I want to make a P2P chat application.
So I have this sig / slot pieces together myself. What I need to achieve is that I want to enter text in the QLineEdit (named it send_box) and display in the QTextedit (named it main_text).
self.send_box.returnPressed.connect(self.sendData)
and here is the function definition
def sendData(self):
self.main_text.setText ('Hello World')
This works. But only send the "Hello World" to the QTextEdit when I press Enter key.
What I need is to send the text from the send_box (QLineEdit).
To get text from send_box and
replace text in main_text
self.main_text.setText( self.send_box.text() )
append to existing text in main_text
self.main_text.append( self.send_box.text() )
And then you can clear text in send_box
self.send_box.clear()
See doc for Qt5 (it's similar for PyQt5): QTextEdit and QLineEdit
Full example
from PyQt5 import QtGui, QtWidgets
import sys
class MyWindow(QtWidgets.QWidget):
def __init__(self):
super().__init__()
self.vbox = QtWidgets.QVBoxLayout()
self.setLayout(self.vbox)
self.vbox.addWidget(QtWidgets.QLabel(text='Input:'))
self.linetext = QtWidgets.QLineEdit()
self.vbox.addWidget(self.linetext)
self.linetext.returnPressed.connect(self.on_press_enter)
self.vbox.addWidget(QtWidgets.QLabel(text='Output:'))
self.textedit = QtWidgets.QTextEdit()
self.vbox.addWidget(self.textedit)
self.show()
def on_press_enter(self):
# copy from LineText to TextEdit
#self.textedit.setText(self.linetext.text())
self.textedit.append(self.linetext.text())
# clear LineText
self.linetext.clear()
app = QtWidgets.QApplication(sys.argv)
window = MyWindow()
app.exec()
Related
I need help figuring out how to use the value written in a textbox in PyQT5, and use that value to build an IF statement. Any suggestions on how to do it? I have tried to declare the text in the textbox as a variable and use it in the IF statement but I can't seem to figure it out how to do it properly, and every time i run the code, some exit code shows (-1073741819 (0xC0000005) ).
Summing up, can't use pass the value of the textbox to the variable in order to do an IF statement.
I had this code down below:
from PyQt5 import QtWidgets
from PyQt5.QtWidgets import QApplication, QMainWindow, QPushButton, QTextEdit
def window():
app = QApplication(sys.argv)
win = QMainWindow()
win.setGeometry(200, 200, 400, 400)
win.setWindowTitle("Register Program")
label = QtWidgets.QLabel(win)
label.setText("Random Text")
label.move(169, 15)
label2 = QtWidgets.QLabel(win)
label2.resize(300, 100)
label2.setText("1- Register new person\n2- See all regestries\n3- See last regestry\n\nPress ESC to exit\n")
label2.move(70, 50)
textbox = QtWidgets.QLineEdit(win)
textbox.setText("")
textbox.resize(250, 25)
textbox.move(70, 250)
button1 = QtWidgets.QPushButton(win)
button1.move(150, 300)
button1.setText("Submit")
button1.clicked.connect(clicked)
button2 = QtWidgets.QPushButton(win)
button2.move(150, 335)
button2.setText("Close")
button2.clicked.connect(close)
win.show()
sys.exit(app.exec_())
def clicked():
inpt = int(window().textbox.text)
if inpt == 1:
print("Hello")
def close():
sys.exit()
window()```
If you're just looking to get user input, there's a builtin static method you can call for requesting input of a particular type: https://doc.qt.io/qt-5/qinputdialog.html#getText
If you want to make your own widget however, you need to use the signals and slots to trigger a python method to store the value. This is easiest to do in a class. You can trigger the method whenever the text changes with the textChanged signal and do whatever you need to do with it.
(Note, I haven't run this as I don't have PyQt5 currently installed, but it should work)
from PyQt5 import QtCore, QtGui, QtWidgets
class Widget(QtWidgets.QWidget):
def __init__(self, parent=None):
# type: (QtWidgets.QWidget) -> None
super(Widget, self).__init__(parent)
self.line_edit = QtWidgets.QLineEdit()
main_layout = QtWidgets.QVBoxLayout()
main_layout.addWidget(self.line_edit)
self.setLayout(main_layout)
self.line_edit.textChanged.connect(self.on_text_changed)
def get_text(self):
return self.line_edit.text()
def on_text_changed(self, text):
print("The text was changed to:", text)
if __name__ == '__main__':
app = QtWidgets.QApplication([])
widget = Widget()
widget.show()
app.exec_()
Edit: Also, to clarify why you're getting an error, QApplication is a singleton. This means there can only ever be one created. If you try to create a second, you'll get an error. The best way to access the current QApplication is to call QApplication.instance(). You also only call app.exec_() once, as once the application is running it will continue to run in the background. You should use signal/slots to interact with the UI and trigger the code you want to run.
