first rev

direct/src/showbase/DelayedCallback.py

@@ -0,0 +1,31 @@
+from direct.task.Task import Task
+
+class DelayedCallback:
+    """ waits N frames and then calls a callback """
+    def __init__(self, frames, callback, cancelFunc=None):
+        # checkFunc is optional; called every frame, if returns True, FrameDelay is cancelled
+        # and callback is not called
+        self._frames = frames
+        self._callback = callback
+        self._cancelFunc = cancelFunc
+        self._taskName = uniqueName(self.__class__.__name__)
+        self._startTask()
+    def destroy(self):
+        self._stopTask()
+    def finish(self):
+        self._callback()
+        self.destroy()
+    def _startTask(self):
+        taskMgr.add(self._frameTask, self._taskName)
+        self._counter = 0
+    def _stopTask(self):
+        taskMgr.remove(self._taskName)
+    def _frameTask(self, task=None):
+        if self._cancelFunc():
+            self.destroy()
+            return Task.done
+        self._counter += 1
+        if self._counter >= self._frames:
+            self.finish()
+            return Task.done
+        return Task.cont