Building a gui app using wxPython

Question

Am building a gui app using wxpython,i have created two separate windows in two different files,i.e app1.py and app2.py,I want to open the 2nd window(app2.py) using a button click on first window(app1.py). How do i achieve this. It would be great if someone can help,Thanks!!

Answer 1

I am assuming you're using wxPython's definition of "window" (i.e. anything that is actually viewable in the GUI), not the regular definition of "separate box with stuff in it and an X button in the corner" (which wxPython calls a "frame")

When I was writing my first wxPython GUI I was faced with a similar probem. I wanted actions in one panel to affect the data shown in another. My first solution was to write methods that blindly passed the request to the panel's parent until it reached the top level (my "main frame", if you will). This worked, but obviously it's a terrible solution.

My second solution was to use wxPython Events, just like catching button presses for a wx.Panel. My idea was I would create a button in one frame and bind wx.EVT_BUTTON with that button's ID in another. I made custom Events and CommandEvents. While trying to implement this solution I discovered that do not propogate and that CommandEvents will only propogate through the parents. So, if left uncaught a CommandEvent will eventually hit your "main frame" but it will never hit the second panel unless that panel happens to be a parent of where the Event came from. Obviously, this won't work for you since the parent can't be hidden but a child be visible. Plus it would leave your main frame cluttered with code and methods to delegate commands.

Finally, I found the answer! wx.lib.pubsub! Basically, you bind the button press in app1.py, just like normal. Now, in the handler you use pubsub to publish a custom message. Next, in the init for app2.py, you use pubsub to subscribe to your custom message (I like having a "message.py" where I declare all my messages as constants). When you subscribe to a message you assign a handler method, just like for events.\

Read this: http://wiki.wxpython.org/WxLibPubSub

Since you said you wanted the window to APPEAR, maybe in the init method for app2.py you call the Hide() method then when you receive the message, call Show().

When I implemented this in my application I was using wxPython2.8. I am now using 2.9 so I don't know if this is still necessary but I found that I need the top import in order to call pubsub.subscribe() and pubsub.sendMessage(). I kept getting errors otherwise. I can't remember how I figured this out, I think I saw it in a code sample and added it in a desperate attempt to make my code work. I suggest you read the documentation I linked above and try to implement your code WITHOUT that import first.

import wx
from wx.lib.pubsub import setupkwargs #I need this to force pubsub to work. I don't know why.
from wx.lib.pubsub import pub

ID_MYBUTTON = wx.NewId()

class App1(wx.Panel):
    def __init__(self, parent):
        wx.Panel.__init___(self, parent)

        button = wx.Button(self, ID_MYBUTTON, "Show App2")
        self.Bind(wx.EVT_BUTTON, self.handleButton, id=ID_MYBUTTON

    def handleButton(self, event):
        pubsub.sendMessage("mybutton.pressed") #send the message

class App2(wx.Window):
    def __init__(self, parent):
        wx.Window.__init__(self, parent)

        self.Hide() #I don't want to be seen yet

        pubsub.subscribe(self.gotMessage, "mybutton.pressed") #listen for the message

    def gotMessage(self):
        self.Show() #Now I want to be seen!

-----EDIT-----

I found this SO question that might help: Creating child frames of main frame in wxPython

Please tell us in detail what you're trying to do? wxPython also has "dialogs" which would be better than a frame if all you're doing is showing the user a message or asking for a bit more information. http://wxpython.org/docs/api/wx.Dialog-class.html

It really depends on what you're trying to accomplish. We can't help you unless you explain what problem you're trying to solve.

-----EDIT AGIAN-----

It's looking like the person asking the question did indeed want a wx.Dialog. For a tutorial, see http://zetcode.com/wxpython/dialogs/ Also see Python WX - Returning user input from wx Dialog