Implement retained target sessions, runtime sizing and Component navigation

designer-standalone/src/main/java/de/neitzel/fxdesigner/standalone/DesignerApplication.java

@@ -13,6 +13,7 @@ public final class DesignerApplication extends Application {
   private HostLaunch launch;
   private StandaloneHost host;
   private int windows;
+  private final java.util.Map<Path, Stage> editors = new java.util.HashMap<>();
 
   @Override
   public void start(Stage stage) throws Exception {
@@ -75,6 +76,14 @@ public final class DesignerApplication extends Application {
   }
 
   private void open(Stage stage, Path file) throws Exception {
+    Path identity = file.toRealPath();
+    var existing = editors.get(identity);
+    if (existing != null) {
+      existing.show();
+      existing.toFront();
+      existing.requestFocus();
+      return;
+    }
     if (host == null)
       host =
           new StandaloneHost(
@@ -97,6 +106,7 @@ public final class DesignerApplication extends Application {
     stage.setTitle("Neitzel FX Designer — " + file.getFileName());
     stage.setScene(new Scene(pane, 1300, 850));
     windows++;
+    editors.put(identity, stage);
     boolean[] closing = {false};
     stage.setOnCloseRequest(
         event -> {
@@ -181,6 +191,7 @@ public final class DesignerApplication extends Application {
         });
     stage.setOnHidden(
         e -> {
+          editors.remove(identity, stage);
           pane.close();
           if (--windows == 0) host.close();
         });

designer-standalone/src/main/java/de/neitzel/fxdesigner/standalone/FileDocuments.java

@@ -17,6 +17,14 @@ public final class FileDocuments implements HostServices.Documents, AutoCloseabl
   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);
@@ -186,6 +194,7 @@ public final class FileDocuments implements HostServices.Documents, AutoCloseabl
               Files.deleteIfExists(temp);
             }
             s.saved = s.text;
+            saves.forEach(listener -> listener.accept(s.file.toUri()));
             return FileDocuments.snapshot(s);
           });
     }