unable to override OnDropFiles

rwagner -- rwagner@genre.com
Monday, January 20, 1997


Robert Wagner@GRN
01/20/97 02:35 PM

Environment: Visual C++ 4.2-flat, Win95

Overriding OnDropFiles in the CMainframe class and then opening the file(s)
that the user dropped in is pretty straightforward, and I can make this
work.

However, I am trying to implement dropping a file on a CComboBox control in
a dialog box, and find that I cannot.  I would like to be able to drop a
text file on a CCombobox and then populate the selections from lines in the
file.

I had ClassWizard provide the override, but it never gets called, even
though Windows allows me to drop the file onto this control but noplace
else in the dialog; conceivably because I checked 'Accept Files' in the
Extended Styles part of Control Properties, which you get by doubleclicking
on the control in the Resource Editor.

Any ideas or sample code on how to implement this?

Thanks
Rob

---

Stuart Downing -- sdowning@fame.com
Wednesday, January 22, 1997

[Mini-digest: 5 responses]

See...
http://www.visionx.com/mfcpro/mfc-l/t7361.htm
for a previous discussion of this.
-----
Stuart Downing
sdowning@fame.com
FAME Information Services, Inc.

----------
From:  rwagner@genre.com[SMTP:rwagner@genre.com]
Sent:  Monday, January 20, 1997 9:35 AM
To:  mfc-l@netcom.com
Subject:  unable to override OnDropFiles


Robert Wagner@GRN
01/20/97 02:35 PM

Environment: Visual C++ 4.2-flat, Win95

Overriding OnDropFiles in the CMainframe class and then opening the file(s)
that the user dropped in is pretty straightforward, and I can make this
work.

However, I am trying to implement dropping a file on a CComboBox control in
a dialog box, and find that I cannot.  I would like to be able to drop a
text file on a CCombobox and then populate the selections from lines in the
file.

I had ClassWizard provide the override, but it never gets called, even
though Windows allows me to drop the file onto this control but noplace
else in the dialog; conceivably because I checked 'Accept Files' in the
Extended Styles part of Control Properties, which you get by doubleclicking
on the control in the Resource Editor.

Any ideas or sample code on how to implement this?

Thanks
Rob




-----From: Rob Hill 

Ive done something similar, but with a treeview , the dropfiles message =
goes to the parent of my tree control, not the treecontrol itself. Its =
my treecontrol-containing view that processes the dropfiles message, and =
then fills the tree control up.
Have you tried handling the message in the combo-boxe's parent?

Rob.

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Robert J. Hill
Programming Manager=20
Team17 Software Ltd, Longlands House,
Wakefield Road, Ossett, W.Yorks, WF5 9JS
TEL: 0192 426 7776
FAX: 0192 426 7658
Check out Team17's Home  http://www.team17.com=20
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--------------


-----Original Message-----
From:	rwagner@genre.com [SMTP:rwagner@genre.com]
Sent:	Monday, January 20, 1997 2:35 PM
To:	mfc-l@netcom.com
Subject:	unable to override OnDropFiles


Robert Wagner@GRN
01/20/97 02:35 PM

Environment: Visual C++ 4.2-flat, Win95

Overriding OnDropFiles in the CMainframe class and then opening the =
file(s)
that the user dropped in is pretty straightforward, and I can make this
work.

However, I am trying to implement dropping a file on a CComboBox control =
in
a dialog box, and find that I cannot.  I would like to be able to drop a
text file on a CCombobox and then populate the selections from lines in =
the
file.

I had ClassWizard provide the override, but it never gets called, even
though Windows allows me to drop the file onto this control but noplace
else in the dialog; conceivably because I checked 'Accept Files' in the
Extended Styles part of Control Properties, which you get by =
doubleclicking
on the control in the Resource Editor.

Any ideas or sample code on how to implement this?

