Move ClientConnector.setParent to Component and Extension (#11777)

Change-Id: I1f0b2597f621160329ddc432869277b2758efd52

3 files changed, 52 insertions, 11 deletions

diff --git a/server/src/com/vaadin/ui/AbstractComponent.java b/server/src/com/vaadin/ui/AbstractComponent.java
index 9ff36a42d2..0bf27435fb 100644
--- a/server/src/com/vaadin/ui/AbstractComponent.java
+++ b/server/src/com/vaadin/ui/AbstractComponent.java
@@ -28,7 +28,6 @@ import java.util.regex.Pattern;
 import com.vaadin.event.ActionManager;
 import com.vaadin.event.ShortcutListener;
 import com.vaadin.server.AbstractClientConnector;
-import com.vaadin.server.ClientConnector;
 import com.vaadin.server.ComponentSizeValidator;
 import com.vaadin.server.ErrorHandler;
 import com.vaadin.server.ErrorMessage;
@@ -94,6 +93,8 @@ public abstract class AbstractComponent extends AbstractClientConnector
 
     private boolean visible = true;
 
+    private HasComponents parent;
+
     /* Constructor */
 
     /**
@@ -451,17 +452,32 @@ public abstract class AbstractComponent extends AbstractClientConnector
      */
     @Override
     public HasComponents getParent() {
-        return (HasComponents) super.getParent();
+        return parent;
     }
 
     @Override
-    public void setParent(ClientConnector parent) {
-        if (parent == null || parent instanceof HasComponents) {
-            super.setParent(parent);
-        } else {
-            throw new IllegalArgumentException(
-                    "The parent of a Component must implement HasComponents, which "
-                            + parent.getClass() + " doesn't do.");
+    public void setParent(HasComponents parent) {
+        // If the parent is not changed, don't do anything
+        if (parent == this.parent) {
+            return;
+        }
+
+        if (parent != null && this.parent != null) {
+            throw new IllegalStateException(getClass().getName()
+                    + " already has a parent.");
+        }
+
+        // Send a detach event if the component is currently attached
+        if (isAttached()) {
+            detach();
+        }
+
+        // Connect to new parent
+        this.parent = parent;
+
+        // Send attach event if the component is now attached
+        if (isAttached()) {
+            attach();
         }
     }
 
diff --git a/server/src/com/vaadin/ui/Component.java b/server/src/com/vaadin/ui/Component.java
index 20958812fc..485327bb54 100644
--- a/server/src/com/vaadin/ui/Component.java
+++ b/server/src/com/vaadin/ui/Component.java
@@ -333,6 +333,32 @@ public interface Component extends ClientConnector, Sizeable, Serializable {
     public void setVisible(boolean visible);
 
     /**
+     * Sets the parent connector of the component.
+     * 
+     * <p>
+     * This method automatically calls {@link #attach()} if the component
+     * becomes attached to the session, regardless of whether it was attached
+     * previously. Conversely, if the component currently is attached to the
+     * session, {@link #detach()} is called for the connector before attaching
+     * it to a new parent.
+     * </p>
+     * <p>
+     * This method is rarely called directly.
+     * {@link ComponentContainer#addComponent(Component)} or a
+     * {@link HasComponents} specific method is normally used for adding
+     * components to a parent and the used method will call this method
+     * implicitly.
+     * </p>
+     * 
+     * @param parent
+     *            the parent connector
+     * @throws IllegalStateException
+     *             if a parent is given even though the connector already has a
+     *             parent
+     */
+    public void setParent(HasComponents parent);
+
+    /**
      * Gets the parent component of the component.
      * 
      * <p>
diff --git a/server/src/com/vaadin/ui/Window.java b/server/src/com/vaadin/ui/Window.java
index 9f64c9118e..700d0eb387 100644
--- a/server/src/com/vaadin/ui/Window.java
+++ b/server/src/com/vaadin/ui/Window.java
@@ -31,7 +31,6 @@ import com.vaadin.event.ShortcutAction;
 import com.vaadin.event.ShortcutAction.KeyCode;
 import com.vaadin.event.ShortcutAction.ModifierKey;
 import com.vaadin.event.ShortcutListener;
-import com.vaadin.server.ClientConnector;
 import com.vaadin.server.PaintException;
 import com.vaadin.server.PaintTarget;
 import com.vaadin.shared.MouseEventDetails;
@@ -139,7 +138,7 @@ public class Window extends Panel implements FocusNotifier, BlurNotifier,
      * )
      */
     @Override
-    public void setParent(ClientConnector parent) {
+    public void setParent(HasComponents parent) {
         if (parent == null || parent instanceof UI) {
             super.setParent(parent);
         } else {