PyQt - Tab Management from Outside Class - python

I am designing an application using PyQt that will manage multiple instances of Selenium. Each instance has a QFrame with unique information and controls and can be tabbed through from the main window.
class Instance(QFrame):
def __init__(self):
super().__init__()
self.username = "whatever"
...
self.startButton = QPushButton('Start')
self.startButton.clicked.connect(lambda: self.engineStart())
self.exitButton = QPushButton('Exit')
self.exitButton.clicked.connect(lambda: self.engineExit())
...
How it looks
Users should be able to create and delete instances at will.
Creating a tab is no problem. I have a "+" button set as the QTabWidget's cornerWidget. It is connected to a simple method to add the tab.
class App(QFrame):
def __init__(self):
...
def addNewTab(self):
t = Instance()
self.tabs.addTab(t, t.username)
The problem is, how can I use the "Exit" button from the "inside" Instance class to remove the tabs that are managed from the main window's "outside" class? I need some way to call removeTab()

To do what you want you must create a slot in the main window, and connect it to the clicked signal of the button as shown below:
class App(QFrame):
def __init__(self):
...
def addNewTab(self):
t = Instance()
self.tabs.addTab(t, t.username)
t.exitButton.clicked.connect(self.slot)
def slot(self):
self.tabs.removeTab(your_index)

Related

Access items and attributes across multiple windows

i have a main GUI-Window from which i open a new Window (FCT-popup) with a buttonclick:
class MainWindow(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.ui = Ui_MainWindow() # sets ui = to the main window from the ui-file
self.ui.setupUi(self)
[...]
def enter_fct_results(self):
self.FCTpopup = FCT_Window()
self.FCTpopup.show()
In the Window i have a QTable to fill and a button to submit the data and close the window:
class FCT_Window(QMainWindow):
def __init__(self):
QMainWindow.__init__(self)
self.ui = Ui_FCT_Window()
self.ui.setupUi(self)
[...]
self.ui.pushButton_submitFCT.clicked.connect(lambda: MainWindow.store_fct_data(MainWindow, self.on_submit()[0]))
def on_submit(self): # event when user clicks
fct_nparray = np.zeros((self.ui.tableFCTinputs.rowCount(), self.ui.tableFCTinputs.columnCount()))
for j in range(self.ui.tableFCTinputs.columnCount()):
for i in range(self.ui.tableFCTinputs.rowCount()):
fct_nparray[i, j] = float(self.ui.tableFCTinputs.item(i, j).text())
return fct_nparray, lambda: self.close()
self.ui.pushButton_submitFCT.clicked.connect(lambda: MainWindow.store_fct_data(MainWindow, self.on_submit()[0]))
The receiving function iin the main window looks like ths:
def store_fct_data(self, data):
self.fct_data = data
Now i just want to understand how i can make either the mainwindow or the pushbutton which opens the 2nd window disabled. Disabling inside enter_fct_results() works, but if i want to enable it again with either store_fct_data or on_submit provides errors like this:
self.ui.pushButton_FCTresults.setEnabled(1)
self.ui.pushButton_submitFCT.clicked.connect(lambda: MainWindow.store_fct_data(MainWindow, self.on_submit()[0]))
AttributeError: type object 'MainWindow' has no attribute 'ui'
I dont think i have understood it here how to deal with multiple windows and stuff. For example how would i change a the color of a button in the main window by using a button in window2. How do i access the widgets? if i am inside the same Window i do that easily by
self.ui.pushbutton.setText("New Text")
I dont get how to access items and attributes across Windows :( Can you help me?
Access to attributes of another instance
There is a fundamental difference between disabling the button of the second window in enter_fct_results and what you tried in the lambda: in the first case, you're accessing an instance attribute (for instance, self.FCTpopup.ui.pushButton), while in the second you're trying to access a class attribute.
The self.ui object is created in the __init__ (when the class instance is created), so the instance will have an ui attribute, not the class:
class Test:
def __init__(self):
self.value = True
test = Test()
print(test.value)
>>> True
print(Test.value)
>>> AttributeError: type object 'Test' has no attribute 'value'
Provide a reference
The simple solution is to create a reference of the instance of the first window for the second:
def enter_fct_results(self):
self.FCTpopup = FCT_Window(self)
self.FCTpopup.show()
class FCT_Window(QMainWindow):
def __init__(self, mainWindow):
QMainWindow.__init__(self)
self.mainWindow = mainWindow
self.ui.pushButton_submitFCT.clicked.connect(self.doSomething)
def doSomething(self):
# ...
self.mainWindow.ui.pushButton.setEnabled(True)
Using modal windows (aka, dialogs)
Whenever a window is required for some temporary interaction (data input, document preview, etc), a dialog is preferred: the main benefit of using dialogs is that they are modal to the parent, preventing interaction on that parent until the dialog is closed; another benefit is that (at least on Qt) they also have a blocking event loop within their exec() function, which will only return as soon as the dialog is closed. Both of these aspects also make unnecessary disabling any button in the parent window. Another important reason is that QMainWindow is not intended for this kind of operation, also because it has features that generally unnecessary for that (toolbars, statusbars, menus, etc).
def enter_fct_results(self):
self.FCTpopup = FCT_Window(self)
self.FCTpopup.exec_()
class FCT_Window(QDialog):
def __init__(self, parent):
QMainWindow.__init__(self, parent)
self.ui.pushButton_submitFCT.clicked.connect(self.doSomething)
def doSomething(self):
# ...
self.accept()
The above makes mandatory to recreate the ui in designer using a QDialog (and not a QMainWindow) instead. You can just create a new one and drag&drop widgets from the original one.
i finally found my mistake: It was the place of the signal connection. It has to be right before the 2nd window is opened:
def enter_fct_results(self):
self.FCTpopup = Dialog(self.fct_data)
self.FCTpopup.submitted.connect(self.store_fct_data)
self.FCTpopup.exec_()
With this now i can send the stored data from the mainwindow to the opened window, import into the table, edit it and send it back to the main window on submit.

