www.gusucode.com > 基于Visual C++高级界面特效制作百例源码程序 > 基于Visual C++高级界面特效制作百例源码程序/code/char13/range_edit/CRangeEdit.cpp
//*****************************************************************************
// implementation file
//*****************************************************************************
//
// FILE NAME: CRangeEdit.cpp
//
// DESCRIPTION: This file contains the methods for the
// CRangeEdit class.
//
//*****************************************************************************
//
// MODIFICATION HISTORY:
// Rev # Date Author
// 001 3/2/1998 Donald R. Kichline (drkich@csrlink.net)
// 002 3/6/1998 Donald R. Kichline
//
//*****************************************************************************
//
// MODIFICATION SUMMARY:
//
// Rev # Description
// 001 Created the class
// 002 1. Moved range validation from OnChar() to OnUpdate().
//
// 2. Removed the OnChar() member function.
//
// 3. Added a member variable to hold the last valid value
// entered by the operator.
//
// 4. Seperated the code to remove the leading zeros from
// a string, into a seperate function.
//
// 5. Allow NULL to be a valid value entered by an operator.
// This occurs when the operator deletes the number in
// the control.
//
//*****************************************************************************
// Include Files
//
#include "stdafx.h"
#include "CRangeEdit.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
// Defines
//
#define BLANK_ENTRY -1
//*****************************************************************************
//
// METHOD NAME : CRangeEdit constructor
//
// DESCRIPTION : This is the CRangeEdit constructor.
//
// PARAMETERS :
// NAME I/O TYPE DESCRIPTION
// n/a
//
// RETURN TYPE :
// TYPE DESCRIPTION
// n/a
//
//*****************************************************************************
CRangeEdit::CRangeEdit() :
myMin ( 0 ), // Initialize member variables to zero
myMax ( 100 ),
myLastValidValue ( 0 )
{
}
//*****************************************************************************
//
// METHOD NAME : CRangeEdit destructor
//
// DESCRIPTION : This is the CRangeEdit destructor.
//
// PARAMETERS :
// NAME I/O TYPE DESCRIPTION
// n/a
//
// RETURN TYPE :
// TYPE DESCRIPTION
// n/a
//
//*****************************************************************************
CRangeEdit::~CRangeEdit()
{
}
//*****************************************************************************
//
// METHOD NAME : BEGIN_MESSAGE_MAP and END_MESSAGE_MAP macros
//
// DESCRIPTION : Each CCmdTarget-derived class must provide a message
// map to handle messages. The BEGIN_MESSAGE_MAP macro
// is followed by entries for each message-handler
// function in this class and the END_MESSAGE_MAP macro.
//
// PARAMETERS :
// NAME I/O TYPE DESCRIPTION
// n/a I CRangeEdit Class type
// n/a I CEdit Class type
//
// RETURN TYPE :
// TYPE DESCRIPTION
// n/a
//
//*****************************************************************************
BEGIN_MESSAGE_MAP(CRangeEdit, CEdit)
//{{AFX_MSG_MAP(CRangeEdit)
ON_CONTROL_REFLECT(EN_UPDATE, OnUpdate)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
//*****************************************************************************
//
// METHOD NAME : CRangeEdit.OnUpdate
//
// DESCRIPTION : This member function is called when the edit control is
// about to display altered text.
//
// This member function firsts removes all leading zeros from
// the edit control. Then it will validate the number entered
// by the operator. If the number is invalid, then the last
// valid value is restored..
//
// PARAMETERS :
// NAME I/O TYPE DESCRIPTION
// n/a
//
// RETURN TYPE :
// TYPE DESCRIPTION
// n/a
//
//*****************************************************************************
void CRangeEdit::OnUpdate()
{
// Local Variables
//
CString strWindowText;
LONG ValidationNumber;
// Initialize Variables
//
strWindowText.Empty ( );
ValidationNumber = 0;
// Remove the leading zeros from the
// edit control
//
RemoveLeadingZeros ( );
// Copy the contents of the edit control
// to a string
//
GetWindowText ( strWindowText );
// Check if the edit control is blank
//
if ( strWindowText.IsEmpty ( ) )
{
// The operator erased the last number. Thus the last valid value
// entered by the operator is NULL.
