Add support for completable future to carry the Window result

api/src/main/java/com/bartlomiejpluta/base/api/gui/Window.java

@@ -13,7 +13,7 @@ public interface Window extends Widget {
 
    <T extends Component> T reference(String ref, Class<T> type);
 
-   CompletableFuture<Window> getFuture();
+   CompletableFuture<Object> getFuture();
 
    default void onOpen(WindowManager manager, Object[] args) {
       // do nothing

api/src/main/java/com/bartlomiejpluta/base/api/gui/WindowManager.java

@@ -82,7 +82,7 @@ public final class WindowManager extends BaseWidget {
       }
    }
 
-   public CompletableFuture<Window> open(@NonNull Window window, Object... args) {
+   public CompletableFuture<Object> open(@NonNull Window window, Object... args) {
       if (windows.isEmpty()) {
          input.addKeyEventHandler(this::forwardKeyEventToTopWindow);
       }
@@ -94,6 +94,10 @@ public final class WindowManager extends BaseWidget {
       return window.getFuture();
    }
 
+   public <T> CompletableFuture<T> openForResult(Class<T> resultClass, @NonNull Window window, Object... args) {
+      return open(window, args).thenApply(resultClass::cast);
+   }
+
    private void forwardKeyEventToTopWindow(KeyEvent event) {
       var topWindow = windows.peekLast();
       if (topWindow != null) {
@@ -108,7 +112,7 @@ public final class WindowManager extends BaseWidget {
       }
    }
 
-   public void close() {
+   public void resolve(Object result) {
       if (windows.isEmpty()) {
          return;
       }
@@ -121,7 +125,11 @@ public final class WindowManager extends BaseWidget {
          input.removeKeyEventHandler(this::forwardKeyEventToTopWindow);
       }
 
-      window.getFuture().complete(window);
+      window.getFuture().complete(result == null ? window : result);
+   }
+
+   public void close() {
+      resolve(null);
    }
 
    public int size() {

api/src/main/java/com/bartlomiejpluta/base/lib/gui/BaseContainer.java

@@ -37,6 +37,10 @@ public abstract class BaseContainer extends BaseComponent {
       component.setParent(null);
    }
 
+   public void removeAllChildren() {
+      this.children.clear();
+   }
+
    protected float maxChildrenWidth() {
       var theWidestChild = 0.0f;
 

api/src/main/java/com/bartlomiejpluta/base/lib/gui/BaseWindow.java

@@ -23,7 +23,7 @@ public abstract class BaseWindow extends BaseWidget implements Window {
    protected WindowPosition windowPosition = WindowPosition.CENTER;
 
    @Getter
-   protected CompletableFuture<Window> future;
+   protected CompletableFuture<Object> future;
 
    protected BaseWindow(Context context, GUI gui, Map<String, Component> refs) {
       this.context = context;
@@ -31,6 +31,18 @@ public abstract class BaseWindow extends BaseWidget implements Window {
       this.refs = refs;
    }
 
+   protected void close() {
+      if (manager != null) {
+         manager.close();
+      }
+   }
+
+   protected void resolve(Object result) {
+      if (manager != null) {
+         manager.resolve(result);
+      }
+   }
+
    @Override
    public void setContent(Component component) {
       if (this.content != null) {