I've written the following code to open image file using a menubar in PyQt5. It is able to select the file but not able to display it in the window. I've successfully opened text file but not able to do the same for images. Can you please rectify my error?
import sys
from PyQt5.QtWidgets import QMainWindow, QApplication, QWidget, QLabel, QFileDialog, QAction
from PyQt5.QtGui import QIcon, QPixmap
class MainWindow(QMainWindow):
def __init__(self, parent = None):
super(MainWindow, self).__init__(parent)
menubar = self.menuBar()
fileMenu = menubar.addMenu('File')
editMenu = menubar.addMenu('Edit')
self.resize(500, 500)
dlg = QFileDialog(self)
openAction = QAction('Open Image', self)
openAction.triggered.connect(self.openImage)
fileMenu.addAction(openAction)
closeAction = QAction('Exit', self)
closeAction.triggered.connect(self.close)
fileMenu.addAction(closeAction)
def openImage(self):
# This function is called when the user clicks File->Open Image.
label = QLabel(self)
filename = QFileDialog.getOpenFileName()
imagePath = filename[0]
print(imagePath)
pixmap = QPixmap(imagePath)
label.setPixmap(pixmap)
self.resize(pixmap.width(),pixmap.height())
self.show()
def main():
app = QApplication(sys.argv)
win = MainWindow()
win.show()
app.exec_()
if __name__ == '__main__':
sys.exit(main())
When you call show() the widget makes children visible, in your case QLabel is not a child when that method is used, so a trivial but partial solution is to make it visible:
def openImage(self):
label = QLabel(self)
label.show()
# or
# self.show()
But in the case of QMainWindow is not suitable, QMainWindow is a very special widgets because it has a definite structure as shown in the following image:
As you can see, QLabel is the centralWidget and create it only once, and then you only have to replace the QPixmap if you select a new image:
import sys
from PyQt5.QtWidgets import QMainWindow, QApplication, QLabel, QFileDialog, QAction
from PyQt5.QtGui import QPixmap
class MainWindow(QMainWindow):
def __init__(self, parent = None):
super(MainWindow, self).__init__(parent)
menubar = self.menuBar()
fileMenu = menubar.addMenu('File')
editMenu = menubar.addMenu('Edit')
self.resize(500, 500)
openAction = QAction('Open Image', self)
openAction.triggered.connect(self.openImage)
fileMenu.addAction(openAction)
closeAction = QAction('Exit', self)
closeAction.triggered.connect(self.close)
fileMenu.addAction(closeAction)
self.label = QLabel()
self.setCentralWidget(self.label)
def openImage(self):
imagePath, _ = QFileDialog.getOpenFileName()
pixmap = QPixmap(imagePath)
self.label.setPixmap(pixmap)
self.resize(pixmap.size())
self.adjustSize()
def main():
app = QApplication(sys.argv)
win = MainWindow()
win.show()
return app.exec_()
if __name__ == '__main__':
sys.exit(main())
Related
This question already has answers here:
How do I assert the identity of a PyQt5 signal?
(2 answers)
Closed 2 years ago.
