Data Transfer, COM Enums, and Windows Controls
By Matthew Wilson, November 01, 2003
Transferring information from COM enumerators to windows controls can be complex. Two methods are presented here: a C-API written in C, which sacrifices run-time efficiency for succinct client code and run-time flexibility, and a method using STL sequences and function objects, which is more elegant and also likely to be more efficient.
Data Transfer, COM Enums, and Windows Controls
Listing 5 Implementation of control handlers
/* /////////////////////////////////////////////////////////////
* ...
*
* Extract from MOCtlFns.c
*
* Copyright (C) 1998-2003, Synesis Software Pty Ltd.
* (Licensed under the Synesis Software Standard Public License:
* http://www.synesis.com.au/licenses/ssspl.html)
*
* ...
* ////////////////////////////////////////////////////////// */
/* Listbox */
HRESULT ListBox_PutItem(HWND hwnd, LPVOID value, UInt32 flags, UInt32 param)
{
HRESULT hr;
if(IsWindowUnicode(hwnd))
{
hr = (ListBox_AddString(hwnd, (LPCOLESTR)value) < 0)
? E_FAIL : S_OK;
}
else
{
. . . // Do conversion to ANSI and add
}
return hr;
}
void ListBox_Reset(HWND hwnd)
{
ListBox_ResetContent(hwnd);
}
/* Combobox */
HRESULT ComboBox_PutItem(HWND hwnd, LPVOID value, UInt32 flags, UInt32 param)
{
HRESULT hr;
if(IsWindowUnicode(hwnd))
{
hr = (ComboBox_AddString(hwnd, (LPCOLESTR)value) < 0)
? E_FAIL : S_OK;
}
else
{
. . . // Do conversion to ANSI and add
}
return hr;
}
void ComboBox_Reset(HWND hwnd)
{
ComboBox_ResetContent(hwnd);
}
/* Listview */
HRESULT ListView_PutItem(HWND hwnd, LPVOID value, UInt32 flags, UInt32 param)
{
LV_ITEMW item;
item.mask = LVIF_TEXT;
item.iItem = ListView_GetItemCount(hwnd); /* add to end */
item.iSubItem = 0;
item.pszText = (LPWSTR)value;
return (int)SendMessage(hwnd, LVM_INSERTITEMW, 0, (LPARAM)&item) < 0
? E_FAIL : S_OK;
}
void ListView_Reset(HWND hwnd)
{
ListView_DeleteAllItems(hwnd);
}
/* Edit */
HRESULT Edit_PutItem(HWND hwnd, LPVOID value, UInt32 flags, UInt32 param)
{
HRESULT hr;
SendMessage(hwnd, EM_SETSEL, (WPARAM)-1, (LPARAM)-1);
if(IsWindowUnicode(hwnd))
{
hr = SendMessage(hwnd, EM_REPLACESEL, 0, (LPARAM)(LPCOLESTR)value)
? S_OK : E_FAIL;
if(SUCCEEDED(hr))
{
SendMessage(hwnd, EM_SETSEL, (WPARAM)-1, (LPARAM)-1);
hr = SendMessage(hwnd, EM_REPLACESEL, 0, (LPARAM)L"\r\n")
? S_OK : E_FAIL;
}
}
else
{
. . . // Do conversion to ANSI and add
}
return hr;
}
void Edit_Reset(HWND hwnd)
{
SetWindowText(hwnd, "");
}
