Opening a wx.Frame in Python via a new thread - python

I have a frame that exists as a start up screen for the user to make a selection before the main program starts. After the user makes a selection I need the screen to stay up as a sort of splash screen until the main program finishes loading in back.
I've done this by creating an application and starting a thread:
class App(wx.App):
'''
Creates the main frame and displays it
Returns true if successful
'''
def OnInit(self):
try:
'''
Initialization
'''
self.newFile = False
self.fileName = ""
self.splashThread = Splash.SplashThread(logging, self)
self.splashThread.start()
#...More to the class
which launches a frame:
class SplashThread(threading.Thread):
def __init__(self, logger, app):
threading.Thread.__init__(self)
self.logger = logger
self.app = app
def run(self):
frame = Frame(self.logger, self.app)
frame.Show()
The app value is needed as it contains the callback which allows the main program to continue when the user makes their selection. The problem is that the startup screen only flashes for a millisecond then goes away, not allowing the user to make a selection and blocking the rest of start up.
Any ideas? Thanks in advance!

You don't need threads for this. The drawback is that the splash window will block while loading but that is an issue only if you want to update it's contents (animate it) or if you want to be able to drag it. An issue that can be solved by periodically calling wx.SafeYield for example.
import time
import wx
class Loader(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None)
sizer = wx.BoxSizer(wx.VERTICAL)
self.SetSizer(sizer)
self.btn1 = wx.Button(self, label="Option 1")
self.btn2 = wx.Button(self, label="Option 2")
sizer.Add(self.btn1, flag=wx.EXPAND)
sizer.Add(self.btn2, flag=wx.EXPAND)
self.btn1.Bind(wx.EVT_BUTTON, self.OnOption1)
self.btn2.Bind(
wx.EVT_BUTTON, lambda e: wx.MessageBox("There is no option 2")
)
def OnOption1(self, event):
self.btn1.Hide()
self.btn2.Hide()
self.Sizer.Add(
wx.StaticText(self, label="Loading Option 1..."),
1, wx.ALL | wx.EXPAND, 15
)
self.Layout()
self.Update()
AppFrame(self).Show()
class AppFrame(wx.Frame):
def __init__(self, parent):
wx.Frame.__init__(self, parent)
time.sleep(3)
parent.Hide()
# the top window (Loader) is hidden so the app needs to be told to exit
# when this window is closed
self.Bind(wx.EVT_CLOSE, lambda e: wx.GetApp().ExitMainLoop())
app = wx.PySimpleApp()
app.TopWindow = Loader()
app.TopWindow.Show()
app.MainLoop()

Related

wxPython application does not respond

I have a complex application, with a GUI that needs to dialogue with some I/O devices and with some WebAPI. I put my wx.Frame class in the main file, as I read that the GUI should be in the main thread to avoid freezing
if __name__ == "__main__":
app = wx.App()
frame = Window()
app.MainLoop()
but still the GUI freezes very often, and sometimes it doesn't show at all and a message saying "My_app is not responding" appears.
All the I/O and webAPI management is done in separate threads that are created by frame. The only GUI elements that are not in the main file are the pages that compose my notebook
from PageOne import PageOne
from PageTwo import PageTwo
from PageThree import PageThree
...
self.page1 = PageOne(self.nb)
self.page2 = PageTwo(self.nb)
self.page3 = PageThree(self.nb)
self.nb.AddPage(self.page1, "Page1")
self.nb.AddPage(self.page2, "Page2")
self.nb.AddPage(self.page3, "Page3")
All the communications between secondary threads and the GUI are done using wx.lib.newevent.NewEvent() in the main file and wx.PostEvent(self.parent, my_evt) in the threads.
I am using wxpython 4.1.1 and Ubuntu 20.04.2 LTS.
Any suggestion on how to prevent the GUI from not responding or freezing? Is maybe a better idea to use multiprocessing instead of multithreading? I know that threads are usually better for I/O applications...but is it still true in my case where the threads are all enless loops?
def run(self):
while True:
do_stuff()
This is not an answer per se.
However it might help track down a solution.
Given that we have no idea, none, what your code is doing, no one can answer a question like this.
It's the equivalent of asking, How long is a piece of string?
