Filter Library

Camera

Interface Physics

CFilterEdit Class Reference
[Numeric Edit Control]

#include <ControlFilterEdit.h>

Inheritance diagram for CFilterEdit:

List of all members.

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Detailed Description

CFilterEdit is the base class for edit fields that can filter their input. This can be used to limit the input to data that is valid in a certian context, for example only positive integer numbers.

Base class CFilterEdit lets you specify several ascpects of its behaviour:

• validate as the user types (also settable in the constructor), SetProcessChars()
• check that the entire input is valid when the control loses focus; set focus back to the control if the input is invalid when the control loses focus, SetAutoValidate()
• show invalid input visually: set the background color to a specified color if the input is invalid, draw a wavy line under the text if the input is invalid, SetShowInvalid()
• set the error colors, SetBackgroundColourError(), SetForegroundColourError()
• set the normal ('OK') colors, SetForegroundColourOK(), SetBackgroundColourOK()
• beep, if, when a final validation is performed, the validation fails, SetBeepOnInvalid()

To implement the checking behaviour, do the following.

• derive your class publicly from CFilterEdit
• implement methods Check() and Match()

Note: CFilterEdit can also be used by itself solely with the purpose to create a colored edit field.

Make sure that the control is included in method DoDataExchange() of the dialog classes where you use the edit control.

Class CFilterEdit is a modification of the class CFilterEdit by Ben Hanson [FILTEREDIT] in that the regular expression pattern matching [REGEXP] is replaced by a simple lexical scanner [Aho et al.].

Another interesting article is: A Validating Edit Control by Joseph M. Newcomer [VALEDTCTL]. This article describes the use of a tooltip to indicate the reason the contents of an edit control is invalid.

The following example shows an edit field that limits its input to signed integer numbers in octal, decimal or hexadecimal notation.

The interface.

 // ControlOctDecHexEdit.h - class declaration.

 #ifndef CFL_CONTROLOCTDECHEXEDIT_H
 #define CFL_CONTROLOCTDECHEXEDIT_H

 #if _MSC_VER > 1000
 #pragma once
 #endif // _MSC_VER > 1000

 #include <cfl/ControlFilterEdit.h>      // for base class CFilterEdit

 //
 // COctDecHexEdit
 //

 class COctDecHexEdit : public CFilterEdit
 {
 public:
    ~COctDecHexEdit();
    COctDecHexEdit( bool bSigned = true );

 protected:
    bool Check( const CString &csText );
    bool Match( const CString &csText );

 private:
    bool m_bSigned;
 };

 //
 // destructor.
 //

 inline COctDecHexEdit::~COctDecHexEdit()
 {
    ; // do nothing
 }

 //
 // destructor.
 //

 inline COctDecHexEdit::COctDecHexEdit( bool bSigned ) :
    CFilterEdit(), m_bSigned( bSigned )
 {
    ; // do nothing
 }

 #endif // CFL_CONTROLOCTDECHEXEDIT_H

The implementation.

 // ControlOctDecHexEdit.cpp - class implementation.

 #include "stdafx.h"                     // for common (pre-compiled) headers
 #include <cfl/ControlOctDecHexEdit.h>   // header

 //
 // true if input is complete and valid.
 //

 bool COctDecHexEdit::Check( const CString &csText )
 {
    TCHAR* ePtr;

    // let strtol() determine the base:
    (void) _tcstol( csText, &ePtr, 0 );

    // ok if all characters are used for conversion
    return _TCHAR('\0') == *ePtr;
 }

 //
 // true if (partial) input valid.
 //

 //      number : sign? ( octal | decimal | hexadecimal )
 //        sign : [+-]
 //       octal : "0" [0-7]+
 //     decimal : [1-9][0-9]*
 // hexadecimal : "0" [xX] [0-9a-fA-F]+
 //

 bool COctDecHexEdit::Match( const CString &csText )
 {
    int base = 10;

    const TCHAR* cPtr = csText;

    // optional sign?

    if ( _TCHAR('+') == *cPtr || ( m_bSigned && _TCHAR('-') == *cPtr ) )
       ++cPtr;

    // leading octal/hexadecimal 0?

    if ( _TCHAR('0') == *cPtr )
    {
       ++cPtr;
       base = 8;
    }

    // leading hexadecimal 0x, 0X?

    if ( 8 == base && ( _TCHAR('x') == *cPtr || _TCHAR('X') == *cPtr ) )
    {
       ++cPtr;
       base = 16;
    }

    // scan remaining digits:

    if ( 8 == base )
    {
       while ( *cPtr && _TCHAR('0') <= *cPtr && *cPtr <= _TCHAR('7') )
         ++cPtr;
    }
    else if ( 10 == base )
    {
       while ( *cPtr && _istdigit( *cPtr ) )
         ++cPtr;
    }
    else if ( 16 == base )
    {
       while ( *cPtr && _istxdigit( *cPtr ) )
         ++cPtr;
    }

    // ok if all characters matched:
    return cPtr == (const TCHAR*) csText + csText.GetLength();
 }

Definition at line 335 of file ControlFilterEdit.h.