I've created a search engine in PyQt5, using the code below:
import sys
from PyQt5.QtWidgets import (
QWidget, QLineEdit, QLabel, QScrollArea, QMainWindow,
QApplication, QHBoxLayout, QVBoxLayout, QSpacerItem, QSizePolicy, QCompleter, QPushButton
)
from PyQt5 import QtCore
from PyQt5.QtCore import Qt
tlist = ['thing1', 'thing2', 'thing3', 'thing4']
class Label(QWidget):
def __init__(self, name):
super(Label, self).__init__()
self.name = name
self.lbl = QLabel(self.name)
self.lbl.setTextInteractionFlags(QtCore.Qt.TextSelectableByMouse)
self.btn = QPushButton("Preview")
self.btn.setMaximumSize(QtCore.QSize(100,100))
self.btn.clicked.connect(self.printsignal)
self.hbox = QHBoxLayout()
self.hbox.addWidget(self.lbl)
self.hbox.addWidget(self.btn)
self.setLayout(self.hbox)
def show(self):
for labels in [self, self.lbl]:
labels.setVisible(True)
def hide(self):
for labels in [self, self.lbl]:
labels.setVisible(False)
def printsignal(self):
print("clicked")
class MainWindow(QMainWindow):
def __init__(self, *args, **kwargs):
super().__init__()
self.controls = QWidget()
self.controlsLayout = QVBoxLayout()
self.widgets = []
for name in tlist:
item = Label(name)
self.controlsLayout.addWidget(item)
self.widgets.append(item)
spacer = QSpacerItem(1, 1, QSizePolicy.Minimum, QSizePolicy.Expanding)
self.controlsLayout.addItem(spacer)
self.controls.setLayout(self.controlsLayout)
self.scroll = QScrollArea()
self.scroll.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
self.scroll.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.scroll.setWidgetResizable(True)
self.scroll.setWidget(self.controls)
self.searchbar = QLineEdit()
self.searchbar.textChanged.connect(self.update_display)
self.completer = QCompleter(tlist)
self.completer.setCaseSensitivity(Qt.CaseInsensitive)
self.searchbar.setCompleter(self.completer)
container = QWidget()
containerLayout = QVBoxLayout()
containerLayout.addWidget(self.searchbar)
containerLayout.addWidget(self.scroll)
container.setLayout(containerLayout)
self.setCentralWidget(container)
self.setGeometry(600, 100, 800, 600)
self.setWindowTitle('Search Engine')
def update_display(self, text):
for widget in self.widgets:
if text.lower() in widget.name.lower():
widget.show()
else:
widget.hide()
app = QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
The problem I have is, all the buttons share the same function and I don't know how to make them have different signals, as they are generated automatically. Basically, if I run the code it will show up like
this:
and when I press any of the buttons, it will print "clicked" (as in printsignal function). What I want is a different function for each button. Is there a way to do that?
Normally you can use self.sender().text() to get text from QButton which generated signal.
But because you create own widget Label with QButton and QLabel and you want text from label so you can get directly self.name
def printsignal(self):
print("clicked", self.name)
eventually self.lbl.text()
def printsignal(self):
print("clicked", self.lbl.text())
Working code.
I removed show(), hide() because you don't need it
import sys
from PyQt5.QtWidgets import (
QWidget, QLineEdit, QLabel, QScrollArea, QMainWindow,
QApplication, QHBoxLayout, QVBoxLayout, QSpacerItem, QSizePolicy, QCompleter, QPushButton
)
from PyQt5 import QtCore
from PyQt5.QtCore import Qt
tlist = ['thing1', 'thing2', 'thing3', 'thing4']
class Label(QWidget):
def __init__(self, name):
super().__init__()
self.name = name
self.lbl = QLabel(self.name)
self.lbl.setTextInteractionFlags(QtCore.Qt.TextSelectableByMouse)
self.btn = QPushButton("Preview")
self.btn.setMaximumSize(QtCore.QSize(100,100))
self.btn.clicked.connect(self.printsignal)
self.hbox = QHBoxLayout()
self.hbox.addWidget(self.lbl)
self.hbox.addWidget(self.btn)
self.setLayout(self.hbox)
def printsignal(self):
print("clicked", self.name)
class MainWindow(QMainWindow):
def __init__(self, *args, **kwargs):
super().__init__()
self.controls = QWidget()
self.controlsLayout = QVBoxLayout()
self.widgets = []
for name in tlist:
item = Label(name)
self.controlsLayout.addWidget(item)
self.widgets.append(item)
spacer = QSpacerItem(1, 1, QSizePolicy.Minimum, QSizePolicy.Expanding)
self.controlsLayout.addItem(spacer)
self.controls.setLayout(self.controlsLayout)
self.scroll = QScrollArea()
self.scroll.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOn)
self.scroll.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
self.scroll.setWidgetResizable(True)
self.scroll.setWidget(self.controls)
self.searchbar = QLineEdit()
self.searchbar.textChanged.connect(self.update_display)
self.completer = QCompleter(tlist)
self.completer.setCaseSensitivity(Qt.CaseInsensitive)
self.searchbar.setCompleter(self.completer)
container = QWidget()
containerLayout = QVBoxLayout()
containerLayout.addWidget(self.searchbar)
containerLayout.addWidget(self.scroll)
container.setLayout(containerLayout)
self.setCentralWidget(container)
self.setGeometry(600, 100, 800, 600)
self.setWindowTitle('Search Engine')
def update_display(self, text):
for widget in self.widgets:
if text.lower() in widget.name.lower():
widget.show()
else:
widget.hide()
app = QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
I'd like to create a widget inside a MainWindow that gets its design from a file created with QtDesigner.
the .ui file I created is test.ui
I have a MainWindow instance inheriting from QMainWindow that will create a stacked widget with many widgets inside it. For simplicity in this example, it will create just a widget as central widget.
