如何根据 PyQt6 和 Pyqtgraph 悬停的项目来更改鼠标行为？

Question

我正在使用 PyQt6 和 PyQtGraph 创建 DICOM 图像可视化界面。我使用

ImageContainer

类（

pg.ImageView

的子类）显示图像。我使用

mousePressEvent

和

mouseMoveEvent

修改了单击期间的鼠标行为。我还使用

eventFilter

显示鼠标悬停的像素值，无需单击。

我允许用户使用

CustomEllipseROI

类（

pg.EllipseROI

的子类）添加椭圆形感兴趣区域 (ROI)。默认情况下，ROI 是可移动和可调整大小的，但由于我修改了

ImageContainer

实例的鼠标行为，它不再起作用。

我尝试在

CustomEllipseROI

类中实现另一个 eventFilter，但失败了。

问题： 如何再次启用 ROI 的移动和大小调整，甚至专门针对 ROI 自定义鼠标行为？

这是一个最小的可重现示例。感谢您的帮助！

import sys
import pyqtgraph as pg
import numpy as np

from PyQt6.QtWidgets import QApplication
from PyQt6.QtCore import Qt, QEvent

class CustomEllipseROI(pg.EllipseROI):
    def __init__(self, pos, size, **args):
        super().__init__(pos, size, **args)
   
    def hoverEvent(self, event):
        print("Hover ROI")

class ImageContainer(pg.ImageView):
    def __init__(self, parent = None):
        super().__init__(parent)
        self.create_data()
        self.init_image()
        self.create_ROI()

    def create_data(self):
        dataRed = np.ones((100, 200, 200)) * np.linspace(90, 150, 100)[:, np.newaxis, np.newaxis]
        dataRed += pg.gaussianFilter(np.random.normal(size=(200, 200)), (5, 5)) * 100
        dataGrn = np.ones((100, 200, 200)) * np.linspace(90, 180, 100)[:, np.newaxis, np.newaxis]
        dataGrn += pg.gaussianFilter(np.random.normal(size=(200, 200)), (5, 5)) * 100
        dataBlu = np.ones((100, 200, 200)) * np.linspace(180, 90, 100)[:, np.newaxis, np.newaxis]
        dataBlu += pg.gaussianFilter(np.random.normal(size=(200, 200)), (5, 5)) * 100
        self.data = np.concatenate(
            (dataRed[:, :, :, np.newaxis], dataGrn[:, :, :, np.newaxis], dataBlu[:, :, :, np.newaxis]), axis=3
        )

    def init_image(self):
        self.setImage(self.data)
        self.ui.histogram.hide()
        self.ui.roiBtn.hide()
        self.ui.menuBtn.hide()
        self.ui.roiPlot.hide()

        self.setAttribute(Qt.WidgetAttribute.WA_Hover)
        self.installEventFilter(self)

        self.view.mousePressEvent = self.mouse_press_event
        self.view.mouseMoveEvent = self.mouse_move_event

    def create_ROI(self):
        self.ellipseROI_item = CustomEllipseROI((50, 50), (50, 50))
        self.view.addItem(self.ellipseROI_item)

    def eventFilter(self, obj, event):
        if event.type() == QEvent.Type.HoverMove:
            print("Hover Image")
            # Call function that displays the image value at mouse position
        elif event.type() == QEvent.Type.HoverLeave:
            print("Leave Image")
            # Clear value display
        return super().eventFilter(obj, event)
    
    def mouse_press_event(self, event):
        self.prevPos = event.pos()

    def mouse_move_event(self, event):
        if event.buttons() == Qt.MouseButton.MiddleButton:
            print("Middle Button on Image")
            # Call function to change contrast
        elif event.buttons() == Qt.MouseButton.LeftButton:
            print("Left Button on Image")
            # Call function to move across slices of a volume
        elif event.buttons() == Qt.MouseButton.RightButton:
            print("Right Button on Image")
            # Call function to zoom in/out

if __name__ == "__main__":
    app = QApplication(sys.argv)
    main = ImageContainer()
    main.show()
    sys.exit(app.exec())```

Answer 1

问题是您重写了

self.view.mousePressEvent

方法而不调用原始方法。最佳实践是通过调用您要重写的任何方法的原始方法来返回。

我的解决方案添加了对

self.view.mousePressEvent

和

self.view.mouseMoveEvent

的返回调用，因为这是最佳实践，但该错误仅因

self.view.mousePressEvent

而发生。

class ImageContainer(pg.ImageView)

    def init_image(self):
        # Other stuff.. .

        self.original_view_mouse_press_event = self.view.mousePressEvent
        self.original_view_mouse_move_event = self.view.mouseMoveEvent
        self.view.mousePressEvent = self.mouse_press_event
        self.view.mouseMoveEvent = self.mouse_move_event
    
    
    def mouse_press_event(self, event):
        self.prevPos = event.pos()
        return self.original_view_mouse_press_event(event)
    
    def mouse_move_event(self, event):
        if event.buttons() == Qt.MouseButton.MiddleButton:
            print("Middle Button on Image")
            # Call function to change contrast
        elif event.buttons() == Qt.MouseButton.LeftButton:
            print("Left Button on Image")
            # Call function to move across slices of a volume
        elif event.buttons() == Qt.MouseButton.RightButton:
            print("Right Button on Image")
            # Call function to zoom in/out
        return self.original_view_mouse_move_event(event)