From e7cb7f66ced7106044bc8b8294f5104ff05d0c34 Mon Sep 17 00:00:00 2001
From: Denis Zhdanov <Denis.Zhdanov@jetbrains.com>
Date: Mon, 13 Dec 2010 12:07:17 +0300
Subject: [PATCH] IDEA-62830 AE at
 com.intellij.openapi.editor.impl.softwrap.mapping.SoftWrapApplianceManager.a

1. Ensuring that collapsed fold region may be soft wrapped all the time;
2. Corresponding test is added;
---
 .../mapping/SoftWrapApplianceManager.java     | 22 ++++++++++++++-----
 ...apApplianceOnDocumentModificationTest.java | 15 +++++++++++++
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/platform/platform-impl/src/com/intellij/openapi/editor/impl/softwrap/mapping/SoftWrapApplianceManager.java b/platform/platform-impl/src/com/intellij/openapi/editor/impl/softwrap/mapping/SoftWrapApplianceManager.java
index 1e1f076c5044..6c6da2a5a619 100644
--- a/platform/platform-impl/src/com/intellij/openapi/editor/impl/softwrap/mapping/SoftWrapApplianceManager.java
+++ b/platform/platform-impl/src/com/intellij/openapi/editor/impl/softwrap/mapping/SoftWrapApplianceManager.java
@@ -249,9 +249,14 @@ public class SoftWrapApplianceManager implements FoldingListener, DocumentListen
 
     myContext.logicalLineData.update(foldRegion.getStartOffset());
     SoftWrap softWrap = registerSoftWrap(
-      myContext.softWrapStartOffset, myContext.tokenStartOffset, myContext.tokenStartOffset, myContext.getSpaceWidth(), myContext.logicalLineData
+      myContext.softWrapStartOffset, myContext.tokenStartOffset, myContext.tokenStartOffset, myContext.getSpaceWidth(),
+      myContext.logicalLineData
     );
-    assert softWrap != null; // We expect that it's always possible to wrap collapsed fold region placeholder text
+    if (softWrap == null) {
+      // If we're here that means that we can't find appropriate soft wrap offset before the fold region.
+      // However, we expect that it's always possible to wrap collapsed fold region placeholder text
+      softWrap = registerSoftWrap(myContext.tokenStartOffset, myContext.getSpaceWidth(), myContext.logicalLineData);
+    }
     myContext.softWrapStartOffset = softWrap.getStart();
     if (softWrap.getStart() < myContext.tokenStartOffset) {
       revertListeners(softWrap.getStart(), myContext.currentPosition.visualLine);
@@ -524,19 +529,24 @@ public class SoftWrapApplianceManager implements FoldingListener, DocumentListen
       return null;
     }
 
+    return registerSoftWrap(softWrapOffset, spaceSize, lineData);
+  }
+  
+  @NotNull
+  private SoftWrap registerSoftWrap(int offset, int spaceSize, LogicalLineData lineData) {
     int indentInColumns = 0;
     int indentInPixels = myPainter.getMinDrawingWidth(SoftWrapDrawingType.AFTER_SOFT_WRAP);
     if (myCustomIndentUsedLastTime) {
       indentInColumns = myCustomIndentValueUsedLastTime + lineData.indentInColumns;
       indentInPixels += lineData.indentInPixels + (myCustomIndentValueUsedLastTime * spaceSize);
     }
-    SoftWrapImpl softWrap = new SoftWrapImpl(
-      new TextChangeImpl("\n" + StringUtil.repeatSymbol(' ', indentInColumns), softWrapOffset, softWrapOffset),
+    SoftWrapImpl result = new SoftWrapImpl(
+      new TextChangeImpl("\n" + StringUtil.repeatSymbol(' ', indentInColumns), offset, offset),
       indentInColumns + 1/* for 'after soft wrap' drawing */,
       indentInPixels
     );
-    myStorage.storeOrReplace(softWrap, true);
-    return softWrap;
+    myStorage.storeOrReplace(result, true);
+    return result;
   }
 
   /**
diff --git a/platform/platform-impl/testSrc/com/intellij/openapi/editor/impl/softwrap/mapping/SoftWrapApplianceOnDocumentModificationTest.java b/platform/platform-impl/testSrc/com/intellij/openapi/editor/impl/softwrap/mapping/SoftWrapApplianceOnDocumentModificationTest.java
index 3f1faa390fbb..f051b7849536 100644
--- a/platform/platform-impl/testSrc/com/intellij/openapi/editor/impl/softwrap/mapping/SoftWrapApplianceOnDocumentModificationTest.java
+++ b/platform/platform-impl/testSrc/com/intellij/openapi/editor/impl/softwrap/mapping/SoftWrapApplianceOnDocumentModificationTest.java
@@ -420,6 +420,21 @@ public class SoftWrapApplianceOnDocumentModificationTest extends AbstractEditorP
     assertEquals(startOffset, myEditor.logicalPositionToOffset(myEditor.visualToLogicalPosition(new VisualPosition(2, 0))));
   }
   
+  public void testFoldRegionThatStartsAtLineEnd() throws IOException {
+    String text =
+      "line1\n" +
+      "line2\n" +
+      "line3\n" +
+      "line4\n" +
+      "line5";
+    
+    init(30, text);
+    int start = text.indexOf("line3") - 1;
+    addCollapsedFoldRegion(start, text.length(), "...");
+    assertEquals(1, getSoftWrapModel().getRegisteredSoftWraps().size());
+    assertEquals(start, getSoftWrapModel().getRegisteredSoftWraps().get(0).getStart());
+  }
+  
   public void testHomeProcessing() throws IOException {
     String text = 
       "class Test {\n" +