The best advice is to use something like the code below, adapting the thread to perform something akin to what your thread/threads are doing and see if you can replicate the behaviour and hopefully find the cause.
import time
import wx
from threading import Thread
import wx.lib.newevent
progress_event, EVT_PROGRESS_EVENT = wx.lib.newevent.NewEvent()
class ThreadFrame(wx.Frame):
def __init__(self, title, parent=None):
wx.Frame.__init__(self, parent=parent, title=title)
panel = wx.Panel(self)
self.btn = wx.Button(panel,label='Stop Long running process', size=(200,30), pos=(10,10))
self.btn.Bind(wx.EVT_BUTTON, self.OnExit)
self.progress = wx.Gauge(panel,size=(240,10), pos=(10,50), range=240)
#Bind to the progress event issued by the thread
self.Bind(EVT_PROGRESS_EVENT, self.OnProgress)
#Bind to Exit on frame close
self.Bind(wx.EVT_CLOSE, self.OnExit)
self.Show()
self.mythread = TestThread(self)
#Enable the GUI to be responsive by briefly returning control to the main App
while self.mythread.isAlive():
time.sleep(0.1)
wx.GetApp().Yield()
continue
try:
self.OnExit(None)
except:
pass
def OnProgress(self, event):
self.progress.SetValue(event.count)
#or for indeterminate progress
#self.progress.Pulse()
def OnExit(self, event):
if self.mythread.isAlive():
self.mythread.terminate() # Shutdown the thread
self.mythread.join() # Wait for it to finish
self.Destroy()
class TestThread(Thread):
def __init__(self,parent_target):
Thread.__init__(self)
self.parent = parent_target
self.stopthread = False
self.time = time.time()
self.start() # start the thread
def run(self):
# A loop that will run for 2 minutes then terminate
while self.stopthread == False:
curr_loop = int(time.time() - self.time)
if curr_loop < 240:
time.sleep(0.1)
evt = progress_event(count=curr_loop)
#Send back current count for the progress bar
try:
wx.PostEvent(self.parent, evt)
except: # The parent frame has probably been destroyed
self.terminate()
else:
self.terminate()
def terminate(self):
self.stopthread = True
class MyPanel(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent)
self.text_count = 0
self.thread_count = 0
self.parent=parent
btn = wx.Button(self, wx.ID_ANY, label='Start Long running process', size=(200,30), pos=(10,10))
btn.Bind(wx.EVT_BUTTON, self.Thread_Frame)
btn2 = wx.Button(self, wx.ID_ANY, label='Is the GUI still active?', size=(200,30), pos=(10,50))
btn2.Bind(wx.EVT_BUTTON, self.AddText)
self.txt = wx.TextCtrl(self, wx.ID_ANY, style= wx.TE_MULTILINE, pos=(10,90),size=(400,100))
def Thread_Frame(self, event):
self.thread_count += 1
frame = ThreadFrame(title='Threaded Task '+str(self.thread_count), parent=self.parent)
def AddText(self,event):
self.text_count += 1
txt = "Gui is still active " + str(self.text_count)+"\n"
self.txt.write(txt)
class MainFrame(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title='Main Frame', size=(600,400))
panel = MyPanel(self)
self.Show()
if __name__ == '__main__':
app = wx.App(False)
frame = MainFrame()
app.MainLoop()

wxPython - Automatically closing nested modal dialogs

Python 2.7, WxPython 3.0.2
We are trying to automatically close an entire program under certain conditions. For various reasons, we can't just kill the process. We've had some level of success with it. We can close it if there's no modal dialogs, or a single modal dialog. Once we introduce the second modal dialog (nested), it fails to stop properly.
The actual error received appears to be:
wx._core.PyAssertionError: C++ assertion "IsRunning()" failed at ..\..\src\common\evtloopcmn.cpp(83) in wxEventLoopBase::Exit(): Use ScheduleExit() on not running loop
Here's a working example of our issue. The frame will automatically close after 5 seconds. Clicking the button will load a dialog. Clicking the button on the dialog will open another dialog. It works fine until the last dialog is opened.
from threading import Thread
from time import sleep
import wx
class MainFrame(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title="TEST", size=(400, 400))
self.Show()
self.__someDialog = None
self.__myThread = None
self.__okButton = wx.Button(self, -1, "Press me")
self.Bind(wx.EVT_BUTTON, self.__onOK)
self.__myThread = Thread(target=self.__waitThenClose, name="Closer")
self.__myThread.setDaemon(True)
self.__myThread.start()
def __onOK(self, evt):
self.__someDialog = SomeDialog(self)
self.__someDialog.ShowModal()
def closeOpenDialogs(self):
lst = wx.GetTopLevelWindows()
for i in range(len(lst) - 1, 0, -1):
if isinstance(lst[i], wx.Dialog):
print "Closing " + str(lst[i])
lst[i].Close(True)
#lst[i].Destroy()
def __waitThenClose(self):
for x in range(0, 5):
print "Sleeping..."
