lang-api/src/com/intellij/lang/folding/FoldingBuilder.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   3  *
   4  *  Licensed under the Apache License, Version 2.0 (the "License");
   5  *  you may not use this file except in compliance with the License.
   6  *  You may obtain a copy of the License at
   7  *
   8  *  http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  *  Unless required by applicable law or agreed to in writing, software
  11  *  distributed under the License is distributed on an "AS IS" BASIS,
  12  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  *  See the License for the specific language governing permissions and
  14  *  limitations under the License.
  15  */
  16 package com.intellij.lang.folding;
  17
  18 import com.intellij.lang.ASTNode;
  19 import com.intellij.lang.Language;
  20 import com.intellij.openapi.editor.Document;
  21 import org.jetbrains.annotations.Nullable;
  22
  23 /**
  24  * Allows a custom language plugin to define rules for folding code in the language handled
  25  * by the plugin.
  26  *
  27  * @author max
  28  * @see LanguageFolding#forLanguage(Language)
  29  */
  30
  31 public interface FoldingBuilder {
  32   /**
  33    * Builds the folding regions for the specified node in the AST tree and its children.
  34    *
  35    * @param node     the node for which folding is requested.
  36    * @param document the document for which folding is built. Can be used to retrieve line
  37    *                 numbers for folding regions.
  38    * @return the array of folding descriptors.
  39    */
  40   FoldingDescriptor[] buildFoldRegions(ASTNode node, Document document);
  41
  42   /**
  43    * Returns the text which is displayed in the editor for the folding region related to the
  44    * specified node when the folding region is collapsed.
  45    *
  46    * @param node the node for which the placeholder text is requested.
  47    * @return the placeholder text.
  48    */
  49   @Nullable
  50   String getPlaceholderText(ASTNode node);
  51
  52   /**
  53    * Returns the default collapsed state for the folding region related to the specified node.
  54    *
  55    * @param node the node for which the collapsed state is requested.
  56    * @return true if the region is collapsed by default, false otherwise.
  57    */
  58   boolean isCollapsedByDefault(ASTNode node);
  59 }