com.google.gwt.dev.shell.ServerMethods Maven / Gradle / Ivy
/*
* Copyright 2009 Google Inc.
*
* 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.google.gwt.dev.shell;
import com.google.gwt.dev.shell.BrowserChannel.FreeMessage;
import com.google.gwt.dev.shell.BrowserChannel.InvokeSpecialMessage;
import com.google.gwt.dev.shell.BrowserChannel.ReturnMessage;
import com.google.gwt.dev.shell.BrowserChannel.Value;
import com.google.gwt.dev.shell.BrowserChannel.SessionHandler.SpecialDispatchId;
import com.google.gwt.dev.shell.BrowserChannelClient.SessionHandlerClient;
import java.io.IOException;
/**
* A class to encapsulate function invocations of objects on the server side.
*/
public class ServerMethods {
/**
* Tell the server that the client no longer has any references to the
* specified Java object.
*
* @param ids IDs of objects to free
* @return false if an error occurred
*/
static boolean freeJava(BrowserChannelClient channel, int ids[]) {
if (!channel.isConnected()) {
// ignoring freeJava after disconnect.
return true;
}
try {
new FreeMessage(channel, ids).send();
} catch (IOException e) {
return false;
}
return true;
}
/**
* Get the value of a property on an object.
*
* @param objectRef ID of object to fetch field on
* @param dispatchId dispatch ID of field
* @return the value of the property, undef if none (or on error)
*/
static Value getProperty(BrowserChannelClient channel,
SessionHandlerClient handler, int objectRef, int dispatchId) {
if (!channel.isConnected()) {
// ignoring getProperty() after disconnect
return new Value();
}
Value args[] = new Value[2];
args[0] = new Value();
args[0].setInt(objectRef);
args[1] = new Value();
args[1].setInt(dispatchId);
synchronized (handler.getSynchronizationObject()) {
try {
new InvokeSpecialMessage(channel, SpecialDispatchId.GetProperty, args).send();
ReturnMessage returnMessage = channel.reactToMessagesWhileWaitingForReturn(handler);
if (!returnMessage.isException()) {
return returnMessage.getReturnValue();
}
} catch (IOException e) {
} catch (BrowserChannelException e) {
}
}
return new Value();
}
/**
* Set the value of a property on an object.
*
* @param objectRef ID of object to fetch field on
* @param dispatchId dispatch ID of field
* @param value value to store in the property
* @return false if an error occurred
*/
static boolean setProperty(BrowserChannelClient channel,
SessionHandlerClient handler, int objectRef, int dispatchId, Value value) {
Value args[] = new Value[3];
for (int i = 0; i < args.length; i++) {
args[i] = new Value();
}
args[0].setInt(objectRef);
args[1].setInt(dispatchId);
args[2] = value;
synchronized (handler.getSynchronizationObject()) {
try {
new InvokeSpecialMessage(channel, SpecialDispatchId.SetProperty, args).send();
ReturnMessage returnMessage = channel.reactToMessagesWhileWaitingForReturn(handler);
if (!returnMessage.isException()) {
return true;
}
} catch (IOException e) {
} catch (BrowserChannelException e) {
}
}
// TODO: use the returned exception?
return false;
}
}