sleep(1)
self.closeOpenDialogs()
wx.CallAfter(self.Close, True)
class SomeDialog(wx.Dialog):
def __init__(self, parent):
wx.Dialog.__init__(self, parent, id=-1, title='Some Dialog')
self.SetSize((300, 300))
self.__anotherDialog = None
self.__okButton = wx.Button(self, -1, "Press me")
self.Bind(wx.EVT_BUTTON, self.__onOK)
wx.EVT_CLOSE(self, self.__on_btn_cancel)
def __onOK(self, evt):
self.__anotherDialog = AnotherDialog(self)
self.__anotherDialog.ShowModal()
def __on_btn_cancel(self, event):
self.EndModal(wx.ID_CANCEL)
class AnotherDialog(wx.Dialog):
def __init__(self, parent):
wx.Dialog.__init__(self, None, id=-1, title='Another Dialog')
self.SetSize((200, 200))
wx.EVT_CLOSE(self, self.__on_btn_cancel)
def __on_btn_cancel(self, event):
self.EndModal(wx.ID_CANCEL)
if __name__ == "__main__":
app = wx.App()
mainFrame = MainFrame()
app.MainLoop()
I think what is happening here is that the first call to ShowModal() blocks the at the app level (not just the frame level) which is preventing the second dialog from becoming fully initialized. To work around this issue I would call Show() instead of ShowModal() and add wx.FRAME_FLOAT_ON_PARENT to the dialog style flags. You can also call Disable() on the parts of the program you don't want the user to interact with while the dialogs are open.
EDIT: Here is a working example:
from threading import Thread
from time import sleep
import wx
class MainFrame(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title="TEST", size=(400, 400))
self.Show()
self.__someDialog = None
self.__okButton = wx.Button(self, -1, "Press me")
self.Bind(wx.EVT_BUTTON, self.__onOK)
self.__myThread = Thread(target=self.__waitThenClose, name="Closer")
self.__myThread.setDaemon(True)
self.__myThread.start()
def __onOK(self, evt):
self.__someDialog = SomeDialog(self)
self.__someDialog.ShowModal()
def closeOpenDialogs(self, evt=None):
lst = wx.GetTopLevelWindows()
for i in range(len(lst) - 1, 0, -1):
dialog = lst[i]
if isinstance(dialog, wx.Dialog):
print "Closing " + str(dialog)
# dialog.Close(True)
wx.CallAfter(dialog.Close)
# sleep(1)
# dialog.Destroy()
def __waitThenClose(self):
for x in range(0, 10):
print "Sleeping..."
sleep(1)
wx.CallAfter(self.closeOpenDialogs)
wx.CallAfter(self.Close, True)
class SomeDialog(wx.Dialog):
def __init__(self, parent):
wx.Dialog.__init__(self, parent, id=-1, title='Some Dialog')
self.SetSize((300, 300))
self.__anotherDialog = None
self.__okButton = wx.Button(self, -1, "Press me")
self.Bind(wx.EVT_BUTTON, self.__onOK)
wx.EVT_CLOSE(self, self.__on_btn_cancel)
def __onOK(self, evt):
self.__anotherDialog = AnotherDialog(self)
self.__anotherDialog.SetWindowStyleFlag(
wx.FRAME_FLOAT_ON_PARENT|wx.DEFAULT_DIALOG_STYLE)
self.__anotherDialog.Show()
def __on_btn_cancel(self, event):
event.Skip()
self.EndModal(wx.ID_CANCEL)
class AnotherDialog(wx.Dialog):
def __init__(self, parent):
wx.Dialog.__init__(self, parent, id=-1, title='Another Dialog')
self.SetSize((200, 200))
wx.EVT_CLOSE(self, self.__on_btn_cancel)
parent.Disable()
def __on_btn_cancel(self, event):
event.Skip()
self.GetParent().Enable()
# self.EndModal(wx.ID_CANCEL)
if __name__ == "__main__":
app = wx.App()
mainFrame = MainFrame()
app.MainLoop()
The only way to reliably gracefully close all the modal dialogs, whether they were explicitly opened by your own code or not, is to use wxModalDialogHook to remember all the opened dialogs and then close them all, in the reverse (i.e. LIFO) order, before quitting the application.
Unfortunately I don't know if wxModalDialogHook is available in Python.

How to link multiple wx.Dialogs in wxPython

I want to make a game in wxPython (no other modules) and I want to make it so that you can enter some values in popup screens before the game starts, and then the game will be drawn on a canvas which in turn is drawn on a panel, which is bound to the main game.
