The MASM Forum

Hi Guys

I´m trying to enable and disabled a richeditcontrol using GetWindowLong and ES_READONLY, but it is not working.

I inserted a richeditcontrol on a dialog. This richedit control have his own background color settled by EM_SETBKGNDCOLOR

I´m trying to use &ES_READONLY to alternate in between enabled and disabled.

For example, whenever i press a button (Enabled), it allows editing of the text on the richedit control

And when pressing Disabled it shoulw disabled the edition. But i´m not being able to do this

I tried this pseudo code:

If BtnEnabled =  TRUE

            call 'USER32.GetWindowLongA' D@hREdit, &GWL_STYLE
            Test_If eax &ES_READONLY
                xor eax &ES_READONLY
            Test_End
            call 'user32.SetWindowLongA' D@hREdit, &GWL_STYLE, eax
Endif

If BtnDisabled = &TRUE
            call 'USER32.GetWindowLongA' D@hREdit, &GWL_STYLE
            or eax &ES_READONLY
    call 'user32.SetWindowLongA' D@hREdit, &GWL_STYLE, eax
Endif


But it is not working.


It only works if i create the richedit control (from the resources) with the ES_READONLY flag settled (But cannot enabled programmatically either)

Hi Guga!

Why not EnableWindow?

Quote from: HSE on October 12, 2020, 10:12:44 AM
Hi Guga!

Why not EnableWindow?

Hi HSE, because if i use EnableWindow, the background color of the RichEdit Control won´t show anymore. The bgcolor of the richeditcontropl is, for example, yellow. I want it to remain yellow even if the control is disabled.  The problem is that i´m not being able to disabled the control programatically and also keeping the bgcolor

Then you have to subclass RichEdit and to capture events in subclass  :eusa_boohoo:

- protect the entire text
- return TRUE to the EN_PROTECTED notification

more (https://www.codeguru.com/cpp/controls/richedit/article.php/c2401/Setting-selected-text-to-readonly.htm)

Quote from: jj2007 on October 12, 2020, 06:18:51 PM
- protect the entire text
- return TRUE to the EN_PROTECTED notification

more (https://www.codeguru.com/cpp/controls/richedit/article.php/c2401/Setting-selected-text-to-readonly.htm)

Hi JJ and HSE, many tks.

JJ, i read the links and found another message that can be used when trying to find the GetEvenMask api (It works only with RichEdit ole, right ?. I don´t know how to use RichEdit in Ole) and it seems to work only with Vista.

Then i found this: http://computer-programming-forum.com/82-mfc/1302f222e23246ff.htm that provided an alternative way handling the WM_ENABLE message and overriding the WM_CHAR, WM_SETFOCUS message to simulate a
disabled RTF box.  But this also could be too overhead

Since i don´t know how to use RichEditOle and the other alternative  (WM_ENABLE) etc, seem too much code for a simple function, i ended up using EM_SETREADONLY passed with sendmessage  :smiley:


    ...If D@Message = &WM_INITDIALOG

        lea eax D@hStringList
        call SetupLibRichEdit D@Adressee, IDC_EDIT_STRINGS, eax
        call InitStringsList D@hStringList, D$StringsList
       
        If D$WhatRsrcControlsCommand = RSRC_DELETE_VALUE
            mov eax {B$ "Strings Delete", 0}
            call 'USER32.SetWindowTextA' D@Adressee, eax
            call 'User32.SetDlgItemTextA' D@Adressee, &IDOK, {B$ "Delete", 0}
            call 'USER32.SendMessageA' D@hStringList, &EM_SETREADONLY , &TRUE, 0 ; <--------- Enable read only if The Menu Option "Delete Strings is selected)

        Else_If D$WhatRsrcControlsCommand = RSRC_SAVE_VALUE
            mov eax {B$ "String Save to Disk", 0}
            call 'USER32.SetWindowTextA' D@Adressee, eax
            call 'User32.SetDlgItemTextA' D@Adressee, &IDOK, {B$ "Save", 0}
            call 'USER32.SendMessageA' D@hStringList, &EM_SETREADONLY , &TRUE, 0 ; <--------- Enable read only if The Menu Option "Save Strings is selected)
        Else
            mov eax {B$ "String View", 0}
            call 'USER32.SetWindowTextA' D@Adressee, eax
            call 'User32.SetDlgItemTextA' D@Adressee, &IDOK, {B$ "Ok", 0}
            call 'USER32.SendMessageA' D@hStringList, &EM_SETREADONLY , &FALSE, 0 ; <--------- Disable read only in all other cases (for editing, viewing)
        End_If

        call 'USER32.SetClassLongA' D@Adressee &GCL_HICON D$wc_hIcon


The EM_SETREADONLY also works on XP or only for vista and above (As getevenmask seems to do) ?

Good solution, Guga (and it works on XP, too) :thumbsup:

Works but more complicated:
invoke SendMessage, hRichEdit, EM_SETEVENTMASK, 0, ENM_PROTECTED
invoke SendMessage, hRichEdit, EM_SETCHARFORMAT, SCF_ALL, esp
... in WndProc:
  .if uMsg_==WM_NOTIFY
mov edx, lParam_ ; Pointer to NOTIFY structure
mov eax, [edx.NMHDR.code]
.if [edx.NMHDR.code]==EN_PROTECTED
or eax, -1
ret ; bypass DefWindowProc
.endif
  .endif