Splitter in an MFC dialog based application

This post is OT, but since this is most recent active article on splitter I hope nobody will get too exited about my post.
I have a 8 panes , current count, splitter which I would like to modify so I can select and maximize a pane with minimal “point and click” , not by dragging the splitter bars.
I am thinking about adding a tab to the splitter frame to do this, or building a subsubmenu in “Window” menu.
Any comments would be appreciated, and again, sorry for OT post.
Vaclav

-- modified 9-Mar-14 11:03am.

When using this splitter control in a dialog, I found that when I mouse over other buttons in the same dialog the mouse pointer changes to the left/right arrow used when mousing over the splitter bar. Is this a bug in the code which sets the cursor?

This must be a BUG. Thank you for your input.

I love programming

Mouse Leave on Splitter should be catched, but there is no window message WM_MOUSELEAVE to do it.
A timer that will revert the cursor.

I love programming

maybe just reset the cursor when the user releases the mouse button after dragging the splitter?

Thanks for the great article. As for the question, below code will work on my tests. Wink | ;)

BOOL CControlSplitter::OnSetCursor(CWnd*, UINT, UINT)
{
	if (m_hCursor != NULL)
	{
		DestroyCursor(m_hCursor);
		m_hCursor = NULL;
	}
	m_hCursor = ::LoadCursor(NULL, (CS_HORZ == m_nType) ? IDC_SIZENS : IDC_SIZEWE);
	::SetCursor(m_hCursor); //Affect only current window
	return TRUE; //Halt further processing
}

modified 18-Feb-13 5:13am.

That worked great! Thanks for the suggestion.

Great article!

Nice article! I tried using this in a resizable dialog and ran into an issue. When the dialog size changes, I update the controls (including the splitter) to account for the new size. I found that after doing this the splitter bar would "lock up" and refuse to move beyond a certain point. It appears the below code was causing the problem. After resizing the window this would get hit and return, not allowing the movement of the splitter.

C++

if((m_nType == CS_HORZ) && ((m_rectMax.top >= rect.top) || (m_rectMax.bottom <= rect.bottom)))
{
    return;
}
else if((m_nType == CS_VERT) && ((m_rectMax.left >= rect.left) || (m_rectMax.right <= rect.right)))
{
    return;
}

I modified the code as follows to support using it in a resizable dialog. I added min/max pos variables which can be set. I the replaced the above code with something that considers the direction the splitter is attempting to move and those limits. The modified code is shown below.

C++

class CControlSplitter : public CButton
{
   // ...
public:
   void SetMinMaxSplitterPos(int minSplitterPos, int maxSplitterPos);
private:
   int minSplitterPos;
   int maxSplitterPos;
};

C++

CControlSplitter::CControlSplitter()
{
   // ...
   minSplitterPos = -1;
   maxSplitterPos = -1;
	
}

C++

void CControlSplitter::SetMinMaxSplitterPos(int minSplitterPos, int maxSplitterPos)
{
   this->minSplitterPos = minSplitterPos;
   this->maxSplitterPos = maxSplitterPos;
}

C++

void CControlSplitter::OnMouseMove(UINT nFlags, CPoint point) 
{		
	if(m_bDragging)
	{
		CRect rect;
		::GetWindowRect(m_hWnd,&rect);		
		CPoint ptMouse;
		GetCursorPos(&ptMouse);
		CSize sizeDiff = ptMouse - m_ptStartDrag;
		CSize sizeMove = m_ptStartPos-rect.TopLeft();
		CRect rectBefore = rect;
		rect.OffsetRect(sizeMove);
		if(m_nType == CS_HORZ)
		{							
			rect.OffsetRect(0, sizeDiff.cy);
		}else{
			rect.OffsetRect(sizeDiff.cx,0);
		}
		CRect rectAfter = rect;
		CRect cr = rect;
		GetParent()->ScreenToClient(cr);
		if (m_nType == CS_HORZ)
		{
			if ((minSplitterPos >= 0) && (rectAfter.top < rectBefore.top))
			{
				if (cr.top <= minSplitterPos)
					return;
			}
			else if ((maxSplitterPos >= 0) && (rectAfter.bottom > rectBefore.bottom))
			{
				if (cr.bottom >= maxSplitterPos)
					return;
			}
		}
		else if (m_nType == CS_VERT)
		{
			if ((minSplitterPos >= 0) && (rectAfter.left < rectBefore.left))
			{
				if (cr.left <= minSplitterPos)
					return;
			}
			else if ((maxSplitterPos >= 0) && (rectAfter.right > rectBefore.right))
			{
				if (cr.right >= maxSplitterPos)
					return;
			}
		}
		std::vector<DWORD>::iterator it;
		GetParent()->ScreenToClient(&rect);	
		/*
		if((m_nType == CS_HORZ) && ((m_rectMax.top >= rect.top) || (m_rectMax.bottom <= rect.bottom)))
		{
			return;
		}
		else if((m_nType == CS_VERT) && ((m_rectMax.left >= rect.left) || (m_rectMax.right <= rect.right)))
		{
			return;
		}
		*/

Thanks Dave

I love programming

Hi,

Nice Article. Thank you for sharing with all.

