Simple Word Processing with an Edit Control
The following example implements much of the functionality of a simple word processor by filling the client area of a window with a multiline edit control. The system automatically performs wordwrap operations for this edit control and also handles the processing for the vertical scroll bar (created by specifying ES_AUTOVSCROLL in the call to the CreateWindow function). The WM_COMMAND message processes menu items; they allow the user to undo the previous action, cut or copy selections to the clipboard, paste text from the clipboard, and delete the current selection.
LONG APIENTRY MainWndProc(
HWND hwnd, /* window handle */
UINT message, /* type of message */
UINT wParam, /* additional information */
LONG lParam) /* additional information */
{
static HWND hwndEdit;
CHAR lpszTrouble[] = "When in the Course of human Events "
"it becomes necessary for one People "
"to dissolve the Political Bands which "
"have connected them with another, and "
"to assume among the Powers of the "
"Earth, the separate and equal Station "
"to which the Laws of Nature and of "
"Nature's God entitle them, a decent "
"Respect to the Opinions of Mankind "
"requires that they should declare the "
"causes which impel them to the "
"Separation. ";
switch (message) {
case WM_CREATE:
hwndEdit = CreateWindow(
"EDIT", /* predefined class */
NULL, /* no window title */
WS_CHILD | WS_VISIBLE | WS_VSCROLL |
ES_LEFT | ES_MULTILINE | ES_AUTOVSCROLL,
0, 0, 0, 0, /* set size in WM_SIZE message */
hwnd, /* parent window */
(HMENU) ID_EDITCHILD, /* edit control ID */
(HINSTANCE) GetWindowLong(hwnd, GWL_HINSTANCE),
NULL); /* pointer not needed */
/* Add text to the window. */
SendMessage(hwndEdit, WM_SETTEXT, 0,
(LPARAM) lpszTrouble);
return 0;
case WM_COMMAND:
switch (wParam) {
case IDM_EDUNDO:
/*
* Send WM_UNDO only if there is something
* to be undone.
*/
if (SendMessage(hwndEdit, EM_CANUNDO, 0, 0))
SendMessage(hwndEdit, WM_UNDO, 0, 0);
else
MessageBox(hwndEdit,
"Nothing to undo.",
"Undo notification", MB_OK);
break;
case IDM_EDCUT:
SendMessage(hwndEdit, WM_CUT, 0, 0);
break;
case IDM_EDCOPY:
SendMessage(hwndEdit, WM_COPY, 0, 0);
break;
case IDM_EDPASTE:
SendMessage(hwndEdit, WM_PASTE, 0, 0);
break;
case IDM_EDDEL:
SendMessage(hwndEdit, WM_CLEAR, 0, 0);
break;
case IDM_PASSWORD:
DialogBox(hinst, /* current instance */
"PassBox", /* resource to use */
hwnd, /* parent handle */
(DLGPROC) PassProc);
break;
case IDM_WRAP:
SendMessage(hwndEdit,
EM_SETWORDBREAKPROC,
(WPARAM) 0,
(LPARAM) (EDITWORDBREAKPROC) WordBreakProc);
SendMessage(hwndEdit,
EM_FMTLINES,
(WPARAM) TRUE,
(LPARAM) 0);
SendMessage(hwndEdit,
EM_SETSEL,
0, -1); /* select all text */
SendMessage(hwndEdit, WM_CUT, 0, 0);
SendMessage(hwndEdit, WM_PASTE, 0, 0);
break;
case IDM_ABOUT:
DialogBox(hinst, /* current instance */
"AboutBox", /* resource to use */
hwnd, /* parent handle */
(DLGPROC) About);
break;
default:
return DefWindowProc(hwnd, message, wParam, lParam);
}
break;
case WM_SETFOCUS:
SetFocus(hwndEdit);
return 0;
case WM_SIZE:
/*
* Make the edit control the size of the window's
* client area.
*/
MoveWindow(hwndEdit,
0, 0, /* starting x- and y-coordinates */
LOWORD(lParam), /* width of client area */
HIWORD(lParam), /* height of client area */
TRUE); /* repaint window */
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
default:
return DefWindowProc(hwnd, message, wParam, lParam);
}
return NULL;
}