plugins/editorconfig/src/org/editorconfig/configmanagement/EditorSettingsManager.java

package org.editorconfig.configmanagement;

import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.editor.Document;
import com.intellij.openapi.editor.ex.EditorSettingsExternalizable;
import com.intellij.openapi.editor.impl.TrailingSpacesStripper;
import com.intellij.openapi.fileEditor.FileDocumentManager;
import com.intellij.openapi.fileEditor.FileDocumentManagerAdapter;
import com.intellij.openapi.util.Key;
import com.intellij.openapi.vfs.VirtualFile;
import org.editorconfig.Utils;
import org.editorconfig.core.EditorConfig;
import org.editorconfig.plugincomponents.SettingsProviderComponent;
import org.jetbrains.annotations.NotNull;

import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class EditorSettingsManager extends FileDocumentManagerAdapter {
  // Handles the following EditorConfig settings:
  private static final String trimTrailingWhitespaceKey = "trim_trailing_whitespace";
  private static final String insertFinalNewlineKey = "insert_final_newline";
  private static final Map<String, String> trimMap;

  static {
    Map<String, String> map = new HashMap<String, String>();
    map.put("true", EditorSettingsExternalizable.STRIP_TRAILING_SPACES_WHOLE);
    map.put("false", EditorSettingsExternalizable.STRIP_TRAILING_SPACES_NONE);
    trimMap = Collections.unmodifiableMap(map);
  }

  private static final Map<String, Boolean> newlineMap;

  static {
    Map<String, Boolean> map = new HashMap<String, Boolean>();
    map.put("true", Boolean.TRUE);
    map.put("false", Boolean.FALSE);
    newlineMap = Collections.unmodifiableMap(map);
  }

  private static final Logger LOG = Logger.getInstance("#org.editorconfig.configmanagement.EditorSettingsManager");

  @Override
  public void beforeDocumentSaving(@NotNull Document document) {
    // This is fired when any document is saved, regardless of whether it is part of a save-all or
    // a save-one operation
    final VirtualFile file = FileDocumentManager.getInstance().getFile(document);
    applySettings(file);
  }

  private static void applySettings(VirtualFile file) {
    if (file == null || !file.isInLocalFileSystem()) return;
    // Get editorconfig settings
    final String filePath = file.getCanonicalPath();
    final SettingsProviderComponent settingsProvider = SettingsProviderComponent.getInstance();
    final List<EditorConfig.OutPair> outPairs = settingsProvider.getOutPairs(filePath);
    // Apply trailing spaces setting
    final String trimTrailingWhitespace = Utils.configValueForKey(outPairs, trimTrailingWhitespaceKey);
    applyConfigValueToUserData(file, TrailingSpacesStripper.OVERRIDE_STRIP_TRAILING_SPACES_KEY,
                               trimTrailingWhitespaceKey, trimTrailingWhitespace, trimMap);
    // Apply final newline setting
    final String insertFinalNewline = Utils.configValueForKey(outPairs, insertFinalNewlineKey);
    applyConfigValueToUserData(file, TrailingSpacesStripper.OVERRIDE_ENSURE_NEWLINE_KEY,
                               insertFinalNewlineKey, insertFinalNewline, newlineMap);
  }

  private static <T> void applyConfigValueToUserData(VirtualFile file, Key<T> userDataKey, String editorConfigKey,
                                                     String configValue, Map<String, T> configMap) {
    if (configValue.isEmpty()) {
      file.putUserData(userDataKey, null);
    }
    else {
      final T data = configMap.get(configValue);
      if (data == null) {
        LOG.warn(Utils.invalidConfigMessage(configValue, editorConfigKey, file.getCanonicalPath()));
      }
      else {
        file.putUserData(userDataKey, data);
        LOG.debug("Applied " + editorConfigKey + " settings for: " + file.getCanonicalPath());
      }
    }
  }
}