在视频帧的顶部放置一个 QToolButton

Question

以下是视频监控系统的代码。我想在每个相机的右下角添加一个 QToolButton。

我对这个按钮有两个要求。首先是按钮只有在我将鼠标悬停在视频帧上时才可见。其次，我想要下拉功能而不是下拉。

编辑：如果可能，我还想删除 QToolButton 的小箭头符号。

我怎样才能做到这一点？

from PyQt4 import QtCore, QtGui
from threading import Thread
from collections import deque
from datetime import datetime
import time
import sys
import cv2
import imutils

class CameraWidget(QtGui.QWidget):
    """Independent camera feed
    Uses threading to grab IP camera frames in the background

    @param width - Width of the video frame
    @param height - Height of the video frame
    @param stream_link - IP/RTSP/Webcam link
    @param aspect_ratio - Whether to maintain frame aspect ratio or force into fraame
    """

    def __init__(self, width, height, stream_link=0, aspect_ratio=False, parent=None, deque_size=1):
        super(CameraWidget, self).__init__(parent)

        # Initialize deque used to store frames read from the stream
        self.deque = deque(maxlen=deque_size)

        # Slight offset is needed since PyQt layouts have a built in padding
        # So add offset to counter the padding 
        self.offset = 16
        self.screen_width = width - self.offset
        self.screen_height = height - self.offset
        self.maintain_aspect_ratio = aspect_ratio

        self.camera_stream_link = stream_link

        # Flag to check if camera is valid/working
        self.online = False
        self.capture = None
        self.video_frame = QtGui.QLabel()

        self.load_network_stream()

        # Start background frame grabbing
        self.get_frame_thread = Thread(target=self.get_frame, args=())
        self.get_frame_thread.daemon = True
        self.get_frame_thread.start()

        # Periodically set video frame to display
        self.timer = QtCore.QTimer()
        self.timer.timeout.connect(self.set_frame)
        self.timer.start(.5)

        print('Started camera: {}'.format(self.camera_stream_link))

    def load_network_stream(self):
        """Verifies stream link and open new stream if valid"""

        def load_network_stream_thread():
            if self.verify_network_stream(self.camera_stream_link):
                self.capture = cv2.VideoCapture(self.camera_stream_link)
                self.online = True
        self.load_stream_thread = Thread(target=load_network_stream_thread, args=())
        self.load_stream_thread.daemon = True
        self.load_stream_thread.start()

    def verify_network_stream(self, link):
        """Attempts to receive a frame from given link"""

        cap = cv2.VideoCapture(link)
        if not cap.isOpened():
            return False
        cap.release()
        return True

    def get_frame(self):
        """Reads frame, resizes, and converts image to pixmap"""

        while True:
            try:
                if self.capture.isOpened() and self.online:
                    # Read next frame from stream and insert into deque
                    status, frame = self.capture.read()
                    if status:
                        self.deque.append(frame)
                    else:
                        self.capture.release()
                        self.online = False
                else:
                    # Attempt to reconnect
                    print('attempting to reconnect', self.camera_stream_link)
                    self.load_network_stream()
                    self.spin(2)
                self.spin(.001)
            except AttributeError:
                pass

    def spin(self, seconds):
        """Pause for set amount of seconds, replaces time.sleep so program doesnt stall"""

        time_end = time.time() + seconds
        while time.time() < time_end:
            QtGui.QApplication.processEvents()

    def set_frame(self):
        """Sets pixmap image to video frame"""

        if not self.online:
            self.spin(1)
            return

        if self.deque and self.online:
            # Grab latest frame
            frame = self.deque[-1]

            # Keep frame aspect ratio
            if self.maintain_aspect_ratio:
                self.frame = imutils.resize(frame, width=self.screen_width)
            # Force resize
            else:
                self.frame = cv2.resize(frame, (self.screen_width, self.screen_height))


            # Convert to pixmap and set to video frame
            self.img = QtGui.QImage(self.frame, self.frame.shape[1], self.frame.shape[0], QtGui.QImage.Format_RGB888).rgbSwapped()
            self.pix = QtGui.QPixmap.fromImage(self.img)
            self.video_frame.setPixmap(self.pix)

    def get_video_frame(self):
        return self.video_frame


if __name__ == '__main__':

    # Create main application window
    app = QtGui.QApplication([])
    app.setStyle(QtGui.QStyleFactory.create("Cleanlooks"))
    mw = QtGui.QMainWindow()
    mw.setWindowTitle('Camera GUI')

    cw = QtGui.QWidget()
    ml = QtGui.QGridLayout()
    cw.setLayout(ml)
    mw.setCentralWidget(cw)
    mw.showMaximized()

