Qt QCheckBox右键功能定制：实现高级交互逻辑

from PyQt5.QtWidgets import QCheckBox, QApplication
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QMouseEvent

class MyCheckBoxInitial(QCheckBox):
    def __init__(self):
        super().__init__()
        self.setTristate(True) # 启用三态
        self.clicked.connect(lambda: print(f"Clicked! Current state: {self.checkState()}"))

    def mousePressEvent(self, event: QMouseEvent):
        if event.button() == Qt.MouseButton.RightButton:
            # 伪装成左键按下，以便父类处理视觉反馈
            event = QMouseEvent(event.type(), event.position(), Qt.MouseButton.LeftButton, event.buttons(), event.modifiers())
        super().mousePressEvent(event)

    def mouseReleaseEvent(self, event: QMouseEvent):
        if event.button() == Qt.MouseButton.RightButton:
            # 记录右键释放，并在特定状态下改变行为
            if self.checkState() == Qt.CheckState.PartiallyChecked:
                self.setCheckState(Qt.CheckState.Unchecked)
            else:
                # 模拟左键释放，以便触发clicked信号
                event = QMouseEvent(event.type(), event.position(), Qt.MouseButton.LeftButton, event.buttons(), event.modifiers())
        super().mouseReleaseEvent(event)

from PyQt5.QtWidgets import QCheckBox, QApplication, QVBoxLayout, QWidget
from PyQt5.QtCore import Qt
from PyQt5.QtGui import QMouseEvent

class MyCheckBox(QCheckBox):
    # 内部标志，用于区分是左键还是右键触发的状态改变
    _isRightButton = False

    def __init__(self, parent=None):
        super().__init__(parent)
        self.setTristate(True) # 启用三态功能
        self.setText("Custom CheckBox")
        self.clicked.connect(self._on_clicked)

    def _on_clicked(self):
        """处理clicked信号，可以用于调试或额外的逻辑"""
        print(f"Clicked signal emitted. Current state: {self.checkState().name}")

    def mousePressEvent(self, event: QMouseEvent):
        # 即使是右键按下，也将其伪装成左键按下传递给父类
        # 这样可以确保父类在鼠标按下时提供正确的视觉反馈（如阴影）
        if event.button() == Qt.MouseButton.RightButton:
            event = QMouseEvent(event.type(), event.position(), Qt.MouseButton.LeftButton, event.buttons(), event.modifiers())
        super().mousePressEvent(event)

    def mouseMoveEvent(self, event: QMouseEvent):
        # 当右键被按下且鼠标移动时，需要修改事件的buttons()属性
        # 这是为了让父类能够正确处理拖拽时的视觉反馈（如阴影的出现和消失）
        # 注意：这里将event.button()设置为NoButton，但event.buttons()设置为LeftButton
        # 这样可以模拟左键拖拽的行为，同时避免与实际的右键按下冲突
        if event.buttons() == Qt.MouseButton.RightButton:
            event = QMouseEvent(
                event.type(), event.position(),
                Qt.MouseButton.NoButton,  # 单个按钮设置为NoButton
                Qt.MouseButton.LeftButton, # 按下的按钮集设置为LeftButton
                event.modifiers()
            )
        super().mouseMoveEvent(event)

    def mouseReleaseEvent(self, event: QMouseEvent):
        # 检查是否是右键释放
        is_right_button_release = event.button() == Qt.MouseButton.RightButton

        if is_right_button_release:
            # 设置内部标志，指示接下来的状态改变是右键触发的
            self._isRightButton = True
            # 将右键释放事件伪装成左键释放事件
            # 这样可以确保父类的逻辑（如触发clicked信号）能够被执行
            event = QMouseEvent(
                event.type(), event.position(),
                Qt.MouseButton.LeftButton,  # 伪装成左键释放
                event.buttons(),
                event.modifiers()
            )

        # 调用父类的mouseReleaseEvent，处理原生逻辑
        super().mouseReleaseEvent(event)

        if is_right_button_release:
            # 释放后重置标志
            self._isRightButton = False

    def nextCheckState(self):
        """
        重写此方法以定制状态切换逻辑。
        这是QCheckBox在收到点击后决定下一个状态的地方。
        """
        if self._isRightButton and self.checkState() == Qt.CheckState.PartiallyChecked:
            # 如果是右键点击且当前是PartiallyChecked，则切换到Unchecked
            self.setCheckState(Qt.CheckState.Unchecked)
        else:
            # 否则，使用父类的默认状态切换逻辑
            super().nextCheckState()

# 示例应用
if __name__ == '__main__':
    app = QApplication([])
    window = QWidget()
    layout = QVBoxLayout()

    checkbox1 = MyCheckBox()
    checkbox1.setText("Custom CheckBox (Initial PartiallyChecked)")
    checkbox1.setCheckState(Qt.CheckState.PartiallyChecked)
    layout.addWidget(checkbox1)

    checkbox2 = MyCheckBox()
    checkbox2.setText("Custom CheckBox (Initial Unchecked)")
    layout.addWidget(checkbox2)

    checkbox3 = MyCheckBox()
    checkbox3.setText("Custom CheckBox (Initial Checked)")
    checkbox3.setCheckState(Qt.CheckState.Checked)
    layout.addWidget(checkbox3)

    window.setLayout(layout)
    window.setWindowTitle("Custom QCheckBox Right-Click Example")
    window.show()
    app.exec_()