Question

I have a small program that batch handles files. These files use a map file to load certain settings. The map file has a line at the top that specifies for what directory it is for.

Currently I am able to read the line and assign it to the source path variable (sPath). I want to update the TextCtrl for the Source Directory, however it is in the MainFrame class and I load the map file in a different class.

class Process(wx.Panel):

    def loadMap(self, event):
    MainFrame.sPath = str(mapFile.readline()).strip("\n")
    MainFrame.loadSource(MainFrame())

class MainFrame(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, title="DICOM Toolkit", size=(800,705))
        self.srcTc = wx.TextCtrl(self.panel, 131, '', size=(600,25), style=wx.TE_READONLY)

    def loadSource(self):
        self.srcTc.SetValue(MainFrame.sPath)

I eliminated most of the code and what’s above is where it is giving me trouble. How do I change self.srcTc in the MainFrame class from either the Process class or a function in the MainFrame class? I am having trouble actually pointing to self.srcTc without a handler that stems from the MainFrame class.

Answer 1

I think what you want has to look like something like that (without a working example):

class Process(wx.Panel):
    def loadMap(self, event):
        frame = MainFrame()
        frame.sPath = str(mapFile.readline()).strip("\n")
        frame.loadSource()

when using MainFrame.sPath = ... you’re not actually changing sPath to a MainFrame you created, but to the class itself, then you create it, in MainFrame() without storing a reference to it (assign it to a variable for example). So, you can’t access it from somewhere other than “inside” the class itself as self.

The solution is to create an instance of a MainFrame and operate on it. Once you create it and assign it to a variable, you can manipulate the .sPath attribute and call loadSource().

UPDATE: From you code snippet, it seems you create the MainFrame instance in the end of the file: MainFrame().Show(), and then in the loadMap method, you create a new one.

What you should do is this, in the end of your file:

app = wx.App(0)
#MainFrame().Show()
mainFrame = MainFrame() # or, insteadof making it a global variable, pass it as an argument to the objects you create, or store a reference to it anywhere else.
mainFrame.Show()
app.MainLoop()

and in the loadMap method:

def loadMap(self, event):
    global mainFrame # or wherever you stored the reference to it
    # ...
    # remove this:
    # mainFrame = MainFrame()
    # set the sPath to the OBJECT mainFrame not the CLASS MainFrame
    mainFrame.sPath = str(mapFile.readline()).strip("\n")
    mainFrame.srcTc.SetValue(MainFrame.sPath)

Now this way, it should work.
The problem was that you are creating another frame, changing its path and updating its text, but you are not showing it. The correction is to store the actual window that is being shown, and update this one.