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Introduction
First off, I would like to acknowledge that most of this code came from others at CodeGuru. I took code from
some of the articles submitted by Zafir Anjum, so look at his article "Editable Subitems" as a basis for this
article.
This project demonstrates how the list view/control can be used to edit information in the
form of a table (multiple-editable columns). I have captured the Tab, Page Down, Page Up, Up,
Down, Home, and End keys to allow easy navigation through the control.
As shown in "Editable Subitems", I subclassed the CEdit
control with my class called gxEditCell
. Then, I added
a new parameter to it's constructor. This new parameter is a pointer to the parent list control so that my edit
box could inform the list control of any important events, like a key press. Then when I get a key event, I simply
tell the list control which subitem I want to edit next
based off the current cell that is being edited. This can be seen in the OnKeyDown
function below. As you can see,
when I receive the VK_UP
key event, I am telling the list control to edit the subitem located directly above the current
cell. I check, of course, to see if it is a valid cell first.
The reason I caught some events in the KeyDown
, some in
the KeyUp
, and some in the OnChar
, had to do with how the application behaved. If I would have caught the VK_PRIOR
or
VK_NEXT
in the OnKeyDown
, I would get several calls depending on how long the button was pressed. This is very annoying.
If you don't believe me, move the code, add several items to the list and try it (it isn't pretty).
I also caught the ESC key so that I could cancel an edit. The return key is being used to end an edit and when it is on
the last record, it insert a new one. Just don't forget to override the OnGetDlgCode()
so that you can get the arrow
keys and tabs.
gxEditCell::gxEditCell (gxListCtrl* pCtrl, int iItem, int iSubItem, CString sInitText)
: bEscape (FALSE)
{
pListCtrl = pCtrl;
Item = iItem;
SubItem = iSubItem;
InitText = sInitText;
}
void gxEditCell::OnKeyDown (UINT nChar, UINT nRepCnt, UINT nFlags)
{
BOOL Control = GetKeyState (VK_CONTROL) < 0;
switch (nChar)
{
case VK_UP :
{
if (Item > 0)
pListCtrl->EditSubItem (Item - 1, SubItem);
return;
case VK_DOWN :
{
pListCtrl->EditSubItem (Item + 1, SubItem);
return;
}
case VK_HOME :
{
if (!Control)
break;
pListCtrl->EditSubItem (0, SubItem);
return;
}
case VK_END :
{
if (!Control)
break;
int Count = pListCtrl->GetItemCount() - 1;
pListCtrl->EditSubItem (Count, SubItem);
return;
}
}
CEdit::OnKeyDown(nChar, nRepCnt, nFlags);
}
void gxEditCell::OnKeyUp (UINT nChar, UINT nRepCnt, UINT nFlags)
{
switch (nChar)
{
case VK_NEXT :
{
int Count = pListCtrl->GetItemCount();
int NewItem = Item + pListCtrl->GetCountPerPage();
if (Count > NewItem)
pListCtrl->EditSubItem (NewItem, SubItem);
else
pListCtrl->EditSubItem (Count - 1, SubItem);
return;
}
case VK_PRIOR :
{
int NewItem = Item - pListCtrl->GetCountPerPage();
if (NewItem > 0)
pListCtrl->EditSubItem (NewItem, SubItem);
else
pListCtrl->EditSubItem (0, SubItem);
return;
}
}
CEdit::OnKeyUp (nChar, nRepCnt, nFlags);
}
void gxEditCell::OnChar (UINT nChar, UINT nRepCnt, UINT nFlags)
{
BOOL Shift = GetKeyState (VK_SHIFT) < 0;
switch (nChar)
{
case VK_ESCAPE :
{
if (nChar == VK_ESCAPE)
bEscape = TRUE;
GetParent()->SetFocus();
return;
}
case VK_RETURN :
{
SetListText();
pListCtrl->EditSubItem (Item + 1, 0);
return;
}
case VK_TAB :
{
if (Shift)
{
if (SubItem > 0)
pListCtrl->EditSubItem (Item, SubItem - 1);
else
{
if (Item > 0)
pListCtrl->EditSubItem (Item - 1, 2);
}
}
else
{
if (SubItem < 2)
pListCtrl->EditSubItem (Item, SubItem + 1);
else
pListCtrl->EditSubItem (Item + 1, 0);
}
return;
}
}
CEdit::OnChar (nChar, nRepCnt, nFlags);
CString Text;
GetWindowText (Text);
CWindowDC DC (this);
CFont *pFont = GetParent()->GetFont();
CFont *pFontDC = DC.SelectObject (pFont);
CSize Size = DC.GetTextExtent (Text);
DC.SelectObject (pFontDC);
Size.cx += 5;
CRect Rect, ParentRect;
GetClientRect (&Rect);
GetParent()->GetClientRect (&ParentRect);
ClientToScreen (&Rect);
GetParent()->ScreenToClient (&Rect);
if (Size.cx > Rect.Width())
{
if (Size.cx + Rect.left < ParentRect.right )
Rect.right = Rect.left + Size.cx;
else
Rect.right = ParentRect.right;
MoveWindow (&Rect);
}
}
UINT gxEditCell::OnGetDlgCode()
{
return CEdit::OnGetDlgCode() | DLGC_WANTARROWS | DLGC_WANTTAB;
}