Clipboard will persist if owner window is hidden (STR #1019)

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.1@4565 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

CHANGES

@@ -3,6 +3,7 @@ CHANGES IN FLTK 1.1.7
 	- Documentation fixes (STR #571, STR #648, STR #692, STR
 	  #730, STR #744, STR #745, STR #931, STR #942, STR #960,
 	  STR #969)
+	- Clipboard will persist if owner window is hidden (STR #1019)
 	- Fixed handling of Win32 Device Contexts (STR #1007)
 	- Fixed C Plus Plus style comments in C files (STR #997)
 	- Fixed signednes of scanf argument (STR #996)

src/Fl.cxx

@@ -849,6 +849,16 @@ void Fl_Window::hide() {
   handle(FL_HIDE);
 
 #ifdef WIN32
+  // this little trick keeps the current clipboard alive, even if we are about
+  // to destroy the window that owns the selection.
+  if (GetClipboardOwner()==ip->xid) {
+    Fl_Window *w1 = Fl::first_window();
+    if (w1 && OpenClipboard(fl_xid(w1))) {
+      EmptyClipboard();
+      SetClipboardData(CF_TEXT, NULL);
+      CloseClipboard();
+    }
+  }
   // Send a message to myself so that I'll get out of the event loop...
   PostMessage(ip->xid, WM_APP, 0, 0);
   if (ip->private_dc) fl_release_dc(ip->xid, ip->private_dc);