Simulate user clicking in QSystemTrayIcon

Even through the activated slot is being executed, the menu is still not showing. I traced through manually clicking the tray icon and the simulated click, and its going through the same execution logic.
Currently I have
class MyClass(QObject):
def __init__():
self._testSignal.connect(self._test_show)
self.myTrayIcon.activated.connect(lambda reason: self._update_menu_and_show(reason))
def show():
self._testSignal.emit()
#pyqtSlot()
def _test_show():
self._trayIcon.activated.emit(QtWidgets.QSystemTrayIcon.Trigger)
#QtCore.pyqtSlot()
def _update_menu_and_show(reason):
if reason in (QtWidgets.QSystemTrayIcon.Trigger):
mySystemTrayIcon._update_menu()
...
class MySystemTrayIcon(QSystemTrayIcon):
def _update_menu(self):
# logic to populate menu
self.setContextMenu(menu)
...
MyClass().show()
Here is how I made the context menu associated with the tray icon pop up
class MyClass(QObject):
def __init__():
self._testSignal.connect(self._test_show)
self.myTrayIcon.activated.connect(lambda reason: self._update_menu_and_show(reason))
def show():
self._testSignal.emit()
#pyqtSlot()
def _test_show():
self._trayIcon.activated.emit(QSystemTrayIcon.Context)
#QtCore.pyqtSlot()
def _update_menu_and_show(reason):
if reason in (QSystemTrayIcon.Trigger, QSystemTrayIcon.Context):
mySystemTrayIcon._update_menu()
# Trigger means user initiated, Context used for simulated
# if simulated seems like we have to tell the window to explicitly show
if reason == QSystemTrayIcon.Context:
mySystemTrayIcon.contextMenu().setWindowFlags(QtCore.Qt.WindowStaysOnTopHint|QtCore.Qt.FramelessWindowHint)
pos = mySystemTrayIcon.geometry().bottomLeft()
mySystemTrayIcon.contextMenu().move(pos)
mySystemTrayIcon.contextMenu().show()
...
class MySystemTrayIcon(QSystemTrayIcon):
def _update_menu(self):
# logic to populate menu
self.setContextMenu(menu)
...
MyClass().show()
It seems you have to set the WindowStaysOnTopHint on the context menu so that it will appear.
This solution is specific to mac since it assumes the taskbar is on the top.
One side effect is that the context menu is always on top, even if the user clicks somewhere else. I placed an event filter on the context menu, the only useful event that it registered was QEvent.Leave

How can I choose which classes run in Python?

