Develop Reference

PyQt/PySide QGraphicsScene, Hover event on Ellipse Item not working

I'm currently learning how to use Qt's Qgraphics and i cant get the hoverEnterEvent to work on an QGraphicsEllipseItem object. I am setting setAcceptHoverEvents to True and implemented the hoverEnterEvent function, yet the function isn't getting called.
here's my code:
import sys
from PySide6.QtWidgets import (
QApplication,
QMainWindow,
QGraphicsView,
QGraphicsScene,
QGraphicsEllipseItem,
)
from PySide6.QtGui import QPainterPath, QTransform, QPen, QBrush, QColor, QPainter
from PySide6.QtCore import Qt
PORT_PEN_COLOR = "#000000"
PORT_BRUSH_COLOR = "#ebebeb"
EDGE_PEN_COLOR = "#474747"
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.setGeometry(0, 0, 800, 600)
self.setCentralWidget(GraphicsView())
self.show()
class GraphicsView(QGraphicsView):
def __init__(self, parent=None):
super().__init__(parent)
self.setMouseTracking(True)
self.setScene(GraphicsScene())
self.setRenderHint(QPainter.RenderHint.Antialiasing)
class GraphicsScene(QGraphicsScene):
def __init__(self, parent=None):
super().__init__(parent)
self.setSceneRect(-10000, -10000, 20000, 20000)
self._port_pen = QPen(QColor(PORT_PEN_COLOR))
self._port_brush = QBrush(QColor(PORT_BRUSH_COLOR))
self._edge_pen = QPen(QColor(EDGE_PEN_COLOR))
self._edge_pen.setWidth(4)
def mousePressEvent(self, event):
clicked_item = self.itemAt(event.scenePos(), QTransform())
if event.buttons() == Qt.MouseButton.LeftButton:
if clicked_item is not None:
# edge item
pos = clicked_item.scenePos()
pos.setX(pos.x() + 6)
pos.setY(pos.y() + 6)
self.edge = self.addPath(QPainterPath())
self.edge.setPen(self._edge_pen)
self.start_pos = pos
self.end_pos = self.start_pos
self.update_path()
else:
x = event.scenePos().x()
y = event.scenePos().y()
# port item
start_port = Ellipse()
start_port.setPos(x - 6, y - 6)
start_port.setPen(self._port_pen)
start_port.setBrush(self._port_brush)
start_port.setZValue(10000.0)
self.addItem(start_port)
# edge item
self.edge = self.addPath(QPainterPath())
self.edge.setPen(self._edge_pen)
self.start_pos = event.scenePos()
self.end_pos = self.start_pos
self.update_path()
def mouseMoveEvent(self, event):
if event.buttons() == Qt.MouseButton.LeftButton:
print(f"moving, x : {event.scenePos().x()}, y : {event.scenePos().y()}")
self.end_pos = event.scenePos()
try:
self.update_path()
except AttributeError:
pass
def mouseReleaseEvent(self, event) -> None:
released_item = self.itemAt(event.scenePos(), QTransform())
if event.button() == Qt.MouseButton.LeftButton:
if released_item is not None and released_item.type() != 2:
self.end_pos = released_item.scenePos()
self.end_pos.setX(self.end_pos.x() + 6)
self.end_pos.setY(self.end_pos.y() + 6)
if not self.start_pos.isNull() and not self.end_pos.isNull():
path = QPainterPath()
path.moveTo(self.start_pos.x() - 1, self.start_pos.y() - 1)
path.lineTo(self.end_pos)
self.edge.setPath(path)
else:
x = event.scenePos().x() + 1
y = event.scenePos().y() + 1
end_port = QGraphicsEllipseItem(0, 0, 10, 10)
end_port.setPos(x - 6, y - 6)
end_port.setPen(self._port_pen)
end_port.setBrush(self._port_brush)
end_port.setZValue(10000.0)
self.addItem(end_port)
def update_path(self):
if not self.start_pos.isNull() and not self.end_pos.isNull():
path = QPainterPath()
path.moveTo(self.start_pos.x() - 1, self.start_pos.y() - 1)
path.lineTo(self.end_pos)
self.edge.setPath(path)
class Ellipse(QGraphicsEllipseItem):
def __init__(self):
super().__init__()
self.setRect(0, 0, 10, 10)
self.setAcceptHoverEvents(True)
def hoverEnterEvent(self, event) -> None:
print("hovered")
if __name__ == "__main__":
app = QApplication(sys.argv)
win = MainWindow()
sys.exit(app.exec())
What am i doing wrong here, how do i get the hover event to work please ?
