#include "afxwin.h"
#include "SimpleDialog.h"
#include "resource.h"

CSimpleDialog::CSimpleDialog() : CDialog(ADDITION) {
	m_nTotal = 0;
}

afx_msg void CSimpleDialog::OnAdd() {
	const TEXT_SIZE = 16;
	char szText[TEXT_SIZE + 1];

	CEdit* pTotal = (CEdit*) GetDlgItem(IDC_TOTAL);
	CEdit* pNum = (CEdit*) GetDlgItem(IDC_NUMBER);

	pNum->GetWindowText(szText, TEXT_SIZE);
	m_nTotal += atoi(szText);

	itoa(m_nTotal, szText, 10);

	pTotal->SetWindowText(szText);

	pNum->SetWindowText("");
	pNum->SetFocus();
}

afx_msg void CSimpleDialog::OnClear() {
	CEdit* pTotal = (CEdit*) GetDlgItem(IDC_TOTAL);
	CEdit* pNum = (CEdit*) GetDlgItem(IDC_NUMBER);

	m_nTotal = 0;

	pTotal->SetWindowText("0");
	pNum->SetWindowText("");
	pNum->SetFocus();
}

BEGIN_MESSAGE_MAP(CSimpleDialog, CDialog)
	ON_COMMAND(IDC_ADD, OnAdd)
	ON_COMMAND(IDC_CLEAR, OnClear)
END_MESSAGE_MAP()

class CAdditionExample : public CWinApp {
public:
	BOOL InitInstance() {
		CSimpleDialog additionDialog;

		CEdit* pTotal = (CEdit*) additionDialog.GetDlgItem(IDC_TOTAL);
		pTotal->SetWindowText("0");

		additionDialog.DoModal();
		return FALSE;
	}
};

CAdditionExample addition_example;