Send ComboBox focus/blur with RPC (#19929)

Send focus and blur events using RPC instead of in UIDL.
This change does not use ConnectorFocusAndBlurHandler to preserve
old timings.

Change-Id: I1d58756e3955a11864b1ef00abcd27525a4db593

client/src/main/java/com/vaadin/client/ui/VFilterSelect.java

@@ -2206,9 +2206,8 @@ public class VFilterSelect extends Composite implements Field, KeyDownHandler,
                 // If a focus event is not going to be sent, send the options
                 // request immediately; otherwise queue in the same burst as the
                 // focus event. Fixes #8321.
-                ApplicationConnection client = connector.getConnection();
                 boolean immediate = focused
-                        || !client.hasEventListeners(this, EventId.FOCUS);
+                        || !connector.hasEventListener(EventId.FOCUS);
                 filterOptions(-1, "", immediate);
                 popupOpenerClicked = true;
                 lastFilter = "";
@@ -2303,14 +2302,12 @@ public class VFilterSelect extends Composite implements Field, KeyDownHandler,
         }
         addStyleDependentName("focus");
 
-        ApplicationConnection client = connector.getConnection();
-        if (client.hasEventListeners(this, EventId.FOCUS)) {
-            client.updateVariable(paintableId, EventId.FOCUS, "", true);
+        if (connector.sendFocusEvent()) {
             afterUpdateClientVariables();
         }
 
-        client.getVTooltip().showAssistive(
-                connector.getTooltipInfo(getElement()));
+        connector.getConnection().getVTooltip()
+                .showAssistive(connector.getTooltipInfo(getElement()));
     }
 
     /**
@@ -2366,9 +2363,7 @@ public class VFilterSelect extends Composite implements Field, KeyDownHandler,
         }
         removeStyleDependentName("focus");
 
-        ApplicationConnection client = connector.getConnection();
-        if (client.hasEventListeners(this, EventId.BLUR)) {
-            client.updateVariable(paintableId, EventId.BLUR, "", true);
+        if (connector.sendBlurEvent()) {
             afterUpdateClientVariables();
         }
     }

client/src/main/java/com/vaadin/client/ui/combobox/ComboBoxConnector.java

@@ -31,6 +31,8 @@ import com.vaadin.client.ui.AbstractFieldConnector;
 import com.vaadin.client.ui.SimpleManagedLayout;
 import com.vaadin.client.ui.VFilterSelect;
 import com.vaadin.client.ui.VFilterSelect.FilterSelectSuggestion;
+import com.vaadin.shared.EventId;
+import com.vaadin.shared.communication.FieldRpc.FocusAndBlurServerRpc;
 import com.vaadin.shared.ui.Connect;
 import com.vaadin.shared.ui.combobox.ComboBoxConstants;
 import com.vaadin.shared.ui.combobox.ComboBoxServerRpc;
@@ -45,6 +47,9 @@ public class ComboBoxConnector extends AbstractFieldConnector implements
     protected ComboBoxServerRpc rpc = RpcProxy.create(ComboBoxServerRpc.class,
             this);
 
+    protected FocusAndBlurServerRpc focusAndBlurRpc = RpcProxy.create(
+            FocusAndBlurServerRpc.class, this);
+
     // oldSuggestionTextMatchTheOldSelection is used to detect when it's safe to
     // update textbox text by a changed item caption.
     private boolean oldSuggestionTextMatchTheOldSelection;
@@ -440,4 +445,46 @@ public class ComboBoxConnector extends AbstractFieldConnector implements
                 immediate);
     }
 
+    /**
+     * Notify the server that the combo box received focus.
+     * 
+     * For timing reasons, ConnectorFocusAndBlurHandler is not used at the
+     * moment.
+     * 
+     * This method is for internal use only and may be removed in future
+     * versions.
+     * 
+     * @since
+     * @return true if an event was sent (there are registered listeners), false
+     *         otherwise
+     */
+    public boolean sendFocusEvent() {
+        boolean registeredListeners = hasEventListener(EventId.FOCUS);
+        if (registeredListeners) {
+            focusAndBlurRpc.focus();
+        }
+        return registeredListeners;
+    }
+
+    /**
+     * Notify the server that the combo box lost focus.
+     * 
+     * For timing reasons, ConnectorFocusAndBlurHandler is not used at the
+     * moment.
+     * 
+     * This method is for internal use only and may be removed in future
+     * versions.
+     * 
+     * @since
+     * @return true if an event was sent (there are registered listeners), false
+     *         otherwise
+     */
+    public boolean sendBlurEvent() {
+        boolean registeredListeners = hasEventListener(EventId.BLUR);
+        if (registeredListeners) {
+            focusAndBlurRpc.blur();
+        }
+        return registeredListeners;
+    }
+
 }

server/src/main/java/com/vaadin/ui/ComboBox.java

@@ -29,6 +29,7 @@ import com.vaadin.data.util.filter.SimpleStringFilter;
 import com.vaadin.event.FieldEvents;
 import com.vaadin.event.FieldEvents.BlurEvent;
 import com.vaadin.event.FieldEvents.BlurListener;
+import com.vaadin.event.FieldEvents.FocusAndBlurServerRpcImpl;
 import com.vaadin.event.FieldEvents.FocusEvent;
 import com.vaadin.event.FieldEvents.FocusListener;
 import com.vaadin.server.PaintException;
@@ -90,6 +91,13 @@ public class ComboBox extends AbstractSelect implements
         }
     };
 
+    FocusAndBlurServerRpcImpl focusBlurRpc = new FocusAndBlurServerRpcImpl(this) {
+        @Override
+        protected void fireEvent(LegacyEvent event) {
+            ComboBox.this.fireEvent(event);
+        }
+    };
+
     /**
      * Holds value of property pageLength. 0 disables paging.
      */
@@ -170,6 +178,7 @@ public class ComboBox extends AbstractSelect implements
      */
     private void init() {
         registerRpc(rpc);
+        registerRpc(focusBlurRpc);
 
         setNewItemsAllowed(false);
         setImmediate(true);
@@ -759,14 +768,6 @@ public class ComboBox extends AbstractSelect implements
             }
             requestRepaint();
         }
-
-        if (variables.containsKey(FocusEvent.EVENT_ID)) {
-            fireEvent(new FocusEvent(this));
-        }
-        if (variables.containsKey(BlurEvent.EVENT_ID)) {
-            fireEvent(new BlurEvent(this));
-        }
-
     }
 
     @Override