//
myLastValidValue = BLANK_ENTRY;
}
else
{
// There is a number to validate in the string
//
// Convert the string to a LONG
//
ValidationNumber = atol ( strWindowText );
// Check if the number falls within the specified range
//
if ( ( ValidationNumber < myMin ) || ( ValidationNumber > myMax ) )
{
// The number is invalid, it is out of the specified range
//
// Check what type of value the last Valid Value is:
// 1. A number: which is indicated by a value greater than
// or equal to 0.
//
// 2. NULL: which is indicated by BLANK_ENTRY (-1).
//
if ( myLastValidValue >= 0 )
{
// The last value is a number
//
strWindowText.Format ( "%d", myLastValidValue );
}
else
{
// The last value was a NULL
//
strWindowText.Empty ( );
}
// Set the Edit control with the Last Valid Value
//
SetWindowText ( strWindowText );
// Place the cursor at the end of the string
//
SetSel ( strWindowText.GetLength ( ), strWindowText.GetLength ( ) );
// Alert the operator of the error
//
MessageBeep ( 0xFFFFFFFF );
}
else
{
// The number is valid, that is, it is in the specified range
//
// Set the last valid value to the current number
// in the edit control
//
myLastValidValue = ValidationNumber;
}
}
}
//*****************************************************************************
//
// METHOD NAME : CRangeEdit.SetRange
//
// DESCRIPTION : This member function will set the member variables that
// represents the minimum and maximum number the edit
// control will accept.
//
// PARAMETERS :
// NAME I/O TYPE DESCRIPTION
// inLMin I LONG Contains the minimum number the
// edit control will accept.
// inLMax I LONG Contains the maximum number the
// edit control will accept.
//
// RETURN TYPE :
// TYPE DESCRIPTION
// n/a
//
//*****************************************************************************
void CRangeEdit::SetRange ( LONG inLMin, LONG inLMax )
{
// Set the member variables
//
myMin = inLMin;
myMax = inLMax;
myLastValidValue = myMin;
}
//*****************************************************************************
//
// METHOD NAME : CRangeEdit.RemoveLeadingZeros
//
// DESCRIPTION : This member function will remove all leading zeros
// from the edit control.
//
// PARAMETERS :
// NAME I/O TYPE DESCRIPTION
// n/a
//
// RETURN TYPE :
// TYPE DESCRIPTION
// n/a
//
//*****************************************************************************
void CRangeEdit::RemoveLeadingZeros ( void )
{
// Local Variables
//
CString strWindowText;
SHORT index;
// Initialize Variables
//
strWindowText.Empty ( );
index = 0;
// Copy the contents of the edit control
// to a string
//
GetWindowText ( strWindowText );
// Check if the length of the text in the edit
// control is greater than 1
//
// If the length is 1 then there can not be any
// leading zeroes
//
if ( strWindowText.GetLength ( ) > 1 )
{
// Get the index of the first
// non-zero character
//
index = strWindowText.FindOneOf ( "123456789" );
// Check if there are any leading zeroes
// if the first non-zero character
// is at any position but 0, then
// there are leading zeros
//
if ( index > 0 )
{
// Leading zeroes were found
// Remove them
//
strWindowText = strWindowText.Mid ( index );
}
// Check if no non-zero characters were found
// That means there are only zeros in the
// string
//
else if ( index == -1 )
{
// There is only zeroes in the string
// change the string to only one zero
//
strWindowText = "0";
}
// Check if the text was formatted, the index is not 0
//
if ( index != 0 )
{
// The text was formatted, update the edit controls text
//
SetWindowText ( strWindowText );
// Set the cursor position
//
SetSel ( 0, 0 );
}
}
}
// Undefine the BLANK_ENTRY definition
//
#undef BLANK_ENTRY