Support StateChangeHandler for selected parts of the state (#8598)

5 files changed, 169 insertions, 37 deletions

diff --git a/client/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java b/client/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java
index 664a73dc12..32b15d6d87 100644
--- a/client/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java
+++ b/client/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java
@@ -1473,9 +1473,12 @@ public class ApplicationConnection {
                                     .getName(), null), stateJson, state,
                                     ApplicationConnection.this);
 
-                            StateChangeEvent event = GWT
-                                    .create(StateChangeEvent.class);
-                            event.setConnector(connector);
+                            Set<String> changedProperties = new HashSet<String>();
+                            addJsonFields(stateJson, changedProperties, "");
+
+                            StateChangeEvent event = new StateChangeEvent(
+                                    connector, changedProperties);
+
                             events.add(event);
                         }
                     } catch (final Throwable e) {
@@ -1487,6 +1490,30 @@ public class ApplicationConnection {
             }
 
             /**
+             * Recursively adds the names of all fields in all objects in the
+             * provided json object.
+             * 
+             * @param json
+             *            the json object to process
+             * @param fields
+             *            a set of all currently added fields
+             * @param context
+             *            the base name of the current object
+             */
+            private void addJsonFields(JSONObject json, Set<String> fields,
+                    String context) {
+                for (String key : json.keySet()) {
+                    String fieldName = context + key;
+                    fields.add(fieldName);
+
+                    JSONObject object = json.get(key).isObject();
+                    if (object != null) {
+                        addJsonFields(object, fields, fieldName + ".");
+                    }
+                }
+            }
+
+            /**
              * Updates the connector hierarchy and returns a list of events that
              * should be fired after update of the hierarchy and the state is
              * done.
diff --git a/client/src/com/vaadin/terminal/gwt/client/ServerConnector.java b/client/src/com/vaadin/terminal/gwt/client/ServerConnector.java
index ff37f04f04..8788de74bf 100644
--- a/client/src/com/vaadin/terminal/gwt/client/ServerConnector.java
+++ b/client/src/com/vaadin/terminal/gwt/client/ServerConnector.java
@@ -75,7 +75,7 @@ public interface ServerConnector extends Connector {
             String rpcInterfaceId);
 
     /**
-     * Adds a handler that is called whenever some part of the state has been
+     * Adds a handler that is called whenever any part of the state has been
      * updated by the server.
      * 
      * @param handler
@@ -86,6 +86,21 @@ public interface ServerConnector extends Connector {
     public HandlerRegistration addStateChangeHandler(StateChangeHandler handler);
 
     /**
+     * Adds a handler that is called whenever the given part of the state has
+     * been updated by the server.
+     * 
+     * @param propertyName
+     *            the name of the property for which the handler should be
+     *            called
+     * @param handler
+     *            The handler that should be added.
+     * @return A handler registration reference that can be used to unregister
+     *         the handler
+     */
+    public HandlerRegistration addStateChangeHandler(String propertyName,
+            StateChangeHandler handler);
+
+    /**
      * Sends the given event to all registered handlers.
      * 
      * @param event
diff --git a/client/src/com/vaadin/terminal/gwt/client/communication/StateChangeEvent.java b/client/src/com/vaadin/terminal/gwt/client/communication/StateChangeEvent.java
index e1847bdab7..8ed32bc94b 100644
--- a/client/src/com/vaadin/terminal/gwt/client/communication/StateChangeEvent.java
+++ b/client/src/com/vaadin/terminal/gwt/client/communication/StateChangeEvent.java
@@ -16,8 +16,11 @@
 package com.vaadin.terminal.gwt.client.communication;
 
 import java.io.Serializable;
+import java.util.Collections;
+import java.util.Set;
 
 import com.google.gwt.event.shared.EventHandler;
+import com.vaadin.terminal.gwt.client.ServerConnector;
 import com.vaadin.terminal.gwt.client.communication.StateChangeEvent.StateChangeHandler;
 
 public class StateChangeEvent extends
@@ -27,12 +30,25 @@ public class StateChangeEvent extends
      */
     public static final Type<StateChangeHandler> TYPE = new Type<StateChangeHandler>();
 
+    private Set<String> changedProperties;
+
     @Override
     public Type<StateChangeHandler> getAssociatedType() {
         return TYPE;
     }
 