I am trying to create a GUI for my python program. One of the tools that I need is a text input box.
Now, I want a text label for this box saying "Please insert texts." Is there a function to add a label that shows inside the input textbox as default and disappear when user click the box to type?
I don't mind to use qt designer or pyqt5 coding.
Thank you guys.
placeholderText : QString
This property holds the line edit's placeholder text
import sys
from PyQt5.QtWidgets import QLineEdit, QVBoxLayout, QApplication, QWidget
class Test(QWidget):
def __init__(self):
super().__init__()
self.lineEdit = QLineEdit(placeholderText="Please insert texts.") # <---
vbox = QVBoxLayout(self)
vbox.addWidget(self.lineEdit)
if __name__ == '__main__':
app = QApplication(sys.argv)
w = Test()
w.show()
sys.exit(app.exec_())
I am begginer like you and my English is not so good. But I recommend you use Qt Designer. It's easier, fastter for you draw your app. I am using pyside2 project and recommend you read docummentatio each widgets you wanna use in PySide2 project and Qt Project. Try code below
enter image description here
import sys
from PySide2.QtWidgets import QApplication
from PySide2.QtWidgets import QDialog
from PySide2.QtWidgets import QTextEdit
from PySide2.QtWidgets import QVBoxLayout
from PySide2.QtCore import Qt
class MainDialog(QDialog):
def __init__(self, parent=None):
super(MainDialog, self).__init__(parent)
# Create Widget TextEdit
self.text = QTextEdit()
# I think that you wanna this function in your program
# https://doc.qt.io/qtforpython/PySide2/QtWidgets/QLineEdit.html?highlight=qlineedit#PySide2.QtWidgets.PySide2.QtWidgets.QLineEdit.setPlaceholderText
# http://doc.qt.io/qt-5/qlineedit.html#placeholderText-prop
self.text.setPlaceholderText('''Yes! this is exactly what I want!
Thank you, what if you have a big text box (more than 10 lines) and
you want to scale up the place holder and align it in center?? ''')
# https://doc.qt.io/qtforpython/PySide2/QtWidgets/QLineEdit.html?highlight=qlineedit#PySide2.QtWidgets.PySide2.QtWidgets.QLineEdit.setAlignment
# http://doc.qt.io/qt-5/qlineedit.html#alignment-prop
self.text.setAlignment(Qt.AlignCenter)
# Layout
layout = QVBoxLayout()
layout.addWidget(self.text)
self.setLayout(layout)
def main():
app = QApplication()
mainDialog = MainDialog()
mainDialog.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
I need to execute a block of code when the user clicks on the tab of a tabbified QDockWidget. So far I've been doing this via a hack using the "visibilityChanged" event but this is now causing issues (for example, if I have several tabbified dock widgets and I drag one out so that it is floating, the tabbified one underneath will fire its "visibilityChanged" event which I will mistakenly interpret as the user clicking the tab). How can I receive proper notification when a user clicks on a QDockWidgets' tab? I've experimented with the "focusInEvent" of QDockWidget but it doesn't seem to fire when the tab is clicked.
When you use tabifyDockWidget() method QMainWindow creates a QTabBar, this is not directly accessible but using findChild() you can get it, and then use the tabBarClicked signal
from PyQt4 import QtCore, QtGui
class MainWindow(QtGui.QMainWindow):
def __init__(self, parent=None):
super(MainWindow, self).__init__(parent)
first_dock = None
for i in range(10):
dock = QtGui.QDockWidget("title {}".format(i), self)
dock.setWidget(QtGui.QTextEdit()) # testing
self.addDockWidget(QtCore.Qt.TopDockWidgetArea, dock)
if first_dock:
self.tabifyDockWidget(first_dock, dock)
else:
first_dock = dock
dock.raise_()
tabbar = self.findChild(QtGui.QTabBar, "")
tabbar.tabBarClicked.connect(self.onTabBarClicked)
def onTabBarClicked(self, index):
tabbar = self.sender()
text = tabbar.tabText(index)
print("index={}, text={}".format(index, text))
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
w = MainWindow()
w.show()
sys.exit(app.exec_())
I'm working on a small application for work w/ python and PyQt4 for the GUI. What I'm trying to accomplish is having a tabbed GUI where when a user clicks on a menu item, the action taken adds a tab to the QTabWidget. I'm currently having trouble getting an action to do such a thing. I've tried creating the GUI by hand and with QT designer, but I cant figure out how, if at all possible, to get an action to add a tab to the QTabWidget. This is my python code:
import sys
from PyQt4 import QtGui, uic
class TestGUI(QtGui.QMainWindow):
def __init__(self):
super(TestGUI, self).__init__()
uic.loadUi('TEST.ui', self)
self.show()
self.actionAdd_Tab.triggered.connect(addTab)
def addTab():
print 'This works'
#Add new tab to GUI
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
window = TestGUI()
sys.exit(app.exec_())
Pressing the menu item prints 'This works' to the console, so I know that its calling the addTab() function, but how do I get it to add a Tab?