I am trying to use this code in Resizable Dialog. I read this above information, but I am still facing problem like: After resizing the window this would get hit and return, not allowing the movement of the splitter.

Any solution to this? Can any one share the modified version for resize splitter for same if tried in Resize Dialog.

Thank you in advance.

How can I restrict splitter to some limits? Currently I can move it outside the window, and when that happens controls in second pane (right/bottom) also resize out of the window. Also, I was able to create two vertical splitters, but when I move left splitter over the right one controls resize incorrectly.

Hi Mihajlo Cvetanovic,

Apologize for the late response. I have been busy in my current project.

Replace the implementation of the methods:
1)

C++

void CControlSplitter::AddToTopOrLeftCtrls(UINT nCtrlId, WORD nFlags);

and
2)

C++

void CControlSplitter::AddToBottomOrRightCtrls(UINT nCtrlId, WORD nFlags)

Replace it with the code below:

C++

#ifndef CTRL_MINWIDTH
#define CTRL_MINWIDTH 15
#endif
void CControlSplitter::AddToTopOrLeftCtrls(UINT nCtrlId, WORD nFlags)
{
	ASSERT(m_nType);
	m_vtTopLeftControls.push_back(MAKELONG(nCtrlId,nFlags));
	if(m_rectMax.IsRectEmpty())
	{
		GetParent()->GetClientRect(m_rectMax);	
	}
	
	CWnd * pCtrl = GetParent()->GetDlgItem(nCtrlId);

	if(pCtrl != NULL)
	{
		CRect rect;
		pCtrl->GetWindowRect(&rect);
		GetParent()->ScreenToClient(&rect);
		if(m_vtTopLeftControls.size() == 1)
		{
			m_rectMax.top = rect.top + CTRL_MINWIDTH;
			m_rectMax.left = rect.left + CTRL_MINWIDTH;
		}

		if((m_nType == CS_HORZ) &&(m_rectMax.top < rect.top))
		{
			m_rectMax.top = rect.top;
		}
		if((m_nType == CS_VERT) && (m_rectMax.left < rect.left))
		{
			m_rectMax.left = rect.left;
		}
	}
}

void CControlSplitter::AddToBottomOrRightCtrls(UINT nCtrlId, WORD nFlags)
{
	ASSERT(m_nType);
	m_vtBottomRightControls.push_back(MAKELONG(nCtrlId,nFlags));
	if(m_rectMax.IsRectEmpty())
	{
		GetParent()->GetClientRect(m_rectMax);		
	}
	CWnd * pCtrl = GetParent()->GetDlgItem(nCtrlId);
	if(pCtrl != NULL)
	{
		CRect rect;
		pCtrl->GetWindowRect(&rect);
		GetParent()->ScreenToClient(&rect);
		if(m_vtBottomRightControls.size() == 1)
		{
			m_rectMax.right = rect.right - CTRL_MINWIDTH;
			m_rectMax.bottom = rect.bottom - CTRL_MINWIDTH;
		}
		if((m_nType == CS_HORZ) &&(m_rectMax.bottom > rect.bottom))
		{
			m_rectMax.bottom = rect.bottom;
		}
		if((m_nType == CS_VERT) &&(m_rectMax.right > rect.right))
		{
			m_rectMax.right = rect.right;
		}
	}	
}

Modification:

Used GetClientRect instead of GetWindowRect when setting the maximum region cause the position of the parent window/dialog does not matter.
If adding top/left control at the first time set the top/left max region to the top/left of added control
If adding bottom/right control at the first time set the bottom/right max region to the bottom/right of added control

CTRL_MINWIDTH is the minimum width or height the control would reside.

Hope this will fix the problem.

Best Regards,

Lucman

I love programming

I was persuaded by CP community to have a SDI project, so I am using my own class derived from MFC's CSplitterWnd, and there I made some changes in GetHitRect code to restrict splitbar moving. Thank you for the answer anyway, it may come useful in the future.

Hi,

Thank you for your code.
When i tried it, i saw a bug : default cursor on button (CButton) is the same as the one for your CControlSplitter. I guess you change the global cursor of button...

Quick workaround?

BOOL CControlSplitter::OnSetCursor(CWnd* pWnd, UINT nHitTest, UINT message)
{
...

