don't expand single-line closure foldings when editing inside them

java/java-impl/src/com/intellij/codeInsight/folding/impl/JavaFoldingBuilder.java

@@ -15,6 +15,7 @@
  */
 package com.intellij.codeInsight.folding.impl;
 
+import com.intellij.codeInsight.daemon.impl.CollectHighlightsUtil;
 import com.intellij.codeInsight.folding.JavaCodeFoldingSettings;
 import com.intellij.codeInsight.generation.OverrideImplementUtil;
 import com.intellij.lang.ASTNode;
@@ -47,7 +48,10 @@ import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import java.util.*;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
 
 public class JavaFoldingBuilder extends CustomFoldingBuilder implements DumbAware {
   private static final Logger LOG = Logger.getInstance("#com.intellij.codeInsight.folding.impl.JavaFoldingBuilder");
@@ -312,7 +316,9 @@ public class JavaFoldingBuilder extends CustomFoldingBuilder implements DumbAwar
       if (importKeyword == null) return null;
       int startOffset = importKeyword.getTextRange().getEndOffset() + 1;
       int endOffset = statements[statements.length - 1].getTextRange().getEndOffset();
-      return new TextRange(startOffset, endOffset);
+      if (!hasErrorElementsNearby(element.getContainingFile(), startOffset, endOffset)) {
+        return new TextRange(startOffset, endOffset);
+      }
     }
     if (element instanceof PsiDocComment) {
       return element.getTextRange();
@@ -330,6 +336,16 @@ public class JavaFoldingBuilder extends CustomFoldingBuilder implements DumbAwar
     return null;
   }
 
+  public static boolean hasErrorElementsNearby(final PsiFile file, int startOffset, int endOffset) {
+    endOffset = CharArrayUtil.shiftForward(file.getText(), endOffset, " \t\n");
+    for (PsiElement element : CollectHighlightsUtil.getElementsInRange(file, startOffset, endOffset)) {
+      if (element instanceof PsiErrorElement) {
+        return true;
+      }
+    }
+    return false;
+  }
+
   @Nullable
   private static TextRange getFileHeader(PsiJavaFile file) {
     PsiElement first = file.getFirstChild();

java/java-tests/testSrc/com/intellij/codeInsight/folding/JavaFoldingTest.groovy

@@ -167,6 +167,32 @@ class Test {
     assertEquals(2, closureFolds.size())
   }
 
+  public void "test closure folding doesn't expand when editing inside"() {
+    def text = """\
+class Test {
+    void test() {
+     new Runnable() {
+      public void run() {
+        System.out.println(<caret>);
+      }
+    };
+  }
+}
+"""
+
+    configure text
+    def foldingModel = myFixture.editor.foldingModel as FoldingModelImpl
+    def closureStartFold = foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable"))
+    assertNotNull closureStartFold
+    assertFalse closureStartFold.expanded
+    assert text.substring(closureStartFold.endOffset).startsWith('System') //one line closure
+
+    myFixture.type('2')
+    myFixture.doHighlighting()
+    closureStartFold = foldingModel.getCollapsedRegionAtOffset(text.indexOf("Runnable"))
+    assert closureStartFold
+  }
+
   public void testFindInFolding() {
     def text = """\
 class Test {

platform/lang-impl/src/com/intellij/codeInsight/editorActions/moveUpDown/MoverWrapper.java

@@ -131,7 +131,6 @@ class MoverWrapper {
         }
       });
     }
-    CodeFoldingManager.getInstance(project).allowFoldingOnCaretLine(editor);
 
     if (hasSelection) {
       restoreSelection(editor, selectionStart, selectionEnd, start, myInfo.range2.getStartOffset());

platform/lang-impl/src/com/intellij/codeInsight/folding/CodeFoldingManager.java

@@ -50,14 +50,4 @@ public abstract class CodeFoldingManager {
 
   public abstract void releaseFoldings(Editor editor);
   public abstract void buildInitialFoldings(Editor editor);
-
-  /**
-   * Asks do not perform automatic expansion of fold region that is located on the caret line during the next fold regions update.
-   * <p/>
-   * This method is necessary because fold regions that are located on caret line are automatically expanded to prevent problem
-   * from IDEA-64687. However, we don't want such an expansion when we, for example, move method up or down.
-   * 
-   * @param editor    target editor
-   */
-  public abstract void allowFoldingOnCaretLine(@NotNull Editor editor);
 }

platform/lang-impl/src/com/intellij/codeInsight/folding/impl/CodeFoldingManagerImpl.java

