How to create custom trackbar control appearance(channel,thumb) using Custom Draw?

Hello,

I will state that I am a beginner in WIN32 programming and want to make custom drawing trackbar channel and thumb but without using MFC library, i.e. only with pure WIN32 in C/C++.

According to Customizing the Appearance of CSliderCtrl Using Custom Draw found on CodeProject:
https://www.codeproject.com/Articles...rCtrl-Using-Cu

which unfortunately is using MFC besides the fact it is very well documented. I have searched everywhere and must admit did not find any other solution to this problem. Therefore, I am asking for your willingness to post a simple code example on how to custom draw a trackbar thumb with a dialog and the trackbar would be enough just to understand on how it is done in pure WIN32 by not using MFC.

Just to state that I have done this by using a bitmap as a resource for only changing the appearance of the thumb of the trackbar, and have no idea on how to custom draw it:

Code:

---

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

#include <string>
#include <Windows.h>
#include <CommCtrl.h>

using namespace std;

HWND window = nullptr;
HWND trackBar = nullptr;
HWND progressBar = nullptr;
HWND staticText = nullptr;
WNDPROC defWndProc = nullptr;

static HBITMAP hBitmapThumb, hBitmapBar;
static BITMAP bm;

LRESULT OnWindowClose(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) {
        PostQuitMessage(0);
        return CallWindowProc(defWndProc, hwnd, message, wParam, lParam);
}

LRESULT OnTrackBarChanged(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) {
        LRESULT value = SendMessage(trackBar, TBM_GETPOS, 0, 0);
        SendMessage(progressBar, PBM_SETPOS, value, 0);
        SendMessage(staticText, WM_SETTEXT, 0, (LPARAM)to_wstring(value).c_str());
        return CallWindowProc(defWndProc, hwnd, message, wParam, lParam);
}

void DrawBitmapTransparent(HDC hDCDest, int nXDest, int nYDest, int nBitmapWidth, int nBitmapHeight, HBITMAP hBitmap, int nXSrc, int nYSrc, int nTransparentColor)
{
        HDC hDCSrc;
        HBITMAP hBitmapOld;
        HDC hDCMask;
        HBITMAP hBitmapMask;
        HBITMAP hBitmapMaskOld;
        HDC hDCMem;
        HBITMAP hBitmapMem;
        HBITMAP hBitmapMemOld;
        int nBkColorOld;
        int nTextColorOld;
        BITMAP bm;

        GetObject( hBitmap, sizeof( BITMAP ), &bm );

        if (!nBitmapWidth) {
                nBitmapWidth = bm.bmWidth;
        }

        if (!nBitmapHeight) {
                nBitmapHeight = bm.bmHeight;
        }

        hDCSrc = CreateCompatibleDC( hDCDest );
        hBitmapOld = (HBITMAP)SelectObject( hDCSrc, hBitmap );
        hDCMask = CreateCompatibleDC( hDCDest );
        hBitmapMask = CreateBitmap( nBitmapWidth, nBitmapHeight, 1, 1, 0 );
        hBitmapMaskOld = (HBITMAP)SelectObject( hDCMask, hBitmapMask );
        hDCMem = CreateCompatibleDC( hDCDest );
        hBitmapMem = CreateCompatibleBitmap( hDCDest, nBitmapWidth,        nBitmapHeight );
        hBitmapMemOld = (HBITMAP)SelectObject( hDCMem, hBitmapMem );
        nBkColorOld = SetBkColor( hDCSrc, nTransparentColor );
        BitBlt( hDCMask, 0, 0, nBitmapWidth, nBitmapHeight, hDCSrc, nXSrc, nYSrc, SRCCOPY );
        SetBkColor( hDCSrc, nBkColorOld );
        nBkColorOld = SetBkColor( hDCDest, RGB(255,255,255) );
        nTextColorOld = SetTextColor( hDCDest, RGB(0,0,0) );
        BitBlt( hDCMem, 0, 0, nBitmapWidth, nBitmapHeight, hDCDest, nXDest, nYDest, SRCCOPY );
        BitBlt( hDCMem, 0, 0, nBitmapWidth, nBitmapHeight, hDCSrc, nXSrc, nYSrc, SRCINVERT );
        BitBlt( hDCMem, 0, 0, nBitmapWidth, nBitmapHeight, hDCMask, 0, 0, SRCAND );
        BitBlt( hDCMem, 0, 0, nBitmapWidth, nBitmapHeight, hDCSrc, nXSrc, nYSrc, SRCINVERT );
        BitBlt( hDCDest, nXDest, nYDest, nBitmapWidth, nBitmapHeight, hDCMem, 0, 0, SRCCOPY );
        SetBkColor( hDCDest, nBkColorOld );
        SetTextColor( hDCDest, nTextColorOld );
        SelectObject( hDCMem, hBitmapMemOld );
        DeleteDC( hDCMem );
        DeleteObject( hBitmapMem );
        SelectObject( hDCMask, hBitmapMaskOld );
        DeleteDC( hDCMask );
        DeleteObject( hBitmapMask );
        SelectObject( hDCSrc, hBitmapOld );
        DeleteDC( hDCSrc );
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) {
        switch(message) {
                case WM_NOTIFY:
                {
                        LPNMHDR lpNmhdr = (LPNMHDR)lParam;
                        if (lpNmhdr->code == NM_CUSTOMDRAW)
                        {
                                LPNMCUSTOMDRAW lpNMCustomDraw = (LPNMCUSTOMDRAW)lParam;

