Still leaks - can't find Project with focus when 4th project closed.

max_opened_projects/src/main/java/org/intellij/sdk/maxOpenPrj/ProjectCountingService.java

@@ -8,26 +8,36 @@ package org.intellij.sdk.maxOpenPrj;
  */
 public class ProjectCountingService {
   // Sets the maximum allowed number of opened projects.
-  private final int MAX_OPEN_PRJ_LIMIT = 3;
+  private final static int MAX_OPEN_PRJ_LIMIT = 3;
   // The count of open projects must always be >= 0
-  private int openProjectCount = 0;
+  private int myOpenProjectCount = 0;
 
    public void incrProjectCount() {
-    if (openProjectCount < 0) {
+    myOpenProjectCount = verifyProjectCount(myOpenProjectCount);
-      openProjectCount = 0;
+    myOpenProjectCount++;
-    }
-    openProjectCount++;
   }
 
   public void decrProjectCount() {
-    openProjectCount--;
+    myOpenProjectCount--;
-    if (openProjectCount < 0) {
+    myOpenProjectCount = verifyProjectCount(myOpenProjectCount);
-      openProjectCount = 0;
-    }
   }
 
   public boolean projectLimitExceeded() {
-    return openProjectCount > MAX_OPEN_PRJ_LIMIT;
+    return myOpenProjectCount > MAX_OPEN_PRJ_LIMIT;
+  }
+
+  public int getProjectCount() {
+    return myOpenProjectCount;
+  }
+
+  /**
+   * Anti-bugging to ensure the count of open projects never goes below zero.
+   * @param openProjectCount    The count of currently open projects
+   * @return                    0 if openProjectCount<0
+   *                            openProjectCount otherwise
+   */
+  private int verifyProjectCount(int openProjectCount) {
+    return openProjectCount<0 ? 0 : openProjectCount;
   }
 
 }

max_opened_projects/src/main/java/org/intellij/sdk/maxOpenPrj/ProjectOpenCloseListener.java

@@ -6,6 +6,7 @@ import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.components.ServiceManager;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.project.ProjectManagerListener;
+import com.intellij.openapi.ui.Messages;
 import org.intellij.sdk.utils.SdkBalloonHelper;
 import org.jetbrains.annotations.NotNull;
 
@@ -15,7 +16,7 @@ import org.jetbrains.annotations.NotNull;
  * Depends on org.intellij.sdk.utils.SdkBalloonHelper
  */
 public class ProjectOpenCloseListener implements ProjectManagerListener {
-  private static final String MAX_OPEN_PROJ_DISCLAIM = "This is an IntelliJ Platform SDK demo.<br><br>";
+  private static final String MAX_OPEN_PROJ_DISCLAIM = "\nThis is an IntelliJ Platform SDK demo message.\n\n";
 
   /**
    * Invoked on project open.

max_opened_projects/src/main/java/org/intellij/sdk/utils/SdkBalloonHelper.java

@@ -7,12 +7,17 @@ import com.intellij.openapi.project.ProjectManager;
 import com.intellij.openapi.ui.popup.Balloon;
 import com.intellij.openapi.ui.popup.JBPopupFactory;
 import com.intellij.openapi.util.Disposer;
+import com.intellij.openapi.wm.IdeFocusManager;
+import com.intellij.openapi.wm.IdeFrame;
 import com.intellij.openapi.wm.WindowManager;
+import com.intellij.openapi.wm.ex.WindowManagerEx;
+import com.intellij.openapi.wm.impl.WindowManagerImpl;
 import com.intellij.util.ui.UIUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import javax.swing.*;
+import java.awt.*;
 
 /**
  * This is just a utility class to help communicate the state of this plugin using Popups
@@ -27,23 +32,17 @@ public class SdkBalloonHelper {
 
