Question

I have created a simple app which uses bare TextCtrl widgets with wxFILTER_NUMERIC in order to accept only numerical values (see code below).

I want the values to have a fixed display precision irrespective of how user inputs them (e.g. will always show 17.0000 in case of 17.0 or 17.000000 values being specified). I found that in wxPython there is an option to use a derived NumCtrl widget (http://wxpython.org/docs/api/wx.lib.masked.numctrl-module.html) which does the job but I can’t find it in the basic wxWidgets libraries.

So, is there a ready solution for this available somewhere which I simply cannot find or do I have to write a function which will change the format of the number manually once it has been inserted (handling EVT_TEXT and EVT_TEXT_ENTER events and modifying the input string)?

What I have so far:

Event table

BEGIN_EVENT_TABLE(MyFrame, wxFrame) 
    EVT_MENU(ID_Quit, MyFrame::OnQuit)
    EVT_MENU(ID_About, MyFrame::OnAbout)
    EVT_TEXT(ID_textBox, MyFrame::ValueChanged)
    EVT_TEXT_ENTER(ID_textBox, MyFrame::ValueChanged)
END_EVENT_TABLE()

Implementation of the text box inside MyFrame

wxPanel *panel = new wxPanel(this, -1);

    _textBox1 = new wxTextCtrl(panel,
         ID_textBox, 
         "0.0000", 
         wxPoint(100, 100), 
         wxSize(80,20),
         wxTE_PROCESS_ENTER,
         wxTextValidator(wxFILTER_NUMERIC,&_myValue),
         wxTextCtrlNameStr); 

Handling function

void MyFrame::ValueChanged(wxCommandEvent& WXUNUSED(event))
{
    // modify the string or do something clever
}

SOLUTION ADOPTED
Thanks to the answer the problem has been resolved. Here’s what I went with:

`

wxFloatingPointValidator<double> _val(2,&_myValue,wxNUM_VAL_ZERO_AS_BLANK);
    _val.SetRange(0.,100.);     // set allowable range

_textBox1 = new wxTextCtrl(panel,   // create a textCtrl
     ID_textBox, 
     "0.0000", 
     wxPoint(100, 30), 
     wxSize(80,20),
     wxTE_PROCESS_ENTER,
     _val,          // associate the text box with the desired validator
     wxTextCtrlNameStr); 

`

Answer 1

See wxFloatingPointValidator available in wxWidgets 2.9.