Include a stripped-down version of FLTK in tree and add a USE_INCLUDED_FLTK option to build against it.


git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@4603 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/common/fltk/src/Fl_add_idle.cxx b/common/fltk/src/Fl_add_idle.cxx
new file mode 100644
index 0000000..6059ae1
--- /dev/null
+++ b/common/fltk/src/Fl_add_idle.cxx
@@ -0,0 +1,123 @@
+//
+// "$Id: Fl_add_idle.cxx 7903 2010-11-28 21:06:39Z matt $"
+//
+// Idle routine support for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 1998-2010 by Bill Spitzak and others.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Library General Public
+// License as published by the Free Software Foundation; either
+// version 2 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Library General Public License for more details.
+//
+// You should have received a copy of the GNU Library General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+// USA.
+//
+// Please report all bugs and problems on the following page:
+//
+//     http://www.fltk.org/str.php
+//
+
+// Allows you to manage an arbitrary set of idle() callbacks.
+// Replaces the older set_idle() call (which is used to implement this)
+
+#include <FL/Fl.H>
+
+struct idle_cb {
+  void (*cb)(void*);
+  void* data;
+  idle_cb *next;
+};
+
+// the callbacks are stored linked in a ring.  last points at the one
+// just called, first at the next to call.  last->next == first.
+
+static idle_cb* first;
+static idle_cb* last;
+static idle_cb* freelist;
+
+static void call_idle() {
+  idle_cb* p = first;
+  last = p; first = p->next;
+  p->cb(p->data); // this may call add_idle() or remove_idle()!
+}
+
+/**
+  Adds a callback function that is called every time by Fl::wait() and also
+  makes it act as though the timeout is zero (this makes Fl::wait() return
+  immediately, so if it is in a loop it is called repeatedly, and thus the
+  idle fucntion is called repeatedly).  The idle function can be used to get
+  background processing done.
+    
+  You can have multiple idle callbacks. To remove an idle callback use
+  Fl::remove_idle().
+    
+  Fl::wait() and Fl::check() call idle callbacks, but Fl::ready() does not.
+    
+  The idle callback can call any FLTK functions, including Fl::wait(),
+  Fl::check(), and Fl::ready().
+
+  FLTK will not recursively call the idle callback.
+*/
+void Fl::add_idle(Fl_Idle_Handler cb, void* data) {
+  idle_cb* p = freelist;
+  if (p) freelist = p->next;
+  else p = new idle_cb;
+  p->cb = cb;
+  p->data = data;
+  if (first) {
+    last->next = p;
+    last = p;
+    p->next = first;
+  } else {
+    first = last = p;
+    p->next = p;
+    set_idle(call_idle);
+  }
+}
+
+/**
+  Returns true if the specified idle callback is currently installed.
+*/
+int Fl::has_idle(Fl_Idle_Handler cb, void* data) {
+  idle_cb* p = first;
+  if (!p) return 0;
+  for (;; p = p->next) {
+    if (p->cb == cb && p->data == data) return 1;
+    if (p==last) return 0;
+  }
+}
+
+/**
+  Removes the specified idle callback, if it is installed.
+*/
+void Fl::remove_idle(Fl_Idle_Handler cb, void* data) {
+  idle_cb* p = first;
+  if (!p) return;
+  idle_cb* l = last;
+  for (;; p = p->next) {
+    if (p->cb == cb && p->data == data) break;
+    if (p==last) return; // not found
+    l = p;
+  }
+  if (l == p) { // only one
+    first = last = 0;
+    set_idle(0);
+  } else {
+    last = l;
+    first = l->next = p->next;
+  }
+  p->next = freelist;
+  freelist = p;
+}
+
+//
+// End of "$Id: Fl_add_idle.cxx 7903 2010-11-28 21:06:39Z matt $".
+//