diff --git a/java/java-tests/testSrc/com/intellij/codeInsight/JavaReformatOnTypingTest.java b/java/java-tests/testSrc/com/intellij/codeInsight/JavaReformatOnTypingTest.java
new file mode 100644
index 000000000000..1c0f2258dc5c
--- /dev/null
+++ b/java/java-tests/testSrc/com/intellij/codeInsight/JavaReformatOnTypingTest.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2000-2016 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.codeInsight;
+
+import com.intellij.codeInsight.editorActions.AutoFormatTypedHandler;
+import com.intellij.ide.highlighter.JavaFileType;
+import com.intellij.lang.Language;
+import com.intellij.lang.java.JavaLanguage;
+import com.intellij.openapi.project.Project;
+import com.intellij.psi.codeStyle.CodeStyleSettings;
+import com.intellij.psi.codeStyle.CodeStyleSettingsManager;
+import com.intellij.psi.codeStyle.CommonCodeStyleSettings;
+import com.intellij.testFramework.fixtures.LightPlatformCodeInsightFixtureTestCase;
+
+public class JavaReformatOnTypingTest extends LightPlatformCodeInsightFixtureTestCase {
+  
+  @Override
+  public void setUp() throws Exception {
+    super.setUp();
+    AutoFormatTypedHandler.setEnabledInTests(true);
+  }
+
+  @Override
+  public void tearDown() throws Exception {
+    AutoFormatTypedHandler.setEnabledInTests(false);
+    //noinspection SuperTearDownInFinally
+    super.tearDown();
+  }
+
+  private static void useSpacesAroundAssignmentOperator(boolean value, Project project, Language language) {
+    CodeStyleSettings settings = CodeStyleSettingsManager.getInstance(project).getCurrentSettings();
+    CommonCodeStyleSettings common = settings.getCommonSettings(language);
+    common.SPACE_AROUND_ASSIGNMENT_OPERATORS = value;
+  }
+
+  public void test_AddSpacesAroundAssignmentOperator() throws Exception {
+    doTest("class T { int<caret> }", "=", "class T { int = <caret> }");
+  }
+  
+  public void test_IgnoreSpacePressedAfterAssignmentOperator() {
+    useSpacesAroundAssignmentOperator(true, myFixture.getProject(), JavaLanguage.INSTANCE);
+    myFixture.configureByText(JavaFileType.INSTANCE, "class T { int<caret> }");
+    myFixture.type('=');
+    myFixture.type(' ');
+    myFixture.checkResult("class T { int = <caret> }");
+  }
+  
+  public void test_DoNotInsertDoubleSpaceBeforeAssignment() {
+    doTest("class T { int <caret> }", 
+           "=", 
+           "class T { int = <caret> }");
+  }
+  
+  public void test_DoNotInsertDoubleSpaceAnywhere() {
+    useSpacesAroundAssignmentOperator(true, myFixture.getProject(), JavaLanguage.INSTANCE);
+    myFixture.configureByText(JavaFileType.INSTANCE, "class T { int <caret> }");
+    myFixture.type('=');
+    myFixture.type(' ');
+    myFixture.checkResult("class T { int = <caret> }");
+  }
+  
+  public void test_DoNotInsertSpaceIfNotAssignment() {
+    doTest("1 <caret>", "!=", "1 != <caret>");
+    doTest("c <caret>", ">=", "c >= <caret>");
+    doTest("c <caret>", "<=", "c <= <caret>");
+    doTest("c <caret>", "+=", "c += <caret>");
+    doTest("c <caret>", "-=", "c -= <caret>");
+    doTest("c <caret>", "*=", "c *= <caret>");
+    doTest("c <caret>", "/=", "c /= <caret>");
+    doTest("c <caret>", "&=", "c &= <caret>");
+    doTest("c <caret>", "%=", "c %= <caret>");
+    doTest("c <caret>", "^=", "c ^= <caret>");
+    doTest("c <caret>", "|=", "c |= <caret>");
+  }
+
+  private void doTest(String before, String typing, String after) {
+    useSpacesAroundAssignmentOperator(true, myFixture.getProject(), JavaLanguage.INSTANCE);
+    myFixture.configureByText(JavaFileType.INSTANCE, before);
+    myFixture.type(typing);
+    myFixture.checkResult(after);
+  }
+}
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/editorActions/AutoFormatTypedHandler.java b/platform/lang-impl/src/com/intellij/codeInsight/editorActions/AutoFormatTypedHandler.java
new file mode 100644
index 000000000000..6697def3dd13
--- /dev/null
+++ b/platform/lang-impl/src/com/intellij/codeInsight/editorActions/AutoFormatTypedHandler.java
@@ -0,0 +1,125 @@
+/*
+ * Copyright 2000-2016 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.codeInsight.editorActions;
+
+import com.intellij.codeInsight.template.impl.editorActions.TypedActionHandlerBase;
+import com.intellij.lang.Language;
+import com.intellij.openapi.actionSystem.CommonDataKeys;
+import com.intellij.openapi.actionSystem.DataContext;
+import com.intellij.openapi.application.ApplicationManager;
+import com.intellij.openapi.editor.CaretModel;
+import com.intellij.openapi.editor.Document;
+import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.editor.EditorModificationUtil;
+import com.intellij.openapi.editor.actionSystem.TypedActionHandler;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.registry.Registry;
+import com.intellij.psi.PsiFile;
+import com.intellij.psi.codeStyle.CodeStyleSettings;
