IDEA-88507 Throwable at ToolWindowManagerImpl.notifyByBalloon() from notification

platform/platform-api/src/com/intellij/openapi/wm/ToolWindowManager.java

@@ -27,6 +27,8 @@ import javax.swing.event.HyperlinkListener;
 
 public abstract class ToolWindowManager {
 
+  public abstract boolean canShowNotification(@NotNull String toolWindowId);
+
   public static ToolWindowManager getInstance(Project project){
     return project.getComponent(ToolWindowManager.class);
   }

platform/platform-impl/src/com/intellij/notification/impl/NotificationsManagerImpl.java

@@ -46,7 +46,6 @@ import javax.swing.event.HyperlinkEvent;
 import javax.swing.event.HyperlinkListener;
 import java.awt.*;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 
 /**
@@ -142,7 +141,7 @@ public class NotificationsManagerImpl extends NotificationsManager implements No
     NotificationDisplayType type = settings.getDisplayType();
     String toolWindowId = NotificationsConfigurationImpl.getNotificationsConfigurationImpl().getToolWindowId(groupId);
     if (type == NotificationDisplayType.TOOL_WINDOW &&
-        (toolWindowId == null || project == null || !Arrays.asList(ToolWindowManager.getInstance(project).getToolWindowIds()).contains(toolWindowId))) {
+        (toolWindowId == null || project == null || !ToolWindowManager.getInstance(project).canShowNotification(toolWindowId))) {
       type = NotificationDisplayType.BALLOON;
     }
 

platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowHeadlessManagerImpl.java

@@ -56,6 +56,10 @@ import java.util.List;
 
 @SuppressWarnings({"ConstantConditions"})
 public class ToolWindowHeadlessManagerImpl extends ToolWindowManagerEx {
+  @Override
+  public boolean canShowNotification(@NotNull String toolWindowId) {
+    return false;
+  }
 
   @Override
   public void notifyByBalloon(@NotNull final String toolWindowId, @NotNull final MessageType type, @NotNull final String htmlBody) {

platform/platform-impl/src/com/intellij/openapi/wm/impl/ToolWindowManagerImpl.java

@@ -1288,6 +1288,16 @@ public final class ToolWindowManagerImpl extends ToolWindowManagerEx implements
     return IdeFocusManager.getInstance(myProject);
   }
 
+  @Override
+  public boolean canShowNotification(@NotNull final String toolWindowId) {
+    if (!Arrays.asList(getToolWindowIds()).contains(toolWindowId)) {
+      return false;
+    }
+    final Stripe stripe = myToolWindowsPane.getStripeFor(toolWindowId);
+    return stripe.getButtonFor(toolWindowId) != null;
+
+  }
+
   @Override
   public void notifyByBalloon(@NotNull final String toolWindowId, @NotNull final MessageType type, @NotNull final String htmlBody) {
     notifyByBalloon(toolWindowId, type, htmlBody, null, null);

platform/testFramework/src/com/intellij/mock/Mock.java

@@ -531,6 +531,12 @@ public class Mock {
   }
 
   public static class MyToolWindowManager extends ToolWindowManager {
+
+    @Override
+    public boolean canShowNotification(@NotNull String toolWindowId) {
+      return false;
+    }
+
     @Override
     public ToolWindow registerToolWindow(@NotNull String id, @NotNull JComponent component, @NotNull ToolWindowAnchor anchor) {
       return null;