I made the gamescreen with all fancy stuff (works solo)
I made the input screens
But I cannot link them.
How do I start the game so it will open a dialog box, then on the closure of it open another one, and then open the game ?
I tried the following, but it will not open my canvas:
# makes a game by showing 2 dialogs
# after dialogs have been answered, starts the game by drawing the canvas.
# imports
import wx
import Speelveld3
# globals
SCRWIDTH = 950
SCRHEIGHT = 700
# dialogbox class
class MyDialog1(wx.Dialog):
def __init__(self, parent):
wx.Dialog.__init__(self, parent)
self.username = wx.TextCtrl(self)
self.okButton = wx.Button(self, wx.ID_OK, "OK")
class MyDialog2(wx.Dialog):
def __init__(self, parent):
wx.Dialog.__init__(self, parent)
self.canvasWidth = wx.TextCtrl(self)
self.okButton = wx.Button(self, wx.ID_OK, "OK")
# main class
class Game(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, -1, title='My game', size=(SCRWIDTH, SCRHEIGHT))
self.username = ""
self.canvasWidth = 10
# hide the frame for now
self.Hide()
def OnInit(self):
#Make your dialogs
dlg1 = MyDialog1(self)
#if the user pressed "OK" (i.e. NOT "Cancel" or any other button you might add)
if dlg1.ShowModal() == wx.ID_OK:
#get the username from the dialog
self.username = dlg1.username.GetValue()
#clean up the dialog (AFTER you get the username)
dlg1.Destroy()
dlg2 = MyDialog2(self)
#if the user pressed "OK" (i.e. NOT "Cancel" or any other button you might add)
if dlg2.ShowModal() == wx.ID_OK:
#get the username from the dialog
self.canvasWidth = dlg2.canvasWidth.GetValue()
#clean up the dialog (AFTER you get the username)
dlg2.Destroy()
# Now that you have your settings, Make the gameboard
# THIS PART IS STILL BROKEN!
# I can paste the whole board class (structure of it is taken from the tetris tutorial)
# but that seems a bit much tbh...
self.gameBoard = Board.Board(self)
self.gameBoard = SetFocus()
self.gameBoard.start()
self.Centre()
self.Show(True) #show the frame
if __name__ == '__main__':
# how can I start the game here?
app = wx.App()
frame = Game()
board = Speelveld3.Speelveld(frame)
board.start()
frame.Show()
app.MainLoop()
You've double posted, and the lack of any wx.Dialog in your sample code suggests to me that you haven't even looked at a tutorial yet, but I will give you the benefit of the doubt.
First, if you want to return information from a dialog, the easiest way is to define a custom dialog. Define a new class that inherits from wx.Dialog and then set it up just like you would a normal panel or a frame. It seems to me that you will need two of these. They'll look something like this:
class MyDialog1(wx.Dialog):
def __init__(self, parent):
wx.Dialog.__init__(self, parent)
self.username = wx.TextCtrl(self) #this is where users will enter their username
self.okButton = wx.Button(self, wx.ID_OK, "OK") #Note that I'm using wx.ID_OK. This is important
Now, for the logic you want. Pretty much every object in wxPython that you actually see has the functions Show() and Hide() (API here). You don't want to show your frame until AFTER the dialogs are finished, so in your __init__(), call Hide(). I'm also initializing a variable, username, which is where I will store the data from my dialog.
class Game(wx.Frame):
def __init__(self, parent, id, title):
wx.Frame.__init__(self, parent, id, title, size=(SCRWIDTH, SCRHEIGHT))
self.username = ""
self.Hide() #don't show the frame just yet
#self.Hide() is the exact same as self.Show(False)
Now, for your dialogs. Like Mike Driscoll suggested, you call your dialogs BEFORE making your canvas. wx.Dialogs are launched using ShowModal(). By setting the ID of self.okButton to the constant wx.ID_OK, wxPython recognizes that the dialog should be closed after the button in clicked. You should also be aware of wx.ID_CANCEL.
def OnInit(self):
#Make your dialogs
dlg1 = MyDialog1(self)
if dlg1.ShowModal() == wx.ID_OK:
#if the user pressed "OK" (i.e. NOT "Cancel" or any other button you might add)
self.username = dlg1.username.GetValue() #get the username from the dialog
dlg1.Destroy() #clean up the dialog (AFTER you get the username)
#do this again for your second dialog
#Now that you have your settings, Make the gameboard
self.gameBoard = Board.Board(self)
self.gameBoard = SetFocus()
self.gameBoard.start()
self.Centre()
self.Show(True) #show the frame
In your OnInit you just need to call your dialogs and show them modally BEFORE you create your Board instance. Then it should work correctly.
