psi.search.FilenameIndex;
-import com.intellij.util.Alarm;
+import com.intellij.util.containers.ContainerUtil;
+import com.intellij.util.ui.update.MergingUpdateQueue;
+import com.intellij.util.ui.update.Update;
 import org.jetbrains.annotations.NotNull;
 
-import javax.swing.*;
 import java.util.*;
 
-public class ImagesProjectNode extends AbstractTreeNode<VirtualFile> {
+public class ImagesProjectNode extends ProjectViewNode<VirtualFile> {
 
   private static final Key<Set<VirtualFile>> IMAGES_PROJECT_DIRS = Key.create("images.files.or.directories");
 
-  public ImagesProjectNode(final Project project) {
+  private static final List<String> SUPPORTED_IMAGE_EXTENSIONS = List.of("jpg", "jpeg", "png", "svg");
-    super(project, ProjectUtil.guessProjectDir(project));
+
+  private final MergingUpdateQueue updateQueue;
+
+  /**
+   * Creates root node.
+   */
+  public ImagesProjectNode(@NotNull Project project,
+                           @NotNull ViewSettings settings,
+                           @NotNull VirtualFile rootDir,
+                           @NotNull Disposable parentDisposable) {
+    super(project, rootDir, settings);
     scanImages(project);
-
+    setupImageFilesRefresher(project, parentDisposable); // subscribe to changes only in the root node
-    subscribeToVFS(project);
+    updateQueue = new MergingUpdateQueue(ImagesProjectNode.class.getName(), 200, true, null, parentDisposable, null);
   }
 
-  public ImagesProjectNode(Project project, VirtualFile file) {
+  /**
-    super(project, file);
+   * Creates child node.
+   */
+  private ImagesProjectNode(@NotNull Project project,
+                            @NotNull ViewSettings settings,
+                            @NotNull VirtualFile file,
+                            @NotNull MergingUpdateQueue updateQueue) {
+    super(project, file, settings);
+    this.updateQueue = updateQueue;
   }
 
-  private void scanImages(Project project) {
+  private void scanImages(@NotNull Project project) {
-    addAllByExt(project, "png");
+    for (String imageExtension : SUPPORTED_IMAGE_EXTENSIONS) {
-    addAllByExt(project, "jpg");
+      addAllByExt(project, imageExtension);
-    addAllByExt(project, "svg");
+    }
   }
 
-  // Creates a collection of image files asynchronously
+  private void addAllByExt(@NotNull Project project, @NotNull String extension) {
-  private void addAllByExt(Project project, String ext) {
+    Set<VirtualFile> imagesFiles = getImagesFiles(project);
-    final Set<VirtualFile> imagesFiles = getImagesFiles(project);
+    VirtualFile projectDir = ProjectUtil.guessProjectDir(project);
-    final VirtualFile projectDir = ProjectUtil.guessProjectDir(project);
+    Collection<VirtualFile> files = ReadAction.compute(() -> FilenameIndex.getAllFilesByExt(project, extension));
-
+    for (VirtualFile file : files) {
-    try {
+      while (file != null && !file.equals(projectDir)) {
-      final Collection<VirtualFile> files = ReadAction.compute(() -> FilenameIndex.getAllFilesByExt(project, ext));
+        imagesFiles.add(file);
-
+        file = file.getParent();
-      for (VirtualFile file : files) {
-        while (file != null && !file.equals(projectDir)) {
-          imagesFiles.add(file);
-          file = file.getParent();
-        }
       }
-
-    } catch (Throwable throwable) {
-      throwable.printStackTrace();
     }
   }
 
   @NotNull
-  private Set<VirtualFile> getImagesFiles(Project project) {
+  private Set<VirtualFile> getImagesFiles(@NotNull Project project) {
     Set<VirtualFile> files = project.getUserData(IMAGES_PROJECT_DIRS);
     if (files == null) {
       files = new HashSet<>();
@@ -75,15 +89,57 @@ public class ImagesProjectNode extends AbstractTreeNode<VirtualFile> {
     return files;
   }
 
+  private void setupImageFilesRefresher(@NotNull Project project, @NotNull Disposable parentDisposable) {
+    project.getMessageBus().connect(parentDisposable)
+        .subscribe(VirtualFileManager.VFS_CHANGES, new BulkFileListener() {
+          @Override
+          public void after(@NotNull List<? extends @NotNull VFileEvent> events) {
+            boolean hasAnyImageUpdate = false;
+            FileIndex fileIndex = ProjectRootManager.getInstance(project).getFileIndex();
+            for (VFileEvent event : events) {
+              VirtualFile file = event.getFile();
+              if (file == null || !fileIndex.isInContent(file)) {
+                continue;
+              }
+              String extension = file.getExtension();
+              if (extension != null && SUPPORTED_IMAGE_EXTENSIONS.contains(extension)) {
+                hasAnyImageUpdate = true;
+                break;
+              }
+            }
+            if (hasAnyImageUpdate) {
+              updateQueue.queue(new Update("UpdateImages") {
+                public void run() {
+                  getImagesFiles(project).clear();
+                  scanImages(project);
+                  ApplicationManager.getApplication().invokeLater(() ->
+                        ProjectView.getInstance(project)
+                            .getProjectViewPaneById(ImagesProjectViewPane.ID)
+                            .updateFromRoot(true),
+                      project.getDisposed()
+                  );
+                }
+              });
+            }
+          }
+        });
+  }
+
   @Override
-  protected VirtualFile getVirtualFile() {
+  public boolean contains(@NotNull VirtualFile file) {
+    return file.equals(getVirtualFile());
+  }
+
+  @Override
+  @NotNull
+  public VirtualFile getVirtualFile() {
     return getValue();
   }
 
