diff --git a/platform/platform-impl/src/com/intellij/ide/actions/ToolWindowsGroup.java b/platform/platform-impl/src/com/intellij/ide/actions/ToolWindowsGroup.java
index 01aee3f80f96..7be9a633c3ea 100644
--- a/platform/platform-impl/src/com/intellij/ide/actions/ToolWindowsGroup.java
+++ b/platform/platform-impl/src/com/intellij/ide/actions/ToolWindowsGroup.java
@@ -28,6 +28,7 @@ import com.intellij.openapi.wm.ToolWindowId;
 import com.intellij.openapi.wm.ex.ToolWindowManagerAdapter;
 import com.intellij.openapi.wm.ex.ToolWindowManagerEx;
 import com.intellij.util.containers.HashMap;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import javax.swing.*;
@@ -132,7 +133,7 @@ public final class ToolWindowsGroup extends ActionGroup {
   }
 
   private final class MyToolWindowManagerListener extends ToolWindowManagerAdapter{
-    public void toolWindowRegistered(String id){
+    public void toolWindowRegistered(@NotNull String id){
       addActionForToolWindow(id);
     }
   }
diff --git a/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/EditorTabbedContainer.java b/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/EditorTabbedContainer.java
index b801faaf87a3..407962dda71e 100644
--- a/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/EditorTabbedContainer.java
+++ b/platform/platform-impl/src/com/intellij/openapi/fileEditor/impl/EditorTabbedContainer.java
@@ -106,7 +106,7 @@ final class EditorTabbedContainer implements Disposable {
         updateTabBorder();
       }
 
-      public void toolWindowRegistered(final String id) {
+      public void toolWindowRegistered(@NotNull final String id) {
         updateTabBorder();
       }
     });
diff --git a/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerAdapter.java b/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerAdapter.java
index cbe101e04e85..ce95fa2763bf 100644
--- a/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerAdapter.java
+++ b/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerAdapter.java
@@ -19,10 +19,11 @@
  */
 package com.intellij.openapi.wm.ex;
 
+import org.jetbrains.annotations.NotNull;
 
 
 public class ToolWindowManagerAdapter implements ToolWindowManagerListener{
-  public void toolWindowRegistered(final String id){}
+  public void toolWindowRegistered(@NotNull final String id){}
 
   public void stateChanged(){}
 }
diff --git a/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerEx.java b/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerEx.java
index 27ef6b896319..981ced945fd2 100644
--- a/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerEx.java
+++ b/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerEx.java
@@ -17,21 +17,21 @@ package com.intellij.openapi.wm.ex;
 
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Condition;
-import com.intellij.openapi.wm.ToolWindowManager;
 import com.intellij.openapi.wm.ToolWindowAnchor;
+import com.intellij.openapi.wm.ToolWindowManager;
 import com.intellij.openapi.wm.impl.DesktopLayout;
+import org.jetbrains.annotations.NotNull;
 
 import javax.swing.*;
 import java.util.List;
 
-public abstract class ToolWindowManagerEx extends ToolWindowManager{
+public abstract class ToolWindowManagerEx extends ToolWindowManager {
   public static ToolWindowManagerEx getInstanceEx(final Project project){
     return (ToolWindowManagerEx)getInstance(project);
   }
 
-  public abstract void addToolWindowManagerListener(ToolWindowManagerListener l);
-
-  public abstract void removeToolWindowManagerListener(ToolWindowManagerListener l);
+  public abstract void addToolWindowManagerListener(@NotNull ToolWindowManagerListener l);
+  public abstract void removeToolWindowManagerListener(@NotNull ToolWindowManagerListener l);
 
   /**
    * @return <code>ID</code> of tool window that was activated last time.
@@ -55,11 +55,11 @@ public abstract class ToolWindowManagerEx extends ToolWindowManager{
   /**
    * Copied <code>layout</code> into internal layout and rearranges tool windows.
    */
-  public abstract void setLayout(DesktopLayout layout);
+  public abstract void setLayout(@NotNull DesktopLayout layout);
 
   public abstract void clearSideStack();
 
-  public abstract void hideToolWindow(String id, boolean hideSide);
+  public abstract void hideToolWindow(@NotNull String id, boolean hideSide);
 
-  public abstract List<String> getIdsOn(final ToolWindowAnchor anchor);
+  public abstract List<String> getIdsOn(@NotNull ToolWindowAnchor anchor);
 }
diff --git a/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerListener.java b/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerListener.java
index 72f5c981129b..79e769a4e016 100644
--- a/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerListener.java
+++ b/platform/platform-impl/src/com/intellij/openapi/wm/ex/ToolWindowManagerListener.java
@@ -15,16 +15,16 @@
  */
 package com.intellij.openapi.wm.ex;
 
-import com.intellij.openapi.wm.ToolWindowManager;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.EventListener;
 
 public interface ToolWindowManagerListener extends EventListener{
   /**
-   * Invoked when tool window with specified <code>id</code> is registered in <code>ToolWindowMnagare</code>.
+   * Invoked when tool window with specified <code>id</code> is registered in {@link ToolWindowManagerEx}.
    * @param id <code>id</code> of registered tool window.
    */
-  void toolWindowRegistered(String id);
+  void toolWindowRegistered(@NotNull String id);
 
   void stateChanged();
 }
\ No newline at end of file
diff --git a/platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowManagerImpl.java b/platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowManagerImpl.java
index eb653d04a749..440ab961135d 100644
--- a/platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowManagerImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowManagerImpl.java
@@ -293,11 +293,11 @@ public final class ToolWindowManagerImpl extends ToolWindowManagerEx implements
     execute(commandsList);
   }
 
-  public void addToolWindowManagerListener(final ToolWindowManagerListener l) {
+  public void addToolWindowManagerListener(@NotNull final ToolWindowManagerListener l) {
     myListenerList.add(ToolWindowManagerListener.class, l);
   }
 
-  public void removeToolWindowManagerListener(final ToolWindowManagerListener l) {
+  public void removeToolWindowManagerListener(@NotNull final ToolWindowManagerListener l) {
     myListenerList.remove(ToolWindowManagerListener.class, l);
   }
 
@@ -571,7 +571,7 @@ public final class ToolWindowManagerImpl extends ToolWindowManagerEx implements
     return myLayout.getInfo(id, true);
   }
 
-  public List<String> getIdsOn(final ToolWindowAnchor anchor) {
+  public List<String> getIdsOn(@NotNull final ToolWindowAnchor anchor) {
     return myLayout.getVisibleIdsOn(anchor, this);
   }
 
@@ -593,7 +593,7 @@ public final class ToolWindowManagerImpl extends ToolWindowManagerEx implements
     execute(commandList);
   }
 
-  public void hideToolWindow(final String id, final boolean hideSide) {
+  public void hideToolWindow(@NotNull final String id, final boolean hideSide) {
     hideToolWindow(id, hideSide, true);
   }
 
@@ -913,7 +913,7 @@ public final class ToolWindowManagerImpl extends ToolWindowManagerEx implements
     return myLayoutToRestoreLater;
   }
 
-  public void setLayout(final DesktopLayout layout) {
+  public void setLayout(@NotNull final DesktopLayout layout) {
     ApplicationManager.getApplication().assertIsDispatchThread();
     final ArrayList<FinalizableCommand> commandList = new ArrayList<FinalizableCommand>();
     // hide tool window that are invisible in new layout