EDIT (6-28-12): Here's some code:
import wx
########################################################################
class MyDlg(wx.Dialog):
""""""
#----------------------------------------------------------------------
def __init__(self):
"""Constructor"""
wx.Dialog.__init__(self, None, title="I'm a dialog!")
lbl = wx.StaticText(self, label="Hi from the panel's init!")
btn = wx.Button(self, id=wx.ID_OK, label="Close me")
sizer = wx.BoxSizer(wx.VERTICAL)
sizer.Add(lbl, 0, wx.ALL, 5)
sizer.Add(btn, 0, wx.ALL, 5)
self.SetSizer(sizer)
########################################################################
class MyPanel(wx.Panel):
""""""
#----------------------------------------------------------------------
def __init__(self, parent):
"""Constructor"""
wx.Panel.__init__(self, parent)
# show a custom dialog
dlg = MyDlg()
dlg.ShowModal()
dlg.Destroy()
self.Bind(wx.EVT_PAINT, self.OnPaint)
def OnPaint(self, evt):
pdc = wx.PaintDC(self)
try:
dc = wx.GCDC(pdc)
except:
dc = pdc
rect = wx.Rect(0,0, 100, 100)
for RGB, pos in [((178, 34, 34), ( 50, 90)),
(( 35, 142, 35), (110, 150)),
(( 0, 0, 139), (170, 90))
]:
r, g, b = RGB
penclr = wx.Colour(r, g, b, wx.ALPHA_OPAQUE)
brushclr = wx.Colour(r, g, b, 128) # half transparent
dc.SetPen(wx.Pen(penclr))
dc.SetBrush(wx.Brush(brushclr))
rect.SetPosition(pos)
dc.DrawRoundedRectangleRect(rect, 8)
########################################################################
class MyFrame(wx.Frame):
""""""
#----------------------------------------------------------------------
def __init__(self):
"""Constructor"""
wx.Frame.__init__(self, None, title="Example frame")
# show a MessageDialog
style = wx.OK|wx.ICON_INFORMATION
dlg = wx.MessageDialog(parent=None,
message="Hello from the frame's init",
caption="Information", style=style)
dlg.ShowModal()
dlg.Destroy()
# create panel
panel = MyPanel(self)
if __name__ == "__main__":
app = wx.App(False)
frame = MyFrame()
frame.Show()
app.MainLoop()

Return value from wxPython Frame

Could someone show me how I could return a value from a wxPython Frame? When the use clicks close, I popup a message dialog asking him a question. I would like to return the return code of this message dialog to my calling function.
Thanks
Because the wxFrame has events that process via the app.MainLoop() functionality, the only way to get at the return value of a wx.Frame() is via catching an event.
The standard practice of handling events is typically from within the class which derives from wx.Window itself (e.g., Frame, Panel, etc.). Since you want code exterior to the wx.Frame to receive information that was gathered upon processing the OnClose() event, then the best way to do that is to register an event handler for your frame.
The documentation for wx.Window::PushEventHandler is probably the best resource and even the wxpython wiki has a great article on how to do this. Within the article, they register a custom handler which is an instance of "MouseDownTracker." Rather than instantiating within the PushEventHandler call, you'd want to instantiate it prior to the call so that you can retain a handle to the EventHandler derived class. That way, you can check on your derived EventHandler class-variables after the Frame has been destroyed, or even allow that derived class to do special things for you.
