Properly determine checkbox state for custom draw

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C++

Win32

checkbox

INTRODUCTION AND RELEVANT INFORMATION:

I need to have themed common controls but with different text color, and transparent background. I have ran into a problem that is well documented in this question[^].

I have made some progress by handling NM_CUSTOMDRAW and have decided to finish the checkbox first.

PROBLEM:

I got stuck with determining the state of the checkbox, so I can not pass the correct parameter for DrawThemeBackground().

Code speaks more than words, so here is the snippet:

case WM_NOTIFY:
    {
        if( ((LPNMHDR)lParam)->code == NM_CUSTOMDRAW )
        {
            switch( ((LPNMHDR)lParam)->idFrom ) 
            {
            case IDC_CHECK1:
                {
                    switch( ((LPNMCUSTOMDRAW)lParam)->dwDrawStage  )
                    {
                    case CDDS_PREERASE:
                        {
                            HRESULT hr = 
                            DrawThemeParentBackground( (
                                (LPNMCUSTOMDRAW)lParam)->hdr.hwndFrom,
                                ((LPNMCUSTOMDRAW)lParam)->hdc,
                                &((LPNMCUSTOMDRAW)lParam)->rc );
                            
                            if( FAILED(hr) )
                            {
                                SetWindowLongPtr( hDlg, DWLP_MSGRESULT, 
                                    (LONG_PTR)CDRF_DODEFAULT );
                                return TRUE;
                            }
                            
                            HTHEME hTheme = 
                                OpenThemeData( 
                                    ((LPNMCUSTOMDRAW)lParam)->hdr.hwndFrom, 
                                    L"BUTTON" );
                            
                            if(!hTheme)
                            {
                                CloseThemeData(hTheme);
                                SetWindowLongPtr( hDlg, 
                                    DWLP_MSGRESULT, 
                                    (LONG_PTR)CDRF_DODEFAULT );
                                return TRUE;
                            }
                            
                            // draw the state
                            
                            LRESULT state = SendMessage( 
                                ((LPNMCUSTOMDRAW)lParam)->hdr.hwndFrom,
                                BM_GETSTATE, 0, 0 );
                            
                            int stateID;
                            
                            switch( ((LPNMCUSTOMDRAW)lParam)->uItemState )
                            {
                            case CDIS_HOT:
                                {
                                    if( IsDlgButtonChecked( hDlg, 
                                        ((LPNMCUSTOMDRAW)lParam)->hdr.idFrom ) )
                                        stateID = CBS_CHECKEDHOT;
                                    else
                                        stateID = CBS_UNCHECKEDHOT;
                                    break;
                                }
                            case CDIS_DEFAULT:
                                {
                                    if( IsDlgButtonChecked( hDlg, 
                                        ((LPNMCUSTOMDRAW)lParam)->hdr.idFrom ) )
                                        stateID = CBS_CHECKEDNORMAL;
                                    else
                                        stateID = CBS_UNCHECKEDNORMAL;
                                    break;
                                }
                            case CDIS_FOCUS:
                                {
                                    if( IsDlgButtonChecked( hDlg, 
                                        ((LPNMCUSTOMDRAW)lParam)->hdr.idFrom ) )
                                        stateID = CBS_CHECKEDNORMAL;
                                    else
                                        stateID = CBS_UNCHECKEDNORMAL;
                                    break;
                                }
                            case CDIS_SELECTED:
                                {
                                    if( IsDlgButtonChecked( hDlg, 
                                        ((LPNMCUSTOMDRAW)lParam)->hdr.idFrom ) )
                                        stateID = CBS_CHECKEDPRESSED;
                                    else
                                        stateID = CBS_UNCHECKEDPRESSED;
                                    break;
                                }
                            }
                            
                            RECT r;
                            SIZE s;
                            
                            GetThemePartSize( hTheme, 
                                ((LPNMCUSTOMDRAW)lParam)->hdc, 
                                BP_CHECKBOX,
                                stateID, 
                                NULL, 
                                TS_TRUE ,&s );
                            
                            r.left = ((LPNMCUSTOMDRAW)lParam)->rc.left;
                            r.top = ((LPNMCUSTOMDRAW)lParam)->rc.top;
                            r.right = ((LPNMCUSTOMDRAW)lParam)->rc.left + s.cx;
                            r.bottom = ((LPNMCUSTOMDRAW)lParam)->rc.top + s.cy;
                            
                            DrawThemeBackground( hTheme, 
                                ((LPNMCUSTOMDRAW)lParam)->hdc,
                                BP_CHECKBOX, stateID,
                                &r,
                                NULL );
                            
                            ((LPNMCUSTOMDRAW)lParam)->rc.left +=  2 + s.cx;
                            
                            DrawText( ((LPNMCUSTOMDRAW)lParam)->hdc,
                                L"Example text", 
                                -1, &((LPNMCUSTOMDRAW)lParam)->rc,
                                DT_SINGLELINE | DT_VCENTER );
                            
                            CloseThemeData(hTheme);
                            SetWindowLongPtr( hDlg, DWLP_MSGRESULT, 
                                (LONG_PTR)CDRF_SKIPDEFAULT );
                            return TRUE;
                        }
                    }
                }
                break;
            }
        }
    }
    break;

The text color and text background are set in the WM_CTLCOLORSTATIC handler:

case WM_CTLCOLORSTATIC:
    {
        SetTextColor( (HDC)wParam, RGB( 255, 0, 0 ) );
        SetBkMode( (HDC)wParam, TRANSPARENT );
    }
    return (INT_PTR)( (HBRUSH)GetStockObject(NULL_BRUSH) );

I have included common controls 6 with the #pragma comment and InitCommonControlsEx().

QUESTION:

All I need for now is to pass proper state for the DrawThemeBackground. Can someone help me with this?

EDIT:

The solution that satisfied my needs can be found here[^].

The only problem was in the line bool bChecked = (uiItemState & CDIS_CHECKED);.

It threw C4800 warning[^].

After numerous tries I had to rewrite the offensive line to bool bChecked = ( BST_CHECKED == IsDlgButtonChecked( hDlg, ((LPNMCUSTOMDRAW)lParam)->hdr.idFrom ) );.

In order for everything to work properly I also had to rearrange the order of if statements :

if (uiItemState & CDIS_SELECTED)
    stateID = (bChecked) ? CBS_CHECKEDPRESSED : CBS_UNCHECKEDPRESSED;
else 
    if (uiItemState & CDIS_HOT)
        stateID = (bChecked) ? CBS_CHECKEDHOT : CBS_UNCHECKEDHOT;
    else
        stateID = (bChecked) ? CBS_CHECKEDNORMAL : CBS_UNCHECKEDNORMAL;

The only thing left is to handle keyboard focus by drawing focus rectangle, but I have trouble in using the correct color.

END OF EDIT

Thank you.

Best regards.