-    public StateChangeEvent() {
+    /**
+     * Creates a new state change event.
+     * 
+     * @param connector
+     *            the event whose state has changed
+     * @param changedProperties
+     *            a set of names of the changed properties
+     */
+    public StateChangeEvent(ServerConnector connector,
+            Set<String> changedProperties) {
+        setConnector(connector);
+        this.changedProperties = changedProperties;
     }
 
     @Override
@@ -40,7 +56,30 @@ public class StateChangeEvent extends
         listener.onStateChanged(this);
     }
 
+    /**
+     * Event handler that gets notified whenever any part of the state has been
+     * updated by the server.
+     * 
+     * @author Vaadin Ltd
+     * @version @VERSION@
+     * @since 7.0.0
+     */
     public interface StateChangeHandler extends Serializable, EventHandler {
+        /**
+         * Notifies the event handler that the state has changed.
+         * 
+         * @param stateChangeEvent
+         *            the state change event with details about the change
+         */
         public void onStateChanged(StateChangeEvent stateChangeEvent);
     }
+
+    /**
+     * Gets the properties that have changed.
+     * 
+     * @return a set of names of the changed properties
+     */
+    public Set<String> getChangedProperties() {
+        return Collections.unmodifiableSet(changedProperties);
+    }
 }
diff --git a/client/src/com/vaadin/terminal/gwt/client/ui/AbstractConnector.java b/client/src/com/vaadin/terminal/gwt/client/ui/AbstractConnector.java
index 514f63fdd8..435fff8a5b 100644
--- a/client/src/com/vaadin/terminal/gwt/client/ui/AbstractConnector.java
+++ b/client/src/com/vaadin/terminal/gwt/client/ui/AbstractConnector.java
@@ -48,6 +48,7 @@ public abstract class AbstractConnector implements ServerConnector,
     private String id;
 
     private HandlerManager handlerManager;
+    private Map<String, HandlerManager> statePropertyHandlerManagers;
     private Map<String, Collection<ClientRpc>> rpcImplementations;
     private final boolean debugLogging = false;
 
@@ -168,6 +169,17 @@ public abstract class AbstractConnector implements ServerConnector,
         if (handlerManager != null) {
             handlerManager.fireEvent(event);
         }
+        if (statePropertyHandlerManagers != null
+                && event instanceof StateChangeEvent) {
+            for (String property : ((StateChangeEvent) event)
+                    .getChangedProperties()) {
+                HandlerManager manager = statePropertyHandlerManagers
+                        .get(property);
+                if (manager != null) {
+                    manager.fireEvent(event);
+                }
+            }
+        }
     }
 
     protected HandlerManager ensureHandlerManager() {
@@ -185,6 +197,25 @@ public abstract class AbstractConnector implements ServerConnector,
     }
 
     @Override
+    public HandlerRegistration addStateChangeHandler(String propertyName,
+            StateChangeHandler handler) {
+        return ensureHandlerManager(propertyName).addHandler(
+                StateChangeEvent.TYPE, handler);
+    }
+
+    private HandlerManager ensureHandlerManager(String propertyName) {
+        if (statePropertyHandlerManagers == null) {
+            statePropertyHandlerManagers = new HashMap<String, HandlerManager>();
+        }
+        HandlerManager manager = statePropertyHandlerManagers.get(propertyName);
+        if (manager == null) {
+            manager = new HandlerManager(this);
+            statePropertyHandlerManagers.put(propertyName, manager);
+        }
+        return manager;
+    }
+
+    @Override
     public void onStateChanged(StateChangeEvent stateChangeEvent) {
         if (debugLogging) {
             VConsole.log("State change event for "
diff --git a/client/src/com/vaadin/terminal/gwt/client/ui/button/ButtonConnector.java b/client/src/com/vaadin/terminal/gwt/client/ui/button/ButtonConnector.java
index 59e187014c..59f90a9840 100644
--- a/client/src/com/vaadin/terminal/gwt/client/ui/button/ButtonConnector.java
+++ b/client/src/com/vaadin/terminal/gwt/client/ui/button/ButtonConnector.java
@@ -16,6 +16,8 @@
 
 package com.vaadin.terminal.gwt.client.ui.button;
 
