TemplateDataLanguagePusher.java

/*
 * Copyright 2000-2016 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 com.intellij.psi.templateLanguages;

import com.intellij.lang.Language;
import com.intellij.openapi.module.Module;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.roots.impl.FilePropertyPusher;
import com.intellij.openapi.roots.impl.PushedFilePropertiesUpdater;
import com.intellij.openapi.util.Conditions;
import com.intellij.openapi.util.Key;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.openapi.vfs.newvfs.FileAttribute;
import com.intellij.openapi.vfs.newvfs.persistent.VfsDependentEnum;
import com.intellij.util.io.DataInputOutputUtil;
import com.intellij.util.io.EnumeratorStringDescriptor;
import com.intellij.util.messages.MessageBus;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;

/**
 * @author Konstantin.Ulitin
 */
public class TemplateDataLanguagePusher implements FilePropertyPusher<Language> {

  public static final Key<Language> KEY = Key.create("TEMPLATE_DATA_LANGUAGE");

  private static final VfsDependentEnum<String> ourLanguagesEnumerator = new VfsDependentEnum<>(
    "languages",
    EnumeratorStringDescriptor.INSTANCE,
    1
  );

  @Override
  public void initExtra(@NotNull Project project, @NotNull MessageBus bus, @NotNull Engine languageLevelUpdater) {

  }

  @NotNull
  @Override
  public Key<Language> getFileDataKey() {
    return KEY;
  }

  @Override
  public boolean pushDirectoriesOnly() {
    return false;
  }

  @NotNull
  @Override
  public Language getDefaultValue() {
    return Language.ANY;
  }

  @Nullable
  @Override
  public Language getImmediateValue(@NotNull Project project, @Nullable VirtualFile file) {
    return TemplateDataLanguageMappings.getInstance(project).getImmediateMapping(file);
  }

  @Nullable
  @Override
  public Language getImmediateValue(@NotNull Module module) {
    return null;
  }

  @Override
  public boolean acceptsFile(@NotNull VirtualFile file) {
    return true;
  }

  @Override
  public boolean acceptsDirectory(@NotNull VirtualFile file, @NotNull Project project) {
    return true;
  }

  private static final FileAttribute PERSISTENCE = new FileAttribute("template_language", 2, true);

  @Override
  public void persistAttribute(@NotNull Project project, @NotNull VirtualFile fileOrDir, @NotNull Language value) throws IOException {
    final DataInputStream iStream = PERSISTENCE.readAttribute(fileOrDir);
    if (iStream != null) {
      try {
        final int oldLanguage = DataInputOutputUtil.readINT(iStream);
        String oldLanguageId = ourLanguagesEnumerator.getById(oldLanguage);
        if (value.getID().equals(oldLanguageId)) return;
      }
      finally {
        //noinspection ThrowFromFinallyBlock
        iStream.close();
      }
    }

    if (value != Language.ANY || iStream != null) {
      final DataOutputStream oStream = PERSISTENCE.writeAttribute(fileOrDir);
      DataInputOutputUtil.writeINT(oStream, ourLanguagesEnumerator.getId(value.getID()));
      oStream.close();
      PushedFilePropertiesUpdater.getInstance(project).filePropertiesChanged(fileOrDir, Conditions.alwaysTrue());
    }
  }

  @Override
  public void afterRootsChanged(@NotNull Project project) {
  }
}