platform/lang-api/src/com/intellij/openapi/editor/LanguageLineWrapPositionStrategy.java

/*
 * Copyright 2000-2011 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.openapi.editor;

import com.intellij.lang.LanguageExtension;
import com.intellij.openapi.project.Project;
import com.intellij.psi.PsiDocumentManager;
import com.intellij.psi.PsiFile;
import org.jetbrains.annotations.NotNull;

/**
 * Exposes {@link LineWrapPositionStrategy} implementations to their clients.
 *
 * @author Denis Zhdanov
 * @since Aug 25, 2010 11:30:21 AM
 */
public class LanguageLineWrapPositionStrategy extends LanguageExtension<LineWrapPositionStrategy> {

  public static final String EP_NAME = "com.intellij.lang.lineWrapStrategy";
  public static final LanguageLineWrapPositionStrategy INSTANCE = new LanguageLineWrapPositionStrategy();

  private LanguageLineWrapPositionStrategy() {
    super(EP_NAME, new DefaultLineWrapPositionStrategy());
  }

  /**
   * Asks to get wrap position strategy to use for the document managed by the given editor.
   *
   * @param editor    editor that manages document which text should be processed by wrap position strategy
   * @return          line wrap position strategy to use for the lines from the document managed by the given editor
   */
  @NotNull
  public LineWrapPositionStrategy forEditor(@NotNull Editor editor) {
    LineWrapPositionStrategy result = getDefaultImplementation();
    Project project = editor.getProject();
    if (project != null && !project.isDisposed()) {
      PsiFile psiFile = PsiDocumentManager.getInstance(project).getPsiFile(editor.getDocument());
      if (psiFile != null) {
        result = INSTANCE.forLanguage(psiFile.getLanguage());
      }
    }
    return result;
  }

  @NotNull
  @Override
  public LineWrapPositionStrategy getDefaultImplementation() {
    return super.getDefaultImplementation();
  }
}