Let me know if you would like to see the .ui file if it will help
The handler for your action needs to create a tab label, and also a widget for the contents of the tab, so that they can be added to the tabwidget.
As a start, try something like this:
import sys
from PyQt4 import QtGui, uic
class TestGUI(QtGui.QMainWindow):
def __init__(self):
super(TestGUI, self).__init__()
uic.loadUi('TEST.ui', self)
self.actionAdd_Tab.triggered.connect(self.handleAddTab)
def handleAddTab(self):
contents = QtGui.QWidget(self.tabWidget)
layout = QtGui.QVBoxLayout(contents)
# add other widgets to the contents layout here
# i.e. layout.addWidget(widget), etc
self.tabWidget.addTab(contents, 'Tab One')
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
window = TestGUI()
window.show()
sys.exit(app.exec_())
QTabWidget's addTab() method, coincidentally named the same, adds a tab.
Hello I am working on data archive program with python 2.7. I have one mainWindow and there is some elements (Buttons, text lines etc.) Clicking a button open a dialog form page. User select their answer on that dialog page. Dialog page has a button named 'save'. When clicking save button dialog class saving user's selections to database. I want to do, when user clicked to save button on dialog, It will enable some elements on the mainWindow which is not enabled. I am doing this with these codes entering to dialog class and save button function:
self.ui.onceBut.setEnabled(True) etc.
But I am taking an error:
AttributeError: 'onceDlg' object has no attribute 'onceBut'
onceDlg is dialog pages class name.
How can I solve this and I can do what I want? Thanks in advance.
self in self.ui.onceBut.setEnabled(True) refers to dialog, so you get error because your onceBut is in your mainWindow not in onceDlg dialog.
Solution: as #Radio say - Communication between components in Qt are often done using signals and slots, but it's not the only way.
Easier way is to simply pass main window to dialog window, so you can manipulate with it's buttons, or whatever you want, inside dialog window. In next example I've done that in line dialog = Dialog(self), where self refers to MainWindow and it is used as mainWin inside Dialog. Run it, click on first button, dialog will show, click save button in dialog and second button in main will be changed and disabled.
I hope I've helped you.
import sys
from PyQt4 import QtCore, QtGui
class Dialog(QtGui.QDialog):
def __init__(self, mainWin):
QtGui.QDialog.__init__(self,mainWin)
self.setWindowTitle(self.tr("Dialog window"))
self.main = mainWin
button = QtGui.QPushButton()
button.setText( "Save (disable dummy button)" )
layout = QtGui.QVBoxLayout()
layout.addWidget(button)
self.setLayout(layout)
self.connect(button, QtCore.SIGNAL("clicked()"), self.save)
self.resize(200, 100)
def save(self):
self.main.button2.setEnabled(False)
self.main.button2.setText( "changed from dialog" )
class MainWindow(QtGui.QMainWindow):
def __init__(self):
super(MainWindow, self).__init__()
self.setWindowTitle(self.tr("Main window"))
self.button1 = QtGui.QPushButton()
self.button2 = QtGui.QPushButton()
self.button1.setText( "Open dialog" )
self.button2.setText( "Dummy" )
layout = QtGui.QVBoxLayout()
layout.addWidget(self.button1)
layout.addWidget(self.button2)
self.window = QtGui.QWidget()
self.window.setLayout(layout)
self.setCentralWidget(self.window);
self.connect(self.button1, QtCore.SIGNAL("clicked()"), self.showDialog)
self.resize(360, 145)
def showDialog(self):
dialog = Dialog(self)
dialog.show()
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
main = MainWindow()
main.show();
sys.exit(app.exec_())