diff --git a/platform/platform-impl/src/com/intellij/openapi/wm/impl/FocusManagerImpl.java b/platform/platform-impl/src/com/intellij/openapi/wm/impl/FocusManagerImpl.java
index 36aeab68f038..ecb65b6a575a 100644
--- a/platform/platform-impl/src/com/intellij/openapi/wm/impl/FocusManagerImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/wm/impl/FocusManagerImpl.java
@@ -29,6 +29,7 @@ import com.intellij.openapi.application.ModalityState;
 import com.intellij.openapi.application.ex.ApplicationManagerEx;
 import com.intellij.openapi.components.impl.ServiceManagerImpl;
 import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.openapi.project.Project;
 import com.intellij.openapi.ui.popup.JBPopup;
 import com.intellij.openapi.util.*;
 import com.intellij.openapi.util.registry.Registry;
@@ -1071,32 +1072,77 @@ public class FocusManagerImpl extends IdeFocusManager implements Disposable {
   private class AppListener extends ApplicationActivationListener.Adapter {
     @Override
     public void applicationActivated(final IdeFrame ideFrame) {
+
+      if (Registry.is("trace.focus.on.app.activation")) {
+        LOG.info("Application is activating");
+      }
+
       final FocusCommand cmd = myFocusCommandOnAppActivation;
       ActionCallback callback = myCallbackOnActivation;
       myFocusCommandOnAppActivation = null;
       myCallbackOnActivation = null;
 
       if (cmd != null) {
+        if (Registry.is("trace.focus.on.app.activation")) {
+          LOG.info("Use focus command that we have saved on deactivation");
+          LOG.info(cmd.getAllocation());
+        }
         requestFocus(cmd, true).notify(callback);
       } else {
-        focusLastFocusedComponent(ideFrame);
+        Component lastFocusedComponent = focusLastFocusedComponent(ideFrame);
+        if (Registry.is("trace.focus.on.app.activation")) {
+          final Project project = ideFrame.getProject();
+          if (project != null) {
+            LOG.info("Use last focused component because we do not have a focus command");
+            LOG.info("Component in [" + project.getName() + "]: " + (lastFocusedComponent != null ? lastFocusedComponent.getClass().getName() : null));
+          }
+        }
       }
     }
 
     @Override
     public void applicationDeactivated(IdeFrame ideFrame) {
+
+      if (Registry.is("trace.focus.on.app.activation")) {
+        LOG.info("Application is deactivating");
+      }
+
       final Component owner = KeyboardFocusManager.getCurrentKeyboardFocusManager().getFocusOwner();
       Component parent = UIUtil.findUltimateParent(owner);
 
       if (parent == ideFrame) {
         myLastFocusedAtDeactivation.put(ideFrame, owner);
+        if (Registry.is("trace.focus.on.app.activation")) {
+          final Project project = ideFrame.getProject();
+          String projectName = null;
+          if (project != null) {
+            projectName = project.getName();
+          }
+          LOG.info("The next component is set as ths last focused for [" + projectName +"]");
+        }
+      } else {
+        if (Registry.is("trace.focus.on.app.activation")) {
+          if (owner != null) {
+            final Project project = ideFrame.getProject();
+            String projectName = null;
+            if (project != null) {
+              projectName = project.getName();
+            }
+            LOG.error("The last focused component " +
+                      (owner != null ? owner.getClass().getName() : null) +
+                      " is not in the deactivating frame [" + projectName + "]. Skip it.");
+          } else {
+            LOG.info("The last focused component is null");
+          }
+        }
       }
     }
 
-    private void focusLastFocusedComponent(IdeFrame ideFrame) {
+    private Component focusLastFocusedComponent(IdeFrame ideFrame) {
       final KeyboardFocusManager mgr = KeyboardFocusManager.getCurrentKeyboardFocusManager();
+      Component c = null;
       if (mgr.getFocusOwner() == null) {
-        Component c = getComponent(myLastFocusedAtDeactivation, ideFrame);
+        c = getComponent(myLastFocusedAtDeactivation, ideFrame);
         if (c == null || !c.isShowing()) {
           c = getComponent(myLastFocusedAtDeactivation, ideFrame);
         }
@@ -1119,6 +1165,7 @@ public class FocusManagerImpl extends IdeFocusManager implements Disposable {
       }
 
       myLastFocusedAtDeactivation.remove(ideFrame);
+      return c;
     }
   }
 
diff --git a/platform/util/resources/misc/registry.properties b/platform/util/resources/misc/registry.properties
index e68c86255fc1..199ee3e4b330 100644
--- a/platform/util/resources/misc/registry.properties
+++ b/platform/util/resources/misc/registry.properties
@@ -658,4 +658,8 @@ ide.mac.new.color.picker=false
 
 trace.clipboard.events=false
 trace.clipboard.events.description=Enable detection and logging of OS notifications about external clipboard changes
-trace.clipboard.events.restartRequired=true
\ No newline at end of file
+trace.clipboard.events.restartRequired=true
+
+trace.focus.on.app.activation=false
+trace.focus.on.app.activation.description=Focus tracing on application activation and deactivation
+trace.focus.on.app.restartRequired=false