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Numeric edit and numeric spin controls

Posted by T. VU KHAC on February 2nd, 1999
In my application I needed an edit control which accepts only numeric numbers. In many science applications this is indispensable, but it is actually not implemented in MS-Visual C/C++. It is not difficult to implement this control and I see that some people implemented it. In my own code, some new features were enriched as error messages and range defines, etc.
Note: to use the CNumEdit class properly, the ES_NUMBER, ES_MULTILINE must not be set.

Another control added in my work is CNumSpinCtrl which enables using a spin control as a numeric one which is also not implemented in MFC.

Note: to use the CNumSpinCtrl class properly, the ES_AUTOBUDDY, ES_SETBUDDYINTEGER must not be set.

Your suggestions are appreciated. Enjoy! 



class CNumEdit : public CEdit
{
	DECLARE_DYNAMIC(CNumEdit)
public:
	CNumEdit();
	virtual ~CNumEdit();
	enum {VALID = 0x00, OUT_OF_RANGE = 0x01, INVALID_CHAR = 0x02};
	virtual void ChangeAmount(int step);
	virtual float GetDelta();
	virtual void SetDelta(float delta);
	virtual void GetRange(float &min, float &max)const; 
	virtual void SetRange(float min, float max);
	virtual void Verbose(BOOL v);
	virtual BOOL Verbose()const; 
	virtual int IsValid()const; 
	virtual int IsValid(const CString &str)const; 
	virtual BOOL SetValue(float val);
	virtual float GetValue()const; 
protected:
	virtual CString& ConstructFormat(CString &str, float num);
	BYTE m_NumberOfNumberAfterPoint;
	BOOL m_Verbose;
	float m_Delta, m_MinValue, m_MaxValue;
	DECLARE_MESSAGE_MAP()
};

class CNumSpinCtrl : public CSpinButtonCtrl
{
	DECLARE_DYNAMIC(CNumSpinCtrl)
public:
	CNumSpinCtrl();
	virtual ~CNumSpinCtrl();
	virtual void SetDelta(float delta);
	virtual float GetDelta();
	virtual void SetBuddy(CNumEdit *edit);
	virtual CNumEdit* GetBuddy() const;
	virtual void GetRange(float &lower, float& upper ) const;
	virtual void SetRange(float nLower, float nUpper );
	virtual float GetPos();
	virtual void SetPos(float val);
};

Download demo project - 16 KB

Date Last Updated: May 17, 1999

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Comments

  • Float edit control in C#

    Posted by yagnesh on 01/20/2005 04:27am

    How to make my own float edit text box in c#. It should work based on masking provided. e.g. if ####.## is a mask then 1234.56 should accept not 12.3345. Plz mail me the solution on yagneshpatel.windowmaker.com

    Reply

  • how to use

    Posted by Legacy on 05/07/2001 12:00am

    Originally posted by: Julia

    Do you mind telling me how to use your class in viewform?

    Thank you very much,

    Julia

    Reply

  • Thank's

    Posted by Legacy on 12/21/2000 12:00am

    Originally posted by: Flo 

    Great code !!!


    Thank's for your code and thank's Codeguru team!

    Reply

  • Numeric edit and numeric spin controls

    Posted by Legacy on 12/12/1999 12:00am

    Originally posted by: Pilar Garc�a

    Excellent! I have tried with usual Edit and CSpinButtonCtrl controls but your classes are much better. With the first, the edit box must be "only read", for example.

    I�m learning much with codeguru. Thank you very much!

    Reply

  • /editctrl/NumericSpin.shtml

    Posted by Legacy on 06/10/1999 12:00am

    Originally posted by: Julie Dinh

    Hi!! I was looking at codeguru and found your article...
    I am sorry but "are u vietnames???" ...your name kindda looks like one....anyway...back to the question...
    "how do u disable a CEdit"...that is you have a small edit
    box....if the edit box is not in used...i want to disable it or greyed it out...but i don't know how...so ....heeeeelp...

    your reply is truly appreciated....
    Julie

    Reply

  • Modification for wrap, minus, and decimal

    Posted by Legacy on 04/29/1999 12:00am

    Originally posted by: Corey McKenzie 

    These modifications allow you to enter a decimal as the first character (it already accepted it after a
number), a minus sign, and to support Wrap on the spin control.


    In NumEdit.cpp:

    int CNumEdit::IsValid() const

    {

    	CString str;

    	GetWindowText(str);

    	return IsValid( str );

    }


    int CNumEdit::IsValid(const CString &str) const

    {

    	int res = VALID;

    	float f;

    	char lp[10];

    	// need this to accept a minus sign.

    	if( str.GetLength() == 1 && (str[0] == '-' || str[0] == '.'))

    		return VALID;

    	if (sscanf(str, "%f%s", &f, lp) != 1) res = INVALID_CHAR;

    	if (f > m_MaxValue && f < m_MinValue) res = OUT_OF_RANGE;

    	if (m_Verbose && res != VALID)

    	{

    		CString msg;

    		msg.Empty();

    		if (res & OUT_OF_RANGE) msg += _T("Given value is out of range.\n");

    		if (res & INVALID_CHAR) msg += _T("Characters must be a number.\n");

    		AfxMessageBox(str, MB_OK | MB_ICONSTOP);

    	}

    	return res;

    }


    void CNumEdit::ChangeAmount(int step, BOOL bWrap)

    {

    	float fDelta = step*m_Delta;

    	float f = GetValue();

    	// This messy bit of code gets around a floating point resolution problem.

    	// For example, if your step is -1 and m_Delta is .1, you would end up

    	// with -1.49xxx e-9 and it would never set the control to zero. The old

    	// 0 != 0 problem.

    	if( f == -fDelta )

    		f = 0;

    	else

    		f += fDelta;

    	if (f > m_MaxValue)

    	{

    		if( bWrap )

    			f = m_MinValue;

    		else

    			f = m_MaxValue;

    	}

    	else if (f < m_MinValue)

    	{

    		if( bWrap )

    			f = m_MaxValue;

    		else

    			f = m_MinValue;

    	}

    	SetValue(f);

    }


    In NumEdit.h

    	virtual void ChangeAmount(int step, BOOL bWrap);


    In NumSpinCtrl.cpp

    void CNumSpinCtrl::OnDeltapos(NMHDR* pNMHDR, LRESULT* pResult) 

    {

    	NM_UPDOWN* pNMUpDown = (NM_UPDOWN*)pNMHDR;

    	DWORD bWrap = (GetStyle() & UDS_WRAP);

    	if ((pNMUpDown->iPos <= pNMUpDown->iDelta) ||

    		(pNMUpDown->iPos >= 1000 - pNMUpDown->iDelta)) pNMUpDown->iPos = 500;

    	CNumEdit *m_Edit = GetBuddy();

    	if (m_Edit)

    		if (m_Edit->IsKindOf(RUNTIME_CLASS(CNumEdit)))

    			m_Edit->ChangeAmount(pNMUpDown->iDelta, bWrap);

    	*pResult = 0;

    }

    Reply
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