/*
* Copyright 2003-2016 JetBrains s.r.o.
*
* 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 jetbrains.mps.smodel;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.mps.openapi.module.ModelAccess;
import org.jetbrains.mps.openapi.module.SRepository;
import org.jetbrains.mps.openapi.module.SRepositoryListener;
/**
* Handy facility to (un)register a listener to a repository, with respect to model read access constraint.
* Not exposed in openapi as I'm not sure why we don't allow to attach listeners from anywhere (we need RA to walk modules, however SRepository
* could grab read access as needed)
*/
public class RepoListenerRegistrar implements Runnable {
// XXX could use name Plug instead of Registrar.
private final SRepository myRepo;
private final SRepositoryListener myListener;
private boolean myIsAttach = false;
public RepoListenerRegistrar(@NotNull SRepository repo, @NotNull SRepositoryListener ca) {
myRepo = repo;
myListener = ca;
}
@Override
public void run() {
if (myIsAttach) {
myRepo.addRepositoryListener(myListener);
} else {
myRepo.removeRepositoryListener(myListener);
}
}
public void attach() {
myIsAttach = true;
final ModelAccess ma = myRepo.getModelAccess();
if (ma.canRead()) {
run();
} else {
ma.runReadAction(this);
}
}
public void detach() {
myIsAttach = false;
final ModelAccess ma = myRepo.getModelAccess();
if (ma.canRead()) {
run();
} else {
ma.runReadAction(this);
}
}
}