TRACKMOUSEEVENT tme;
tme.cbSize = sizeof(TRACKMOUSEEVENT);
tme.dwFlags = TME_LEAVE;
tme.hwndTrack = this->m_hWnd;
::_TrackMouseEvent(&tme);

return CButton::OnSetCursor(pWnd, nHitTest, message);
}

LRESULT CControlSplitter::OnMouseLeave(WPARAM wParam, LPARAM lParam)
{
// TODO: Add your message handler code here and/or call default
if(m_hCursor != NULL)
{
DestroyCursor(m_hCursor);
}
m_hCursor = ::LoadCursor(NULL,IDC_ARROW);
SetClassLong(m_hWnd,GCL_HCURSOR,(LONG)m_hCursor);
return TRUE;
}

As far as I can see ReadMe is in Japanese, as are the comments in the files. Could Mr Abdulrachman provide an english version ?

The text in ReadMe is gibberish ! How about fixing it ?
Raymond Mercier

rm459@cam.ac.uk

Hi Raymond,

Apologies for the Japanese text. The reason it was Japanese is ReadMe.txt was actually created by MFC AppWizzard since I'm using Japanese environment.

I translated it by the way.

See text below:

Best Regards,

Lucman

Readme.txt

<br />
========================================================================<br />
       MICROSOFT FOUNDATION CLASS Library : Splitter<br />
========================================================================<br />
<br />
<br />
AppWizard has created this Splitter application for you.  This application<br />
not only demonstrates the basics of using the Microsoft Foundation classes<br />
but is also a starting point for writing your application.<br />
<br />
This file contains a summary of what you will find in each of the files that<br />
make up your Splitter application.<br />
<br />
Splitter.dsp<br />
    This file (the project file) contains information at the project level and<br />
    is used to build a single project or subproject. Other users can share the<br />
    project (.dsp) file, but they should export the makefiles locally.<br />
<br />
Splitter.h<br />
    This is the main header file for the application.  It includes other<br />
    project specific headers (including Resource.h) and declares the<br />
    CSplitterApp application class.<br />
<br />
Splitter.cpp<br />
    This is the main application source file that contains the application<br />
    class CSplitterApp.<br />
<br />
Splitter.rc<br />
    This is a listing of all of the Microsoft Windows resources that the<br />
    program uses.  It includes the icons, bitmaps, and cursors that are stored<br />
    in the RES subdirectory.  This file can be directly edited in Microsoft<br />
	Visual C++.<br />
<br />
Splitter.clw<br />
    This file contains information used by ClassWizard to edit existing<br />
    classes or add new classes.  ClassWizard also uses this file to store<br />
    information needed to create and edit message maps and dialog data<br />
    maps and to create prototype member functions.<br />
<br />
res\Splitter.ico<br />
    This is an icon file, which is used as the application's icon.  This<br />
    icon is included by the main resource file Splitter.rc.<br />
<br />
res\Splitter.rc2<br />
    This file contains resources that are not edited by Microsoft <br />
	Visual C++.  You should place all resources not editable by<br />
	the resource editor in this file.<br />
<br />
<br />
<br />
<br />
/////////////////////////////////////////////////////////////////////////////<br />
<br />
AppWizard creates one dialog class:<br />
<br />
SplitterDlg.h, SplitterDlg.cpp - the dialog<br />
    These files contain your CSplitterDlg class.  This class defines<br />
    the behavior of your application's main dialog.  The dialog's<br />
    template is in Splitter.rc, which can be edited in Microsoft<br />
	Visual C++.<br />
<br />
<br />
/////////////////////////////////////////////////////////////////////////////<br />
Other standard files:<br />
<br />
StdAfx.h, StdAfx.cpp<br />
    These files are used to build a precompiled header (PCH) file<br />
    named Splitter.pch and a precompiled types file named StdAfx.obj.<br />
<br />
Resource.h<br />
    This is the standard header file, which defines new resource IDs.<br />
    Microsoft Visual C++ reads and updates this file.<br />
<br />
/////////////////////////////////////////////////////////////////////////////<br />
Other notes:<br />
<br />
AppWizard uses "TODO:" to indicate parts of the source code you<br />
should add to or customize.<br />
<br />
If your application uses MFC in a shared DLL, and your application is <br />
in a language other than the operating system's current language, you<br />
will need to copy the corresponding localized resources MFC42XXX.DLL<br />
from the Microsoft Visual C++ CD-ROM onto the system or system32 directory,<br />
and rename it to be MFCLOC.DLL.  ("XXX" stands for the language abbreviation.<br />
For example, MFC42DEU.DLL contains resources translated to German.)  If you<br />
don't do this, some of the UI elements of your application will remain in the<br />
language of the operating system.<br />
<br />
/////////////////////////////////////////////////////////////////////////////<br />

In Journey the leader of the people is their servant. -RSAW

modified on Sunday, July 24, 2011 9:28 PM

Dear Lucman,

Many thanks for that. Since the text was produced by MFC it is what I have seen already in projects created by MFC, so not new after all !.

Yours Raymond Mercier

Splitter in an MFC dialog based application

Introduction

Background

Using the code

Setup your splitter in the OnInitDialog() method of your dialog

Class working methods

Class working member variables

History

License

Comments and Discussions