Properly handle subitem editing ( or canceling of subitem editing ) in listview with editable subitems

INTRODUCTION:

I am trying to implement listview control with editable subitems. For in-place editing of items/subitems I use edit control.

I believe that I have managed to properly code placing of the edit control above item/subitem.

PROBLEM:

I do not know on which events I should end/cancel subitem editing ( hide edit control, set subitem text etc ) and how should I do it.

To clarify, I speak of the moment when user finishes/cancels in place editing.

At this point edit control is no longer needed, so I should hide it ( I do not like recreating it every time; I believe that creating it once and then showing/hiding it when needed is more efficient ).

I am targeting the behavior Properties window has in Visual Studio ( see attached image to see exactly the window I refer to ).

I want to achieve editing/canceling the same way this window does when user presses ESC key/clicks on another window/clicks on scrollbar etc.

MY EFFORTS TO SOLVE THIS:

Using Google, I found few examples but they are old and do not address all of the relevant cases, so that is why I ask here for help.

However, I was able to find out that one of the events I must consider are EN_KILLFOCUS, case when user presses ESC/ENTER key and the case when user clicks on something other than edit control.

EDIT:

I have managed to handle ESC and ENTER keys, as well as the case when user clicks on the another sibling control or switches windows with ALT + TAB. I have updated SSCCE with relevant changes

QUESTION:

In order to achieve default behavior for a grid ( if there is one for Windows apps ), which messages/events must I handle?

Can you also point out where should I edit subitem and hide edit control, and where should I just hide edit control?

EDIT:

My only problem remained is to handle the case when user clicks on the listview scrollbars, or on the background of the main window. I just do not know how to handle this and would appreciate all the help I can get.

RELEVANT INFORMATION:

I use Visual Studio 2013, on Windows 7 x86;

I am developing in C++ using raw WinAPI;

SSCCE:

Below is the solution I have so far. I have tried to thoroughly comment it, but if more info is required leave a comment and I will update my post.

#include <windows.h>
#include <windowsx.h>   // various listview macros etc
#include <CommCtrl.h>
#include <stdio.h>      // swprintf_s()

// enable Visual Styles
#pragma comment( linker, "/manifestdependency:\"type="win32" \
                         name="Microsoft.Windows.Common-Controls" version='6.0.0.0' \
                         processorArchitecture="*" publicKeyToken='6595b64144ccf1df' \
                         language="*"\"")

// link with Common Controls library
#pragma comment( lib, "comctl32.lib") 

//global variables
HINSTANCE hInst;

// listview subclass procedure
LRESULT CALLBACK ListViewSubclassProc(HWND hwnd, UINT message, 
    WPARAM wParam, LPARAM lParam,
    UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
    switch (message)
    {
    case WM_VSCROLL:
    case WM_HSCROLL:
        // if edit control has the focus take it away and give to listview
        if (GetFocus() == GetDlgItem(GetParent(hwnd), 5000))
            SetFocus(hwnd);  // use WM_NEXTDLGCTL for dialogbox !!!!
        break;
    case WM_NCDESTROY:
        ::RemoveWindowSubclass(hwnd, ListViewSubclassProc, uIdSubclass);
        return DefSubclassProc(hwnd, message, wParam, lParam);
    }
    return ::DefSubclassProc(hwnd, message, wParam, lParam);
}

// subclass procedure for edit control
LRESULT CALLBACK InPlaceEditControl_SubclassProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam,
    UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
    switch (message)
    {
    case WM_GETDLGCODE:
        return (DLGC_WANTALLKEYS | DefSubclassProc(hwnd, message, wParam, lParam));
    case WM_KILLFOCUS:
        ShowWindow(hwnd, SW_HIDE);
        return DefSubclassProc(hwnd, message, wParam, lParam);
    case WM_CHAR:
        //Process this message to avoid message beeps.
        switch (wParam)
        {
        case VK_RETURN:
            return 0L;
        case VK_ESCAPE:
            return 0L;
        default:
            return ::DefSubclassProc(hwnd, message, wParam, lParam);
        }
        break;
    case WM_KEYDOWN:
        switch (wParam)
        {
        case VK_RETURN:
        {
            // get listview handle
            HWND hwndLV = GetDlgItem(GetParent(hwnd), 2000);
            // get edit control's client rectangle
            RECT rc = { 0 };
            GetClientRect(hwnd, &rc);
            // since edit control lies inside item rectangle
            // we can test any coordinate inside edit control's
            // client rectangle
            // I chose ( rc.left, rc.top )
            MapWindowPoints(hwnd, hwndLV, (LPPOINT)&rc, (sizeof(RECT) / sizeof(POINT)));
            // get item and subitem indexes
            LVHITTESTINFO lvhti = { 0 };
            lvhti.pt.x = rc.left;
            lvhti.pt.y = rc.top;
            ListView_SubItemHitTest(hwndLV, &lvhti);
            // get edit control's text
            wchar_t txt[50] = L"";
            Edit_GetText(hwnd, txt, 50);
            // edit cell text
            ListView_SetItemText(hwndLV, lvhti.iItem, lvhti.iSubItem, txt);
            // restore focus to listview
            // this triggers EN_KILLFOCUS
            // which will hide edit control
            SetFocus(hwndLV);
        }
            return 0L;
        case VK_ESCAPE:
            SetFocus(GetDlgItem(GetParent(hwnd), 2000));
            return 0L;
        default:
            return ::DefSubclassProc(hwnd, message, wParam, lParam);
        }
        break;
    case WM_NCDESTROY:
        ::RemoveWindowSubclass(hwnd, InPlaceEditControl_SubclassProc, uIdSubclass);
        return DefSubclassProc(hwnd, message, wParam, lParam);