I am using PyQt4 in Python 3.3, making a GUI and have multiple classes, some of which I don't want running until I have clicked a certain button to do so. How can I connect such a class to only run when the button is clicked, and not on the start-up of the program.
Here is how I am currently connecting this class to my button within another class.
btns.clicked.connect(self.tableshow2)
def tableshow2(self):
table5.show()
This is the first class where the button is.
class CustTableSearch(QtGui.QDialog):
def __init__(self, parent=None):
super(CustTableSearch, self).__init__(parent)
with sqlite3.connect('database.db') as db:
cursor=db.cursor()
num = QtGui.QInputDialog.getText(self, 'Insert TelephoneNumber',
'Enter TeleNum:')
table5 = CustTableSearch()
This is part of the class which the button activates, which runs on start-up of the python shell. I have tried putting this in a function within the class with the button, but then i can't have it show up using .show() (it's a screen with a table).
Assuming that both classes are in the same module, you can create an instance of CustomTableSearch in tableshow2(self) method.
...
def tableshow2(self):
self.table5 = CustomTableSearch(self)
self.table5.show()
...
One way to do this is to create the dialog only on demand, rather than creating it straight away when the module is loaded.
class ProfilePage(QtGui.QMainWindow):
def __init__(self):
super(ProfilePage, self).__init__()
self.table5 = None
self.initUI()
def initUI(self):
...
btns.clicked.connect(self.tableshow2)
def tableshow2(self):
if self.table5 is None:
self.table5 = CustomTableSearch()
self.table5.show()