Thank you

simpledialog.askstring window from tkinter freezes

I have a problem using simpledialog.askstring from tkinter, it opens two pop up windows, one of them is the regular one to input a value, but the other is a blank window that freezes completely and you have to force the cloosure of the window, enter image description hereas shown in the image in the link. I'm using spyder.
What could be happening?
This is what I have so far:
from PyQt5 import QtWidgets, QtCore, QtGui
from PyQt5.QtCore import pyqtSignal, QObject
from PyQt5.QtWidgets import QApplication, QMainWindow, QComboBox,
QLabel, QPushButton, QGroupBox
import tkinter as tk
from tkinter import simpledialog
from PIL import ImageGrab
import sys
import cv2
import numpy as np
# import imageToString
import pyperclip
import webbrowser
import pytesseract
pytesseract.pytesseract.tesseract_cmd =
r"C:\Users\amc\AppData\Local\Programs\Tesseract-OCR\tesseract.exe"
class Communicate(QObject):
snip_saved = pyqtSignal()
class MyWindow(QMainWindow):
def __init__(self, parent=None):
super(MyWindow, self).__init__()
self.win_width = 340
self.win_height = 200
self.setGeometry(50, 50, self.win_width, self.win_height)
self.setWindowTitle("PSD Generator")
self.initUI()
def initUI(self):
#Define buttons
self.searchOpen = QPushButton(self)
self.searchOpen.setText("Digitilize Graph")
self.searchOpen.move(10,75)
self.searchOpen.setFixedSize(150,40)
self.searchOpen.clicked.connect(self.snip_graph_clicked)
self.copyPartNum = QPushButton(self)
self.copyPartNum.setText("Snip Table")
self.copyPartNum.move((self.win_width/2)+10, 75)
self.copyPartNum.setFixedSize(150,40)
self.copyPartNum.clicked.connect(self.snip_table_clicked)
self.notificationBox = QGroupBox("Notification Box", self)
self.notificationBox.move(10,135)
self.notificationBox.setFixedSize(self.win_width-20,55)
self.notificationText = QLabel(self)
self.notificationText.move(20, 145)
self.reset_notif_text()
def snip_graph_clicked(self):
self.snipWin = SnipWidget(False, True, self)
self.snipWin.notification_signal.connect(self.reset_notif_text)
self.snipWin.show()
self.notificationText.setText("Snipping... Press ESC to quit snipping")
self.update_notif()
def snip_table_clicked(self):
self.snipWin = SnipWidget(True, False, self)
self.snipWin.notification_signal.connect(self.reset_notif_text)
self.snipWin.show()
self.notificationText.setText("Snipping... Press ESC to quit snipping")
self.update_notif()
def reset_notif_text(self):
self.notificationText.setText("Idle...")
self.update_notif()
def define_notif_text(self, msg):
print('notification was sent')
self.notificationText.setText('notification was sent')
self.update_notif()
def update_notif(self):
self.notificationText.move(20, 155)
self.notificationText.adjustSize()
class SnipWidget(QMainWindow):
notification_signal = pyqtSignal()
def __init__(self, copy_table, scan_graph, parent):
super(SnipWidget, self).__init__()
self.copy_table = copy_table
self.scan_graph = scan_graph
root = tk.Tk()# instantiates window
screen_width = root.winfo_screenwidth()
screen_height = root.winfo_screenheight()
self.setGeometry(0, 0, screen_width, screen_height)
self.setWindowTitle(' ')
self.begin = QtCore.QPoint()
self.end = QtCore.QPoint()
self.setWindowOpacity(0.3)
self.is_snipping = False
QtWidgets.QApplication.setOverrideCursor(