Here is an adaptation of that code from the wx python wiki (admittedly a little convoluted due to the requirement of handling the results of a custom event with a "calling" function):
import sys
import wx
import wx.lib.newevent
(MyCustomEvent, EVT_CUSTOM) = wx.lib.newevent.NewEvent()
class CustomEventTracker(wx.EvtHandler):
def __init__(self, log, processingCodeFunctionHandle):
wx.EvtHandler.__init__(self)
self.processingCodeFunctionHandle = processingCodeFunctionHandle
self.log = log
EVT_CUSTOM(self, self.MyCustomEventHandler)
def MyCustomEventHandler(self, evt):
self.log.write(evt.resultOfDialog + '\n')
self.processingCodeFunctionHandle(evt.resultOfDialog)
evt.Skip()
class MyPanel2(wx.Panel):
def __init__(self, parent, log):
wx.Panel.__init__(self, parent)
self.log = log
def OnResults(self, resultData):
self.log.write("Result data gathered: %s" % resultData)
class MyFrame(wx.Frame):
def __init__(self, parent, ID=-1, title="", pos=wx.DefaultPosition, size=wx.DefaultSize, style=wx.DEFAULT_FRAME_STYLE):
wx.Frame.__init__(self, parent, ID, title, pos, size, style)
self.panel = panel = wx.Panel(self, -1, style=wx.TAB_TRAVERSAL | wx.CLIP_CHILDREN | wx.FULL_REPAINT_ON_RESIZE)
sizer = wx.BoxSizer(wx.VERTICAL)
sizer.Add((25, 25))
row = wx.BoxSizer(wx.HORIZONTAL)
row.Add((25,1))
m_close = wx.Button(self.panel, wx.ID_CLOSE, "Close")
m_close.Bind(wx.EVT_BUTTON, self.OnClose)
row.Add(m_close, 0, wx.ALL, 10)
sizer.Add(row)
self.panel.SetSizer(sizer)
def OnClose(self, evt):
dlg = wx.MessageDialog(self, "Do you really want to close this frame?", "Confirm Exit", wx.OK | wx.CANCEL | wx.ICON_QUESTION)
result = dlg.ShowModal()
dlg.Destroy()
if result == wx.ID_CANCEL:
event = MyCustomEvent(resultOfDialog="User Clicked CANCEL")
self.GetEventHandler().ProcessEvent(event)
else: # result == wx.ID_OK
event = MyCustomEvent(resultOfDialog="User Clicked OK")
self.GetEventHandler().ProcessEvent(event)
self.Destroy()
app = wx.App(False)
f2 = wx.Frame(None, title="Frame 1 (for feedback)", size=(400, 350))
p2 = MyPanel2(f2, sys.stdout)
f2.Show()
eventTrackerHandle = CustomEventTracker(sys.stdout, p2.OnResults)
f1 = MyFrame(None, title="PushEventHandler Tester (deals with on close event)", size=(400, 350))
f1.PushEventHandler(eventTrackerHandle)
f1.Show()
app.MainLoop()
You can get the result of clicking the OK, CANCEL buttons from the Dialog ShowModal method.
Given dialog is an instance of one of the wxPython Dialog classes:
result = dialog.ShowModal()
if result == wx.ID_OK:
print "OK"
else:
print "Cancel"
dialog.Destroy()
A few years late for the initial question, but when looking for the answer to this question myself, I stumbled upon a built-in method of getting a return value from a modal without messing with any custom event funniness. Figured I'd post here in case anyone else needs it.
It's simply this guy right here:
wxDialog::EndModal void EndModal(int retCode)
Ends a modal dialog, passing a value to be returned from the
*wxDialog::ShowModal invocation.*
Using the above, you can return whatever you want from the Dialog.
An example usage would be subclassing a wx.Dialog, and then placing the EndModal function in the button handlers.
class ProjectSettingsDialog(wx.Dialog):
def __init__(self):
wx.Dialog.__init__(self, None, -1, "Project Settings", size=(600,400))
sizer = wx.BoxSizer(wx.VERTICAL) #main sized
sizer.AddStretchSpacer(1)
msg = wx.StaticText(self, -1, label="This is a sample message")
sizer.Add(msg, 0, wx.ALIGN_CENTER_HORIZONTAL | wx.ALL, 15)
horizontal_sizer = wx.BoxSizer(wx.HORIZONTAL)
okButton = wx.Button(self, -1, 'OK')
self.Bind(wx.EVT_BUTTON, self.OnOK, okButton)
cancelBtn = wx.Button(self, -1, "Cancel")
self.Bind(wx.EVT_BUTTON, self.OnCancel, cancelBtn)
horizontal_sizer.Add(okButton, 0, wx.ALIGN_LEFT)
horizontal_sizer.AddStretchSpacer(1)
horizontal_sizer.Add(cancelBtn, 0, wx.ALIGN_RIGHT)
sizer.Add(horizontal_sizer, 0)
sizer.AddStretchSpacer(1)
self.SetSizer(sizer)
def OnOK(self, event):
self.EndModal(wx.ID_OK) #returns numeric code to caller
self.Destroy()
def OnCancel(self, event):
self.EndModal(wx.ID_CANCEL) #returns numeric code to caller
self.Destroy()
(Note: I just banged this code out quickly; didn't test the sizers)
As you can see, all you need to do is call the EndModal from a button event to return a value to whatever spawned the dialog.
I wanted to do the same thing, to have a graphical "picker" that I could run from within a console app. Here's how I did it.
