PRB: Graying Text in Disabled Multi-line Edit Controls

• Microsoft Windows Software Development Kit (SDK) 3.1

SYMPTOMS

Disabling multi-line edit controls prevents user input to the control, but does not make the text unavailable (gray or dim) in the edit control. However, single line edit controls, when disabled, make the text unavailable, as well as preventing user input.

RESOLUTION

This is a design feature in Windows and is not a bug.

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); 

Additional query words: 3.00 3.10

Keywords : kb16bitonly kbCtrl kbEditCtrl kbSDKPlatform
Version : WINDOWS:3.1
Platform : WINDOWS
Issue type : kbprb