QPalette , set background image Python3 PyQT4 - python-3.x

I am trying to set a background image to a QFrame I am calling in a QMainWindows like such :
class MainWin(QtGui.QMainWindow):
def __init__(self):
super(MainWin, self).__init__()
self.initUI()
def initUI(self):
#central widget
self.theboard = Board(self)
self.setCentralWidget(self.theboard)
class Board(QtGui.QFrame):
def __init__(self, parent):
super(Board, self).__init__(parent)
self.initBoard()
def initBoard(self):
#Set background Image
frame = Board
palette = QPalette()
palette.setBrush(QPalette.Background,QBrush(QPixmap("ImageTest.jpg")))
frame.setPalette(palette)
Using Qpalette / Qpixmap as I have found on some exemple on the net.
But it don't work :
self.palette = QPalette()
NameError: global name 'QPalette' is not defined
Why ? Here my class : class Board(QtGui.QFrame):
I am well inheriting of QtGui so Qpalette should work.
I have to admit I am a bit confuse with the way Qpalette works.
Any help much apreciated,
Thanks !

You didn't write it in your code, so perhaps your issue is you didn't import it.
from PyQt4 import QtCore, QtGui
from PyQt4.QtGui import QPalette
If that isn't the case, try this:
palette = QPalette()
palette.setBrush(QPalette.Background,QBrush(QPixmap("anne.jpg"))) # Haha, aren't I so funny??
frame.setPalette(palette)

Related

How to create Signal for QDockWidget?

When QTabWidget is used, it is straightforward to call a function (e.g. on_tab_changed) when any of the tabs is clicked on with something like self.currentChanged.connect(self.on_tab_changed). However, I cannot figure out how to do similarly with QDockWidget. I was able to come up with a simplified MRE that reads:
from PyQt5.QtWidgets import *
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys
class Window(QMainWindow):
def __init__(self):
super().__init__()
self.setWindowTitle("OOP")
self.uinterface()
self.show()
def uinterface(self):
self.dock = QDockWidget("OOP example", self)
self.listWidget = QListWidget()
self.listWidget.addItem("One")
self.listWidget.addItem("Two")
self.listWidget.addItem("Three")
self.dock.setWidget(self.listWidget)
self.dock.currentChanged.connect(self.on_tab_changed) # This is the line that I'd like to modify
def on_tab_changed(self, index: int) -> None:
print ("DO SOMETHING")
App = QApplication(sys.argv)
window = Window()
sys.exit(App.exec())
This doesn't work because currentChanged is not a Signal for QDockWidget (which is for QTabWidget) although both derive from QWidget. I want to come up with a relatively simple way to accomplish this task as converting QDockWidget into QTabWidget is relatively straightforward for the MRE but a lot more complex and time consuming for the whole app.
P.S. Based on some of the comments, maybe the code could have read
...
self.dock.setWidget(self.listWidget)
self.dock.Clicked.connect(self.on_dockwidget_clicked)
def on_dockwidget_clicked(self) -> None:
print ("DO SOMETHING")
albeit this still would not work and it'd be necessary to use the accepted solution.
You could overwrite the the event method a QDockWidget subclass and listen for mousePressEvents and emit a custom signal that sends some kind of identifier, in case you have multiple dockWidgets and you need to know which one sent the signal. Then you can set your mainWindow to listen for the custom signal and connect you method slot to it.
For Example:
from PyQt5.QtWidgets import *
from PyQt5 import QtCore, QtGui
from PyQt5.QtGui import *
from PyQt5.QtCore import *
import sys
class DockWidget(QDockWidget):
hasFocus = pyqtSignal([QDockWidget])
def __init__(self, text, parent=None):
super().__init__(text, parent=parent)
self.setObjectName(text)
def event(self, event):
if event.type() == QEvent.MouseButtonPress and event.button() == 1:
self.hasFocus.emit(self)
return super().event(event)
class Window(QMainWindow):
def __init__(self):
super().__init__()
self.setWindowTitle("OOP")
self.uinterface()
self.show()
def uinterface(self):
self.dock = DockWidget("OOP example", self)
self.listWidget = QListWidget()
self.listWidget.addItem("One")
self.listWidget.addItem("Two")
self.listWidget.addItem("Three")
self.dock.setWidget(self.listWidget)
self.dock.hasFocus.connect(self.on_dock_focus)
def on_dock_focus(self, dockwidget):
print(f"DO SOMETHING WITH {dockwidget.objectName()}")
App = QApplication(sys.argv)
window = Window()
sys.exit(App.exec())

How to translate ui file + several questions [duplicate]