# Fruit.py
import wx
class Picker (wx.App):
def __init__ (self, title, parent=None, size=(400,300)):
wx.App.__init__(self, False)
self.frame = wx.Frame(parent, title=title, size=size)
self.apple_button = wx.Button(self.frame, -1, "Apple", (0,0))
self.apple_button.Bind(wx.EVT_BUTTON, self.apple_button_click)
self.orange_button = wx.Button(self.frame, -1, "Orange", (0,100))
self.orange_button.Bind(wx.EVT_BUTTON, self.orange_button_click)
self.fruit = None
self.frame.Show(True)
def apple_button_click (self, event):
self.fruit = 'apple'
self.frame.Destroy()
def orange_button_click (self, event):
self.fruit = 'orange'
self.frame.Destroy()
def pick (self):
self.MainLoop()
return self.fruit
Then from a console app, I would run this code.
# Usage.py
import Fruit
picker = Fruit.Picker('Pick a Fruit')
fruit = picker.pick()
print 'User picked %s' % fruit
user1594322's answer works but it requires you to put all of your controls in your wx.App, instead of wx.Frame. This will make recycling the code harder.
My solution involves define a "PassBack" variable when defining your init function. (similar to "parent" variable, but it is normally used already when initiating a wx.Frame)
From my code:
class MyApp(wx.App):
def __init__ (self, parent=None, size=(500,700)):
wx.App.__init__(self, False)
self.frame = MyFrame(parent, -1, passBack=self) #Pass this app in
self.outputFromFrame = "" #The output from my frame
def getOutput(self):
self.frame.Show()
self.MainLoop()
return self.outputFromFrame
and for the frame class:
class MyFrame(wx.Frame):
def __init__(self, parent, ID, passBack, title="My Frame"):
wx.Frame.__init__(self, parent, ID, title, size=(500, 700))
self.passBack = passBack #this will be used to pass back variables/objects
and somewhere during the execution of MyFrame
self.passBack.outputFromFrame = "Hello"
so all in all, to get a string from an application
app = MyApp()
val = app.getOutput()
#Proceed to do something with val
Check this answer on comp.lang.python: Linkie
I don't think a wxFrame can return a value since it is not modal. If you don't need to use a wxFrame, then a modal dialog could work for you. If you really need a frame, I'd consider using a custom event.
It would go something like this:
(1) User clicks to close the wxFrame
(2) You override OnClose (or something like that) to pop up a dialog to ask the user a question
(3) Create and post the custom event
(4) Close the wxFrame
(5) Some other code processes your custom event
I think I just had the same problem as you. Instead of making that popup a frame, I made it a dialog instead. I made a custom dialog by inheriting a wx.dialog instead of a wx.frame. Then you can utilize the code that joaquin posted above. You check the return value of the dialog to see what was entered. This can be done by storing the value of the textctrl when the user clicks ok into a local variable. Then before it's destroyed, you get that value somehow.
The custom dialog section of this site helped me out greatly.
http://zetcode.com/wxpython/dialogs/

Scrolling through a `wx.ScrolledPanel` with the mouse wheel and arrow keys

In my wxPython application I've created a wx.ScrolledPanel, in which there is a big wx.StaticBitmap that needs to be scrolled.
The scroll bars do appear and I can scroll with them, but I'd also like to be able to scroll with the mouse wheel and the arrow keys on the keyboard. It would be nice if the "Home", "Page Up", and those other keys would also function as expected.
How do I do this?
UPDATE:
I see the problem. The ScrolledPanel is able to scroll, but only when it is under focus. Problem is, how do I get to be under focus? Even clicking on it doesn't do it. Only if I put a text control inside of it I can focus on it and thus scroll with the wheel. But I don't want to have a text control in it. So how do I make it focus?
UPDATE 2:
Here is a code sample that shows this phenomena. Uncomment to see how a text control makes the mouse wheel work.
import wx, wx.lib.scrolledpanel
class MyFrame(wx.Frame):
def __init__(self, *args, **kwargs):
wx.Frame.__init__(self, *args, **kwargs)
scrolled_panel = \
wx.lib.scrolledpanel.ScrolledPanel(parent=self, id=-1)
scrolled_panel.SetupScrolling()
text = "Ooga booga\n" * 50
static_text=wx.StaticText(scrolled_panel, -1, text)
sizer=wx.BoxSizer(wx.VERTICAL)
sizer.Add(static_text, wx.EXPAND, 0)
# Uncomment the following 2 lines to see how adding
# a text control to the scrolled panel makes the
# mouse wheel work.
#
#text_control=wx.TextCtrl(scrolled_panel, -1)
#sizer.Add(text_control, wx.EXPAND, 0)
scrolled_panel.SetSizer(sizer)
self.Show()
if __name__=="__main__":
app = wx.PySimpleApp()
my_frame=MyFrame(None, -1)
#import cProfile; cProfile.run("app.MainLoop()")
app.MainLoop()
Problem is on window Frame gets the focus and child panel is not getting the Focus (on ubuntu linux it is working fine). Workaround can be as simple as to redirect Frame focus event to set focus to panel e.g.
