refactoring static methods to Util class, avoiding memory leaks

svn changeset:2337/svn branch:trunk

src/com/itmill/toolkit/terminal/gwt/client/Util.java

@@ -1,18 +1,43 @@
 package com.itmill.toolkit.terminal.gwt.client;
 
+import com.google.gwt.user.client.Element;
+
 public class Util {
 
 	/**
 	 * Helper method for debugging purposes.
 	 * 
 	 * Stops execution on firefox browsers on a breakpoint.
-	 *
+	 * 
 	 */
 	public static native void browserDebugger() /*-{
 		if(window.console)
 			debugger;
 	}-*/;
 
+	/**
+	 * Detects if current browser is IE6. Use to isola
+	 * 
+	 * @return true if IE6
+	 */
+	public static native boolean isIE6() /*-{
+		var browser=$wnd.navigator.appName;
+		var version=parseFloat($wnd.navigator.appVersion);
+		if (browser=="Microsoft Internet Explorer" && (version < 7) ) {
+			return true;
+		}
+		return false;
+	}-*/;
 	
-	
+	/**
+	 * Nulls oncontextmenu function on given element. We need to manually clear
+	 * context menu events due bad browsers memory leaks, since we GWT don't
+	 * support them.
+	 * 
+	 * @param el
+	 */
+	public native static void removeContextMenuEvent(Element el) /*-{
+		el.oncontextmenu = null;
+	}-*/;
+
 }

src/com/itmill/toolkit/terminal/gwt/client/ui/ITree.java

@@ -15,6 +15,7 @@ import com.google.gwt.user.client.ui.TreeListener;
 import com.itmill.toolkit.terminal.gwt.client.ApplicationConnection;
 import com.itmill.toolkit.terminal.gwt.client.Paintable;
 import com.itmill.toolkit.terminal.gwt.client.UIDL;
+import com.itmill.toolkit.terminal.gwt.client.Util;
 
 /**
  * TODO dump GWT's Tree implementation and use Toolkit 4 style
@@ -170,6 +171,11 @@ public class ITree extends Tree implements Paintable {
 			attachContextMenuEvent(getElement());
 		}
 		
+		public void remove() {
+			Util.removeContextMenuEvent(getElement());
+			super.remove();
+		}
+
 		public void setSelected(boolean selected) {
 			if(!selected && !ITree.this.multiselect) {
 				this.setISelected(false);