    }
    return ::DefSubclassProc(hwnd, message, wParam, lParam);
}
// main window procedure
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch (msg)
    {
    case WM_CREATE:
    {
        //================ create controls
        RECT rec = { 0 };
        GetClientRect(hwnd, &rec);

        HWND hwndLV = CreateWindowEx(0, WC_LISTVIEW,
            L"", WS_CHILD | WS_VISIBLE | WS_BORDER | WS_CLIPSIBLINGS | LVS_REPORT, 
            50, 50, 250, 200, hwnd, (HMENU)2000, hInst, 0);
        // in place edit control
        HWND hwndEdit = CreateWindowEx(0, WC_EDIT, L"", ES_AUTOHSCROLL | WS_CHILD | WS_BORDER,
            200, 265, 100, 25, hwnd, (HMENU)5000, hInst, 0);
        // edit control must have the same font as listview
        HFONT hf = (HFONT)SendMessage(hwndLV, WM_GETFONT, 0, 0);
        if (hf)
            SendMessage(hwndEdit, WM_SETFONT, (WPARAM)hf, (LPARAM)TRUE);
        // subclass edit control, so we can edit subitem with ENTER, or
        // cancel editing with ESC
        SetWindowSubclass(hwndEdit, InPlaceEditControl_SubclassProc, 0, 0);
        // set extended listview styles
        ListView_SetExtendedListViewStyle(hwndLV, LVS_EX_FULLROWSELECT | LVS_EX_GRIDLINES | LVS_EX_DOUBLEBUFFER);
        // subclass listview
        SetWindowSubclass(hwndLV, ListViewSubclassProc, 0, 0);

        // add some columns
        LVCOLUMN lvc = { 0 };

        lvc.mask = LVCF_FMT | LVCF_WIDTH | LVCF_TEXT | LVCF_SUBITEM;
        lvc.fmt = LVCFMT_LEFT;

        for (long nIndex = 0; nIndex < 5; nIndex++)
        {
            wchar_t txt[50];
            swprintf_s(txt, 50, L"Column %d", nIndex);

            lvc.iSubItem = nIndex;
            lvc.cx = 60;
            lvc.pszText = txt;

            ListView_InsertColumn(hwndLV, nIndex, &lvc);
        }

        // add some items
        LVITEM lvi;

        lvi.mask = LVIF_TEXT;

        for (lvi.iItem = 0; lvi.iItem < 10000; lvi.iItem++)
        {
            for (long nIndex = 0; nIndex < 5; nIndex++)
            {
                wchar_t txt[50];
                swprintf_s(txt, 50, L"Item %d%d", lvi.iItem, nIndex);

                lvi.iSubItem = nIndex;
                lvi.pszText = txt;

                if (!nIndex)  // item 
                    SendDlgItemMessage(hwnd, 2000, LVM_INSERTITEM, 0, reinterpret_cast<LPARAM>(&lvi));
                else          // sub-item
                    SendDlgItemMessage(hwnd, 2000, LVM_SETITEM, 0, reinterpret_cast<LPARAM>(&lvi));
            }
        }
    }
        return 0L;
    case WM_NOTIFY:
    {
        if (((LPNMHDR)lParam)->code == NM_DBLCLK)  
        {
            switch (((LPNMHDR)lParam)->idFrom)
            {
            case 2000: // remember, this was our listview's ID
            {
                LPNMITEMACTIVATE lpnmia = (LPNMITEMACTIVATE)lParam;

