Initial revision

git-svn-id: file:///fltk/svn/fltk/trunk@2 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 62 insertions, 0 deletions

diff --git a/src/Fl_add_idle.cxx b/src/Fl_add_idle.cxx
new file mode 100644
index 000000000..3b0e127c2
--- /dev/null
+++ b/src/Fl_add_idle.cxx
@@ -0,0 +1,62 @@
+// Fl_add_idle.C
+
+// 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()!
+}
+
+void Fl::add_idle(void (*cb)(void*), 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;
+    p->next = first;
+    first = p;
+  } else {
+    first = last = p;
+    p->next = p;
+    set_idle(call_idle);
+  }
+}
+
+void Fl::remove_idle(void (*cb)(void*), 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;
+}