I am trying to translate my small application written in pyside2/pyqt5 to several languages, for example, Chinese. After googling, I managed to change the main window to Chinese after select from the menu -> language -> Chinese. However, the pop up dialog from menu -> option still remains English version. It seems the translation info is not transferred to the dialog. How do I solve this?
Basically, I build two ui files in designer and convert to two python files:One mainui.py and one dialogui.py. I then convert the two python file into one *.ts file using
pylupdate5 -verbose mainui.py dialogui.py -ts zh_CN.ts
after that, in linguist input the translation words. I can see the items in the dialog, which means this information is not missing. Then I release the file as zh_CN.qm file. All this supporting file I attached below using google drive.
Supporting files for the question
The main file is as
import os
import sys
from PySide2 import QtCore, QtGui, QtWidgets
from mainui import Ui_MainWindow
from dialogui import Ui_Dialog
class OptionsDialog(QtWidgets.QDialog,Ui_Dialog):
def __init__(self,parent):
super().__init__(parent)
self.setupUi(self)
self.retranslateUi(self)
class MainWindow(QtWidgets.QMainWindow,Ui_MainWindow):
def __init__(self):
super().__init__()
self.setupUi(self)
self.actionConfigure.triggered.connect(self.showdialog)
self.actionChinese.triggered.connect(self.change_lang)
def showdialog(self):
dlg = OptionsDialog(self)
dlg.exec_()
def change_lang(self):
trans = QtCore.QTranslator()
trans.load('zh_CN')
QtCore.QCoreApplication.instance().installTranslator(trans)
self.retranslateUi(self)
if __name__=='__main__':
app = QtWidgets.QApplication(sys.argv)
mainWin = MainWindow()
mainWin.show()
ret = app.exec_()
sys.exit(ret)
I think it should be a typical task because almost no application will only have a mainwindow.
You have to overwrite the changeEvent() method and call retranslateUi() when the event is of type QEvent::LanguageChange, on the other hand the QTranslator object must be a member of the class but it will be deleted and it will not exist when the changeEvent() method is called.
Finally assuming that the Language menu is used to establish only translations, a possible option is to establish the name of the .qm as data of the QActions and to use the triggered method of the QMenu as I show below:
from PySide2 import QtCore, QtGui, QtWidgets
from mainui import Ui_MainWindow
from dialogui import Ui_Dialog
class OptionsDialog(QtWidgets.QDialog,Ui_Dialog):
def __init__(self,parent):
super().__init__(parent)
self.setupUi(self)
def changeEvent(self, event):
if event.type() == QtCore.QEvent.LanguageChange:
self.retranslateUi(self)
super(OptionsDialog, self).changeEvent(event)
class MainWindow(QtWidgets.QMainWindow,Ui_MainWindow):
def __init__(self):
super().__init__()
self.setupUi(self)
self.m_translator = QtCore.QTranslator(self)
self.actionConfigure.triggered.connect(self.showdialog)
self.menuLanguage.triggered.connect(self.change_lang)
# set translation for each submenu
self.actionChinese.setData('zh_CN')
#QtCore.Slot()
def showdialog(self):
dlg = OptionsDialog(self)
dlg.exec_()
#QtCore.Slot(QtWidgets.QAction)
def change_lang(self, action):
QtCore.QCoreApplication.instance().removeTranslator(self.m_translator)
if self.m_translator.load(action.data()):
QtCore.QCoreApplication.instance().installTranslator(self.m_translator)
def changeEvent(self, event):
if event.type() == QtCore.QEvent.LanguageChange:
self.retranslateUi(self)
super(MainWindow, self).changeEvent(event)
if __name__=='__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
mainWin = MainWindow()
mainWin.show()
ret = app.exec_()
sys.exit(ret)

