wxCheckBox

Introduction

The wxCheckBox (wxWidgets: wxCheckBox Class Reference) control implements a checkbox.

Example

The wxCheckBox control is easy to use. Below we show a simple example of a checkbox with an event handler that updates the value of a wxTextCtrl control when the checkbox is checked and unchecked. The example is a simple modification of the MinimalApp2 example we presented in the minimal application tutorial. The full source for this example is available from our GitHub repository: wxWidgetsTutorials/StandardControls/WxCheckBox1.

The source files are shown below. The following modifications were made:

  • A wxTextCtrl and wxCheckBox have been added to the frame.
  • The OnCheckBoxEvent method is the event handler for the checkbox. It updates the text of the wxTextCtrl.
  • The event table links the checkbox and its event handler.
 File: StandardControls/WxCheckBox1/src/WxCheckBox1Frame.h
GitHubCopy 
#ifndef _TUTORIALS_WXWIDGETS_WXCHECKBOX1FRAME_H_
#define _TUTORIALS_WXWIDGETS_WXCHECKBOX1FRAME_H_

#include <wx/frame.h>
#include <wx/textctrl.h>

class WxCheckBox1Frame : public wxFrame
{
public:
    WxCheckBox1Frame(const wxString& title);

private:
    void OnCheckBoxEvent(wxCommandEvent& evt);

private:
    wxTextCtrl* m_textctrl;

    wxDECLARE_EVENT_TABLE();
};

#endif
 File: StandardControls/WxCheckBox1/src/WxCheckBox1Frame.cpp
GitHubCopy 
#include "WxCheckBox1Frame.h"
#include "WindowIDs.h"
#include <wx/panel.h>
#include <wx/sizer.h>
#include <wx/checkbox.h>

WxCheckBox1Frame::WxCheckBox1Frame(const wxString& title)
    : wxFrame(NULL, wxID_ANY, title), m_textctrl(0)
{
    // Create a top-level panel to hold all the contents of the frame
    wxPanel* panel = new wxPanel(this, wxID_ANY);
    panel->SetBackgroundColour(*wxWHITE);

    // Create the wxCheckBox control
    wxCheckBox* checkbox = new wxCheckBox(panel, wxID_CHECKBOX, "Checkbox 1");

    m_textctrl = new wxTextCtrl(panel, wxID_ANY, "Checkbox not checked", 
        wxDefaultPosition, wxSize(140, wxDefaultCoord));

    // Set up the sizer for the panel
    wxBoxSizer* panelSizer = new wxBoxSizer(wxVERTICAL);
    panelSizer->AddSpacer(15);
    panelSizer->Add(checkbox, 0, wxCENTER);
    panelSizer->AddSpacer(15);
    panelSizer->Add(m_textctrl, 0, wxCENTER);
    panelSizer->AddSpacer(15);
    panel->SetSizer(panelSizer);

    // Set up the sizer for the frame and resize the frame
    // according to its contents
    wxBoxSizer* topSizer = new wxBoxSizer(wxVERTICAL);
    topSizer->SetMinSize(215, 50);
    topSizer->Add(panel, 1, wxEXPAND);
    SetSizerAndFit(topSizer);
}

void WxCheckBox1Frame::OnCheckBoxEvent(wxCommandEvent& evt)
{
    if (evt.IsChecked())
    {
        m_textctrl->SetValue("Checkbox checked");
    }
    else
    {
        m_textctrl->SetValue("Checkbox not checked");
    }
}

wxBEGIN_EVENT_TABLE(WxCheckBox1Frame, wxFrame)
    EVT_CHECKBOX(wxID_CHECKBOX, WxCheckBox1Frame::OnCheckBoxEvent)
wxEND_EVENT_TABLE()

The application is shown below. Figure 1 shows the application when the checkbox is not checked and Figure 2 shows it when the checkbox is checked.

Figure 1: The WxCheckBox1 application at startup

Figure 2: The WxCheckBox1 application after checking the checkbox

The rest of the source files don't contain significant changes but are shown here for completeness.

 File: StandardControls/WxCheckBox1/src/WindowIDs.h
GitHubCopy 
#ifndef _TUTORIALS_WXWIDGETS_WINDOWIDS_H_
#define _TUTORIALS_WXWIDGETS_WINDOWIDS_H_

#include <wx/defs.h>

const wxWindowID wxID_CHECKBOX = wxID_HIGHEST + 1;

#endif
 File: StandardControls/WxCheckBox1/src/WxCheckBox1App.h
GitHubCopy 
#ifndef _TUTORIALS_WXWIDGETS_WXCHECKBOX1APP_H_
#define _TUTORIALS_WXWIDGETS_WXCHECKBOX1APP_H_

#include <wx/app.h>

class WxCheckBox1App : public wxApp
{
public:
    virtual bool OnInit();
};

#endif
 File: StandardControls/WxCheckBox1/src/WxCheckBox1App.cpp
GitHubCopy 
#include "WxCheckBox1App.h"
#include "WxCheckBox1Frame.h"

wxIMPLEMENT_APP(WxCheckBox1App);

bool WxCheckBox1App::OnInit()
{
    WxCheckBox1Frame* frame = new WxCheckBox1Frame("WxCheckBox1");
    frame->Show(true);
    return true;
}