Public Member Functions
Predicates
bool	IsValidChar ()
	true if last entered character is valid.
bool	IsValidInput ()
	true if the entered text is complete and valid.
Accessors
const CString &	GetProposedText () const
	the entered text, so far.
Mutators
void	SetProcessChars (const bool bProcessChars)
	validate as the user types (also settable in the constructor).
void	SetAutoValidate (const bool bAutoValidate, const bool bModal)
	check that the entire input is valid when the control loses focus (bAutoValidate), set focus back to the control if the input is invalid when the control loses focus (bModal).
void	SetShowInvalid (const bool bShowInvalid, const bool bSetBkOnError, const bool bWavyLineOnError)
	show if the input is invalid (bShowInvalid), via the background color (bSetBkOnError) and with a wavy line under the text (bWavyLineOnError).
void	SetBeepOnInvalid (const bool bBeepOnInvalid)
	beep when the final validation fails (bBeepOnInvalid).
void	SetBackgroundColourOK (const COLORREF crBkOK)
	set the normal ('OK') background color.
void	SetForegroundColourOK (const COLORREF crFgOK)
	set the normal ('OK') foreground color.
void	SetBackgroundColourError (const COLORREF crBkError)
	set the error background color.
void	SetForegroundColourError (const COLORREF crFgError)
	set the error foreground color.
void	Select ()
	focus the control and select it content.
Protected Member Functions
bool	ValidateChar (UINT nChar)
	true if this character is acceptable at this point.
void	ResetValid ()
	restore valid state.
virtual bool	Check (const CString &csText)
	true if input is complete and valid; override in derived classes.
virtual bool	Match (const CString &csText)
	true if partial input is acceptable; override in derived classes.
virtual LRESULT	WindowProc (UINT message, WPARAM wParam, LPARAM lParam)
	handle window message, like cut paste etc.
Mutators
afx_msg void	OnChar (UINT nChar, UINT nRepCnt, UINT nFlags)
	validate new character (if SetProcessChars(true)) and let it be further processed, unless its invalid.
afx_msg void	OnKeyDown (UINT nChar, UINT nRepCnt, UINT nFlags)
	handle control-key press (Del, Ctrl+X, Ctrl+V).
afx_msg void	OnKeyUp (UINT nChar, UINT nRepCnt, UINT nFlags)
	handle control-key release (Ctrl).
afx_msg HBRUSH	CtlColor (CDC *pDC, UINT)
	handle the ON_WM_CTLCOLOR_REFLECT message.
afx_msg void	OnSetFocus (CWnd *pOldWnd)
	handle set focus message.
afx_msg void	OnKillFocus (CWnd *pNewWnd)
	validate on kill focus message.
afx_msg void	OnPaint ()
	handle paint message.
Private Types
typedef CFilterEdit	self
	this type
Private Member Functions
bool	CanDelete ()
	handle cut, Ctrl+X
bool	CanPaste ()
	handle paste, Ctrl+V
	CFilterEdit (CFilterEdit const &)
	prevent copy-assignment construction
self &	operator= (CFilterEdit const &)
	prevent assignment
Private Attributes
bool	m_bProcessChars
	validate characters while typing (flag)
bool	m_bAutoValidate
	(flag)
bool	m_bModal
	(flag)
bool	m_bShowInvalid
	indicate invalid input (flag)
bool	m_bSetBkOnError
	change background color for invalid input (flag)
bool	m_bWavyLineOnError
	draw wavy line if input is invalid (flag)
bool	m_bBeepOnInvalid
	beep if input is invalid (flag)
bool	m_bValid
	input is valid (flag)
bool	m_bCharValid
	current character is valid (flag)
CString	m_strProposedText
	current valid text
bool	m_bControlDown
	control key is down (flag)
COLORREF	m_crFgOK
	ok foreground color
COLORREF	m_crBkOK
	ok background color
COLORREF	m_crFgError
	error foreground color
COLORREF	m_crBkError
	error background color
CBrush	m_brOK
	ok brush
CBrush	m_brError
	error brush

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The documentation for this class was generated from the following files:

• ControlFilterEdit.h
• ControlFilterEdit.cpp

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