PRB: Graying Text in Disabled Multi-line Edit Controls

MORE INFORMATION

The rationale behind this design feature is that the single line edit control is generally used in different circumstances than is the multi-line edit control. The single line edit control is used in such situations as selecting a filename, where making the disabled text unavailable helps make the user interface clearer. Multi-line edit controls are often used as read-only fields, and therefore need to be black when disabled.

One way to make the text of a disabled multi-line edit control unavailable is in the following description.

Whenever a predefined control is about to draw itself, it sends its parent a WM_CTLCOLOR message. The parent can use this message to set the control's text and background colors.

In the window procedure of the multi-line edit control's parent window, process the WM_CTLCOLOR message as follows:

Sample Code

 static HBRUS  hBrush;

 case WM_INITDIALOG:

   hBrush = CreateSolidBrush (GetSysColor (COLOR_WINDOW));
   break;

 case WM_CTLCOLOR:

   /* If the control is disabled, set the text color to gray and the
    * background color to the system window background color.
    */ 

    hCtl = GetDlgItem (hDlg, IDC_MULTIEDIT );

    enabled = IsWindowEnabled(hCtl) ;

    if ((!enabled) && (HIWORD(lParam) == CTLCOLOR_EDIT)) {
      SetTextColor(wParam, RGB(128,128,128) );
      SetBkColor( wParam, GetSysColor (COLOR_WINDOW));
      return ((HBRUSH) hBrush);
    }

    break;

  InvalidateRect (hCtl, NULL, TRUE);
  UpdateWindow (hCtl);