import wx, wx.lib.scrolledpanel
class MyFrame(wx.Frame):
def __init__(self, *args, **kwargs):
wx.Frame.__init__(self, *args, **kwargs)
self.panel = scrolled_panel = \
wx.lib.scrolledpanel.ScrolledPanel(parent=self, id=-1)
scrolled_panel.SetupScrolling()
text = "Ooga booga\n" * 50
static_text=wx.StaticText(scrolled_panel, -1, text)
sizer=wx.BoxSizer(wx.VERTICAL)
sizer.Add(static_text, wx.EXPAND, 0)
scrolled_panel.SetSizer(sizer)
self.Show()
self.panel.SetFocus()
scrolled_panel.Bind(wx.EVT_SET_FOCUS, self.onFocus)
def onFocus(self, event):
self.panel.SetFocus()
if __name__=="__main__":
app = wx.PySimpleApp()
my_frame=MyFrame(None, -1)
app.MainLoop()
or onmouse move over panel, set focus to it, and all keys + mousewheeel will start working e.g.
import wx, wx.lib.scrolledpanel
class MyFrame(wx.Frame):
def __init__(self, *args, **kwargs):
wx.Frame.__init__(self, *args, **kwargs)
self.panel = scrolled_panel = \
wx.lib.scrolledpanel.ScrolledPanel(parent=self, id=-1)
scrolled_panel.SetupScrolling()
scrolled_panel.Bind(wx.EVT_MOTION, self.onMouseMove)
text = "Ooga booga\n" * 50
static_text=wx.StaticText(scrolled_panel, -1, text)
sizer=wx.BoxSizer(wx.VERTICAL)
sizer.Add(static_text, wx.EXPAND, 0)
scrolled_panel.SetSizer(sizer)
self.Show()
def onMouseMove(self, event):
self.panel.SetFocus()
if __name__=="__main__":
app = wx.PySimpleApp()
my_frame=MyFrame(None, -1)
app.MainLoop()
Here's an example that should do what you want, I hope. (Edit: In retrospect, this doesnt' quite work, for example, when there are two scrolled panels... I'll leave it up here though so peole can downvote it or whatever.) Basically I put everything in a panel inside the frame (generally a good idea), and then set the focus to this main panel.
import wx
import wx, wx.lib.scrolledpanel
class MyFrame(wx.Frame):
def __init__(self, *args, **kwargs):
wx.Frame.__init__(self, *args, **kwargs)
main_panel = wx.Panel(self, -1)
main_panel.SetBackgroundColour((150, 100, 100))
self.main_panel = main_panel
scrolled_panel = \
wx.lib.scrolledpanel.ScrolledPanel(parent=main_panel, id=-1)
scrolled_panel.SetupScrolling()
self.scrolled_panel = scrolled_panel
cpanel = wx.Panel(main_panel, -1)
cpanel.SetBackgroundColour((100, 150, 100))
b = wx.Button(cpanel, -1, size=(40,40))
self.Bind(wx.EVT_BUTTON, self.OnClick, b)
self.b = b
text = "Ooga booga\n" * 50
static_text=wx.StaticText(scrolled_panel, -1, text)
main_sizer=wx.BoxSizer(wx.VERTICAL)
main_sizer.Add(scrolled_panel, 1, wx.EXPAND)
main_sizer.Add(cpanel, 1, wx.EXPAND)
main_panel.SetSizer(main_sizer)
text_sizer=wx.BoxSizer(wx.VERTICAL)
text_sizer.Add(static_text, 1, wx.EXPAND)
scrolled_panel.SetSizer(text_sizer)
self.main_panel.SetFocus()
self.Show()
def OnClick(self, evt):
print "click"
if __name__=="__main__":
class MyApp(wx.App):
def OnInit(self):
frame = MyFrame(None, -1)
frame.Show(True)
self.SetTopWindow(frame)
return True
app = MyApp(0)
app.MainLoop()
For keyboard control, like setting action from the home key, I think you'll need to bind to those events, and respond appropriately, such as using mypanel.Scroll(0,0) for the home key (and remember to call evt.Skip() for the keyboard events you don't act on). (Edit: I don't think there are any default key bindings for scrolling. I'm not sure I'd want any either, for example, what should happen if there's a scrolled panel within a scrolled panel?)

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