An Unclickable Button

  Download Source Code and Demo Project

Environment: VC++ 5.0 (SP3) NT 4.0 (SP3), Win95

I wrote this a while back for a friend. It is basically just a normal pushbutton, except that when the user tries to click on it, it moves out of the way making it practically un-clickable.

I have no idea what anyone would ever want to use such a control in their app, apart from wanting to be extremely annoying to users (and hey - don't we all get like that on occasion?) :)

The button is just a normal button with OnMouseMove overridden: (m_nJumpDistance is the distance in pixels to jump once the mouse has moved over the control).

void CTrickButton::OnMouseMove(UINT nFlags, CPoint point) 
{
    CWnd* pParent = GetParent();
    if (!pParent) pParent = GetDesktopWindow();

    CRect ParentRect;                                   // Parent client area (Parent coords)
    pParent->GetClientRect(ParentRect);

    ClientToScreen(&point);                             // Convert point to parent coords
    pParent->ScreenToClient(&point);

    CRect ButtonRect;                                   // Button Dimensions (Parent coords)
    GetWindowRect(ButtonRect);  
    pParent->ScreenToClient(ButtonRect);
    CPoint Center = ButtonRect.CenterPoint();           // Center of button (parent coords)

    CSize CriticalSize(ButtonRect.Width()/6, ButtonRect.Height()/6);


    CRect NewButtonRect = ButtonRect;                    // New position (parent coords)

    if (point.x - CriticalSize.cx > Center.x)            // Mouse is right of center
    {
        if (ButtonRect.left > ParentRect.left + ButtonRect.Width() + m_nJumpDistance)
            NewButtonRect -= CSize(ButtonRect.right - point.x + m_nJumpDistance, 0);
        else
            NewButtonRect += CSize(point.x - ButtonRect.left + m_nJumpDistance, 0);
    }
    else if (point.x + CriticalSize.cx < Center.x)      // Mouse is left of center
    {
        if (ButtonRect.right < ParentRect.right - ButtonRect.Width() - m_nJumpDistance)
            NewButtonRect += CSize(point.x - ButtonRect.left + m_nJumpDistance, 0);
        else
            NewButtonRect -= CSize(ButtonRect.right - point.x + m_nJumpDistance, 0);
    }

    if (point.y - CriticalSize.cy > Center.y)           // Mouse is below center
    {
        if (ButtonRect.top > ParentRect.top + ButtonRect.Height() + m_nJumpDistance)
            NewButtonRect -= CSize(0, ButtonRect.bottom - point.y + m_nJumpDistance);
        else
            NewButtonRect += CSize(0, point.y - ButtonRect.top + m_nJumpDistance);
    }
    else if (point.y + CriticalSize.cy < Center.y)      // Mouse is above center
    {
        if (ButtonRect.bottom < ParentRect.bottom - ButtonRect.Height() - m_nJumpDistance)
            NewButtonRect += CSize(0, point.y - ButtonRect.top + m_nJumpDistance);
        else
            NewButtonRect -= CSize(0, ButtonRect.bottom - point.y + m_nJumpDistance);
    }

    MoveWindow(NewButtonRect);
    RedrawWindow();
    
	CButton::OnMouseMove(nFlags, point);
}

Last updated: 16 June 1998