QtGui.QCursor(QtCore.Qt.CrossCursor)
)
self.setWindowFlags(QtCore.Qt.FramelessWindowHint)
self.c = Communicate()
self.show()
if self.copy_table == True:
# the input dialog
BH_Ref = simpledialog.askstring(title="New PSD",prompt="Borehole Number Ref:")
Depth = simpledialog.askstring(title="New PSD",prompt="Sample depth (m):")
self.c.snip_saved.connect(self.searchAndOpen)
if self.scan_graph == True:
# the input dialog
BH_Ref = simpledialog.askstring(title="New PSD",prompt="Borehole Number Ref:")
Depth = simpledialog.askstring(title="New PSD",prompt="Sample depth (m):")
self.c.snip_saved.connect(self.IdAndCopy)
def paintEvent(self, event):
if self.is_snipping:
brush_color = (0, 0, 0, 0)
lw = 0
opacity = 0
else:
brush_color = (128, 128, 255, 128)
lw = 3
opacity = 0.3
self.setWindowOpacity(opacity)
qp = QtGui.QPainter(self)
qp.setPen(QtGui.QPen(QtGui.QColor('black'), lw))
qp.setBrush(QtGui.QColor(*brush_color))
qp.drawRect(QtCore.QRect(self.begin, self.end))
def keyPressEvent(self, event):
if event.key() == QtCore.Qt.Key_Escape:
print('Quit')
QtWidgets.QApplication.restoreOverrideCursor();
self.notification_signal.emit()
self.close()
event.accept()
def mousePressEvent(self, event):
self.begin = event.pos()
self.end = self.begin
self.update()
def mouseMoveEvent(self, event):
self.end = event.pos()
self.update()
def mouseReleaseEvent(self, event):
x1 = min(self.begin.x(), self.end.x())
y1 = min(self.begin.y(), self.end.y())
x2 = max(self.begin.x(), self.end.x())
y2 = max(self.begin.y(), self.end.y())
self.is_snipping = True
self.repaint()
QtWidgets.QApplication.processEvents()
img = ImageGrab.grab(bbox=(x1, y1, x2, y2))
self.is_snipping = False
self.repaint()
QtWidgets.QApplication.processEvents()
img = cv2.cvtColor(np.array(img), cv2.COLOR_BGR2GRAY)
self.snipped_image = img
QtWidgets.QApplication.restoreOverrideCursor();
self.c.snip_saved.emit()
self.close()
self.msg = 'snip complete'
self.notification_signal.emit()
def searchAndOpen(self):
img_str = self.imgToStr(self.snipped_image)
msg_str = f'Text in snip is {img_str}'
def IdAndCopy(self):
img_str = self.imgToStr(self.snipped_image)
pyperclip.copy(img_str)
def find_str(self, image_data):
img = image_data
h,w = np.shape(img)
asp_ratio = float(w/h)
img_width = 500
img_height = int(round(img_width/asp_ratio))
desired_image_size = (img_width,img_height)
img_resized = cv2.resize(img, desired_image_size)
imgstr = str(pytesseract.image_to_string(img_resized))
print(imgstr)
return imgstr
def imgToStr(self, image):
# img_str = imageToString.main(image)
img_str = self.find_str(image)
return img_str
def window():
app = QApplication(sys.argv)
win = MyWindow()
win.show()
sys.exit(app.exec_())
window()

How to set QGraphicsView 's background Image? [duplicate]

This question already has answers here:
Painting background on QGraphicsView using drawBackground
(1 answer)
How to enable Pan and Zoom in a QGraphicsView
(3 answers)
How to put an image in QGraphicsView's scrollbar area?
(1 answer)
Closed 3 years ago.
I'm wondering how to set QgraphicsView's background Image.
In this painter program, the background is just white color.
I want to load some image(jpg, png, .. whatever) and set it as painter's background.
and after painting it, I want to just save painting (not include background, just what i painted.)
how can i do this? please help me.