+import com.intellij.psi.codeStyle.CodeStyleSettingsManager;
+import com.intellij.psi.codeStyle.CommonCodeStyleSettings;
+import com.intellij.psi.util.PsiUtilBase;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.annotations.TestOnly;
+
+public class AutoFormatTypedHandler extends TypedActionHandlerBase {
+  private static boolean myIsEnabledInTests = false;
+  
+  private static char[] NO_SPACE_AFTER = { '+', '-', '*', '/', '%', '&', '^', '|', '<', '>', '!', '=', ' ' };
+  
+  private boolean myIgnoreNextSpace = false;
+  private Document myLastModifiedDocument = null;
+  private int myLastOffset = -1;
+
+  public AutoFormatTypedHandler(@Nullable TypedActionHandler originalHandler) {
+    super(originalHandler);
+  }
+  
+  private static boolean isEnabled() {
+    return Registry.is("editor.reformat.on.typing") 
+           || myIsEnabledInTests && ApplicationManager.getApplication().isUnitTestMode();
+  }
+  
+  @TestOnly
+  public static void setEnabledInTests(boolean value) {
+    myIsEnabledInTests = value;
+  }
+  
+  @Override
+  public void execute(@NotNull Editor editor, char charTyped, @NotNull DataContext dataContext) {
+    if (isEnabled() && charTyped == ' ' && shouldIgnoreSpace(editor)) {
+      myIgnoreNextSpace = false;
+      return;
+    }
+    
+    Document document = editor.getDocument();
+    boolean addSpaces = isEnabled() && charTyped == '=' && shouldInsertSpaces(editor, dataContext);
+    
+    int caretOffset = editor.getCaretModel().getOffset();
+    CharSequence text = document.getImmutableCharSequence();
+    if (addSpaces && shouldInsertBefore(caretOffset, text)) {
+        EditorModificationUtil.insertStringAtCaret(editor, " ");
+    }
+
+    if (myOriginalHandler != null) myOriginalHandler.execute(editor, charTyped, dataContext);
+    
+    if (addSpaces) {
+      EditorModificationUtil.insertStringAtCaret(editor, " ");
+      myIgnoreNextSpace = true;
+      myLastModifiedDocument = document;
+      myLastOffset = editor.getCaretModel().getOffset();
+    }
+    else {
+      myIgnoreNextSpace = false;
+    }
+  }
+
+  private static boolean shouldInsertBefore(int caretOffset, CharSequence text) {
+    if (caretOffset == 0) return false;
+    char charBefore = text.charAt(caretOffset - 1);
+
+    for (char c : NO_SPACE_AFTER) {
+      if (c == charBefore) {
+        return false;
+      }
+    }
+    
+    return true;
+  }
+
+  private static boolean shouldInsertSpaces(Editor editor, DataContext dataContext) {
+    final Project project = CommonDataKeys.PROJECT.getData(dataContext);
+    PsiFile file = project == null ? null : PsiUtilBase.getPsiFileInEditor(editor, project);
+    if (file != null) {
+      Language language = file.getLanguage();
+      CodeStyleSettings settings = CodeStyleSettingsManager.getInstance(project).getCurrentSettings();
+      CommonCodeStyleSettings common = settings.getCommonSettings(language);
+      return common.SPACE_AROUND_ASSIGNMENT_OPERATORS;
+    }
+    return false;
+  }
+  
+  private boolean shouldIgnoreSpace(@NotNull Editor editor) {
+    if (!myIgnoreNextSpace) {
+      return false;
+    }
+    Document document = editor.getDocument();
+    CaretModel caretModel = editor.getCaretModel();
+    return myLastModifiedDocument == document && myLastOffset == caretModel.getOffset();
+  }
+  
+}
diff --git a/platform/platform-resources/src/META-INF/LangExtensions.xml b/platform/platform-resources/src/META-INF/LangExtensions.xml
index 9ba616080ea8..35a13d58eec3 100644
--- a/platform/platform-resources/src/META-INF/LangExtensions.xml
+++ b/platform/platform-resources/src/META-INF/LangExtensions.xml
@@ -727,6 +727,7 @@
                          order="before hide-hints"/>
 
     <editorTypedHandler implementationClass="com.intellij.codeInsight.lookup.impl.LookupTypedHandler" id="lookup"/>
+    <editorTypedHandler implementationClass="com.intellij.codeInsight.editorActions.AutoFormatTypedHandler"/>
     <typedHandler implementation="com.intellij.codeInsight.editorActions.CompletionAutoPopupHandler" id="completionAutoPopup"
                   order="first"/>
     <typedHandler implementation="com.intellij.codeInsight.editorActions.SelectionQuotingTypedHandler" id="selectionQuoting"/>
diff --git a/platform/util/resources/misc/registry.properties b/platform/util/resources/misc/registry.properties
index 20827b259ea1..0ebaa02a7a97 100644
--- a/platform/util/resources/misc/registry.properties
+++ b/platform/util/resources/misc/registry.properties
@@ -149,6 +149,8 @@ editor.navigation.history.stack.size.description=Stack size limit for back/forwa
 editor.mac.smooth.scrolling=false
 editor.mac.smooth.scrolling.description=Enable precise (with sub-line resolution) scrolling on Mac with mouse or trackpad
 
+editor.reformat.on.typing=false
+
 ide.showIndexRebuildMessage=false
 
 ide.tabbedPane.bufferedPaint=true