IDEA-125470 While in editor, wild re-displaying occurs when soft wraps are enabled

platform/platform-impl/src/com/intellij/openapi/editor/ex/util/EditorUtil.java

@@ -782,15 +782,11 @@ public final class EditorUtil {
 
   /**
    * Finds the start offset of visual line at which given offset is located, not taking soft wraps into account.
-   *
-   * @see #calcSurroundingRange(com.intellij.openapi.editor.Editor, com.intellij.openapi.editor.VisualPosition, com.intellij.openapi.editor.VisualPosition)
    */
   public static int getNotFoldedLineStartOffset(@NotNull Editor editor, int offset) {
     while(true) {
       offset = getLineStartOffset(offset, editor.getDocument());
-      // this assumes that there cannot be two adjacent collapsed fold regions
-      // (such case is not properly handled currently by FoldingModelImpl/FoldRegionsTree anyway)
-      FoldRegion foldRegion = editor.getFoldingModel().getCollapsedRegionAtOffset(offset);
+      FoldRegion foldRegion = editor.getFoldingModel().getCollapsedRegionAtOffset(offset - 1);
       if (foldRegion == null || foldRegion.getStartOffset() >= offset) {
         break;
       }
@@ -801,14 +797,10 @@ public final class EditorUtil {
 
   /**
    * Finds the end offset of visual line at which given offset is located, not taking soft wraps into account.
-   *
-   * @see #calcSurroundingRange(com.intellij.openapi.editor.Editor, com.intellij.openapi.editor.VisualPosition, com.intellij.openapi.editor.VisualPosition)
    */
   public static int getNotFoldedLineEndOffset(@NotNull Editor editor, int offset) {
     while(true) {
       offset = getLineEndOffset(offset, editor.getDocument());
-      // this assumes that there cannot be two adjacent collapsed fold regions
-      // (such case is not properly handled currently by FoldingModelImpl/FoldRegionsTree anyway)
       FoldRegion foldRegion = editor.getFoldingModel().getCollapsedRegionAtOffset(offset);
       if (foldRegion == null || foldRegion.getEndOffset() <= offset) {
         break;

platform/platform-tests/testSrc/com/intellij/openapi/editor/ex/util/EditorUtilTest.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2000-2014 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.openapi.editor.ex.util;
+
+import com.intellij.testFramework.EditorTestUtil;
+import com.intellij.testFramework.LightPlatformCodeInsightTestCase;
+
+public class EditorUtilTest extends LightPlatformCodeInsightTestCase {
+  public void testGetNotFoldedLineStartEndOffsets() throws Exception {
+    configureFromFileText(getTestName(false) + ".txt",
+                          "aaa\nbbb\nccc\nddd");
+    EditorTestUtil.addFoldRegion(myEditor, 4, 8, "...", true);
+
+    assertVisualLineRange(2, 0, 3);
+    assertVisualLineRange(4, 4, 11);
+    assertVisualLineRange(7, 4, 11);
+    assertVisualLineRange(8, 4, 11);
+    assertVisualLineRange(9, 4, 11);
+    assertVisualLineRange(13, 12, 15);
+  }
+
+  private static void assertVisualLineRange(int offset, int lineStartOffset, int lineEndOffset) {
+    assertEquals(lineStartOffset, EditorUtil.getNotFoldedLineStartOffset(myEditor, offset));
+    assertEquals(lineEndOffset, EditorUtil.getNotFoldedLineEndOffset(myEditor, offset));
+  }
+}

platform/platform-tests/testSrc/com/intellij/openapi/editor/impl/softwrap/mapping/SoftWrapApplianceOnDocumentModificationTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2013 JetBrains s.r.o.
+ * Copyright 2000-2014 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.
@@ -1040,6 +1040,17 @@ public class SoftWrapApplianceOnDocumentModificationTest extends AbstractEditorT
     assertFalse(foldRegion.isExpanded());
     assertEquals(foldStart, myEditor.getCaretModel().getOffset());
   }
+
+  public void testFoldRegionEndingAtLineStart() throws IOException {
+    init(100, "aaa\nbbb\nccc\nddd");
+    addCollapsedFoldRegion(4, 8, "...");
+    addCollapsedFoldRegion(13, 15, "...");
+
+    myEditor.getDocument().insertString(10, "C");
+
+    // verify that cached layout data is intact after document change and position recalculation is done correctly
+    assertEquals(new LogicalPosition(0, 0), myEditor.visualToLogicalPosition(new VisualPosition(0, 0)));
+  }
   
   private void init(final int visibleWidthInColumns, @NotNull String fileText) throws IOException {
     init(visibleWidthInColumns, 7, fileText);

platform/testFramework/src/com/intellij/testFramework/EditorTestUtil.java

@@ -30,20 +30,20 @@ import com.intellij.openapi.editor.highlighter.HighlighterIterator;
 import com.intellij.openapi.editor.impl.DefaultEditorTextRepresentationHelper;
 import com.intellij.openapi.editor.impl.SoftWrapModelImpl;
 import com.intellij.openapi.editor.impl.softwrap.mapping.SoftWrapApplianceManager;
+import com.intellij.openapi.util.Ref;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.openapi.util.registry.Registry;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.tree.IElementType;
-import org.junit.Assert;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.junit.Assert;
 
 import java.awt.*;
 import java.util.ArrayList;
 import java.util.List;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.*;
 
 /**
  * @author Maxim.Mossienko
@@ -391,6 +391,21 @@ public class EditorTestUtil {
     Registry.get("editor.allow.multiple.carets").setValue(false);
   }
 
+  public static FoldRegion addFoldRegion(@NotNull Editor editor, final int startOffset, final int endOffset, final String placeholder, final boolean collapse) {
+    final FoldingModel foldingModel = editor.getFoldingModel();
+    final Ref<FoldRegion> ref = new Ref<FoldRegion>();
+    foldingModel.runBatchFoldingOperation(new Runnable() {
+      @Override
+      public void run() {
+        FoldRegion region = foldingModel.addFoldRegion(startOffset, endOffset, placeholder);
+        assertNotNull(region);
+        region.setExpanded(!collapse);
+        ref.set(region);
+      }
+    });
+    return ref.get();
+  }
+
   public static class CaretAndSelectionState {
     public final List<CaretInfo> carets = new ArrayList<CaretInfo>();
     @Nullable