import sys
from PyQt5.QtCore import *
from PyQt5.QtCore import Qt
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtWidgets import (QApplication, QCheckBox, QGridLayout, QGroupBox,
QPushButton, QVBoxLayout, QWidget, QSlider)
QApplication.setAttribute(Qt.AA_EnableHighDpiScaling, True)
class CWidget(QWidget):
def __init__(self):
super().__init__()
# 전체 폼 박스
formbox = QHBoxLayout()
self.setLayout(formbox)
# 좌, 우 레이아웃박스
left = QVBoxLayout()
right = QVBoxLayout()
# 그룹박스2
gb = QGroupBox('펜 설정')
left.addWidget(gb)
grid = QGridLayout()
gb.setLayout(grid)
label = QLabel('펜 색상')
grid.addWidget(label, 1, 0)
self.pencolor = QColor(0, 0, 0)
self.penbtn = QPushButton()
self.penbtn.setStyleSheet('background-color: rgb(0,0,0)')
self.penbtn.clicked.connect(self.showColorDlg)
grid.addWidget(self.penbtn, 1, 1)
label = QLabel('펜 굵기')
grid.addWidget(label, 2, 0)
self.slider = QSlider(Qt.Horizontal)
self.slider.setMinimum(3)
self.slider.setMaximum(21)
self.slider.setValue(5)
self.slider.setFocusPolicy(Qt.StrongFocus)
self.slider.setTickPosition(QSlider.TicksBothSides)
self.slider.setTickInterval(1)
self.slider.setSingleStep(1)
grid.addWidget(self.slider)
# 그룹박스4
gb = QGroupBox('지우개')
left.addWidget(gb)
hbox = QHBoxLayout()
gb.setLayout(hbox)
self.checkbox = QCheckBox('지우개')
self.checkbox.stateChanged.connect(self.checkClicked)
hbox.addWidget(self.checkbox)
left.addStretch(1)
# 우 레이아웃 박스에 그래픽 뷰 추가
self.view = CView(self)
right.addWidget(self.view)
# 전체 폼박스에 좌우 박스 배치
formbox.addLayout(left)
formbox.addLayout(right)
formbox.setStretchFactor(left, 0)
formbox.setStretchFactor(right, 1)
self.setGeometry(100, 100, 800, 500)
def checkClicked(self):
pass
def createExampleGroup(self):
groupBox = QGroupBox("Slider Example")
slider = QSlider(Qt.Horizontal)
slider.setFocusPolicy(Qt.StrongFocus)
slider.setTickPosition(QSlider.TicksBothSides)
slider.setTickInterval(10)
slider.setSingleStep(1)
vbox = QVBoxLayout()
vbox.addWidget(slider)
vbox.addStretch(1)
groupBox.setLayout(vbox)
return groupBox
def showColorDlg(self):
# 색상 대화상자 생성
color = QColorDialog.getColor()
sender = self.sender()
# 색상이 유효한 값이면 참, QFrame에 색 적용
self.pencolor = color
self.penbtn.setStyleSheet('background-color: {}'.format(color.name()))
# QGraphicsView display QGraphicsScene
class CView(QGraphicsView):
def __init__(self, parent):
super().__init__(parent)
self.scene = QGraphicsScene()
self.setScene(self.scene)
self.items = []
self.start = QPointF()
self.end = QPointF()
self.setRenderHint(QPainter.HighQualityAntialiasing)
def moveEvent(self, e):
rect = QRectF(self.rect())
rect.adjust(0, 0, -2, -2)
self.scene.setSceneRect(rect)
def mousePressEvent(self, e):
if e.button() == Qt.LeftButton:
# 시작점 저장
self.start = e.pos()
self.end = e.pos()
def mouseMoveEvent(self, e):
# e.buttons()는 정수형 값을 리턴, e.button()은 move시 Qt.Nobutton 리턴
if e.buttons() & Qt.LeftButton:
self.end = e.pos()
if self.parent().checkbox.isChecked():
pen = QPen(QColor(255, 255, 255), 10)
path = QPainterPath()
path.moveTo(self.start)
path.lineTo(self.end)
self.scene.addPath(path, pen)
self.start = e.pos()
return None
pen = QPen(self.parent().pencolor, self.parent().slider.value())
# Path 이용
path = QPainterPath()
path.moveTo(self.start)
path.lineTo(self.end)
self.scene.addPath(path, pen)
# 시작점을 다시 기존 끝점으로
self.start = e.pos()
def open(self):
fileName, _ = QFileDialog.getOpenFileName(self, "Open File",
QDir.currentPath())
if fileName:
image = QImage(fileName)
if image.isNull():
QMessageBox.information(self, "Image Viewer",
"Cannot load %s." % fileName)
return
self.imageLabel.setPixmap(QPixmap.fromImage(image))
self.scaleFactor = 1.0
self.printAct.setEnabled(True)
self.fitToWindowAct.setEnabled(True)
self.updateActions()
if not self.fitToWindowAct.isChecked():
self.imageLabel.adjustSize()
if __name__ == '__main__':
app = QApplication(sys.argv)
w = CWidget()
w.show()
sys.exit(app.exec_())

You can create an instance of QGraphicsPixmapItem and add it to the scene, here is an example:
import sys
from PyQt5.QtCore import *
from PyQt5.QtCore import Qt
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtWidgets import (QApplication, QCheckBox, QGridLayout, QGroupBox,
QPushButton, QVBoxLayout, QWidget, QSlider)
QApplication.setAttribute(Qt.AA_EnableHighDpiScaling, True)
