The constructor for wx.TextCtrl takes a wx.Size argument, which is in units of pixels. Usually, I don't want to specify the size of a multiline TextCtrl in pixels, but rather in how many characters it can show without scrolling. I find that multiline TextCtrls are often the dominant component in my windows, thus stretching by Sizer is not an option.
The wxPython Phoenix documentation contains a hint as to how to do this, however this is meant more for short text on single line control.
I have started using this utility method:
def _set_textctrl_size_by_chars(self, tc, w, h):
sz = tc.GetTextExtent('X')
sz = wx.Size(sz.x * w, sz.y * h)
tc.SetInitialSize(tc.GetSizeFromTextSize(sz))
along with code like this:
tc = wx.TextCtrl(self, style=wx.TE_MULTILINE)
self._set_textctrl_size_by_chars(tc, 80, 20)
This works, but I consider it a hack. I have looked over the documentation but have not found any other way to do it.
I understand that fonts are not usually monospaced, and using 'X' as a representative character width is inexact, however it's plenty good enough for my usage. Still, it seems there should be some way to do this directly using the wx library.
Using something like text.GetSizeFromTextSize(text.GetTextExtent("99999").x) is indeed the best way to size the text control to fit exactly 5 digits (e.g. a ZIP code in some localities). Notice that this is slightly better than your code because the width of 80 "X"s is not necessarily quite the same as 80 times the width of a single "X". And I'd also recommend using "M" or "W" which can be noticeably wider than "X" in some fonts, but this is not going to changes matters much.
We thought about adding a helper method doing this and it might indeed be useful, but, again, this still won't make things as simple as you'd like because you really need to specify the characters you want to use: "W" for letters, "9" for digits and maybe something like "x" if you want the control to be wide enough to fit the given number of characters on average instead of being wide enough to guarantee fitting the given number of the widest characters because the difference may be noticeable.
The main place where we could make life simpler would be at XRC level and this would be worth doing ("just" a question of time...), but for the code I really don't think we can make things much simpler than what they're now.