                                if (lpNMCustomDraw->dwDrawStage == CDDS_PREPAINT) {
                                        return CDRF_NOTIFYITEMDRAW;
                                }

                                else if (lpNMCustomDraw->dwDrawStage == CDDS_ITEMPREPAINT)
                                {
                                        long nLeft = lpNMCustomDraw->rc.left;
                                        long nTop = lpNMCustomDraw->rc.top;
                                        long nRight = lpNMCustomDraw->rc.right;
                                        long nBottom = lpNMCustomDraw->rc.bottom;

                                        if (lpNMCustomDraw->dwItemSpec == TBCD_THUMB && hBitmapThumb)
                                        {
                                                long nWidth = nRight - nLeft;
                                                long nHeight = nBottom - nTop;

                                                if (nWidth - bm.bmWidth > 0)
                                                {
                                                        nLeft += (nWidth - bm.bmWidth)/2;
                                                        nWidth = bm.bmWidth;
                                                }

                                                if (nHeight - bm.bmHeight > 0)
                                                {
                                                        nTop += (nHeight - bm.bmHeight)/2;
                                                        nHeight = bm.bmHeight;
                                                }

                                                DrawBitmapTransparent(lpNMCustomDraw->hdc , nLeft, nTop, nWidth, nHeight, hBitmapThumb, 0, 0, RGB( 255, 0, 255 ));

                                                return CDRF_SKIPDEFAULT;
                                        }
                                }
                        }
                }
                break;
        }
        if (message == WM_CLOSE && hwnd == window) return OnWindowClose(hwnd, message, wParam, lParam);
        if (message == WM_HSCROLL && hwnd == window && (HWND)lParam == trackBar) return OnTrackBarChanged(hwnd, message, wParam, lParam);
        return CallWindowProc(defWndProc, hwnd, message, wParam, lParam);
}

int main() {
        window = CreateWindowEx(0, WC_DIALOG, L"TrackBar example", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, 300, 300, nullptr, nullptr, nullptr, nullptr);
        trackBar = CreateWindowEx(0, TRACKBAR_CLASS, nullptr, WS_CHILD | TBS_HORZ | TBS_BOTTOM | WS_VISIBLE | TBS_FIXEDLENGTH, 150, 10, 250, 70, window, nullptr, nullptr, nullptr);
        progressBar = CreateWindowEx(0, PROGRESS_CLASS, nullptr, WS_CHILD | PBS_SMOOTH | WS_VISIBLE, 20, 100, 200, 23, window, nullptr, nullptr, nullptr);
        staticText = CreateWindowEx(0, WC_STATIC, L"100", WS_CHILD | WS_VISIBLE, 20, 150, 100, 23, window, nullptr, nullptr, nullptr);

        defWndProc = (WNDPROC)SetWindowLongPtr(window, GWLP_WNDPROC, (LONG_PTR)WndProc);

        // hBitmapThumb = reinterpret_cast<HBITMAP>(LoadImage(NULL, reinterpret_cast<LPCWSTR>("pink.bmp"), IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE));
        hBitmapThumb = (HBITMAP)LoadImage(NULL, (LPCWSTR)L"c:\\Temp\\pink.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
        GetObject( hBitmapThumb, sizeof( BITMAP ), &bm );

        SendMessage(trackBar, TBM_SETRANGEMIN, 1, 0);
        SendMessage(trackBar, TBM_SETRANGEMAX, 1, 200);
        SendMessage(trackBar, TBM_SETTHUMBLENGTH, bm.bmWidth/7, 100);
        SendMessage(progressBar, PBM_SETRANGE32, 0, 200);
        SendMessage(progressBar, PBM_SETPOS, 100, 0);

        ShowWindow(window, SW_SHOW);

        MSG message = { 0 };
        while (GetMessage(&message, nullptr, 0, 0))
        DispatchMessage(&message);
}

---

I am very thankful to anyone who participates towards solving my problem.

Well, MFC is just a wrapper around the plain Win32 API. So you could slightly modify the code from https://www.codeproject.com/Articles...rCtrl-Using-Cu removing the MFC parts and/or change it to raw Win32.
For instance the code in

Code:

---

void CCustomDrawSliderCtrl::OnReflectedCustomDraw(NMHDR* pNMHDR, LRESULT* pResult)

---

after some changes you could place in your CALLBACK WndProc under the case of

Code:

---

if (lpNmhdr->code == NM_CUSTOMDRAW)

---