[libcamera-devel,v2,12/14] py: cam.py: Use new events support
diff mbox series

Message ID 20220629070416.17550-13-tomi.valkeinen@ideasonboard.com
State Superseded
Headers show
Series
  • Python bindings event handling
Related show

Commit Message

Tomi Valkeinen June 29, 2022, 7:04 a.m. UTC 
Convert cam.py to use the new event dispatching. In addition to handling
the request-completed event, handle also disconnect, camera-added and
camera-removed events (which only do a simple print).

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 src/py/cam/cam.py | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

Patch
diff mbox series 

diff --git a/src/py/cam/cam.py b/src/py/cam/cam.py
index 6b6b678b..17a4268b 100755
--- a/src/py/cam/cam.py
+++ b/src/py/cam/cam.py
@@ -230,11 +230,7 @@  class CaptureState:
     # Called from renderer when there is a libcamera event
     def event_handler(self):
         try:
-            reqs = self.cm.get_ready_requests()
-
-            for req in reqs:
-                ctx = next(ctx for ctx in self.contexts if ctx.idx == req.cookie)
-                self.__request_handler(ctx, req)
+            self.cm.dispatch_events()
 
             running = any(ctx.reqs_completed < ctx.opt_capture for ctx in self.contexts)
             return running
@@ -242,7 +238,9 @@  class CaptureState:
             traceback.print_exc()
             return False
 
-    def __request_handler(self, ctx, req):
+    def __request_handler(self, cam, req):
+        ctx = next(ctx for ctx in self.contexts if ctx.camera == cam)
+
         if req.status != libcam.Request.Status.Complete:
             raise Exception('{}: Request failed: {}'.format(ctx.id, req.status))
 
@@ -297,6 +295,9 @@  class CaptureState:
             ctx.camera.queue_request(req)
             ctx.reqs_queued += 1
 
+    def __disconnect_handler(self, cam):
+        print(f'Camera {cam} disconnected')
+
     def __capture_init(self):
         for ctx in self.contexts:
             ctx.acquire()
@@ -310,6 +311,15 @@  class CaptureState:
         for ctx in self.contexts:
             ctx.create_requests()
 
+        for ctx in self.contexts:
+            # These cause circular dependencies:
+            # The callback in the camera points to CaptureState.
+            # The CaptureState points to the camera.
+            # This can be solved by setting the callbacks to None after stopping
+            # or using lambdas here and weakref.WeakMethod.
+            ctx.camera.request_completed = self.__request_handler
+            ctx.camera.disconnected = self.__disconnect_handler
+
     def __capture_start(self):
         for ctx in self.contexts:
             ctx.start()
@@ -321,6 +331,10 @@  class CaptureState:
         for ctx in self.contexts:
             ctx.stop()
 
+        for ctx in self.contexts:
+            ctx.camera.request_completed = None
+            ctx.camera.disconnected = None
+
         for ctx in self.contexts:
             ctx.release()
 
@@ -389,6 +403,9 @@  def main():
 
     cm = libcam.CameraManager.singleton()
 
+    cm.camera_added = lambda c: print('Camera added:', c)
+    cm.camera_removed = lambda c: print('Camera removed:', c)
+
     if args.list:
         do_cmd_list(cm)
 
@@ -447,6 +464,10 @@  def main():
 
         state.do_cmd_capture()
 
+        # This is not strictly needed, but it helps to do a proper cleanup and
+        # so makes it easier to use memory leak detectors.
+        cm.discard_events()
+
     return 0