class CWidget(QWidget):
def __init__(self):
super().__init__()
# 전체 폼 박스
formbox = QHBoxLayout()
self.setLayout(formbox)
# 좌, 우 레이아웃박스
left = QVBoxLayout()
right = QVBoxLayout()
# 그룹박스2
gb = QGroupBox('펜 설정')
left.addWidget(gb)
grid = QGridLayout()
gb.setLayout(grid)
label = QLabel('펜 색상')
grid.addWidget(label, 1, 0)
self.pencolor = QColor(0, 0, 0)
self.penbtn = QPushButton()
self.penbtn.setStyleSheet('background-color: rgb(0,0,0)')
self.penbtn.clicked.connect(self.showColorDlg)
grid.addWidget(self.penbtn, 1, 1)
label = QLabel('펜 굵기')
grid.addWidget(label, 2, 0)
self.slider = QSlider(Qt.Horizontal)
self.slider.setMinimum(3)
self.slider.setMaximum(21)
self.slider.setValue(5)
self.slider.setFocusPolicy(Qt.StrongFocus)
self.slider.setTickPosition(QSlider.TicksBothSides)
self.slider.setTickInterval(1)
self.slider.setSingleStep(1)
grid.addWidget(self.slider)
# 그룹박스4
gb = QGroupBox('지우개')
left.addWidget(gb)
hbox = QHBoxLayout()
gb.setLayout(hbox)
self.checkbox = QCheckBox('지우개')
self.checkbox.stateChanged.connect(self.checkClicked)
hbox.addWidget(self.checkbox)
left.addStretch(1)
# 우 레이아웃 박스에 그래픽 뷰 추가
self.view = CView(self)
right.addWidget(self.view)
# 전체 폼박스에 좌우 박스 배치
formbox.addLayout(left)
formbox.addLayout(right)
formbox.setStretchFactor(left, 0)
formbox.setStretchFactor(right, 1)
self.setGeometry(100, 100, 800, 500)
def checkClicked(self, state):
self.view.stretch(state)
def createExampleGroup(self):
groupBox = QGroupBox("Slider Example")
slider = QSlider(Qt.Horizontal)
slider.setFocusPolicy(Qt.StrongFocus)
slider.setTickPosition(QSlider.TicksBothSides)
slider.setTickInterval(10)
slider.setSingleStep(1)
vbox = QVBoxLayout()
vbox.addWidget(slider)
vbox.addStretch(1)
groupBox.setLayout(vbox)
return groupBox
def showColorDlg(self):
# 색상 대화상자 생성
color = QColorDialog.getColor()
sender = self.sender()
# 색상이 유효한 값이면 참, QFrame에 색 적용
self.pencolor = color
self.penbtn.setStyleSheet('background-color: {}'.format(color.name()))
# QGraphicsView display QGraphicsScene
class CView(QGraphicsView):
def __init__(self, parent):
super().__init__(parent)
self.scene = QGraphicsScene()
self.setScene(self.scene)
self.items = []
self.start = QPointF()
self.end = QPointF()
self.backgroundImage = None
self.graphicsPixmapItem = None
self.setRenderHint(QPainter.HighQualityAntialiasing)
self.open()
def moveEvent(self, e):
rect = QRectF(self.rect())
rect.adjust(0, 0, -2, -2)
self.scene.setSceneRect(rect)
def mousePressEvent(self, e):
if e.button() == Qt.LeftButton:
# 시작점 저장
self.start = e.pos()
self.end = e.pos()
def mouseMoveEvent(self, e):
# e.buttons()는 정수형 값을 리턴, e.button()은 move시 Qt.Nobutton 리턴
if e.buttons() & Qt.LeftButton:
self.end = e.pos()
if self.parent().checkbox.isChecked():
pen = QPen(QColor(255, 255, 255), 10)
path = QPainterPath()
path.moveTo(self.start)
path.lineTo(self.end)
self.scene.addPath(path, pen)
self.start = e.pos()
return None
pen = QPen(self.parent().pencolor, self.parent().slider.value())
# Path 이용
path = QPainterPath()
path.moveTo(self.start)
path.lineTo(self.end)
self.scene.addPath(path, pen)
# 시작점을 다시 기존 끝점으로
self.start = e.pos()
def stretch(self, state):
self._set_image(state == 2)
def open(self):
fileName, _ = QFileDialog.getOpenFileName(self, "Open File", QDir.currentPath(), filter='Images (*.png *.xpm *.jpg)')
if fileName:
image = QImage(fileName)
if image.isNull():
QMessageBox.information(self, "Image Viewer",
"Cannot load %s." % fileName)
return
self.backgroundImage = fileName
self._set_image(False)
def _set_image(self, stretch: bool):
tempImg = QPixmap(self.backgroundImage)
if stretch:
tempImg = tempImg.scaled(self.scene.width(), self.scene.height())
if self.graphicsPixmapItem is not None:
self.scene.removeItem(self.graphicsPixmapItem)
self.graphicsPixmapItem = QGraphicsPixmapItem(tempImg)
self.scene.addItem(self.graphicsPixmapItem)
if __name__ == '__main__':
app = QApplication(sys.argv)
w = CWidget()
w.show()
sys.exit(app.exec_())

AttributeError: 'Settings' object has no attribute 'scene'

I need to add pixmap to my rectangles. When I press the click button then my pixmap will be added to one by one in my rectangles but I got this attribute error. Can any one please guide me how to solve this error? I tried so many ways but I didn't get the proper output.
