scrollback opens in floating pane

src/main/java/com/gregor/jprototerm/Compositor.java

@@ -113,6 +113,16 @@ public final class Compositor {
         layoutVersion++;
     }
 
+    /** Opens a new floating pane, makes it active, and returns it (null when no tab exists). */
+    public TerminalPane openFloatingPane() {
+        if (isEmpty()) {
+            return null;
+        }
+        TerminalPane pane = currentTab().createFloatingPane();
+        layoutVersion++;
+        return pane;
+    }
+
     public void nextFloatingPane() {
         if (isEmpty()) {
             return;

src/main/java/com/gregor/jprototerm/Main.java

@@ -167,11 +167,16 @@ public final class Main extends Application {
 
     private void openScrollbackInEditor() {
         try {
+            // Capture the active pane's scrollback before opening the floating pane, since that
+            // makes the new pane active.
             Path file = Files.createTempFile("jprototerm-scrollback-", ".txt");
             Files.writeString(file, compositor.activePane().scrollbackText());
             file.toFile().deleteOnExit();
 
-            compositor.activePane().send(scrollbackEditorCommand(file) + "\r");
+            TerminalPane pane = compositor.openFloatingPane();
+            if (pane != null) {
+                pane.send(scrollbackEditorCommand(file) + "\r");
+            }
         } catch (IOException ex) {
             System.err.println("Could not open scrollback in editor: " + ex.getMessage());
         }

src/main/java/com/gregor/jprototerm/Tab.java

@@ -257,11 +257,12 @@ final class Tab implements AutoCloseable {
         }
     }
 
-    private void createFloatingPane() {
+    TerminalPane createFloatingPane() {
         TerminalPane pane = openPane(true);
         floating.add(pane);
         floatingVisible = true;
         setActive(pane);
+        return pane;
     }
 
     private boolean navigateFloatingStack(Direction direction) {