Editing using hints - worked example

key : purple - original code / blue - new code

Step 1 :

Continue with the program names.

Step 2 :

Edit the original code in the AddNames() function within the Document. A Hint and a pointer to the required position should be included :

void CNamesDoc::AddNames()
{

CEnterNamesDlg dlg;

if(dlg.DoModal() == IDOK)
{

CName* temp = new CName(dlg.m_strTitle,
dlg.m_strFirstName, dlg.m_strSecondName);
m_NameList.AddTail(temp);
m_nCurrentPosition = m_NameList.GetTailPosition();
CName * pCurrentName = m_NameList.GetAt(m_nCurrentPosition);
UpdateAllViews(NULL, HINT_ADD_NAME, pCurrentName);

}

}

Step 3 :

Edit the original code in the OnRemoveCurrentName() function within the Document. A Hint and a pointer to the required position should be included :

void CNamesDoc::OnRemoveCurrentName()
{

if( !m_NameList.IsEmpty() )
{

//Store current item to be deleted
CName * pCurrentName = GetCurrentName();

//First sort out new current item
POSITION nTemp = m_nCurrentPosition;
m_NameList.GetNext(m_nCurrentPosition);
if(m_nCurrentPosition==NULL)
{

m_nCurrentPosition = nTemp;
m_NameList.GetPrev(m_nCurrentPosition);

}
m_NameList.RemoveAt(nTemp);
UpdateAllViews(NULL,HINT_DELETE_NAME, pCurrentName);
delete pCurrentName;

}
else
{

AfxMessageBox("There are no items to delete.");

}

}

Step 4 :

Edit the original code in the OnRemoveAllNames() function within the Document. A Hint and should be included, a pointer in this case is not necessarry :

void CNamesDoc::OnRemoveAllNames()
{

if( !m_NameList.IsEmpty() )
{

// firstly delete all the pointers to avoid memory leaks
POSITION pos = m_NameList.GetHeadPosition();
while( pos != NULL )
{
delete m_NameList.GetNext( pos );
}

// now delete all the m_NameList
m_NameList.RemoveAll();
m_nCurrentPosition = NULL;
UpdateAllViews(NULL, HINT_DELETE_ALL_NAMES);

}
else
{

AfxMessageBox("There are no items to delete.");

}

}

Step 5 :

The response to these hints must now be put into the OnUpdate() function within NameListView. A switch statement should be used. It should be observed that to delete all of the list only one line of code is required :

void CNameListView::OnUpdate(CView* pSender, LPARAM lHint, CObject* pHint)
{

CListCtrl& listCtrl = GetListCtrl(); // Get list ctrl

// first cast the pHint to a CName type
CName * pName = (CName *)pHint;

long messageType = (long)lHint;

switch (lHint)
{

case HINT_DELETE_ALL_NAMES:
// do not need seperate function as just one line of code
listCtrl.DeleteAllItems();
break;

case HINT_ADD_NAME:
AddNameToListCtrl(pName);
break;

case HINT_DELETE_NAME:
DeleteNameFromListCtrl(pName);
break;

}

}

Step 6 :

Add the code to the AddNameToListCtrl() function :

void CNameListView::AddNameToListCtrl(CName * pNameTemp)
{

CListCtrl& m_listCtrl = GetListCtrl();

LV_ITEM listItem;
listItem.mask = LVIF_TEXT | LVIF_IMAGE;
listItem.iSubItem = 0;

CString* temp = ((pNameTemp->GetTitleAddress()));

LPTSTR pBufTitle = (LPTSTR) temp->GetBuffer(temp->GetLength());
listItem.pszText = pBufTitle;

temp = ((pNameTemp->GetFirstNameAddress()));
LPTSTR pBufFirstName = (LPTSTR) temp->GetBuffer(temp->GetLength());

temp = ((pNameTemp->GetSecondNameAddress()));
LPTSTR pBufSecondName = (LPTSTR) temp->GetBuffer(temp->GetLength());

if( pNameTemp->GetTitle() == "Mr" ||
pNameTemp->GetTitle() == "Sir")
{

listItem.iImage = 0;

}
else if( pNameTemp->GetTitle() == "Dr" ||
pNameTemp->GetTitle() == "Prof")
{

listItem.iImage = 2;

}
else // 99% certain that they must be female
{

listItem.iImage = 1;

}

listItem.iItem = m_listCtrl.GetItemCount();

m_listCtrl.InsertItem( &listItem );

// puts the firstname in col one, second name in col 2
m_listCtrl.SetItemText( listItem.iItem, 1, pBufFirstName );
m_listCtrl.SetItemText( listItem.iItem, 2, pBufSecondName );

temp->ReleaseBuffer();

}

Step 7 :

Now the AddInitialList() function may be simplified using the AddNameToListCtrl() function :

void CNameListView::AddInitialList()
{

CListCtrl& m_listCtrl = GetListCtrl();

POSITION pos;
CNamesDoc* pDoc = (CNamesDoc*)m_pDocument;

pos = pDoc->GetHeadPosition();

while(pos != NULL)
{

CName * pName = ((CNamesDoc*)m_pDocument)->GetNextItem(pos);
AddNameToListCtrl(pName);

}

}

Step 8 :

Add the DeleteNameFromListCtrl() function :

void CNameListView::DeleteNameFromListCtrl(CName * pNameTemp)
{

CListCtrl& m_listCtrl = GetListCtrl();

LV_ITEM listItem;
listItem.mask = LVIF_TEXT | LVIF_IMAGE;
listItem.iSubItem = 0;

CString strtempTitle = (pNameTemp->GetTitle());
CString strtempFirstName = (pNameTemp->GetFirstName());
CString strtempSecondName = (pNameTemp->GetSecondName());

for( int nItem = 0; nItem < m_listCtrl.GetItemCount(); nItem++)
{

if(strtempTitle == m_listCtrl.GetItemText(nItem, 0) &&
strtempFirstName == m_listCtrl.GetItemText(nItem, 1) &&
strtempSecondName == m_listCtrl.GetItemText(nItem, 2))
{

m_listCtrl.DeleteItem(nItem);

}

}

}

Click here for the basic exercise

Click here for the source code

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