How to create child window and communicate with parent in TkInter

I'm creating some dialogs using TkInter and need to be able to open a child sub-window (modal or modeless) on clicking a button in the parent. The child would then allow a data record to be created and this data (either the record or if the operation was cancelled) needs to be communicated back to the parent window. So far I have:
import sel_company_dlg
from Tkinter import Tk
def main():
root = Tk()
myCmp = sel_company_dlg.SelCompanyDlg(root)
root.mainloop()
if __name__ == '__main__':
main()
This invokes the top level dialog which allows the user to select a company. The company selection dialog looks like this:
class SelCompanyDlg(Frame):
def __init__(self, parent):
Frame.__init__(self, parent)
self.parent_ = parent
self.frame_ = Frame( self.parent_ )
// .. more init stuff ..
self.btNew_ = Button( self.frame_, text="New ...", command=self.onNew )
def onNew(self):
root = Toplevel()
myCmp = company_dlg.CompanyDlg(root)
On clicking the New ... button, a Create Company dialog is displayed which allows the user to fill in company details and click on create or cancel. Here's the opening bit of that:
class CompanyDlg(Frame):
def __init__(self, parent):
Frame.__init__(self, parent)
// etc.
I'm struggling with the best way of invoking the child dialog in onNew() - what I have works but I'm not convinced it's the best approach and also, I can't see how to communicate the details to and from the child dialog.
I've tried looking at online tutorials / references but what I've found is either too simplistic or focuses on things like tkMessageBox.showinfo() which iss not what I want.
There are at least a couple ways to solve your problem. Either your dialog can directly send information to the main application, or your dialog can generate an event that tells the main application that data is really to be pulled from the dialog. If the dialog simply changes the appearance of something (for example, a font dialog) I usually generate an event. If the dialog creates or deletes data I typically have it push information back to the application.
I typically have an application object that acts as the controller for the GUI as a whole. Often this is the same class as the main window, or it can be a separate class or even defined as a mixin. This application object has methods that dialogs can call to feed data to the application.
For example:
class ChildDialog(tk.Toplevel):
def __init__(self, parent, app, ...)
self.app = app
...
self.ok_button = tk.Button(parent, ..., command=self.on_ok)
...
def on_ok(self):
# send the data to the parent
self.app.new_data(... data from this dialog ...)
class MainApplication(tk.Tk):
...
def on_show_dialog(self):
dialog = ChildDialog(self)
dialog.show()
def new_data(self, data):
... process data that was passed in from a dialog ...
When creating the dialog, you pass in a reference to the application object. The dialog then knows to call a specific method on this object to send data back to the application.
If you're not into the whole model/view/controller thing you can just as easily pass in a function rather than an object, effectively telling the dialog "call this function when you want to give me data".
In one of my projects I was trying to check within a child tk.Toplevel window (child1) of my root window (self), if a tk.Toplevel window (child2) was created by the user from within the root window, and if this window (child2) is present at the users screen at the moment.
If this wouldn't be the case, the new tk.Toplevel window should gets created by the child window (child1) of the root window, instead of the root window itself. And if it was already created by the root window and is currently present at the users screen, it should get focus() instead of getting reinitialized by "child1".
The root window was wrapped inside a class called App() and both "children" windows were created by methods inside the root class App().
I had to initialize "child2" in a quiet mode if an argument given to the method was True. I suppose that was the entangled mistake. The problem occurred on Windows 7 64 bit, if that's significant.
I tried this (example):
import tkinter as tk
from tkinter import ttk
class App(tk.Tk):
def __init__(self):
tk.Tk.__init__(self)
top = self.winfo_toplevel()
self.menuBar = tk.Menu(top)
top['menu'] = self.menuBar
self.menuBar.add_command(label='Child1', command=self.__create_child1)
self.menuBar.add_command(label='Child2', command=lambda: self.__create_child2(True))
self.TestLabel = ttk.Label(self, text='Use the buttons from the toplevel menu.')
self.TestLabel.pack()
self.__create_child2(False)
def __create_child1(self):
self.Child1Window = tk.Toplevel(master=self, width=100, height=100)
self.Child1WindowButton = ttk.Button(self.Child1Window, text='Focus Child2 window else create Child2 window', command=self.CheckForChild2)
self.Child1WindowButton.pack()
def __create_child2(self, givenarg):
self.Child2Window = tk.Toplevel(master=self, width=100, height=100)
if givenarg == False:
self.Child2Window.withdraw()
# Init some vars or widgets
self.Child2Window = None
else:
self.Child2Window.TestLabel = ttk.Label(self.Child2Window, text='This is Child 2')
self.Child2Window.TestLabel.pack()
def CheckForChild2(self):
if self.Child2Window:
if self.Child2Window.winfo_exists():
self.Child2Window.focus()
else:
self.__create_child2(True)
else:
self.__create_child2(True)
if __name__ == '__main__':
App().mainloop()
Here comes the problem:
I wasn't able to check if "child2" is already present. Got error: _tkinter.TclError: bad window path name
Solution:
The only way to get the right 'window path name' was, instead of calling the winfo_exists() method directly onto the "child2" window, calling the master of the "child1" window and adding the according attributes followed by the attributes of the master window you want to use.
Example (edit of the method CheckForChild2):
def CheckForChild2(self):
if self.Child2Window:
if self.Child1Window.master.Child2Window.winfo_exists():
self.Child1Window.master.Child2Window.focus()
else:
self.__create_child2(True)
else:
self.__create_child2(True)

How can I pass variables between two classes/windows in PyGtk?

I am starting out with PyGtk and am having trouble understanding the interaction of windows.
My very simple question is the following.
Suppose I have a class that simply creates a window with a text-entry field. When clicking the "ok" button in that window, I want to pass the text in the entry field to another window, created by another class, with a gtk menu and create a new entry with the content of the text field.
How do I implement this?
Let's call A the Menu, and B the window with the text-entry field.
If I understood correctly A calls B and when Ok button is pressed in B, A needs to update its menu.
In this scenario you could create a callback function in A, meant to be called when B's ok button is pressed. When you create B you can pass this callback, here's an example:
class B(gtk.Window):
def __init__(self, callback):
gtk.Window.__init__(self)
self.callback = callback
# Create components:
# self.entry, self.ok_button ...
self.ok_button.connect("clicked", self.clicked)
def clicked(self, button):
self.callback(self.entry.get_text())
class A(gtk.Window):
def create_popup(self):
popup = B(self.popup_callback)
popup.show()
def popup_callback(self, text):
# Update menu with new text
# ...

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