+import java.util.Set;
+
 import com.google.gwt.event.dom.client.BlurEvent;
 import com.google.gwt.event.dom.client.BlurHandler;
 import com.google.gwt.event.dom.client.ClickEvent;
@@ -34,6 +36,7 @@ import com.vaadin.terminal.gwt.client.EventHelper;
 import com.vaadin.terminal.gwt.client.MouseEventDetailsBuilder;
 import com.vaadin.terminal.gwt.client.communication.RpcProxy;
 import com.vaadin.terminal.gwt.client.communication.StateChangeEvent;
+import com.vaadin.terminal.gwt.client.communication.StateChangeEvent.StateChangeHandler;
 import com.vaadin.terminal.gwt.client.ui.AbstractComponentConnector;
 import com.vaadin.terminal.gwt.client.ui.Icon;
 import com.vaadin.ui.Button;
@@ -59,6 +62,47 @@ public class ButtonConnector extends AbstractComponentConnector implements
         super.init();
         getWidget().addClickHandler(this);
         getWidget().client = getConnection();
+        addStateChangeHandler("errorMessage", new StateChangeHandler() {
+            @Override
+            public void onStateChanged(StateChangeEvent stateChangeEvent) {
+                if (null != getState().getErrorMessage()) {
+                    if (getWidget().errorIndicatorElement == null) {
+                        getWidget().errorIndicatorElement = DOM.createSpan();
+                        getWidget().errorIndicatorElement
+                                .setClassName("v-errorindicator");
+                    }
+                    getWidget().wrapper.insertBefore(
+                            getWidget().errorIndicatorElement,
+                            getWidget().captionElement);
+
+                } else if (getWidget().errorIndicatorElement != null) {
+                    getWidget().wrapper
+                            .removeChild(getWidget().errorIndicatorElement);
+                    getWidget().errorIndicatorElement = null;
+                }
+            }
+        });
+
+        addStateChangeHandler("icon", new StateChangeHandler() {
+            @Override
+            public void onStateChanged(StateChangeEvent stateChangeEvent) {
+                if (getState().getIcon() != null) {
+                    if (getWidget().icon == null) {
+                        getWidget().icon = new Icon(getConnection());
+                        getWidget().wrapper.insertBefore(
+                                getWidget().icon.getElement(),
+                                getWidget().captionElement);
+                    }
+                    getWidget().icon.setUri(getState().getIcon().getURL());
+                } else {
+                    if (getWidget().icon != null) {
+                        getWidget().wrapper.removeChild(getWidget().icon
+                                .getElement());
+                        getWidget().icon = null;
+                    }
+                }
+            }
+        });
     }
 
     @Override
@@ -68,39 +112,15 @@ public class ButtonConnector extends AbstractComponentConnector implements
                 focusHandlerRegistration);
         blurHandlerRegistration = EventHelper.updateBlurHandler(this,
                 blurHandlerRegistration);
-        // Set text
-        if (getState().isHtmlContentAllowed()) {
-            getWidget().setHtml(getState().getCaption());
-        } else {
-            getWidget().setText(getState().getCaption());
-        }
 
-        // handle error
-        if (null != getState().getErrorMessage()) {
-            if (getWidget().errorIndicatorElement == null) {
-                getWidget().errorIndicatorElement = DOM.createSpan();
-                getWidget().errorIndicatorElement
-                        .setClassName("v-errorindicator");
-            }
-            getWidget().wrapper.insertBefore(getWidget().errorIndicatorElement,
-                    getWidget().captionElement);
-
-        } else if (getWidget().errorIndicatorElement != null) {
-            getWidget().wrapper.removeChild(getWidget().errorIndicatorElement);
-            getWidget().errorIndicatorElement = null;
-        }
-
-        if (getState().getIcon() != null) {
-            if (getWidget().icon == null) {
-                getWidget().icon = new Icon(getConnection());
-                getWidget().wrapper.insertBefore(getWidget().icon.getElement(),
-                        getWidget().captionElement);
-            }
-            getWidget().icon.setUri(getState().getIcon().getURL());
-        } else {
-            if (getWidget().icon != null) {
-                getWidget().wrapper.removeChild(getWidget().icon.getElement());
-                getWidget().icon = null;
+        Set<String> changedProperties = stateChangeEvent.getChangedProperties();
+        if (changedProperties.contains("caption")
+                || changedProperties.contains("htmlContentAllowed")) {
+            // Set text
+            if (getState().isHtmlContentAllowed()) {
+                getWidget().setHtml(getState().getCaption());
+            } else {
+                getWidget().setText(getState().getCaption());
             }
         }