python/src/com/jetbrains/python/editor/PyEnterAtIndentHandler.java

/*
 * Copyright 2000-2013 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.jetbrains.python.editor;

import com.intellij.codeInsight.editorActions.BackspaceHandler;
import com.intellij.codeInsight.editorActions.enter.EnterHandlerDelegateAdapter;
import com.intellij.injected.editor.EditorWindow;
import com.intellij.lang.injection.InjectedLanguageManager;
import com.intellij.openapi.actionSystem.DataContext;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.editor.actionSystem.EditorActionHandler;
import com.intellij.openapi.util.Ref;
import com.intellij.psi.PsiFile;
import com.intellij.psi.impl.source.tree.injected.InjectedLanguageUtil;
import com.jetbrains.python.psi.PyFile;
import org.jetbrains.annotations.NotNull;

/**
 * @author yole
 */
public class PyEnterAtIndentHandler extends EnterHandlerDelegateAdapter {
  @Override
  public Result preprocessEnter(@NotNull PsiFile file,
                                @NotNull Editor editor,
                                @NotNull Ref<Integer> caretOffset,
                                @NotNull Ref<Integer> caretAdvance,
                                @NotNull DataContext dataContext,
                                EditorActionHandler originalHandler) {
    int offset = caretOffset.get();
    if (editor instanceof EditorWindow) {
      file = InjectedLanguageManager.getInstance(file.getProject()).getTopLevelFile(file);
      editor = InjectedLanguageUtil.getTopLevelEditor(editor);
      offset = editor.getCaretModel().getOffset();
    }
    if (!(file instanceof PyFile)) {
      return Result.Continue;
    }

    // honor dedent (PY-3009)
    if (BackspaceHandler.isWhitespaceBeforeCaret(editor)) {
      return Result.DefaultSkipIndent;
    }
    return Result.Continue;
  }
}