From 5383aeb3e29892fbc4e32b8ca7b6d240cf520d1c Mon Sep 17 00:00:00 2001
From: Sergey Malenkov <sergey.malenkov@jetbrains.com>
Date: Mon, 25 Jul 2016 20:05:32 +0300
Subject: [PATCH] IDEA-152049 Project view collapses in unpinned mode after
 some time and changes in editor restore tree state on activation and save it
 on deactivation

---
 .../impl/AbstractProjectViewPSIPane.java      | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/platform/lang-impl/src/com/intellij/ide/projectView/impl/AbstractProjectViewPSIPane.java b/platform/lang-impl/src/com/intellij/ide/projectView/impl/AbstractProjectViewPSIPane.java
index e426c5ce9357..f3c44ba401e4 100644
--- a/platform/lang-impl/src/com/intellij/ide/projectView/impl/AbstractProjectViewPSIPane.java
+++ b/platform/lang-impl/src/com/intellij/ide/projectView/impl/AbstractProjectViewPSIPane.java
@@ -48,6 +48,8 @@ import com.intellij.util.OpenSourceUtil;
 import com.intellij.util.ui.UIUtil;
 import com.intellij.util.ui.accessibility.ScreenReader;
 import com.intellij.util.ui.tree.TreeUtil;
+import com.intellij.util.ui.update.Activatable;
+import com.intellij.util.ui.update.UiNotifyConnector;
 import org.jetbrains.annotations.NotNull;
 
 import javax.swing.*;
@@ -118,6 +120,25 @@ public abstract class AbstractProjectViewPSIPane extends AbstractProjectViewPane
     installComparator();
     initTree();
 
+    Disposer.register(getTreeBuilder(), new UiNotifyConnector(myTree, new Activatable() {
+      private boolean showing;
+
+      @Override
+      public void showNotify() {
+        if (!showing) {
+          showing = true;
+          restoreExpandedPaths();
+        }
+      }
+
+      @Override
+      public void hideNotify() {
+        if (showing) {
+          showing = false;
+          saveExpandedPaths();
+        }
+      }
+    }));
     return myComponent;
   }