Why doesn't this custom QWidget display correctly

I'm retrying this question with a much better code example.
The code below, in its current form, will display a green shaded QWidget in a window, which is what I want. However, when commenting out the line:
self.widget = QWidget(self.centralwidget)
and uncommenting,
self.widget = Widget_1(self.centralwidget)
the green box doesn't display. The Widget_1 class is a simple subclass of QWidget, so I'm trying to wrap my head around where the breakdown is occurring. There are no error messages, and the print("Test") line within the Widget_1 class is outputting just fine, so I know everything is being called properly.
I'm not looking to use any type of automated layouts for reasons I don't need to go into here. Can you help me to understand why the green rectangle isn't displaying, and what correction I would need to make in order to utilize the Widget_1 class?
from PyQt5.QtWidgets import QApplication, QMainWindow, QWidget
from PyQt5.QtCore import QRect
import sys
class Main_Window(object):
def setupUi(self, seating_main_window):
seating_main_window.setObjectName("seating_main_window")
seating_main_window.setEnabled(True)
seating_main_window.resize(400, 400)
self.centralwidget = QWidget(seating_main_window)
self.centralwidget.setObjectName("centralwidget")
########### The following two lines of code are causing the confusion #######
# The following line, when uncommented, creates a shaded green box in a window
self.widget = QWidget(self.centralwidget) # Working line
# The next line does NOT create the same shaded green box. Where is it breaking?
# self.widget = Widget_1(self.centralwidget) # Non-working line
self.widget.setGeometry(QRect(15, 150, 60, 75))
self.widget.setAutoFillBackground(False)
self.widget.setStyleSheet("background: rgb(170, 255, 0)")
self.widget.setObjectName("Widget1")
seating_main_window.setCentralWidget(self.centralwidget)
class Widget_1(QWidget):
def __init__(self, parent=None):
super().__init__()
self.setMinimumSize(10, 30) # I put this in thinking maybe I just couldn't see it
print("Test") # I see this output when run when Widget_1 is used above
class DemoApp(QMainWindow, Main_Window):
def __init__(self):
super().__init__()
self.setupUi(self)
if __name__ == '__main__': # if we're running file directly and not importing it
app = QApplication(sys.argv) # A new instance of QApplication
form = DemoApp() # We set the form to be our ExampleApp (design)
form.show() # Show the form
app.exec_() # run the main function
Accoriding to this Qt Wiki article:
How to Change the Background Color of QWidget
you must implement paintEvent in a custom QWidget subclass in order to use stylesheets. Also, since the widget is not part of a layout, you must give it a parent, otherwise it will not be shown. So your Widget_1 class must look like this:
from PyQt5.QtWidgets import QStyleOption, QStyle
from PyQt5.QtGui import QPainter
class Widget_1(QWidget):
def __init__(self, parent=None):
super().__init__(parent) # set the parent
print("Test")
def paintEvent(self, event):
option = QStyleOption()
option.initFrom(self)
painter = QPainter(self)
self.style().drawPrimitive(QStyle.PE_Widget, option, painter, self)
super().paintEvent(event)

Threads communication in PyQt5

I was looking everywhere but I was unable to figure out answer to my problem. I need your help regarding QThread threading in PyQt5. For the purpose of learning I've created two classes in my main.py file. One of those classes is a GUI class and the other one is a thread created using QThread object.
from PyQt5 import QtCore, QtGui, QtWidgets
import threading_gui # contains GUI generated by pyuic5
class Change_values(QtCore.QThread):
def __init__(self, parent = None, str_variable, int_variable):
self.var1 = str_variable
self.var2 = int_variable
def run(self):
self.var1 += ' testing thread communication'
self.var2 += 4
class MainWindow(QtWidgets.QMainWindow, threading_gui.UI_MainWindow):
change_signal = QtCore.pyqtSignal(str, int, name='change_signal')
def __init__(self, parent = None):
super(MainWindow, self).__init__(parent)
self.setupUi(self)
self.btn_Run.clicked.connect(self.process_data)
self.thread1 = Change_values('I am', 3)
def process_data(self):
self.thread1.start()
This is as far as I managed to do. Now I need someone to explain me how can I emit signal from thread Change_values and display the content of variables var1 and var2 in my GUI thread.
I was able to find examples for PyQt4 but nothing useful when it comes to PyQt5. Thank you all in advance.

PyQt and QtDesigner

I am trying to implement a LED in PyQt named disLDR1 by trying to change the background color. I am trying to use QPalette to change the BackgroundRole. But what is the equivalent of Qt::red?
Is this the correct way to set the background color or is there any other way?
#!/usr/bin/python -d
import sys
from PyQt4 import QtCore, QtGui
from main import Ui_Form
from PyQt4.QtGui import QPalette
class Top(QtGui.QMainWindow):
def __init__(self, parent = None):
QtGui.QWidget.__init__(self, parent)
self.ui = Ui_Form()
self.ui.setupUi(self)
for i in 1, 10:
self.setOff()
self.setOn()
def setOff(self):
self.pal = QPalette(self.ui.disLDR1.palette())
self.pal.setColor(self.ui.disLDR1.backgroundRole(), <<<RED COLOR>>>)
self.ui.disLDR1.setPalette(pal)
def setOn(self):
self.pal = QPalette(self.ui.disLDR1.palette())
self.pal.setColor(self.ui.disLDR1.backgroundRole(), <<<GREEN COLOR>>>)
self.ui.disLDR1.setPalette(pal)
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
myapp = Top()
myapp.show()
sys.exit(app.exec_())
EDIT: I have been trying to take help from In Qt, how do I set the background color of a widget like combobox or double spin box? but don't know what to substitute for QT::red
You can find the list of predefined Qt color objects at this link. In this case you would just need to use QtCore.Qt.red and QtCore.Qt.blue. You could also use the QColor class to generate arbitrary colors.
It's a matter of preference, but I personally think the easiest and most powerful way to go would be to use a style sheet.

Resources