背景：我想使用 PySide2 实现一个 GUI 来控制一堆客户端（通过 RPC 调用与“服务器”控制硬件，如电机、相机等）。
以前的方法：通常，我要做的是创建我的 GUI 并将 UI 信号连接到客户端插槽，反之亦然。这对于更简单的应用程序非常有效。
问题：我希望我的 GUI 能够正确地表示允许的对客户端的调用。最简单的例子：执行后client1.doXY()我想禁用执行该命令的按钮并仅在doZY()完成后重新激活它。虽然使用上述方法完全可以做到这一点，但当事情变得更复杂时会感觉不对：例如，当 GUI 元素依赖于多个客户端的状态时。
方法：因此，我认为使用有限状态机作为客户端和 GUI 之间的中间层是一个好主意，并且遇到了pytransitions，这看起来很有希望。但是，我正在努力寻找结合这两个世界的正确方法。
问题：
一般来说，这是拥有这样一个层的有效设计方法吗？
特别是如工作代码示例中所示，我必须将客户端移动到单独的线程以避免在客户端执行阻塞调用时 GUI 冻结。虽然我的代码工作正常，但它需要一些开销来创建额外的 qt 信号来连接
ClientState和Client对象。这可以更优雅地完成（即没有额外的 xy_requested 信号，但以某种方式直接调用仍然调用线程中的ClientState函数而不是主线程的函数？ClientClientClient
工作示例：
代码：
import io
import logging
from time import sleep
import numpy as np
from PySide2 import QtSvg, QtWidgets
from PySide2.QtCore import Signal, Slot, QObject, QThread
from PySide2.QtWidgets import QWidget, QPushButton, QApplication
from transitions.extensions import GraphMachine
logging.basicConfig(level=logging.DEBUG)
class Client(QObject):
# Client signals
sig_move_done = Signal()
sig_disconnected = Signal()
sig_connected = Signal()
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
@Slot(int)
def client_move(self, dest):
print(f'Client moving to {dest}...')
sleep(3) # some blocking function
if np.random.rand() < 0.5:
print("Error occurred during movement...")
self.sig_disconnected.emit()
else:
print("Movement done...")
self.sig_move_done.emit()
@Slot()
def client_disconnect(self):
# do something then... on success do:
self.sig_disconnected.emit()
@Slot()
def client_connect(self):
# do something ... on success do:
self.sig_connected.emit()
# define states, transitions and extra args for transitions state machine:
states = ['ready', 'moving', 'unknown']
transitions = [
{'trigger': 'move', 'source': 'ready', 'dest': 'moving'},
{'trigger': 'stopped', 'source': 'moving', 'dest': 'ready'},
{'trigger': 'disconnect_', 'source': ['ready', 'moving'], 'dest': 'unknown'},
{'trigger': 'error', 'source': ['ready', 'moving'], 'dest': 'unknown'},
{'trigger': 'connect_', 'source': 'unknown', 'dest': 'ready'}
]
extra_args = dict(initial='unknown', title='Simple state machine',
show_conditions=True, show_state_attributes=True)
class ClientState(QObject):
# machine signals
sig_update_available = Signal()
sig_move_requested = Signal(int) # can this be avoided ? see self.on_enter_moving
sig_connect_requested = Signal() # can this be avoided ?
def __init__(self, client, *args, **kwargs):
super().__init__(*args, **kwargs)
self.client = client
# move client to seperate thread
self.worker_thread = QThread()
self.client.moveToThread(self.worker_thread)
self.worker_thread.start()
self.machine = GraphMachine(model=self, states=states, transitions=transitions,
show_auto_transitions=False, **extra_args, after_state_change="update_available",
send_event=True)
# connecting Client signals to state machine triggers
self.client.sig_disconnected.connect(self.disconnect_)
self.client.sig_connected.connect(self.connect_)
self.client.sig_move_done.connect(self.stopped)
self.update_available = lambda *args, **kwargs: self.sig_update_available.emit()
# can this be avoided ? see self.on_enter_moving
self.sig_move_requested.connect(self.client.client_move)
self.sig_connect_requested.connect(self.client.client_connect)
def on_enter_moving(self, event):
print(event.kwargs)
dest = event.kwargs.get('dest', 0)
# calling self.client_move() directly will cause self.client_move to be called from main thread...
# calling it via a helper signal instead:
self.sig_move_requested.emit(dest)
def show_graph(self, **kwargs):
stream = io.BytesIO()
self.get_graph(**kwargs).draw(stream, prog='dot', format='svg')
return stream.getvalue()
class GUI(QWidget):
def __init__(self, client_state):
super().__init__()
self.client_state = client_state
# setup UI
self.setWindowTitle("State")
self.svgWidget = QtSvg.QSvgWidget()
self.layout = QtWidgets.QVBoxLayout()
self.layout.addWidget(self.svgWidget)
self.btn_move = QPushButton("move")
self.btn_connect = QPushButton("(re-)connect")
self.layout.addWidget(self.btn_move)
self.layout.addWidget(self.btn_connect)
self.setLayout(self.layout)
# Connect Slots/Signals
## machine -> GUI
self.client_state.sig_update_available.connect(self.update_gui)
## GUI --> machine
self.btn_move.clicked.connect(lambda: self.client_state.move(dest=np.random.randint(1, 100)))
self.btn_connect.clicked.connect(
self.client_state.connect_)
# update UI
self.update_gui()
def update_gui(self):
print("Update model graph and GUI...")
self.svgWidget.load(self.client_state.show_graph())
if self.client_state.is_ready():
self.btn_move.setEnabled(True)
self.btn_connect.setDisabled(True)
if self.client_state.is_moving():
self.btn_move.setDisabled(True)
self.btn_connect.setDisabled(True)
if self.client_state.is_unknown():
self.btn_move.setDisabled(True)
self.btn_connect.setEnabled(True)
if __name__ == "__main__":
import sys
app = QApplication(sys.argv)
client = Client()
client_state = ClientState(client)
gui = GUI(client_state)
gui.show()
sys.exit(app.exec_())
