platform/platform-api/src/com/intellij/ide/diff/DiffElement.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.ide.diff;

import com.intellij.openapi.Disposable;
import com.intellij.openapi.actionSystem.DataProvider;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.diff.*;
import com.intellij.openapi.editor.Document;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.editor.EditorFactory;
import com.intellij.openapi.fileEditor.FileDocumentManager;
import com.intellij.openapi.fileTypes.FileType;
import com.intellij.openapi.fileTypes.FileTypeManager;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.project.ProjectManager;
import com.intellij.openapi.util.Disposer;
import com.intellij.openapi.util.text.StringUtil;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.openapi.vfs.encoding.EncodingManager;
import com.intellij.util.diff.FilesTooBigForDiffException;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import javax.swing.*;
import java.awt.*;
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.concurrent.Callable;

/**
 * @author Konstantin Bulenkov
 */
public abstract class DiffElement<T> /*implements Disposable */{
  public static final DiffElement[] EMPTY_ARRAY = new DiffElement[0];
  public static final DiffElement ERROR_NODE = new DiffErrorElement("Can't load elements", "An error has been occurred while getting children");
  private DiffPanel myDiffPanel;
  private Editor myEditor;
  private static final Logger LOG = Logger.getInstance(DiffElement.class.getName());

  public abstract String getPath();

  @NotNull
  public abstract String getName();

  public String getPresentablePath() {
    return getName();
  }

  public abstract long getSize();

  public abstract long getTimeStamp();

  public FileType getFileType() {
    return FileTypeManager.getInstance().getFileTypeByFileName(getName());
  }

  public abstract boolean isContainer();

  public abstract DiffElement[] getChildren() throws IOException;

  /**
   * Returns content data as byte array. Can be null, if element for example is a container
   * @return content byte array
   * @throws java.io.IOException when reading
   */
  @Nullable
  public abstract byte[] getContent() throws IOException;

  public Charset getCharset() {
    return EncodingManager.getInstance().getDefaultCharset();
  }

  @Nullable
  public JComponent getViewComponent(Project project, @Nullable DiffElement target, @NotNull Disposable parentDisposable) {
    disposeViewComponent();
    try {
      FileType fileType = getFileType();
      if (fileType != null && fileType.isBinary()) {
        return getFromProviders(project, target);
      }
      final byte[] content = getContent();
      myEditor = createViewComponentEditor(project, content, fileType);
      return myEditor != null? myEditor.getComponent() : null;
    }
    catch (IOException e) {
      LOG.error(e);
      // TODO
    }
    return null;
  }

  @Nullable
  protected Editor createViewComponentEditor(Project project, @Nullable byte[] content, @Nullable FileType fileType) {
    EditorFactory editorFactory = EditorFactory.getInstance();
    if (editorFactory == null) return null;
    T value = getValue();
    Document document = value instanceof VirtualFile
                        ? FileDocumentManager.getInstance().getDocument((VirtualFile)value)
                        : editorFactory.createDocument(StringUtil.convertLineSeparators(new String(content)));

    if (document != null && fileType != null) {
      return editorFactory.createEditor(document, project, fileType, true);
    }
    return null;
  }

  @Nullable
  protected JComponent getFromProviders(Project project, DiffElement target) {
    return null;
  }

  @Nullable
  public JComponent getDiffComponent(DiffElement element, Project project, Window parentWindow, Disposable disposableParent) throws FilesTooBigForDiffException {
    disposeDiffComponent();

    DiffRequest request;
    try {
      request = createRequest(project, element);
    }
    catch (IOException e) {
      // TODO
      LOG.error(e);
      return null;
    }
    if (request != null) {
      myDiffPanel = DiffManager.getInstance().createDiffPanel(parentWindow, project, disposableParent, null);
      myDiffPanel.setRequestFocus(false);
      myDiffPanel.setDiffRequest(request);
      myDiffPanel.setTitle1(getName());
      myDiffPanel.setTitle2(element.getName());
      return myDiffPanel.getComponent();
    }

    return null;
  }

  @Nullable
  protected DiffRequest createRequest(Project project, DiffElement element) throws IOException {
    final T src = getValue();
    final Object trg = element.getValue();
    if (src instanceof VirtualFile && trg instanceof VirtualFile
        && ((VirtualFile)src).getFileType().isBinary()
        && ((VirtualFile)trg).getFileType().isBinary()) {
      return createRequestForBinaries(project, ((VirtualFile)src), ((VirtualFile)trg));
    }
    if (src instanceof VirtualFile) {
      if (((VirtualFile)src).getFileType().isBinary()) return null;
      if (trg instanceof VirtualFile) {
        if (((VirtualFile)trg).getFileType().isBinary()) return null;
        final FileDocumentManager mgr = FileDocumentManager.getInstance();
        if (mgr.getDocument((VirtualFile)src) != null && mgr.getDocument((VirtualFile)trg) != null) {
          return SimpleDiffRequest.compareFiles((VirtualFile)src, (VirtualFile)trg, project == null ? ProjectManager.getInstance().getDefaultProject() : project);
        }
      }
    }
    final DiffContent srcContent = createDiffContent();
    final DiffContent trgContent = element.createDiffContent();

    if (srcContent != null && trgContent != null) {
      final SimpleDiffRequest request = new SimpleDiffRequest(project, "");
      request.setContents(srcContent, trgContent);
      return request;
    }
    return null;
  }

  @Nullable
  protected DiffRequest createRequestForBinaries(Project project, @NotNull VirtualFile src, @NotNull VirtualFile trg) {
    return SimpleDiffRequest.compareFiles(src, trg, project);
  }

  @Nullable
  protected DiffContent createDiffContent() throws IOException {
    return new SimpleContent(new String(getContent(), getCharset()), getFileType());
  }

  public abstract T getValue();

  public void disposeViewComponent() {
    if (myEditor != null) {
      EditorFactory.getInstance().releaseEditor(myEditor);
      myEditor = null;
    }
  }

  public void disposeDiffComponent() {
    if (myDiffPanel != null) {
      Disposer.dispose(myDiffPanel);
      myDiffPanel = null;
    }
  }

  public String getSeparator() {
    return "/";
  }

  @Nullable
  public Icon getIcon() {
    return null;
  }

  //@Override
  //public void dispose() {
  //}

  @Nullable
  public Callable<DiffElement<T>> getElementChooser(Project project) {
    return null;
  }

  @Nullable
  public DataProvider getDataProvider(Project project) {
    return null;
  }

  /**
   * Defines is it possible to perform such operations as copy or delete through Diff Panel
   *
   * @return <code>true</code> if copy, delete, etc operations are allowed,
   *        <code>false</code> otherwise
   */
  public boolean isOperationsEnabled() {
    return false;
  }

  /**
   * Copies element to the container.
   *
   * @param container file directory or other container
   * @param relativePath relative path from root
   * @return <code>true</code> if coping was completed successfully,
   *        <code>false</code> otherwise
   */
  @Nullable
  public DiffElement<?> copyTo(DiffElement<T> container, String relativePath) {
    return null;
  }

  /**
   * Deletes element
   * @return <code>true</code> if deletion was completed successfully,
   *        <code>false</code> otherwise
   */
  public boolean delete() {
    return false;
  }

  public void refresh(boolean userInitiated) throws IOException{
  }
}