Thank you in advance.
Given below is my code:
from pyface.qt import QtGui, QtCore
import sys
global X,Y
class ScanView(QtGui.QGraphicsView):
def __init__(self,X=5, Y=5, parent=None):
super(ScanView, self).__init__(parent)
self.row = X
self.cols = Y
self.squareLB = 50
self.width = Y*self.squareLB+2*self.squareLB
self.height = X*self.squareLB+2*self.squareLB
self.List = []
if self.width>708:
self.scene = QtGui.QGraphicsScene(0,0,self.width,self.height)
for i in range(self.row):
for j in range(self.cols):
item = self.scene.addRect(QtCore.QRectF(0,0,self.squareLB,self.squareLB))
item.setPos(self.squareLB+j*self.squareLB, X*self.squareLB-(i*self.squareLB))
self.List.append(item)
else:
self.scene = QtGui.QGraphicsScene(0,0,708,self.height)
self.marginLR = (708.0-Y*self.squareLB)/2.0
for i in range(self.row):
for j in range(self.cols):
item = self.scene.addRect(QtCore.QRectF(0,0,self.squareLB,self.squareLB))
item.setPos(self.marginLR+j*self.squareLB, X*self.squareLB-(i*self.squareLB))
self.List.append(item)
self.setScene(self.scene)
class Settings(QtGui.QMainWindow):
def __init__(self, parent=None):
super(Settings, self).__init__(parent)
spacer = QtGui.QWidget(self)
spacer.setSizePolicy(QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Expanding)
QtGui.QToolTip.setFont(QtGui.QFont('SansSerif', 10))
self.vbox = QtGui.QVBoxLayout()
self.save = QtGui.QPushButton("save")
self.open= QtGui.QPushButton("open")
self.folder= QtGui.QPushButton("Folder")
self.folder.clicked.connect(self.showSettings)
self.vbox.addWidget(self.save)
self.vbox.addWidget(self.open)
self.vbox.addWidget(self.folder)
self.grid = QtGui.QGridLayout()
self.grid.addLayout(self.vbox,0,0)
self.scrollArea = QtGui.QScrollArea()
self.scrollArea.setBackgroundRole(QtGui.QPalette.Light)
self.scrollArea.setWidgetResizable(True)
self.grid.addWidget(self.scrollArea,0,1)
self.setCentralWidget(QtGui.QWidget(self))
self.centralWidget().setLayout(self.grid)
self.setGeometry(200,100,300,300)
self.show()
def showSettings(self):
self.MyView = ScanView(5,5)
self.vbox2 = QtGui.QVBoxLayout()
self.Scanbtn1 = QtGui.QPushButton(("click"))
self.Scanbtn1.clicked.connect(self.on_clicked)
self.vbox2.addWidget(self.Scanbtn1)
self.newwidget = QtGui.QWidget()
self.glayout = QtGui.QGridLayout(self.newwidget)
self.glayout.addWidget(self.MyView,0,0)
self.Sw = QtGui.QWidget()
self.Sw.setLayout(self.vbox2)
# self.Sw.setFixedWidth(width - self.scrollArea.viewport().width())
self.glayout.addWidget(self.Sw,0,1)
self.scrollArea.setWidget(self.newwidget)
def on_clicked(self):
print "hellloooooo"
filename1 = "./img/tick.png"
pixmap = QtGui.QPixmap(filename1)
if not pixmap.isNull():
self.MyView.add_pixmap(pixmap)
# pic = QtGui.QPixmap("./img/tick.png")
# scene.addItem(QtGui.QGraphicsPixmapItem(pic))
# # view = self.gv
# self.MyView.setScene(scene)
# self.MyView.setRenderHint(QtGui.QPainter.Antialiasing)
# self.MyView.show()
def main():
app = QtGui.QApplication(sys.argv)
ex = Settings()
sys.exit(app.exec_())
if __name__ == '__main__':
main()

You have that error because scene does not exist in the Settings class, self.scene is a member of the ScanView class plus self.scene is different from scene.
