From a96ea8d35d6a50e025ec00630afdb7031aeaa2e1 Mon Sep 17 00:00:00 2001
From: Denis Zhdanov <Denis.Zhdanov@jetbrains.com>
Date: Wed, 6 Oct 2010 17:45:50 +0400
Subject: [PATCH] IDEA-59220 IAE at
 com.intellij.openapi.editor.impl.DocumentImpl.a

Corrected caret positioning during auto-hard wrap
---
 .../editorActions/AutoHardWrapHandler.java          | 13 +++++++------
 .../intellij/openapi/editor/impl/DocumentImpl.java  |  6 +++++-
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/platform/lang-impl/src/com/intellij/codeInsight/editorActions/AutoHardWrapHandler.java b/platform/lang-impl/src/com/intellij/codeInsight/editorActions/AutoHardWrapHandler.java
index b23803abd1dd..c3b37c768c4d 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/editorActions/AutoHardWrapHandler.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/editorActions/AutoHardWrapHandler.java
@@ -158,9 +158,15 @@ public class AutoHardWrapHandler {
     }
 
     final int[] wrapIntroducedSymbolsNumber = new int[1];
+    final int[] caretOffsetDiff = new int[1];
+    final int baseCaretOffset = caretModel.getOffset();
     DocumentListener listener = new DocumentListener() {
       @Override
       public void beforeDocumentChange(DocumentEvent event) {
+        if (event.getOffset() <= baseCaretOffset) {
+          caretOffsetDiff[0] += event.getNewLength() - event.getOldLength();
+        }
+
         if (event.getNewLength() <= 0) {
           // There is a possible case that document fragment is removed because of auto-formatting. We don't want to process such events.
           return;
@@ -188,12 +194,7 @@ public class AutoHardWrapHandler {
     change.change.setStart(wrapOffset);
     change.change.setEnd(wrapOffset + wrapIntroducedSymbolsNumber[0]);
 
-    int newCaretOffset = caretOffset;
-    if (wrapOffset <= caretOffset && newCaretOffset + wrapIntroducedSymbolsNumber[0] < document.getTextLength()) {
-      newCaretOffset += wrapIntroducedSymbolsNumber[0];
-    }
-    newCaretOffset = Math.min(document.getLineEndOffset(line + 1), newCaretOffset);
-    caretModel.moveToOffset(newCaretOffset);
+    caretModel.moveToOffset(baseCaretOffset + caretOffsetDiff[0]);
   }
 
   private static class AutoWrapChange {
diff --git a/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java b/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
index 336c1a561a1d..9011bd00647b 100644
--- a/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
@@ -468,7 +468,9 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
       return null; // suppress events in shutdown hook
     }
     DocumentEvent event = new DocumentEventImpl(this, offset, oldString, newString, myModificationStamp, wholeTextReplaced);
-
+    //System.out.printf("%nbefore change: offset=%d, old text='%s', new text='%s', document modification stamp=%d%nDocument:'%s'%n",
+    //                  event.getOffset(), event.getOldFragment(), event.getNewFragment(), event.getDocument().getModificationStamp(),
+                      event.getDocument().getText());
     for (int i = myDocumentListeners.size() - 1; i >= 0; i--) {
       try {
         myDocumentListeners.get(i).beforeDocumentChange(event);
@@ -484,6 +486,8 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
 
   @SuppressWarnings({"ForLoopReplaceableByForEach"})
   private void changedUpdate(DocumentEvent event, long newModificationStamp) {
+    //System.out.printf("after change: new modification stamp=%d%ndocument='%s'%n", event.getDocument().getModificationStamp(),
+    //                  event.getDocument().getText());
     if (ShutDownTracker.isShutdownHookRunning()) {
       return; // suppress events in shutdown hook
     }