Flat (cool look) buttons (2)

Flat look (cool) toolbar buttons have been well covered. But what about
including the same sort of button in a Dialog (or form or dialog bar)?
This is not supported by the new common controls, so you have to do it
yourself.

Here is a class that does flat-look buttons for you. Just like a toolbar,
the buttons get borders when the mouse moves over them. The code uses
DrawState to draw the buttons.

This class can be (I’ll send further articles when I get some time 🙂
enhanced to include check-style, optional standard looks, icons as well as
text, change cursor as mouse moves over, color change (for links), 3D text,
size text to fit etc etc. But this is a good starting point 🙂


class CMyFlatButton : public CButton {
DECLARE_DYNAMIC(CMyFlatButton)
private:
bool m_bRaised;
bool m_bDrawBackground;
public:
CMyFlatButton()
: CButton()
, m_bRaised(false) // internal only
, m_bDrawBackground(true) // internal only
{}

// drawing
protected:
virtual void DrawText(CDC* pDC, const CRect& rect, LPCTSTR text, UINT state=0);
virtual void DrawBorders(CDC* pDC, CRect& rect, UINT state=0);
virtual void Draw(CDC* pDC, const CRect& rect, UINT state=0);

protected:
//{{AFX_MSG(CMyFlatButton)
afx_msg BOOL OnEraseBkgnd(CDC* pDC);
afx_msg void OnMouseMove(UINT nFlags, CPoint point);
afx_msg LONG OnMouseLeave(WPARAM, LPARAM);
//}}AFX_MSG
//{{AFX_VIRTUAL(CMyFlatButton)
virtual void PreSubclassWindow();
virtual void DrawItem(LPDRAWITEMSTRUCT lpDIS);
//}}AFX_VIRTUAL
DECLARE_MESSAGE_MAP();
};

///////////////////////////////////////////////////////////////////////////
//
BEGIN_MESSAGE_MAP(CMyFlatButton, CButton)
//{{AFX_MSG_MAP(CMyFlatButton)
ON_WM_ERASEBKGND()
ON_WM_MOUSEMOVE()
ON_MESSAGE(WM_MOUSELEAVE,OnMouseLeave)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
IMPLEMENT_DYNAMIC(CMyFlatButton,CButton)

// this routine uses DrawState to draw the text approriately.
// it automatically centres the text within the button border

void CMyFlatButton::DrawText(CDC* pDC, const CRect& rect, LPCTSTR text, UINT state) {
// we want transparent text
int nBkModeOld = pDC->SetBkMode(TRANSPARENT);
// setup text color
COLORREF textcol = ::GetSysColor(COLOR_BTNTEXT);
COLORREF oldTextColor = pDC->SetTextColor(textcol);
// centre the text
CSize textSizeClient = pDC->GetTextExtent(text,strlen(text));
int x = rect.left+(rect.Width()-textSizeClient.cx)/2;
int y = rect.top+(rect.Height()-textSizeClient.cy)/2;
// draw the text
pDC->DrawState(CPoint(x,y), rect.Size(), text,
(state & ODS_DISABLED?DSS_DISABLED:DSS_NORMAL), true, 0, (HBRUSH)NULL
);
// restore dc
pDC->SetTextColor(oldTextColor);
pDC->SetBkMode(nBkModeOld);
}

// this routine (optionally) draws the borders on the button
// flat buttons use only single-pixel borders, so we cannot use
// DrawFrameControl.

void CMyFlatButton::DrawBorders(CDC* pDC, CRect& rect,UINT state) {
if (state & ODS_SELECTED) {
pDC->Draw3dRect(rect,::GetSysColor(COLOR_3DSHADOW),
::GetSysColor(COLOR_3DHILIGHT));
rect.DeflateRect(1,1);
} else if (! m_bRaised && ! (state & ODS_FOCUS)) {
// no border – flat look
rect.DeflateRect(1,1);
} else {

pDC->Draw3dRect(rect,::GetSysColor(COLOR_3DHILIGHT),
::GetSysColor(COLOR_3DSHADOW));
rect.DeflateRect(1,1);
}
rect.DeflateRect(1,1);
if (state & ODS_SELECTED) {
rect.OffsetRect(1,1); // offset image when pressed
}
}

// Here we draw the appropriate parts of the button

void CMyFlatButton::Draw(CDC* pDC, const CRect& inrect, UINT state) {
CRect rect = inrect;
DrawBorders(pDC,rect,state);
CString text;
GetWindowText(text);
if (! text.IsEmpty()) {
DrawText(pDC,rect,text,state);
}
}

// Overrides
void CMyFlatButton::PreSubclassWindow() {
SetButtonStyle(GetButtonStyle() | BS_OWNERDRAW | BS_NOTIFY);
}

// we use m_bDrawBackground flag to allow us to
// repaint behind the button before drawing on top

void CMyFlatButton::DrawItem(LPDRAWITEMSTRUCT lpDIS) {
if (m_bDrawBackground) {
m_bDrawBackground = false;
// if not redrawing the whole thing,
CWnd* pParent = GetParent();
CRect rect; GetWindowRect(rect);
pParent->ScreenToClient(rect);
pParent->InvalidateRect(rect);
pParent->UpdateWindow();
} else {
m_bDrawBackground = true;
CDC* pDC = CDC::FromHandle(lpDIS->hDC);
ASSERT_VALID(pDC);
CRect rectClient = lpDIS->rcItem;
Draw(pDC,rectClient,lpDIS->itemState);
}
}

// Messages
BOOL CMyFlatButton::OnEraseBkgnd(CDC*) {
return true; // we don’t do any erasing when owner drawn
}

// the m_bRaised flag inidicates whether or not to
// draw the borders. If the mouse is over the button
// the borders are drawn. We use TrackMouseEvent to
// detect when the mouse leaves the button so we can
// turn off the flag

void CMyFlatButton::OnMouseMove(UINT, CPoint) {
if (! m_bRaised) {
// draw with button borders
m_bRaised = true;
Invalidate();
// remember to remove button borders when we leave
TRACKMOUSEEVENT trackmouseevent;
trackmouseevent.cbSize = sizeof(trackmouseevent);
trackmouseevent.dwFlags = TME_LEAVE;
trackmouseevent.hwndTrack = GetSafeHwnd();
trackmouseevent.dwHoverTime = HOVER_DEFAULT;
_TrackMouseEvent(&trackmouseevent);
}
}

LONG CMyFlatButton::OnMouseLeave(WPARAM, LPARAM) {
// remove button borders
m_bRaised = false;
Invalidate();
return 0;
}

Last updated: 13 May 1998

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