Implement retained target sessions, runtime sizing and Component navigation

designer-intellij/src/main/java/de/neitzel/fxdesigner/intellij/IntellijDocuments.java

@@ -26,6 +26,14 @@ public final class IntellijDocuments implements HostServices.Documents, AutoClos
   private final java.util.concurrent.CopyOnWriteArrayList<java.util.function.Consumer<URI>>
       changes = new java.util.concurrent.CopyOnWriteArrayList<>();
 
+  private final java.util.List<java.util.function.Consumer<URI>> saves =
+      new java.util.concurrent.CopyOnWriteArrayList<>();
+
+  public AutoCloseable onSave(java.util.function.Consumer<URI> listener) {
+    saves.add(listener);
+    return () -> saves.remove(listener);
+  }
+
   public AutoCloseable onChange(java.util.function.Consumer<URI> listener) {
     changes.add(listener);
     return () -> changes.remove(listener);
@@ -48,6 +56,18 @@ public final class IntellijDocuments implements HostServices.Documents, AutoClos
     this.project = Objects.requireNonNull(project);
     lifetime = this::disposeResources;
     Disposer.register(project, lifetime);
+    ApplicationManager.getApplication()
+        .getMessageBus()
+        .connect(lifetime)
+        .subscribe(
+            com.intellij.openapi.fileEditor.FileDocumentManagerListener.TOPIC,
+            new com.intellij.openapi.fileEditor.FileDocumentManagerListener() {
+              public void afterDocumentSaved(Document document) {
+                var file = FileDocumentManager.getInstance().getFile(document);
+                if (file != null && file.isInLocalFileSystem())
+                  saves.forEach(listener -> listener.accept(canonicalUri(file)));
+              }
+            });
     EditorFactory.getInstance()
         .getEventMulticaster()
         .addDocumentListener(