    # Dynamically determine screen width/height
    screen_width = QtGui.QApplication.desktop().screenGeometry().width()
    screen_height = QtGui.QApplication.desktop().screenGeometry().height()

    # Create Camera Widgets 
    username = 'Your camera username!'
    password = 'Your camera password!'

    # Stream links
    camera0 = 'rtsp://{}:{}@192.168.1.43:554/cam/realmonitor?channel=1&subtype=0'.format(username, password)
    camera1 = 'rtsp://{}:{}@192.168.1.45/axis-media/media.amp'.format(username, password)
    camera2 = 'rtsp://{}:{}@192.168.1.47:554/cam/realmonitor?channel=1&subtype=0'.format(username, password)
    camera3 = 'rtsp://{}:{}@192.168.1.40:554/cam/realmonitor?channel=1&subtype=0'.format(username, password)
    camera4 = 'rtsp://{}:{}@192.168.1.44:554/cam/realmonitor?channel=1&subtype=0'.format(username, password)
    camera5 = 'rtsp://{}:{}@192.168.1.42:554/cam/realmonitor?channel=1&subtype=0'.format(username, password)
    camera6 = 'rtsp://{}:{}@192.168.1.46:554/cam/realmonitor?channel=1&subtype=0'.format(username, password)
    camera7 = 'rtsp://{}:{}@192.168.1.41:554/cam/realmonitor?channel=1&subtype=0'.format(username, password)

    # Create camera widgets
    print('Creating Camera Widgets...')
    zero = CameraWidget(screen_width//3, screen_height//3, camera0)
    one = CameraWidget(screen_width//3, screen_height//3, camera1)
    two = CameraWidget(screen_width//3, screen_height//3, camera2)
    three = CameraWidget(screen_width//3, screen_height//3, camera3)
    four = CameraWidget(screen_width//3, screen_height//3, camera4)
    five = CameraWidget(screen_width//3, screen_height//3, camera5)
    six = CameraWidget(screen_width//3, screen_height//3, camera6)
    seven = CameraWidget(screen_width//3, screen_height//3, camera7)

    # Add widgets to layout
    print('Adding widgets to layout...')
    ml.addWidget(zero.get_video_frame(),0,0,1,1)
    ml.addWidget(one.get_video_frame(),0,1,1,1)
    ml.addWidget(two.get_video_frame(),0,2,1,1)
    ml.addWidget(three.get_video_frame(),1,0,1,1)
    ml.addWidget(four.get_video_frame(),1,1,1,1)
    ml.addWidget(five.get_video_frame(),1,2,1,1)
    ml.addWidget(six.get_video_frame(),2,0,1,1)
    ml.addWidget(seven.get_video_frame(),2,1,1,1)

    print('Verifying camera credentials...')

    mw.show()

Answer 1

您需要在标签中添加一个 child 按钮，方法是在构造函数中将标签用作父级（这也可以通过 setParent() 来完成）。

class VideoWidget(QtWidgets.QLabel):
    def __init__(self):
        super().__init__()
        # create a button that is a *child* of *this* widget ("self")
        self.button = QtWidgets.QToolButton(self)
        # hide the button, otherwise it will be automatically visible as soon
        # as this VideoWidget will be shown
        self.button.setVisible(False)
        self.buttonOffset = 5

        # just for testing
        self.setPixmap(QtGui.QPixmap('frame.png'))

    def updateButtonGeometry(self):
        # create a rectangle based on the sizeHint of the button, it will 
        # be used to set its geometry
        geo = QtCore.QRect(QtCore.QPoint(), self.button.sizeHint())
        # move the rectangle to the bottom right corner, using an offset 
        # as a margin from the border
        offset = QtCore.QPoint(self.buttonOffset, self.buttonOffset)
        geo.moveBottomRight(self.rect().bottomRight() - offset)
        # apply the geometry
        self.button.setGeometry(geo)

    def enterEvent(self, event):
        self.button.setVisible(True)
        self.updateButtonGeometry()

    def leaveEvent(self, event):
        self.button.setVisible(False)

    def resizeEvent(self, event):
        self.updateButtonGeometry()


class VideoContainer(QtWidgets.QWidget):
    '''
    An example class to display some widgets in a grid layout
    '''
    def __init__(self):
        super().__init__()
        self.videoWidgets = []
        layout = QtWidgets.QGridLayout(self)
        for row in range(3):
            for col in range(3):
                videoWidget = VideoWidget()
                layout.addWidget(videoWidget, row, col)
                self.videoWidgets.append(videoWidget)

关于您的代码的考虑（顺便说一句，这对于这件事来说是不必要的复杂）：您正在创建 VideoWidget 类，但您从未使用它们，这使得它们几乎无用。只需从 QLabel 子类化并直接使用它的实例。