CRicheditctrl- OnMouseMove

Question

In subclassed cricheditctrl,I am using green color for particular format of text( %#__#% embed text) .In onmousemove function if char is embed text I am displaying hand cursor.

To check a char is embed text or not, I am checking the character color using below code. I am unable to select the text(multiple charcaters) in backward since I am Calling SetSel in onmousemove(), but for forward selection I am not facing any problem.

It seems that autoselection fails after a backwards selection.

How to handle this?
void CMyRichEditCtrl::OnMouseMove(UINT nFlags, CPoint point)
{
long char_index=CharFromPos(point);
CHARRANGE crOld;
CHARFORMAT cf;
GetSel(crOld);
SetSel(char_index,char_index+1);
CString strString=GetSelText();
GetSelectionCharFormat(cf);
bEmbed=(!strString.IsEmpty() && cf.crTextColor == EMBEDCOLOR)?true:false;
SetSel(crOld);
if(bEmbed)m_bHandCursor=true;
CRichEditCtrl::OnMouseMove(nFlags, point);
}
Even you can reproduce the same issue just by having below code. if we call setsel inside onmousemove backward autoselection is not working

void CMyRichEditCtrl::OnMouseMove(UINT nFlags, CPoint point)
{

CHARRANGE crOld;
GetSel(crOld);
SetSel(crOld);
CRichEditCtrl::OnMouseMove(nFlags, point);
}

Answer 1

I used the TOM (Text Object Model) interfaces of the rich edit control to determine if the mouse was over green text to avoid changing the control's selection.

Add

#include <RichOle.h>
#include <TOM.h>

Then in the declaration of CMyRichEditCtrl -

....rest of class
public:
 afx_msg void OnMouseMove(UINT nFlags, CPoint point);
 virtual void PreSubclassWindow();
 afx_msg BOOL OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message);
private:
 CComPtr<ITextDocument> m_pDoc;
 HCURSOR m_hand;
 bool m_bOverGreen{ false };
};

In the definition of CMyRichEditCtrl class -

void CMyRichEditCtrl::OnMouseMove(UINT nFlags, CPoint point)
{
 // TODO: Add your message handler code here and/or call default
 CRichEditCtrl::OnMouseMove(nFlags, point);
 ClientToScreen(&point);
 CComPtr<ITextRange> pCursor;
 m_bOverGreen = false;
 if ( SUCCEEDED(m_pDoc->RangeFromPoint(point.x, point.y, &pCursor)))
 {
 CComPtr<ITextFont> pFont;
 if (SUCCEEDED(pCursor->GetFont(&pFont)))
 {
 long clr;
 if (SUCCEEDED(pFont->GetForeColor(&clr)))
 m_bOverGreen = clr == RGB(0, 255, 0);
 }
 }
}


void CMyRichEditCtrl::PreSubclassWindow()
{
 // TODO: Add your specialized code here and/or call the base class
 CComPtr<IRichEditOle> pOle;
 pOle.Attach(GetIRichEditOle());
 ASSERT(pOle);
 pOle.QueryInterface(&m_pDoc);
 CRichEditCtrl::PreSubclassWindow();
}


BOOL CMyRichEditCtrl::OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message)
{
 // TODO: Add your message handler code here and/or call default
 if (m_bOverGreen)
 {
 SetCursor(m_hand);
 return TRUE;
 }
 else
 return CRichEditCtrl::OnSetCursor(pWnd, nHitTest, message);
}

Answer 2

Maybe you should write SetSel(char_index, char_index+1)?