Going to the problem, you must add as a child of the rectangles and you must also change the size of the pixmap is necessary. To obtain the first rectangle you must store it in a list and then create an iterator.
import sys
from pyface.qt import QtGui, QtCore
class ScanView(QtGui.QGraphicsView):
def __init__(self,X=5, Y=5, parent=None):
super(ScanView, self).__init__(parent)
self._squares = []
n_rows, n_cols = X, Y
squareLB = 50
width, height = (Y + 2)*squareLB, (X + 2)*squareLB
self._scene = QtGui.QGraphicsScene(0, 0, max(708, width), height)
p = squareLB if width > 708 else (708.0-Y*squareLB)/2.0
for i in range(n_rows):
for j in range(n_cols):
it = self._scene.addRect(0, 0, squareLB, squareLB)
it.setPos(p + j*squareLB, i*squareLB)
self._squares.append(it)
self.setScene(self._scene)
class Settings(QtGui.QMainWindow):
def __init__(self, parent=None):
super(Settings, self).__init__(parent)
self.save = QtGui.QPushButton("save")
self.open = QtGui.QPushButton("open")
self.folder = QtGui.QPushButton("Folder", clicked=self.showSettings)
central_widget = QtGui.QWidget()
self.setCentralWidget(central_widget)
vbox = QtGui.QVBoxLayout()
vbox.addWidget(self.save)
vbox.addWidget(self.open)
vbox.addWidget(self.folder)
self.scrollArea = QtGui.QScrollArea(widgetResizable=True)
self.scrollArea.setBackgroundRole(QtGui.QPalette.Light)
hlay = QtGui.QHBoxLayout(central_widget)
hlay.addLayout(vbox)
hlay.addWidget(self.scrollArea)
self.setGeometry(200, 100, 300, 300)
def showSettings(self):
self.view = ScanView(5, 5)
self.scanbtn = QtGui.QPushButton("click", clicked=self.on_clicked)
self.newwidget = QtGui.QWidget()
hlay = QtGui.QHBoxLayout(self.newwidget)
hlay.addWidget(self.view)
hlay.addWidget(self.scanbtn)
self.scrollArea.setWidget(self.newwidget)
self._iter_squares = iter(self.view._squares)
def on_clicked(self):
filename = "./img/tick.png"
pixmap = QtGui.QPixmap(filename)
if pixmap.isNull():
return
try:
it = next(self._iter_squares)
except StopIteration:
pass
else:
pixmap = pixmap.scaled(it.rect().size().toSize())
pixmap_it = QtGui.QGraphicsPixmapItem(pixmap, it)
def main():
app = QtGui.QApplication(sys.argv)
ex = Settings()
ex.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()

Make a rectangle blink in PyQt

The purpose of this code is to have a square that appears in a canvas for some time and is then erased. I understand that all painting events must be handled by the overloaded function paintEvent.
However, first, the squares are not being drawn and I believe, that the times at which the squares are supposed to be drawn and erased are not being respected either. My guess is this happens due to the frequency at which the event appears.
I already tried to call QPaintEvent under the functions drawApple and eraseApple. What am I missing?
