WM_POPUP on resize cutting of drawn border - c++

Question

I have a window that i'm trying to draw everything in my self, including title bar, borders.
My problem is that when i drag my window from the bottom right to resize it.
My right/bottom border get cut of when i'm making my window smaller, seems to work fine when dragging it bigger.
If i remove CS_HREDRAW | CS_VREDRAW it just messes up the borders and it all ends up black from where i drag. ( i seen somewhere that it is better to not use these styles to stop flicker)
I'm not sure if im using the correct styles in my window to be able to do what i want here. My end goal is to draw everything in my window including title bar, borders, buttons and all controls.
bool Window::Create(const wchar_t *title, Vector2D size)
{
HINSTANCE instanceHandle = GetModuleHandle(NULL);
if (this->RegisterWindowClass())
{
m_handle = (HWND)CreateWindowEx(0, VERSION, L"", WS_POPUP, CW_USEDEFAULT, CW_USEDEFAULT, size.m_x, size.m_y, NULL, NULL, instanceHandle, this);
if (m_handle)
{
::ShowWindow(m_handle, SW_SHOW);
}
}
return m_handle != 0;
}
bool Window::RegisterWindowClass(const wchar_t *title)
{
static bool registered = false;
if (!registered)
{
HINSTANCE instanceHandle = GetModuleHandle(NULL);
WNDCLASSEX windowClass;
windowClass.cbSize = sizeof(WNDCLASSEX);
windowClass.style = CS_HREDRAW | CS_VREDRAW;
windowClass.lpfnWndProc = (WNDPROC)Window::WindowProc;
windowClass.cbClsExtra = 0;
windowClass.cbWndExtra = 0;
windowClass.hInstance = instanceHandle;
windowClass.hIcon = NULL;
windowClass.hCursor = LoadCursor(NULL, IDC_ARROW);
windowClass.hbrBackground = (HBRUSH)(CreateSolidBrush(RGB(60, 60, 60)));//set back color to window
windowClass.lpszMenuName = NULL;
windowClass.lpszClassName = title;
windowClass.hIconSm = NULL;
if (RegisterClassEx(&windowClass))
registered = true;
}
return registered;
}
void Draw_LeftRightBottom_Rectangles(HDC hdc, HBRUSH brush, RECT rect, int TaskbarHeight)
{
RECT leftrect, rightrect, bottomrect;
leftrect.left = 0;
leftrect.top = TaskbarHeight;
leftrect.right = 2;
leftrect.bottom = rect.bottom;
//fill left rect of window for border
FillRect(hdc, &leftrect, brush);
rightrect.left = rect.right - 2;
rightrect.top = TaskbarHeight;
rightrect.right = rect.right;
rightrect.bottom = rect.bottom;
//fill right rect of window
FillRect(hdc, &rightrect, brush);
bottomrect.left = 0;
bottomrect.top = rect.bottom - 2;
bottomrect.right = rect.right;
bottomrect.bottom = rect.bottom;
//fill bottom rect of window
FillRect(hdc, &bottomrect, brush);
}
LRESULT Window::WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
static int X, Y;
Window* pThis;
if (uMsg == WM_NCCREATE)
{
pThis = static_cast<Window*>(reinterpret_cast<CREATESTRUCT*>(lParam)->lpCreateParams);
SetWindowLongPtr(hwnd, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(pThis));
}
else
pThis = reinterpret_cast<Window*>(GetWindowLongPtr(hwnd, GWLP_USERDATA));
if (pThis != 0)
{
switch (uMsg)
{
case WM_PAINT:
{
RECT clientArea;
GetClientRect(hwnd, &clientArea);
PAINTSTRUCT ps;
if (BeginPaint(hwnd, &ps))
{
//Creating double buffer
HDC hdcMem = CreateCompatibleDC(ps.hdc);
int ndcmem = SaveDC(hdcMem);
HBITMAP hbmMem = CreateCompatibleBitmap(ps.hdc, X, Y);
SelectObject(hdcMem, hbmMem);
//-------------------------------------------------------
// Copy background bitmap into double buffer
BitBlt(hdcMem, 0, 0, clientArea.right, clientArea.bottom, ps.hdc, 0, 0, SRCCOPY);
//---------------------------------------------------------
RECT rect;
rect.bottom = 25;
rect.right = clientArea.right;
HBRUSH brush = CreateSolidBrush(RGB(0, 0, 0));
// Draw Titlebar
FillRect(hdcMem, &rect, brush);
Draw_LeftRightBottom_Rectangles(hdcMem, brush, clientArea, 25);
DeleteObject(brush);
//-----------------------------------------------------------------------------
// Copy double buffer to screen
BitBlt(ps.hdc, 0, 0, X, Y, hdcMem, 0, 0, SRCCOPY);
//--------------------------------------------------
// Clean up
RestoreDC(hdcMem, ndcmem);
DeleteObject(hbmMem);
DeleteDC(hdcMem);
EndPaint(hwnd, &ps);
//--------------------
}
return 0;;
}
case WM_SIZE:
{
X = LOWORD(lParam);
Y = HIWORD(lParam);
break;
}
case WM_NCHITTEST:
{
POINT pt;
RECT rc;
GetClientRect(hwnd, &rc);
pt.x = LOWORD(lParam);
pt.y = HIWORD(lParam);
ScreenToClient(hwnd, &pt);
if (pt.y > (rc.bottom - BORDERWIDTH))
{
if (pt.x>(rc.right - BORDERWIDTH))
{
return HTBOTTOMRIGHT;
}
}
if (pt.y < 25)
{
return HTCAPTION;
}
break;
}
}
}
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}