The My Widget instance inside the MainWindow is the one that has to grab its design from the .ui file
As it is, the application shows a blank window
Here is the code:
from PySide2.QtWidgets import QMainWindow, QApplication, QDesktopWidget, QWidget
from PySide2.QtCore import QCoreApplication, Qt
from PySide2.QtUiTools import QUiLoader
from PySide2.QtCore import QFile
class MyWidget(QWidget):
def __init__(self, parent=None):
super(MyWidget, self).__init__(parent)
ui_file = QFile("test.ui")
ui_file.open(QFile.ReadOnly)
loader = QUiLoader()
window = loader.load(ui_file)
ui_file.close()
class MainWindow(QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
self.ui_dim_percentage = 70/100
self.initUI()
def initUI(self):
self.center()
self.home_widget = MyWidget(self)
self.setCentralWidget(self.home_widget)
self.show()
def center(self): # resizes the UI to a percentage of the screen and centers the widget
screen_size = QDesktopWidget().screenGeometry()
self.resize(screen_size.width()*self.ui_dim_percentage, screen_size.height()*self.ui_dim_percentage)
qr = self.frameGeometry()
cp = QDesktopWidget().availableGeometry().center()
qr.moveCenter(cp)
self.move(qr.topLeft())
def main():
app = QApplication(sys.argv)
ex = MainWindow()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
How should I correct the code?
The problem is that you are confusing concepts, when you use QUiLoader you are creating the window that in this case is the window variable that is a local variable, that is, the .ui does not fill in MyWidget.
The solution is not to create the MyWidget class, just use the window variable.
from PySide2.QtWidgets import QMainWindow, QApplication, QDesktopWidget
from PySide2.QtCore import QFile
from PySide2.QtUiTools import QUiLoader
def create_widget():
ui_file = QFile("test.ui")
if ui_file.open(QFile.ReadOnly):
loader = QUiLoader()
window = loader.load(ui_file)
ui_file.close()
return window
class MainWindow(QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
self.ui_dim_percentage = 70 / 100
self.initUI()
def initUI(self):
self.center()
self.home_widget = create_widget()
self.setCentralWidget(self.home_widget)
self.show()
# resizes the UI to a percentage of the screen and centers the widget
def center(self):
screen_size = QDesktopWidget().screenGeometry()
self.resize(
screen_size.width() * self.ui_dim_percentage,
screen_size.height() * self.ui_dim_percentage,
)
qr = self.frameGeometry()
cp = QDesktopWidget().availableGeometry().center()
qr.moveCenter(cp)
self.move(qr.topLeft())
def main():
import sys
app = QApplication(sys.argv)
ex = MainWindow()
sys.exit(app.exec_())
if __name__ == "__main__":
main()
Have you tried to convert your ui-file?
