1 files changed, 86 insertions, 0 deletions
diff --git a/xml/impl/src/org/jetbrains/notification/SingletonNotificationManager.java b/xml/impl/src/org/jetbrains/notification/SingletonNotificationManager.java
new file mode 100644
index 000000000000..4ea4a10dcf85
--- /dev/null
+++ b/xml/impl/src/org/jetbrains/notification/SingletonNotificationManager.java
@@ -0,0 +1,86 @@
+package org.jetbrains.notification;
+
+import com.intellij.notification.*;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.wm.ToolWindowManager;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+public final class SingletonNotificationManager {
+  private final AtomicReference<Notification> notification = new AtomicReference<Notification>();
+
+  private final NotificationGroup group;
+  private final NotificationType type;
+  @Nullable
+  private final NotificationListener listener;
+
+  private Runnable expiredListener;
+
+  public SingletonNotificationManager(@NotNull String groupId, @NotNull NotificationType type, @Nullable NotificationListener listener) {
+    this(new NotificationGroup(groupId, NotificationDisplayType.STICKY_BALLOON, true), type, listener);
+  }
+
+  public SingletonNotificationManager(@NotNull NotificationGroup group, @NotNull NotificationType type, @Nullable NotificationListener listener) {
+    this.group = group;
+    this.type = type;
+    this.listener = listener;
+  }
+
+  public boolean notify(@NotNull String title, @NotNull String content) {
+    return notify(title, content, null);
+  }
+
+  public boolean notify(@NotNull String title, @NotNull String content, @Nullable Project project) {
+    return notify(title, content, listener, project);
+  }
+
+  public boolean notify(@NotNull String content, @Nullable Project project) {
+    return notify("", content, listener, project);
+  }
+
+  public boolean notify(@NotNull String title,
+                        @NotNull String content,
+                        @Nullable NotificationListener listener,
+                        @Nullable Project project) {
+    Notification oldNotification = notification.get();
+    // !oldNotification.isExpired() is not enough - notification could be closed, but not expired
+    if (oldNotification != null) {
+      if (!oldNotification.isExpired() && (oldNotification.getBalloon() != null ||
+                                           (project != null &&
+                                            group.getDisplayType() == NotificationDisplayType.TOOL_WINDOW &&
+                                            ToolWindowManager.getInstance(project).getToolWindowBalloon(group.getToolWindowId()) != null))) {
+        return false;
+      }
+      oldNotification.whenExpired(null);
+      oldNotification.expire();
+    }
+
+    if (expiredListener == null) {
+      expiredListener = new Runnable() {
+        @Override
+        public void run() {
+          Notification currentNotification = notification.get();
+          if (currentNotification != null && currentNotification.isExpired()) {
+            notification.compareAndSet(currentNotification, null);
+          }
+        }
+      };
+    }
+
+    Notification newNotification = group.createNotification(title, content, type, listener);
+    newNotification.whenExpired(expiredListener);
+    notification.set(newNotification);
+    newNotification.notify(project);
+    return true;
+  }
+
+  public void clear() {
+    Notification oldNotification = notification.getAndSet(null);
+    if (oldNotification != null) {
+      oldNotification.whenExpired(null);
+      oldNotification.expire();
+    }
+  }
+}
+\ No newline at end of file