                // SHIFT/ALT/CTRL/their combination, must not be pressed
                if ((lpnmia->uKeyFlags || 0) == 0)
                {
                    // store item/subitem rectangle
                    RECT rc = { 0, 0, 0, 0 };
                    // helper values, needed for handling partially visible items
                    int topIndex = ListView_GetTopIndex(lpnmia->hdr.hwndFrom);
                    int visibleCount = ListView_GetCountPerPage(lpnmia->hdr.hwndFrom);
                    // if item is vertically partially visible, make it fully visible
                    if ((topIndex + visibleCount) == lpnmia->iItem)
                    {
                        // get the rectangle of the above item -> lpnmia->iItem - 1
                        ListView_GetSubItemRect(lpnmia->hdr.hwndFrom, lpnmia->iItem - 1, lpnmia->iSubItem, LVIR_LABEL, &rc);
                        // ensure clicked item is visible
                        ListView_EnsureVisible(lpnmia->hdr.hwndFrom, lpnmia->iItem, FALSE);
                    }
                    else // item is fully visible, just get its ectangle
                        ListView_GetSubItemRect(lpnmia->hdr.hwndFrom, lpnmia->iItem, lpnmia->iSubItem, LVIR_LABEL, &rc);

                    RECT rcClient = { 0 };  // listview client rectangle, needed if item partially visible
                    GetClientRect(lpnmia->hdr.hwndFrom, &rcClient);
                    // item is horizontally partially visible -> from the right side
                    if (rcClient.right < rc.right)  
                    {
                        // show the whole item
                        ListView_Scroll(lpnmia->hdr.hwndFrom, rc.right - rcClient.right, 0);
                        // adjust rectangle so edit control is properly displayed
                        rc.left -= rc.right - rcClient.right;
                        rc.right = rcClient.right;
                    }
                    // item is horizontally partially visible -> from the left side
                    if (rcClient.left > rc.left)  
                    {
                        // show the whole item
                        ListView_Scroll(lpnmia->hdr.hwndFrom, rc.left - rcClient.left, 0);
                        // adjust rectangle so edit control is properly displayed
                        rc.right += rcClient.left - rc.left;
                        rc.left = rcClient.left;
                    }
                    // it is time to position edit control, we start by getting its window handle
                    HWND hwndEdit = GetDlgItem(hwnd, 5000);
                    //  get item text and set it as edit control's text
                    wchar_t text[51];
                    ListView_GetItemText(lpnmia->hdr.hwndFrom, lpnmia->iItem, lpnmia->iSubItem, text, 50);
                    Edit_SetText(hwndEdit, text);
                    // select entire text
                    Edit_SetSel(hwndEdit, 0, -1);
                    // map listview client rectangle to parent rectangle
                    // so edit control can be properly placed above the item
                    MapWindowPoints(lpnmia->hdr.hwndFrom, hwnd, (LPPOINT)&rc, (sizeof(RECT) / sizeof(POINT)));
                    // move the edit control
                    SetWindowPos(hwndEdit, HWND_TOP, rc.left, rc.top, rc.right - rc.left, 
                        rc.bottom - rc.top, SWP_SHOWWINDOW);
                    // set focus to our edit control
                    HWND previousWnd = SetFocus(hwndEdit);
                }
            }
                break;
            default:
                break;
            }
        }
    }
        break;
    case WM_CLOSE:
        ::DestroyWindow(hwnd);
        return 0L;
    case WM_DESTROY:
    {
        ::PostQuitMessage(0);
    }
        return 0L;
    default:
        return ::DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

// WinMain
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine,
    int nCmdShow)
{
    // store hInstance in global variable for later use
    hInst = hInstance;

    WNDCLASSEX wc;
    HWND hwnd;
    MSG Msg;

    // register main window class
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.style = 0;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInst;
    wc.hIcon = LoadIcon(hInstance, IDI_APPLICATION);
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = GetSysColorBrush(COLOR_WINDOW);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = L"Main_Window";
    wc.hIconSm = LoadIcon(hInstance, IDI_APPLICATION);

    if (!RegisterClassEx(&wc))
    {
        MessageBox(NULL, L"Window Registration Failed!", L"Error!", 
            MB_ICONEXCLAMATION | MB_OK);

        return 0;
    }

    // initialize common controls
    INITCOMMONCONTROLSEX iccex;
    iccex.dwSize = sizeof(INITCOMMONCONTROLSEX);
    iccex.dwICC = ICC_LISTVIEW_CLASSES | ICC_STANDARD_CLASSES;
    InitCommonControlsEx(&iccex);

    // create main window
    hwnd = CreateWindowEx(0, L"Main_Window", L"Grid control",
        WS_OVERLAPPEDWINDOW, 50, 50, 400, 400, NULL, NULL, hInstance, 0);

    ShowWindow(hwnd, nCmdShow);
    UpdateWindow(hwnd);

    while (GetMessage(&Msg, NULL, 0, 0) > 0)
    {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);
    }
    return Msg.wParam;
}

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