You can use pyuic4 command on shell:
pyuic4 test.ui -o test.py
I have two files, one for my main window, which has one image and one button and one for a new window. What I want it to do is that when I push the button from my main window, it lets me load a file and show it in a TextEdit widget in the new window
so here I have the files I'm using:
MainWindow.py
import sys
import os
from PyQt5 import QtWidgets, QtGui
from PyQt5.QtWidgets import QApplication, QWidget
from PyQt5.QtWidgets import QPushButton, QVBoxLayout, QTextEdit, QHBoxLayout, QLabel, QMainWindow, QAction, QFileDialog
class Window(QWidget):
def __init__(self, parent=None):
super(Window, self).__init__(parent)
self.img = QLabel()
self.relleno=QLabel()
self.btn_load = QPushButton('Load')
self.width = 400
self.height = 150
self.init_ui()
def init_ui(self):
self.img.setPixmap(QtGui.QPixmap("someimage.png"))
h_layout = QHBoxLayout()
v_layout = QVBoxLayout()
h_final = QHBoxLayout()
h_layout.addWidget(self.img)
v_layout.addWidget(self.btn_load)
h_final.addLayout(h_layout)
h_final.addLayout(v_layout)
self.btn_load.clicked.connect(self.loadafile)
self.setLayout(h_final)
self.setWindowTitle('This is main window')
self.setGeometry(600,150,self.width,self.height)
self.show()
def loadafile(self):
filename = QFileDialog.getOpenFileName(self, 'Open File', os.getenv('HOME'))
with open(filename[0], 'r') as f:
file_text = f.read()
return file_text
def main():
app = QApplication(sys.argv)
main = Window()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
NewWindow.py
import os
import sys
from PyQt5.QtWidgets import QApplication, QWidget, QTextEdit, QVBoxLayout
from MainWindow import loadafile
info=loadafile()
class SecondWindow(QWidget):
def __init__(self):
super(SecondWindow, self).__init__()
self.text = QTextEdit(self)
self.init_ui()
def init_ui(self):
v_layout = QVBoxLayout()
v_layout.addWidget(self.text)
self.setLayout(v_layout)
self.setText(info)
self.setWindowTitle('Opened Text')
self.show()
app = QApplication(sys.argv)
shower = SecondWindow()
sys.exit(app.exec_())
I think the loadafile does return my file_text variable but I don't know how to open the new window from there. I think I need to use a destructor for main window and then show the new window but I'm not sure of how to do this (This is the first time I try OOP)
A program is not a set of files, especially in OOP a program is the interactions of objects. And the objects interact if they have the same scope, so both windows must be created in one place so that the information from one pass to the other.
On the other hand in Qt there is a fundamental concept that is the signals, this functionality allows to notify the change of a state to another object without a lot of dependency, so in this case I will create a signal that transmits the text to the other object.
NewWindow.py
from PyQt5 import QtWidgets
class SecondWindow(QtWidgets.QWidget):
def __init__(self):
super(SecondWindow, self).__init__()
self.text = QtWidgets.QTextEdit(self)
self.init_ui()
def init_ui(self):
v_layout = QtWidgets.QVBoxLayout(self)
v_layout.addWidget(self.text)
self.setWindowTitle('Opened Text')
self.show()
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
shower = SecondWindow()
sys.exit(app.exec_())
MainWindow.py
import os
import sys
from PyQt5 import QtCore, QtGui, QtWidgets
from NewWindow import SecondWindow
class Window(QtWidgets.QWidget):
textChanged = QtCore.pyqtSignal(str)
def __init__(self, parent=None):
super(Window, self).__init__(parent)
self.img =QtWidgets.QLabel()
self.relleno=QtWidgets.QLabel()
self.btn_load = QtWidgets.QPushButton('Load')
self.width = 400
self.height = 150
self.init_ui()
def init_ui(self):
self.img.setPixmap(QtGui.QPixmap("someimage.png"))
h_final = QtWidgets.QHBoxLayout(self)
h_final.addWidget(self.img)
h_final.addWidget(self.btn_load)
self.btn_load.clicked.connect(self.loadafile)
self.setWindowTitle('This is main window')
self.setGeometry(600,150,self.width,self.height)
self.show()
#QtCore.pyqtSlot()
def loadafile(self):
filename, _ = QtWidgets.QFileDialog.getOpenFileName(self, 'Open File', os.getenv('HOME'))
with open(filename, 'r') as f:
file_text = f.read()
self.textChanged.emit(file_text)
def main():
app = QtWidgets.QApplication(sys.argv)
main = Window()
s = SecondWindow()
main.textChanged.connect(s.text.append)
sys.exit(app.exec_())
if __name__ == '__main__':
main()
I have a QMainWindow with a toolbar, and I'm having troubles with fitting the QPixmap to the window, such that it won't tackle with the toolbar.
I want to display the picture:
And from the code:
import sys
from PyQt5.QtCore import QRect
from PyQt5.QtWidgets import QAction, QMainWindow, QApplication
from PyQt5.QtGui import QPixmap, QPainter
class Menu(QMainWindow):
def __init__(self):
super().__init__()
newAct = QAction('New', self)
self.toolbar = self.addToolBar('Remove')
self.toolbar.addAction(newAct)
self.image = QPixmap("background.png")
self.setGeometry(100, 30, 500, 300)
self.resize(self.image.width(), self.image.height())
self.show()
def paintEvent(self, event):
painter = QPainter(self)
rect = QRect(0, 0, self.image.width(), self.image.height())
painter.drawPixmap(rect, self.image)
if __name__ == '__main__':
app = QApplication(sys.argv)
mainMenu = Menu()
sys.exit(app.exec_())
I get:
And as you can see, The picture is on the toolbar as well, and I don't want that.
