/*
* Copyright 2000-2014 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.vaadin.client.communication;
import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.event.shared.EventHandler;
import com.google.gwt.json.client.JSONObject;
import com.vaadin.client.FastStringSet;
import com.vaadin.client.JsArrayObject;
import com.vaadin.client.Profiler;
import com.vaadin.client.ServerConnector;
import com.vaadin.client.communication.StateChangeEvent.StateChangeHandler;
import com.vaadin.client.metadata.NoDataException;
import com.vaadin.client.metadata.Property;
import com.vaadin.client.ui.AbstractConnector;
public class StateChangeEvent extends
AbstractServerConnectorEvent<StateChangeHandler> {
/**
* Type of this event, used by the event bus.
*/
public static final Type<StateChangeHandler> TYPE = new Type<StateChangeHandler>();
/**
* Used to cache a FastStringSet representation of the properties that have
* changed if one is needed.
*/
@Deprecated
private FastStringSet changedProperties;
/**
* Used to cache a Set representation of the changedProperties if one is
* needed.
*/
@Deprecated
private Set<String> changedPropertiesSet;
private boolean initialStateChange = false;
private JSONObject stateJson;
@Override
public Type<StateChangeHandler> getAssociatedType() {
return TYPE;
}
/**
* Creates a new state change event.
*
* @param connector
* the event whose state has changed
* @param changedPropertiesSet
* a set of names of the changed properties
* @deprecated As of 7.0.1, use
* {@link #StateChangeEvent(ServerConnector, JSONObject, boolean)}
* instead for improved performance.
*/
@Deprecated
public StateChangeEvent(ServerConnector connector,
Set<String> changedPropertiesSet) {
setConnector(connector);
// Keep instance around for caching
this.changedPropertiesSet = changedPropertiesSet;
changedProperties = FastStringSet.create();
for (String property : changedPropertiesSet) {
changedProperties.add(property);
}
}
/**
* Creates a new state change event.
*
* @param connector
* the event whose state has changed
* @param changedProperties
* a set of names of the changed properties
* @deprecated As of 7.0.2, use
* {@link #StateChangeEvent(ServerConnector, JSONObject, boolean)}
* instead for improved performance.
*/
@Deprecated
public StateChangeEvent(ServerConnector connector,
FastStringSet changedProperties) {
setConnector(connector);
this.changedProperties = changedProperties;
}
/**
* /** Creates a new state change event.
*
* @param connector
* the event whose state has changed
* @param stateJson
* the JSON representation of the state change
* @param initialStateChange
* <code>true</code> if the state change is for a new connector,
* otherwise <code>false</code>
*/
public StateChangeEvent(ServerConnector connector, JSONObject stateJson,
boolean initialStateChange) {
setConnector(connector);
this.stateJson = stateJson;
this.initialStateChange = initialStateChange;
}
@Override
public void dispatch(StateChangeHandler listener) {
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
*
* @deprecated As of 7.0.1, use {@link #hasPropertyChanged(String)} instead
* for improved performance.
*/
@Deprecated
public Set<String> getChangedProperties() {
if (changedPropertiesSet == null) {
Profiler.enter("StateChangeEvent.getChangedProperties populate");
changedPropertiesSet = new HashSet<String>();
getChangedPropertiesFastSet().addAllTo(changedPropertiesSet);
Profiler.leave("StateChangeEvent.getChangedProperties populate");
}
return changedPropertiesSet;
}
/**
* Gets the properties that have changed.
*
* @return a set of names of the changed properties
*
* @deprecated As of 7.0.1, use {@link #hasPropertyChanged(String)} instead
* for improved performance.
*/
@Deprecated
public FastStringSet getChangedPropertiesFastSet() {
if (changedProperties == null) {
Profiler.enter("StateChangeEvent.getChangedPropertiesFastSet populate");
changedProperties = FastStringSet.create();
addJsonFields(stateJson, changedProperties, "");
if (isInitialStateChange()) {
addAllStateFields(
AbstractConnector.getStateType(getConnector()),
changedProperties, "");
}
Profiler.leave("StateChangeEvent.getChangedPropertiesFastSet populate");
}
return changedProperties;
}
/**
* Checks whether the give property has changed.
*
* @param property
* the name of the property to check
* @return <code>true</code> if the property has changed, else
* <code>false></code>
*/
public boolean hasPropertyChanged(String property) {
if (isInitialStateChange()) {
// Everything has changed for a new connector
return true;
} else if (stateJson != null) {
// Check whether it's in the json object
return isInJson(property, stateJson.getJavaScriptObject());
} else {
// Legacy cases
if (changedProperties != null) {
// Check legacy stuff
return changedProperties.contains(property);
} else if (changedPropertiesSet != null) {
// Check legacy stuff
return changedPropertiesSet.contains(property);
} else {
throw new IllegalStateException(
"StateChangeEvent should have either stateJson, changedProperties or changePropertiesSet");
}
}
}
/**
* Checks whether the given property name (which might contains dots) is
* defined in some JavaScript object.
*
* @param property
* the name of the property, might include dots to reference
* inner objects
* @param target
* the JavaScript object to check
* @return true if the property is defined
*/
private static native final boolean isInJson(String property,
JavaScriptObject target)
/*-{
var segments = property.split('.');
while (typeof target == 'object') {
var nextSegment = segments.shift();
if (!(nextSegment in target)) {
// Abort if segment is not found
return false;
} else if (segments.length == 0) {
// Done if there are no more segments
return true;
} else {
// Else just go deeper
target = target[nextSegment];
}
}
// Not defined if we reach something that isn't an object
return false;
}-*/;
/**
* Recursively adds the names of all properties in the provided state type.
*
* @param type
* the type to process
* @param changedProperties
* a set of all currently added properties
* @param context
* the base name of the current object
*/
@Deprecated
private static void addAllStateFields(com.vaadin.client.metadata.Type type,
FastStringSet changedProperties, String context) {
try {
JsArrayObject<Property> properties = type.getPropertiesAsArray();
int size = properties.size();
for (int i = 0; i < size; i++) {
Property property = properties.get(i);
String propertyName = context + property.getName();
changedProperties.add(propertyName);
com.vaadin.client.metadata.Type propertyType = property
.getType();
if (propertyType.hasProperties()) {
addAllStateFields(propertyType, changedProperties,
propertyName + ".");
}
}
} catch (NoDataException e) {
throw new IllegalStateException("No property info for " + type
+ ". Did you remember to compile the right widgetset?", e);
}
}
/**
* Recursively adds the names of all fields in all objects in the provided
* json object.
*
* @param json
* the json object to process
* @param changedProperties
* a set of all currently added fields
* @param context
* the base name of the current object
*/
@Deprecated
private static void addJsonFields(JSONObject json,
FastStringSet changedProperties, String context) {
for (String key : json.keySet()) {
String fieldName = context + key;
changedProperties.add(fieldName);
JSONObject object = json.get(key).isObject();
if (object != null) {
addJsonFields(object, changedProperties, fieldName + ".");
}
}
}
/**
* Checks if the state change event is the first one for the given
* connector.
*
* @since 7.1
* @return true if this is the first state change event for the connector,
* false otherwise
*/
public boolean isInitialStateChange() {
return initialStateChange;
}
}