IDEA-115756 Caret is moved on the start of line after formatting, if positioned not on the end of line [CR-IC-2978]

java/java-tests/testSrc/com/intellij/psi/formatter/java/JavaFormatterInEditorTest.java

@@ -23,13 +23,13 @@ import org.jetbrains.annotations.NotNull;
 import java.io.IOException;
 
 /**
- * Is intended to test formatting in editor behavior, i.e. check how formatting affects things like caret position, selection etc. 
- * 
+ * Is intended to test formatting in editor behavior, i.e. check how formatting affects things like caret position, selection etc.
+ *
  * @author Denis Zhdanov
  * @since 6/1/11 6:17 PM
  */
 public class JavaFormatterInEditorTest extends LightPlatformCodeInsightTestCase {
-  
+
   public void testCaretPositionOnLongLineWrapping() throws IOException {
     // Inspired by IDEA-70242
     getCurrentCodeStyleSettings().getCommonSettings(JavaLanguage.INSTANCE).WRAP_LONG_LINES = true;
@@ -39,7 +39,7 @@ public class JavaFormatterInEditorTest extends LightPlatformCodeInsightTestCase
       "\n" +
       "class <caret>Test {\n" +
       "}",
-      
+
       "import static java.util.concurrent\n" +
       "        .atomic.AtomicInteger.*;\n" +
       "\n" +
@@ -47,10 +47,59 @@ public class JavaFormatterInEditorTest extends LightPlatformCodeInsightTestCase
       "}"
     );
   }
-  
+
+  public void testCaretPositionPreserved_WhenOnSameLineWithWhiteSpacesOnly() throws IOException {
+    String text = "class Test {\n" +
+                  "    void test() {\n" +
+                  "         <caret>\n" +
+                  "    }\n" +
+                  "}";
+    doTest(text, text);
+
+    String after = "class Test {\n" +
+                   "    void test() {\n" +
+                   "         <caret>       \n" +
+                   "    }\n" +
+                   "}";
+    doTest(text, after);
+  }
+
+  public void testCaretPositionPreserved_WhenSomeFormattingNeeded() throws IOException {
+    String before = "public class Test {\n" +
+                    "        int a;\n" +
+                    "    \n" +
+                    "    public static void main(String[] args) {\n" +
+                    "                     <caret>\n" +
+                    "    }\n" +
+                    "\n" +
+                    "    static final long j = 2;\n" +
+                    "}";
+    String after = "public class Test {\n" +
+                   "    int a;\n" +
+                   "\n" +
+                   "    public static void main(String[] args) {\n" +
+                   "                     <caret>\n" +
+                   "    }\n" +
+                   "\n" +
+                   "    static final long j = 2;\n" +
+                   "}";
+    doTest(before, after);
+
+    before = "public class Test {\n" +
+             "        int a;\n" +
+             "    \n" +
+             "    public static void main(String[] args) {\n" +
+             "                     <caret>           \n" +
+             "    }\n" +
+             "\n" +
+             "    static final long j = 2;\n" +
+             "}";
+    doTest(before, after);
+  }
+
   public void doTest(@NotNull String before, @NotNull String after) throws IOException {
     configureFromFileText(getTestName(false) + ".java", before);
     CodeStyleManager.getInstance(getProject()).reformatText(getFile(), 0, getEditor().getDocument().getTextLength());
     checkResultByText(after);
   }
-}
+}

platform/lang-impl/src/com/intellij/psi/impl/source/codeStyle/CodeStyleManagerImpl.java

@@ -181,7 +181,7 @@ public class CodeStyleManagerImpl extends CodeStyleManager {
     // So, if 'virtual space in editor' is enabled, we save target visual column. Caret indent is ensured otherwise
     int visualColumnToRestore = -1;
     String caretIndentToRestore = null;
-    RangeMarker caretRangeMarker = null;
+    RangeMarker beforeCaretRangeMarker = null;
 
     if (editor != null) {
       Document document = editor.getDocument();
@@ -202,7 +202,7 @@ public class CodeStyleManagerImpl extends CodeStyleManager {
       if (fixCaretPosition) {
         visualColumnToRestore = editor.getCaretModel().getVisualPosition().column;
         caretIndentToRestore = document.getText(TextRange.create(lineStartOffset, caretOffset));
-        caretRangeMarker = document.createRangeMarker(lineStartOffset, caretOffset);
+        beforeCaretRangeMarker = document.createRangeMarker(0, lineStartOffset);
       }
     }
 
@@ -261,11 +261,11 @@ public class CodeStyleManagerImpl extends CodeStyleManager {
       }
     }
     else {
-      if (caretRangeMarker == null || !caretRangeMarker.isValid() || caretIndentToRestore == null) {
+      if (beforeCaretRangeMarker == null || !beforeCaretRangeMarker.isValid() || caretIndentToRestore == null) {
         return;
       }
-      int offset = caretRangeMarker.getStartOffset();
-      caretRangeMarker.dispose();
+      int offset = beforeCaretRangeMarker.getEndOffset();
+      beforeCaretRangeMarker.dispose();
       if (editor.getCaretModel().getVisualPosition().column == visualColumnToRestore) {
         return;
       }
@@ -484,10 +484,10 @@ public class CodeStyleManagerImpl extends CodeStyleManager {
    * </ol>
    * </pre>
    * <p/>
-   * This method inserts that dummy comment (fallback to identifier <code>xxx</code>, see {@link CodeStyleManagerImpl#createDummy(PsiFile)}) 
+   * This method inserts that dummy comment (fallback to identifier <code>xxx</code>, see {@link CodeStyleManagerImpl#createDummy(PsiFile)})
    * if necessary (if target line contains white space symbols only).
    * <p/>
-   
+
    * <b>Note:</b> it's expected that the whole white space region that contains given offset is processed in a way that all
    * {@link RangeMarker range markers} registered for the given offset are expanded to the whole white space region.
    * E.g. there is a possible case that particular range marker serves for defining formatting range, hence, its start/end offsets