   /**
    * This method constructs a Balloon-type popup and displays it in the middle of a Project window.
-   * Adds the Balloon to the Project's Disposer
    *
    * @param project The Project to host the Balloon.
    * @param title   A short description of what the Balloon conveys
-   * @param message Detailed information
+   * @param message Detailed information to display in HTML format
    */
   public void showBalloon(@Nullable Project project, @NotNull String title, @NotNull String message) {
-    // Ensure the project is open. If not, use the next youngest one to show the balloon
-    Project displayProject = findValidProject(project);
-    if (displayProject == null) return;
 
-    // Verify the place to put the balloon
+    // Create a component to hold the message in HTML format
-    JRootPane pane = getProjectRootPane(displayProject);
-    if (pane == null) return;
-
-    // Construct the balloon
     JLabel component = new JLabel("<html>" + message + "</html>");
+
+    // Construct the balloon using the component
     final Balloon balloon = JBPopupFactory.getInstance().createBalloonBuilder(component)
             .setShadow(true)
             .setHideOnClickOutside(true)
@@ -53,8 +52,18 @@ public class SdkBalloonHelper {
             .setFadeoutTime(6000)
             .createBalloon();
 
-    // Register it for disposal with the project that will display it
+    // Ensure the project is open. If not, find a visible Project to display the balloon.
-    Disposer.register(displayProject, balloon);
+    Project displayProject = findValidProject(project);
+    if (displayProject == null) return;
+
+    // Get the UI element to display the balloon
+    JRootPane pane = getProjectRootPane(displayProject);
+    if (pane == null) return;
+
+    // This is a special case for the message when closing a project.
+    // The closed project is no longer visible, so the next...
+    // Consequently register it for disposal with the project that will display it
+//    Disposer.register(displayProject, balloon);
 
     // Show the balloon in the middle of the project's window - it will disappear per the animation
     balloon.showInCenterOf(pane);
@@ -73,11 +82,43 @@ public class SdkBalloonHelper {
   @Nullable
   private Project findValidProject(@Nullable Project dodgyProject) {
     Project validProject = dodgyProject;
-    if ((validProject == null) || !validProject.isOpen()) {
+    if ((dodgyProject == null) || !dodgyProject.isOpen()) {
       // Find the next most-recently opened Project that is still open.
+      IdeFocusManager focusManager = IdeFocusManager.getGlobalInstance();
+      IdeFrame ideFrameFromFocusMgr = focusManager.getLastFocusedFrame();
+      Project focusMgrProject = ideFrameFromFocusMgr.getProject();
+      System.out.println("\n\nFocus Mgr last focused frame -> project: " + focusMgrProject.toString() + "\n");
+
+
+      final WindowManager windowManager = WindowManagerImpl.getInstance();
+      IdeFrame[] allIdeFrames = windowManager.getAllProjectFrames();
+      for (int i=0; i<allIdeFrames.length; i++) {
+        System.out.println(String.format("Win Mgr IdeFrames[%d] -> project: %s", i, allIdeFrames[i].getProject().toString()));
+      }
+
+      String outcome = String.format("\n\nUsing Win Mgr getIdeFrame(null): ");
+      String focusProject;
+      IdeFrame focusFrame = windowManager.getIdeFrame(null);
+      if (focusFrame != null) {
+        focusProject = String.format("%s", focusFrame.getProject().toString());
+      } else {
+        focusProject = String.format("No focused project found");
+      }
+      System.out.println(outcome + focusProject);
+
+      outcome = String.format("\n\nUsing Win Mgr findFrameFor(null): ");
+      focusFrame = ((WindowManagerImpl) windowManager).findFrameFor(null);
+      if (focusFrame != null) {
+        focusProject = String.format("%s", focusFrame.getProject().toString());
+      } else {
+        focusProject = String.format("No focused project found");
+      }
+      System.out.println(outcome + focusProject);
+
       ProjectManager projectManager = ProjectManager.getInstance();
       Project[] allProjects = projectManager.getOpenProjects();
       validProject = allProjects.length > 0 ? allProjects[allProjects.length - 1] : null;
+      System.out.println("\n\nProjMgr allProjects[last]: " + validProject.toString());
     }
     return validProject;
   }