import cv2
import numpy as np
import sys
from PyQt4 import QtCore
from PyQt4 import QtGui
from picamera.array import PiRGBArray
from picamera import PiCamera
from PyQt4.QtGui import QWidget
from PyQt4.QtCore import pyqtSignal
from imutils.video import VideoStream
from imutils import face_utils
import imutils
import io
camera_port = 0


class ShowVideo(QtCore.QObject):

            #initiating the built in camera
        VideoSignal = QtCore.pyqtSignal(QtGui.QImage)

        def __init__(self, parent = None):
                super(ShowVideo, self).__init__(parent)

        @QtCore.pyqtSlot()
        def startVideo(self):
                camera = PiCamera()
                camera.resolution=(640,480)

                rawCapture = PiRGBArray(camera,size=(640, 480))
                for frame in camera.capture_continuous(rawCapture, format="bgr", use_video_port=True):
                        image = frame.array
                        image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
                        qt_image = QtGui.QImage(image, image.shape[1], image.shape[0], QtGui.QImage.Format_RGB888)



##                        pixmap = QtGui.QPixmap.fromImage(qt_image)
##                        qt_image = pixmap.scaled(320, 240, QtCore.Qt.KeepAspectRatio)
                        qt_image = QtGui.QImage(qt_image)

                        self.VideoSignal.emit(qt_image)
                        rawCapture.truncate(0)



class ImageViewer(QWidget):
    def __init__(self, parent = None):
        super(ImageViewer, self).__init__(parent)
        self.image = QtGui.QImage()
        self.setAttribute(QtCore.Qt.WA_OpaquePaintEvent)



    def paintEvent(self, event):
        painter = QtGui.QPainter(self)
        painter.drawImage(0,0, self.image)
        self.image = QtGui.QImage()

    def initUI(self):
        self.setWindowTitle('Test')


    @QtCore.pyqtSlot(QtGui.QImage)
    def setImage(self, image):
        if image.isNull():
            print("viewer dropped frame!")

        self.image = image
        if image.size() != self.size():
            self.setFixedSize(image.size())
        self.update()


if __name__ == '__main__':

    app = QtGui.QApplication(sys.argv)
    thread = QtCore.QThread()
    thread.start()

    vid = ShowVideo()
    vid.moveToThread(thread)
    image_viewer = ImageViewer()
    #image_viewer.resize(200,400)


    vid.VideoSignal.connect(image_viewer.setImage)

    #Button to start the videocapture:

    push_button = QtGui.QPushButton('Start')
    push_button.clicked.connect(vid.startVideo)
    vertical_layout = QtGui.QVBoxLayout()

    vertical_layout.addWidget(image_viewer)
    vertical_layout.addWidget(push_button)

    layout_widget = QWidget()
    layout_widget.setLayout(vertical_layout)

    main_window = QtGui.QMainWindow()
    main_window.setCentralWidget(layout_widget)
    main_window.resize(720,480)
    main_window.show()
    sys.exit(app.exec_())