   @NotNull
   @Override
   public Collection<? extends AbstractTreeNode<?>> getChildren() {
-    final List<VirtualFile> files = new ArrayList<>(0);
+    List<VirtualFile> files = new ArrayList<>();
     for (VirtualFile file : getValue().getChildren()) {
       if (getImagesFiles(myProject).contains(file)) {
         files.add(file);
@@ -92,30 +148,14 @@ public class ImagesProjectNode extends AbstractTreeNode<VirtualFile> {
     if (files.isEmpty()) {
       return Collections.emptyList();
     }
-    final List<AbstractTreeNode<?>> nodes = new ArrayList<>(files.size());
+    ViewSettings settings = getSettings();
-    final boolean alwaysOnTop = ProjectView.getInstance(myProject).isFoldersAlwaysOnTop("");
+    return ContainerUtil.sorted(
-    files.sort((o1, o2) -> {
+        ContainerUtil.map(files, (file) -> new ImagesProjectNode(myProject, settings, file, updateQueue)),
-      if (alwaysOnTop) {
+        new GroupByTypeComparator(myProject, ImagesProjectViewPane.ID));
-        final boolean d1 = o1.isDirectory();
-        final boolean d2 = o2.isDirectory();
-        if (d1 && !d2) {
-          return -1;
-        }
-        if (!d1 && d2) {
-          return 1;
-        }
-      }
-
-      return StringUtil.naturalCompare(o1.getName(), o2.getName());
-    });
-    for (VirtualFile file : files) {
-      nodes.add(new ImagesProjectNode(myProject, file));
-    }
-    return nodes;
   }
 
   @Override
-  protected void update(PresentationData data) {
+  protected void update(@NotNull PresentationData data) {
     data.setIcon(getValue().isDirectory() ? AllIcons.Nodes.Folder : getValue().getFileType().getIcon());
     data.setPresentableText(getValue().getName());
   }
@@ -135,38 +175,10 @@ public class ImagesProjectNode extends AbstractTreeNode<VirtualFile> {
     FileEditorManager.getInstance(myProject).openFile(getValue(), false);
   }
 
-  private void subscribeToVFS(final Project project) {
+  @Override
-    final Alarm alarm = new Alarm(Alarm.ThreadToUse.POOLED_THREAD, project);
+  public int getTypeSortWeight(boolean sortByType) {
-    LocalFileSystem.getInstance().addVirtualFileListener(new VirtualFileListener() {
+    // required for "Folder Always on Top"
-      {
+    return getVirtualFile().isDirectory() ? 1 : 0;
-        final VirtualFileListener me = this;
-        Disposer.register(project, () -> LocalFileSystem.getInstance().removeVirtualFileListener(me));
-      }
-
-      @Override
-      public void fileCreated(@NotNull VirtualFileEvent event) {
-        handle(event);
-      }
-
-      @Override
-      public void fileDeleted(@NotNull VirtualFileEvent event) {
-        handle(event);
-      }
-
-      void handle(VirtualFileEvent event) {
-        final String filename = event.getFileName().toLowerCase();
-        if (filename.endsWith(".png") || filename.endsWith(".jpg")) {
-          alarm.cancelAllRequests();
-          alarm.addRequest(() -> {
-            getImagesFiles(project).clear();
-            scanImages(project);
-            SwingUtilities.invokeLater(() -> ProjectView.getInstance(myProject)
-                    .getProjectViewPaneById(ImagesProjectViewPane.ID)
-                    .updateFromRoot(true));
-          }, 1000);
-        }
-      }
-    });
   }
 
 }

project_view_pane/src/main/java/org/intellij/sdk/view/pane/ImagesProjectViewPane.java

@@ -7,11 +7,13 @@ import com.intellij.ide.impl.ProjectViewSelectInTarget;
 import com.intellij.ide.projectView.ViewSettings;
 import com.intellij.ide.projectView.impl.*;
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.project.ProjectUtil;
+import com.intellij.openapi.vfs.VirtualFile;
 import org.jetbrains.annotations.NotNull;
 
 import javax.swing.tree.DefaultTreeModel;
 
-public class ImagesProjectViewPane extends AbstractProjectViewPaneWithAsyncSupport {
+public class ImagesProjectViewPane extends ProjectViewPane {
 
   public static final String ID = "IMAGES";
 
@@ -70,7 +72,16 @@ public class ImagesProjectViewPane extends AbstractProjectViewPaneWithAsyncSuppo
     return new ProjectTreeStructure(myProject, ID) {
       @Override
       protected ImagesProjectNode createRoot(@NotNull Project project, @NotNull ViewSettings settings) {
-        return new ImagesProjectNode(project);
+        return new ImagesProjectNode(project, settings, getProjectDir(project), ImagesProjectViewPane.this);
+      }
+
+      @NotNull
+      private static VirtualFile getProjectDir(Project project) {
+        VirtualFile guessedProjectDir = ProjectUtil.guessProjectDir(project);
+        if (guessedProjectDir == null) {
+          throw new IllegalStateException("Could not get project directory");
+        }
+        return guessedProjectDir;
       }
 
       // Children will be searched in async mode