From 57af3e86327a40232216d20256eee155de1145aa Mon Sep 17 00:00:00 2001
From: Mathieu Baudier <mbaudier@argeo.org>
Date: Fri, 15 Dec 2023 07:50:27 +0100
Subject: [PATCH] Use weak references to UIs and regular clean-up

---
 .../src/org/argeo/app/swt/ux/SwtArgeoApp.java | 59 +++++++++++--------
 1 file changed, 35 insertions(+), 24 deletions(-)

diff --git a/swt/org.argeo.app.swt/src/org/argeo/app/swt/ux/SwtArgeoApp.java b/swt/org.argeo.app.swt/src/org/argeo/app/swt/ux/SwtArgeoApp.java
index a81c33e..ef3bb8c 100644
--- a/swt/org.argeo.app.swt/src/org/argeo/app/swt/ux/SwtArgeoApp.java
+++ b/swt/org.argeo.app.swt/src/org/argeo/app/swt/ux/SwtArgeoApp.java
@@ -2,6 +2,7 @@ package org.argeo.app.swt.ux;
 
 import static org.argeo.api.cms.ux.CmsView.CMS_VIEW_UID_PROPERTY;
 
+import java.lang.ref.WeakReference;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -10,6 +11,8 @@ import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
+import java.util.Timer;
+import java.util.TimerTask;
 import java.util.TreeMap;
 import java.util.TreeSet;
 
@@ -91,7 +94,8 @@ public class SwtArgeoApp extends AbstractArgeoApp implements CmsEventSubscriber
 //	private CmsUserManager cmsUserManager;
 
 	// TODO make more optimal or via CmsSession/CmsView
-	private Map<String, SwtAppUi> managedUis = Collections.synchronizedMap(new HashMap<>());
+	private static Timer janitorTimer = new Timer(true);
+	private Map<String, WeakReference<SwtAppUi>> managedUis = new HashMap<>();
 
 	// ACR
 	private ContentRepository contentRepository;
@@ -104,9 +108,6 @@ public class SwtArgeoApp extends AbstractArgeoApp implements CmsEventSubscriber
 			getCmsContext().getCmsEventBus().addEventSubscriber(event.topic(), this);
 		}
 
-		if (log.isDebugEnabled())
-			log.info("Argeo Suite App started");
-
 		if (properties.containsKey(DEFAULT_UI_NAME_PROPERTY))
 			defaultUiName = LangUtils.get(properties, DEFAULT_UI_NAME_PROPERTY);
 		if (properties.containsKey(DEFAULT_THEME_ID_PROPERTY))
@@ -126,25 +127,39 @@ public class SwtArgeoApp extends AbstractArgeoApp implements CmsEventSubscriber
 			// TODO does it make sense to accept that?
 			appPid = "<unknown>";
 		}
+		if (log.isDebugEnabled())
+			log.info("Argeo Suite App " + appPid + " started");
 
 		Objects.requireNonNull(contentRepository, "Content repository must be provided");
 		Objects.requireNonNull(appUserState, "App user state must be provided");
-//		if (pidPrefix == null)
-//			throw new IllegalArgumentException("PID prefix must be set.");
-
-//		headerPid = pidPrefix + "header";
-//		footerPid = pidPrefix + "footer";
-//		leadPanePid = pidPrefix + "leadPane";
-//		adminLeadPanePid = pidPrefix + "adminLeadPane";
-//		loginScreenPid = pidPrefix + "loginScreen";
+		
+		long janitorPeriod = 12 * 60 * 60 * 1000;// 12h
+		janitorTimer.schedule(new TimerTask() {
+
+			@Override
+			public void run() {
+				refs: for (WeakReference<SwtAppUi> uiRef : managedUis.values()) {
+					SwtAppUi ui = uiRef.get();
+					if (ui == null)
+						continue refs;
+					ui.disposeIfTimedout();
+				}
+				if (log.isDebugEnabled())
+					log.debug(managedUis.size() + " UIs being managed by app " + appPid);
+			}
+		}, janitorPeriod, janitorPeriod);
 
 	}
 
 	public void stop(Map<String, Object> properties) {
-		for (SwtAppUi ui : managedUis.values())
+		refs: for (WeakReference<SwtAppUi> uiRef : managedUis.values()) {
+			SwtAppUi ui = uiRef.get();
+			if (ui == null)
+				continue refs;
 			if (!ui.isDisposed() && !ui.getDisplay().isDisposed()) {
 				ui.getDisplay().syncExec(() -> ui.dispose());
 			}
+		}
 		managedUis.clear();
 		if (log.isDebugEnabled())
 			log.info("Argeo Suite App stopped");
@@ -171,9 +186,11 @@ public class SwtArgeoApp extends AbstractArgeoApp implements CmsEventSubscriber
 		if (theme != null)
 			CmsSwtUtils.registerCmsTheme(uiParent.getShell(), theme);
 		SwtAppUi argeoSuiteUi = new SwtAppUi(uiParent, SWT.INHERIT_DEFAULT);
+		// TODO make timeout configurable
+		argeoSuiteUi.setUiTimeout(12 * 60 * 60 * 1000);// 12 hours
 		String uid = cmsView.getUid();
-		managedUis.put(uid, argeoSuiteUi);
 		argeoSuiteUi.addDisposeListener(new CleanUpUi(uid));
+		managedUis.put(uid, new WeakReference<>(argeoSuiteUi));
 		return argeoSuiteUi;
 	}
 
@@ -590,7 +607,10 @@ public class SwtArgeoApp extends AbstractArgeoApp implements CmsEventSubscriber
 	}
 
 	private SwtAppUi getRelatedUi(Map<String, Object> eventProperties) {
-		return managedUis.get(get(eventProperties, CMS_VIEW_UID_PROPERTY));
+		WeakReference<SwtAppUi> uiRef = managedUis.get(get(eventProperties, CMS_VIEW_UID_PROPERTY));
+		if (uiRef == null)
+			return null;
+		return uiRef.get();
 	}
 
 	public static String get(Map<String, Object> eventProperties, String key) {
@@ -672,14 +692,6 @@ public class SwtArgeoApp extends AbstractArgeoApp implements CmsEventSubscriber
 		}
 	}
 
-//	public void setCmsUserManager(CmsUserManager cmsUserManager) {
-//		this.cmsUserManager = cmsUserManager;
-//	}
-
-//	protected ContentRepository getContentRepository() {
-//		return contentRepository;
-//	}
-
 	public void setContentRepository(ContentRepository contentRepository) {
 		this.contentRepository = contentRepository;
 	}
@@ -697,7 +709,6 @@ public class SwtArgeoApp extends AbstractArgeoApp implements CmsEventSubscriber
 		final String uid;
 
 		public CleanUpUi(String uid) {
-			super();
 			this.uid = uid;
 		}
 
-- 
2.30.2