Thanks
Rob
-----From: Shaju Mathew 

Hi,
	I've done an owner-drawn list-box with drag'n drop(your combo-box
should be very similar)While my sample adds the program icons in hte 
combo-box, it should be prettty trivial for you to modify the functionality
to add lines from the files..
///start header file for the list-box
// IconListBox.h : header file
// This class implements an owner-drawn list box. The user can drag 'n
// drop .EXEs/.DLLs from FileManager/Explorer and this listbox will
// retrieve the appropriate icons and display them. Once certain rules
// are defined for key applications(eg. Netscape, Oracle), we'll 
// identify them dynamically and add them in this listbox by default.
// Instantiated from the CSymptomPropertyPage::OnCreate() override

// Overrides of PreCreateWindow(), MeasureItem() and DrawItem() does the job
/////////////////////////////////////////////////////////////////////////////
// CIconListBox window
#ifndef __ICONLISTBOX_H__
#define __ICONLISTBOX_H__

class CIconListBox : public CListBox
{
// Construction
public:
	CIconListBox(void);
	int AddIcon(HICON);

// Attributes
public:

// Operations
public:

// Overrides
	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CIconListBox)
	public:
	virtual void MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct);
	virtual void DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct);
	protected:
	virtual BOOL PreCreateWindow(CREATESTRUCT& cs);
	//}}AFX_VIRTUAL

// Implementation
public:
	virtual ~CIconListBox(void);

	// Generated message map functions
protected:
	//{{AFX_MSG(CIconListBox)
	afx_msg void OnSelchange(void);
	//}}AFX_MSG

	DECLARE_MESSAGE_MAP()
};

#endif
/////////////////////////////////////////////////////////////////////////////
///end header
//start implementation for the list box
// IconListBox.cpp : implementation file
//

#include "stdafx.h"
//#include "glance.h"
#include "IconListBox.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CIconListBox

CIconListBox::CIconListBox(void)
{//nothing to do...
}

CIconListBox::~CIconListBox(void)
{
}

int CIconListBox::AddIcon(HICON hIcon)
{//called by CSymptomPropertyPage members - OnInitDialog()(for default
//apps for which we've already a set of rules defined), OnBrowse() 
//and OnDropFiles()
	int nIndex = AddString("");

	if((LB_ERR != nIndex) && (LB_ERRSPACE != nIndex))
		SetItemData(nIndex, (DWORD)hIcon);

	SetCurSel(nIndex);

	return(nIndex);
}

BEGIN_MESSAGE_MAP(CIconListBox, CListBox)
	//{{AFX_MSG_MAP(CIconListBox)
	ON_CONTROL_REFLECT(LBN_SELCHANGE, OnSelchange)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CIconListBox message handlers

BOOL CIconListBox::PreCreateWindow(CREATESTRUCT& cs) 
{
	// TODO: Add your specialized code here and/or call the base class
	if(!CListBox::PreCreateWindow(cs))
		return(FALSE);

	//cs.dwExStyle |= WS_EX_CLIENTEDGE;
	cs.style &= ~(LBS_OWNERDRAWVARIABLE | LBS_SORT);
	cs.style |= LBS_OWNERDRAWFIXED;
	return(TRUE);
	//return CListBox::PreCreateWindow(cs);
}

void CIconListBox::MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct) 
{
	// TODO: Add your code to determine the size of specified item
	//set the height to that of a large icon
	lpMeasureItemStruct->itemHeight = 36;
}

void CIconListBox::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct) 
{
	// TODO: Add your code to draw the specified item
	CDC dc;
	dc.Attach(lpDrawItemStruct->hDC);
	CRect rect = lpDrawItemStruct->rcItem;
	int nIndex = lpDrawItemStruct->itemID;

	CBrush *brush = new CBrush(::GetSysColor((lpDrawItemStruct->itemState & ODS_SELECTED)
		? COLOR_HIGHLIGHT : COLOR_WINDOW));

	dc.FillRect(rect, brush);
	delete(brush);

	if(lpDrawItemStruct->itemState & ODS_FOCUS)
		dc.DrawFocusRect(rect);

	if(nIndex != (UINT)-1)
		dc.DrawIcon(rect.left + 4, rect.top + 2, (HICON)GetItemData(nIndex));

	//dc.TextOut(rect.left + 40, rect.top + 8, "Icons");
	
	dc.Detach();
}

void CIconListBox::OnSelchange(void) 
{//overridden for later use
	// TODO: Add your control notification handler code here
	//int index = GetCurSel();	
	//HICON hIcon = (HICON)GetItemData(index);
	//ShowWindow(SW_HIDE);
}
//end implementation


Here's the how I create it from the parent:
int CSymptomPropertyPage::OnCreate(LPCREATESTRUCT lpCreateStruct) 
{
	if (CPropertyPage::OnCreate(lpCreateStruct) == -1)
		return -1;
	