@@ -331,9 +331,4 @@ public class CodeFoldingManagerImpl extends CodeFoldingManager implements Projec
       document.putUserData(FOLDING_STATE_INFO_IN_DOCUMENT_KEY, null);
     }
   }
-
-  @Override
-  public void allowFoldingOnCaretLine(@NotNull Editor editor) {
-    editor.putUserData(UpdateFoldRegionsOperation.ALLOW_FOLDING_ON_CARET_LINE_KEY, true);
-  }
 }

platform/lang-impl/src/com/intellij/codeInsight/folding/impl/UpdateFoldRegionsOperation.java

@@ -18,14 +18,12 @@ package com.intellij.codeInsight.folding.impl;
 
 import com.intellij.lang.folding.FoldingDescriptor;
 import com.intellij.lang.injection.InjectedLanguageManager;
-import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.editor.Editor;
 import com.intellij.openapi.editor.FoldRegion;
 import com.intellij.openapi.editor.FoldingGroup;
 import com.intellij.openapi.editor.ex.FoldingModelEx;
 import com.intellij.openapi.progress.ProgressManager;
 import com.intellij.openapi.project.Project;
-import com.intellij.openapi.util.Key;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
@@ -43,9 +41,6 @@ import static com.intellij.util.containers.CollectionFactory.newTroveMap;
  * @author cdr
  */
 class UpdateFoldRegionsOperation implements Runnable {
-
-  static final Key<Boolean> ALLOW_FOLDING_ON_CARET_LINE_KEY = Key.create("AllowFoldingOnCaretLine.KEY");
-
   private final Project myProject;
   private final Editor myEditor;
   private final PsiFile myFile;
@@ -80,9 +75,6 @@ class UpdateFoldRegionsOperation implements Runnable {
     List<FoldRegion> newRegions = addNewRegions(info, foldingModel, rangeToExpandStatusMap, shouldExpand, groupExpand);
 
     applyExpandStatus(newRegions, shouldExpand, groupExpand);
-
-    // Reset the key.
-    myEditor.putUserData(ALLOW_FOLDING_ON_CARET_LINE_KEY, false);
   }
 
   private static void applyExpandStatus(@NotNull List<FoldRegion> newRegions,
@@ -147,24 +139,9 @@ class UpdateFoldRegionsOperation implements Runnable {
       // Considering that this code is executed only on initial fold regions construction on editor opening.
       return !FoldingPolicy.isCollapseByDefault(element);
     }
-    boolean caretInside;
-    if (myEditor.getUserData(ALLOW_FOLDING_ON_CARET_LINE_KEY) == Boolean.TRUE) {
-      caretInside = FoldingUtil.caretInsideRange(myEditor, range);
-    }
-    else {
-      final Document document = myEditor.getDocument();
-      final int firstLine = document.getLineNumber(range.getStartOffset());
-      final int lastLine = document.getLineNumber(range.getEndOffset());
-      int caretOffset = myEditor.getCaretModel().getOffset();
-      if (caretOffset > myEditor.getDocument().getTextLength()) {
-        return false;
-      }
-      final int currentLine = document.getLineNumber(caretOffset);
-      caretInside = firstLine <= currentLine && currentLine <= lastLine;
-    }
 
     final Boolean oldStatus = rangeToExpandStatusMap.get(range);
-    return oldStatus == null || caretInside || oldStatus.booleanValue();
+    return oldStatus == null || FoldingUtil.caretInsideRange(myEditor, range) || oldStatus.booleanValue();
   }
 
   private void removeInvalidRegions(@NotNull EditorFoldingInfo info,

plugins/groovy/src/org/jetbrains/plugins/groovy/lang/folding/GroovyFoldingBuilder.java

@@ -17,6 +17,7 @@
 package org.jetbrains.plugins.groovy.lang.folding;
 
 import com.intellij.codeInsight.folding.JavaCodeFoldingSettings;
+import com.intellij.codeInsight.folding.impl.JavaFoldingBuilder;
 import com.intellij.lang.ASTNode;
 import com.intellij.lang.folding.CustomFoldingBuilder;
 import com.intellij.lang.folding.FoldingDescriptor;
@@ -194,7 +195,7 @@ public class GroovyFoldingBuilder extends CustomFoldingBuilder implements Groovy
         int start = first.getTextRange().getStartOffset();
         int end = marker.getTextRange().getEndOffset();
         int tail = "import ".length();
-        if (start + tail < end) {
+        if (start + tail < end && !JavaFoldingBuilder.hasErrorElementsNearby(first.getContainingFile(), start, end)) {
           descriptors.add(new FoldingDescriptor(first.getNode(), new TextRange(start + tail, end)));
         }
       }