[cp-patches] FYI: Getting the system clipboard in javax/swing/TransferHandler

[Meskauskas Audrius]

The private method getClipboard in TransferHandler was always returning 
the VM local clipboard and not the system clipboard in the case when the 
security manager is not installed (typical case).

With this patch, I am able to paste the external data from the system 
clipboard into the text field if manually calling the .paste() method 
(test case for PR 24733 
<http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24733>). Ctrl-V still does 
not show any signs of life.

PR 24733 <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24733>
2005-11-13  Audrius Meskauskas  <address@hidden>

* javax/swing/TransferHandler.java (getClipboard): Rewritten.

Index: javax/swing/TransferHandler.java
===================================================================
RCS file: /cvsroot/classpath/classpath/javax/swing/TransferHandler.java,v
retrieving revision 1.10
diff -u -r1.10 TransferHandler.java
--- javax/swing/TransferHandler.java    19 Oct 2005 15:45:05 -0000      1.10
+++ javax/swing/TransferHandler.java    13 Nov 2005 19:19:44 -0000
@@ -75,30 +75,38 @@
        }
     }
   
+    /**
+     * Get the system cliboard. If not available, create and return the 
VM-local
+     * clipboard.
+     * 
+     * @param component a component, used to get the toolkit.
+     * @return the clipboard
+     */
     private static Clipboard getClipboard(JComponent component)
     {
-      SecurityManager sm = System.getSecurityManager();
-    
-      if (sm != null)
-       {
-         try
-           {
-             sm.checkSystemClipboardAccess();
+      // Avoid throwing exception if the system clipboard access failed
+      // in the past.
+      if (clipboard != null)
+        return clipboard;
+      else
+        {
+          try
+            {
+              SecurityManager sm = System.getSecurityManager();
+              if (sm != null)
+                sm.checkSystemClipboardAccess();
 
-             // We may access system clipboard.
-             return component.getToolkit().getSystemClipboard();
-           }
-         catch (SecurityException e)
-           {
-             // We may not access system clipboard.
-           }
-       }
-    
-      // Create VM-local clipboard if non exists yet.
-      if (clipboard == null)
-        clipboard = new Clipboard("Clipboard");
-
-      return clipboard;
+              // We may access system clipboard.
+              return component.getToolkit().getSystemClipboard();
+            }
+          catch (Exception e)
+            {
+              // We may not access system clipboard.
+              // Create VM-local clipboard if none exists yet.
+              clipboard = new Clipboard("Clipboard");
+              return clipboard;
+            }
+        }
     }
   }