make promoteActiveFloating -> toggleActiveFloating (works in reverse)

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

@@ -180,11 +180,11 @@ public final class Compositor {
         layoutVersion++;
     }
 
-    public void promoteActiveFloating() {
+    public void toggleActiveFloating() {
         if (isEmpty()) {
             return;
         }
-        currentTab().promoteActiveFloating();
+        currentTab().toggleActiveFloating();
         layoutVersion++;
     }
 

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

@@ -244,19 +244,19 @@ final class Tab implements AutoCloseable {
     }
 
     /** Promotes the active floating pane to a tiled pane, joining the tiled row. No-op otherwise. */
-    void promoteActiveFloating() {
+    void toggleActiveFloating() {
-        TerminalPane promote = active;
+        TerminalPane toggled = active;
-        if (!floating.remove(promote)) {
+        if (floating.remove(toggled)) {
-            return; // active pane is tiled (or there is none); nothing to promote
-        }
-        if (promote == lastFocusedFloating) {
             lastFocusedFloating = floating.isEmpty() ? null : floating.get(floating.size() - 1);
-        }
+            tiled.add(toggled);
-        tiled.add(promote);
-        if (floating.isEmpty()) {
             floatingVisible = false;
+            setActive(toggled);
+        } else if (tiled.remove(toggled)) {
+            lastFocusedTiled = tiled.isEmpty() ? null : tiled.get(tiled.size() -1);
+            floating.add(toggled);
+            floatingVisible = true;
+            setActive(toggled);
         }
-        setActive(promote);
     }
 
     void closeActivePane() {

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

@@ -129,7 +129,7 @@ final class TerminalWindow {
             compositor.nextFloatingPane();
             event.consume();
         } else if (config.keybindings().get("promote_floating").matches(event)) {
-            compositor.promoteActiveFloating();
+            compositor.toggleActiveFloating();
             event.consume();
         } else if (config.keybindings().get("close_pane").matches(event)) {
             // Closing the last pane closes this window, via the compositor's onEmpty hook.