Another try:
import sys
from PyQt5.QtCore import QRect
from PyQt5.QtWidgets import QAction, QMainWindow, QApplication
from PyQt5.QtGui import QPixmap, QPainter
class Menu(QMainWindow):
def __init__(self):
super().__init__()
newAct = QAction('New', self)
self.toolbar = self.addToolBar('Remove')
self.toolbar.addAction(newAct)
self.image = QPixmap("background.png")
self.setGeometry(100, 30, 500, 300)
self.resize(self.image.width(), self.image.height() + self.toolbar.height())
self.show()
def paintEvent(self, event):
painter = QPainter(self)
rect = QRect(0, self.toolbar.height(), self.image.width(), self.image.height() + self.toolbar.height())
painter.drawPixmap(rect, self.image)
if __name__ == '__main__':
app = QApplication(sys.argv)
mainMenu = Menu()
sys.exit(app.exec_())
But I get:
And as you can see, I don't see one of the lines (the blue one).
How can I fix it, so the picture will fit the window excluding the toolbar?
In addition to that, it means I'll have to change all my mouse clicks to move the y-axis. Is there perhaps a way I can set everything such that (x,y)=(0,0) would be at the uppermost left, below the toolbar?
I'm using Python 3.6.5 |Anaconda custom (64-bit) on windows | PyQt version: 5.9.2
Although I can not reproduce the problem, the following solution must work, in it I draw the image in a widget and I set them as centralwidget.
import sys
from PyQt5.QtCore import QRect
from PyQt5.QtWidgets import QAction, QMainWindow, QApplication, QWidget
from PyQt5.QtGui import QPixmap, QPainter
class Widget(QWidget):
def __init__(self, parent=None):
super().__init__(parent)
self.image = QPixmap("background.png")
self.setFixedSize(self.image.size())
def paintEvent(self, event):
painter = QPainter(self)
painter.drawPixmap(self.rect(), self.image)
class Menu(QMainWindow):
def __init__(self):
super().__init__()
newAct = QAction('New', self)
self.toolbar = self.addToolBar('Remove')
self.toolbar.addAction(newAct)
self.setCentralWidget(Widget())
self.setFixedSize(self.sizeHint())
self.show()
if __name__ == '__main__':
app = QApplication(sys.argv)
mainMenu = Menu()
sys.exit(app.exec_())
How do I alter the following code to make it print whatever is written in line edit widget when 'OK' button is pressed? The current version returns "'Example' object has no attribute 'textbox'" error.
import sys
from PyQt5.QtWidgets import QApplication, QWidget,QPushButton,QLineEdit, QHBoxLayout, QLabel, QVBoxLayout
from PyQt5.QtGui import QIcon
class Example(QWidget):
def __init__(self):
super().__init__()
self.initUI()
def initUI(self):
label = QLabel('Keyword')
button = QPushButton('OK')
textbox = QLineEdit()
hbox = QHBoxLayout()
hbox.addWidget(label)
hbox.addWidget(textbox)
hbox.addWidget(button)
vbox = QVBoxLayout()
vbox.addLayout(hbox)
vbox.addStretch(1)
button.clicked.connect(self.button_clicked)
self.setLayout(vbox)
self.setGeometry(300, 300, 300, 220)
self.setWindowTitle('Icon')
self.setWindowIcon(QIcon('web.png'))
self.show()
def button_clicked(self):
print(self.textbox.text())
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = Example()
sys.exit(app.exec_())
`
if you want that a variable can be accessed in all parts of the class as in your case is the button_clicked method you must make it a member of the class for it you must use self when you create it.
class Example(QWidget):
[...]
def initUI(self):
label = QLabel('Keyword')
button = QPushButton('OK')
self.textbox = QLineEdit() # change this line
hbox = QHBoxLayout()
hbox.addWidget(label)
hbox.addWidget(self.textbox) # change this line