import sys, random
import numpy as np
import math
from PyQt4 import QtCore, QtGui
from PyQt4.QtCore import QTimer
from PyQt4.QtCore import QRect
from PyQt4.QtGui import QPaintEvent
class Game(QtGui.QMainWindow):
def __init__(self):
super(Game, self).__init__()
self.initUI()
def initUI(self):
palette = QtGui.QPalette()
palette.setColor(QtGui.QPalette.Background, QtCore.Qt.white)
self.setPalette(palette)
self.tboard = Board(self)
self.setCentralWidget(self.tboard)
self.resize(400, 400)
self.center()
self.setWindowTitle('Game')
self.show()
def center(self):
screen = QtGui.QDesktopWidget().screenGeometry()
size = self.geometry()
self.move((screen.width()-size.width())/2, (screen.height()-size.height())/2)
class Board(QtGui.QFrame):
BoardWidth = 400
BoardHeight = 400
SquareWidth = 15
SquareHeight = 15
Speed = 10000
def __init__(self, parent):
super(Board, self).__init__(parent)
#self.setAutoFillBackground(True)
self.setFocusPolicy(QtCore.Qt.StrongFocus)
self.timer_draw = QtCore.QTimer()
self.timer_draw.timeout.connect(self.drawApple)
self.timer_draw.start(self.Speed)
self.timer_draw.setInterval(self.Speed)
self.timer_erase = QtCore.QTimer()
self.timer_erase.timeout.connect(self.eraseApple)
self.timer_erase.start(self.Speed + self.Speed/2)
self.timer_erase.setInterval(self.Speed)
self.apple_color = QtCore.Qt.red
self.bkg_color = QtCore.Qt.white
self.draw_apple = False
self.x_apple = 0
self.y_apple = 0
self.rect = QRect(self.x_apple, self.y_apple, self.SquareWidth, self.SquareHeight)
def paintEvent(self, event):
painter = QtGui.QPainter(self)
print "Paint Event?"
if self.draw_apple == True:
print "Draw"
self.apple_color = QtCore.Qt.red
else:
print "Do not draw"
self.apple_color = self.bkg_color
painter.setPen(self.apple_color)
painter.drawRect(self.rect)
def drawApple(self):
print "Enters drawApple"
self.x_apple = np.random.randint(0, math.floor(self.BoardWidth/self.SquareWidth)) * self.SquareWidth
self.y_apple = np.random.randint(0, math.floor(self.BoardHeight/self.SquareHeight)) * self.SquareHeight
self.draw_apple == True
def eraseApple(self):
print "Enters eraseApple"
self.draw_apple == True
def main():
app = QtGui.QApplication([])
game = Game()
sys.exit(app.exec_())
if __name__ == '__main__':
main()

You should call the update() function as it calls paintEvent(). Also I recommend using a single timer for that task. You only have to deny the variable draw_apple to change state.
import sys, random
import numpy as np
import math
from PyQt4 import QtCore, QtGui
from PyQt4.QtCore import QTimer, QRect
from PyQt4.QtGui import QPaintEvent
class Game(QtGui.QMainWindow):
def __init__(self):
super(Game, self).__init__()
self.initUI()
def initUI(self):
palette = QtGui.QPalette()
palette.setColor(QtGui.QPalette.Background, QtCore.Qt.white)
self.setPalette(palette)
self.tboard = Board(self)
self.setCentralWidget(self.tboard)
self.resize(400, 400)
self.center()
self.setWindowTitle('Game')
self.show()
def center(self):
screen = QtGui.QDesktopWidget().screenGeometry()
size = self.geometry()
self.move((screen.width()-size.width())/2, (screen.height()-size.height())/2)
class Board(QtGui.QFrame):
BoardWidth = 400
BoardHeight = 400
SquareWidth = 15
SquareHeight = 15
Speed = 10000
def __init__(self, parent):
super(Board, self).__init__(parent)
#self.setAutoFillBackground(True)
self.setFocusPolicy(QtCore.Qt.StrongFocus)
self.timer_draw = QtCore.QTimer(self)
self.timer_draw.timeout.connect(self.drawApple)
self.timer_draw.start(self.Speed)
self.apple_color = QtCore.Qt.red
self.draw_apple = False
self.x_apple = 0
self.y_apple = 0
self.drawApple()
def paintEvent(self, event):
painter = QtGui.QPainter(self)
print "Paint Event?"
if self.draw_apple == True:
print "Draw"
self.apple_color = QtCore.Qt.red
else:
print "Do not draw"
self.apple_color = QtCore.Qt.white
painter.setPen(self.apple_color)
painter.drawRect(self.rect)
def drawApple(self):
self.draw_apple = not self.draw_apple
self.x_apple = np.random.randint(0, math.floor(self.BoardWidth/self.SquareWidth)) * self.SquareWidth
self.y_apple = np.random.randint(0, math.floor(self.BoardHeight/self.SquareHeight)) * self.SquareHeight
self.rect = QRect(self.x_apple, self.y_apple, self.SquareWidth, self.SquareHeight)
self.update()
def main():
app = QtGui.QApplication([])
game = Game()
sys.exit(app.exec_())
if __name__ == '__main__':
main()