	DragAcceptFiles();//to activate COleDropTarget
	// TODO: Add your specialized creation code here
	//create the owner-drawn icon list-box window
	m_IconListBox.Create(WS_CHILD | WS_VISIBLE | WS_VSCROLL | WS_BORDER |
		LBS_NOTIFY | LBS_NOINTEGRALHEIGHT, /*CRect(380, 150, 480, 210)*/CRect(380, 136, 480, 210), 
		this, IDC_ICONLISTBOX);

	return 0;
}
	//The CSymptomPropertyPage(::public CPropertyPage) has a dialog template
resource in which I've a list-box mapping on to m_IconListBox

void CSymptomPropertyPage::OnDropFiles(HDROP hDropInfo) 
{
	// TODO: Add your message handler code here and/or call default
	int nCount = ::DragQueryFile(hDropInfo, (UINT)-1, NULL, 0);

	if(1 == nCount)//process one at a time
	{
		//IconListBox.ResetContent();	
		TCHAR szFileName[MAX_PATH];
		::DragQueryFile(hDropInfo, 0, szFileName, MAX_PATH);

		HICON hIcon = RetrieveIcon(szFileName);
		m_IconListBox.AddIcon(hIcon);
		//m_IconListCtrl.AddIcon(hIcon);
		
		/*int nIcons = (int)::ExtractIcon(NULL, szFileName, (UINT)-1);

		if(nIcons)
		{
			HICON hIcon;
			//for(int i = 0; i < nIcons; i++)
			//{
			hIcon = ::ExtractIcon(AfxGetInstanceHandle(), szFileName, 0);//i);
			m_IconListBox.AddIcon(hIcon);
			m_IconListCtrl.AddIcon(hIcon);
			//}
		} */

		//m_IconListBox.SetCurSel(0);
		//m_IconListCtrl.SetCurSel(0);
	}
	DragFinish(hDropInfo);
	CPropertyPage::OnDropFiles(hDropInfo);
}

Good luck

	Shaju_Mathew@hp.com
> 
> Robert Wagner@GRN
> 01/20/97 02:35 PM
> 
> Environment: Visual C++ 4.2-flat, Win95
> 
> Overriding OnDropFiles in the CMainframe class and then opening the file(s)
> that the user dropped in is pretty straightforward, and I can make this
> work.
> 
> However, I am trying to implement dropping a file on a CComboBox control in
> a dialog box, and find that I cannot.  I would like to be able to drop a
> text file on a CCombobox and then populate the selections from lines in the
> file.
> 
> I had ClassWizard provide the override, but it never gets called, even
> though Windows allows me to drop the file onto this control but noplace
> else in the dialog; conceivably because I checked 'Accept Files' in the
> Extended Styles part of Control Properties, which you get by doubleclicking
> on the control in the Resource Editor.
> 
> Any ideas or sample code on how to implement this?
> 
> Thanks
> Rob
> 
> 
> 
> 


--
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                                   '//|||\\`        Shaju_Mathew@hp.com
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-----From: "John Boehme" 

I ran into a similar problem in an application that I wrote.
My app provides a standard Win95 folder interface for ftp sites. I wanted
to handle the dragging and dropping of files from my computer and have my
app send or receive them to ro from the ftp site.

I over rode OnDropFiles() in my view and it did not work, never got called.
I added the call to DragAcceptFiles() in my InitialUpdate() of my view and
it worked. Even though the documentation stated that the drag file
capability would apply to any child window that this call is made for.

If you need futher code, let me know. Good Luck.

John Boehme
http://www.iglobal.net/pub/johnandce/

---------
> From: rwagner@genre.com
> To: mfc-l@netcom.com
> Subject: unable to override OnDropFiles
> Date: Monday, January 20, 1997 8:35 AM
> 
> 
> Robert Wagner@GRN
> 01/20/97 02:35 PM
> 
> Environment: Visual C++ 4.2-flat, Win95
> 
> Overriding OnDropFiles in the CMainframe class and then opening the
file(s)
> that the user dropped in is pretty straightforward, and I can make this
> work.
> 
> However, I am trying to implement dropping a file on a CComboBox control
in
> a dialog box, and find that I cannot.  I would like to be able to drop a
> text file on a CCombobox and then populate the selections from lines in
the
> file.
> 
> I had ClassWizard provide the override, but it never gets called, even
> though Windows allows me to drop the file onto this control but noplace
> else in the dialog; conceivably because I checked 'Accept Files' in the
> Extended Styles part of Control Properties, which you get by
doubleclicking
> on the control in the Resource Editor.
> 
> Any ideas or sample code on how to implement this?
> 
> Thanks
> Rob
> 
> 

---

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