Environment: The demo project was created with VC++ 6.0 SP1
When scrolling in a document that consists of quite a lot pages it might be helpful for the user to get an information which page of the document would be displayed if he/she >would release to slider of the scrollbar at a certain position.
Microsoft Word has such a feature. It’s a tooltip-like window that displays the page number that corresponds to the current position of the slider during scrolling.
I implemented a class named CScrollViewPageCounter that displays such a page number in a window that looks like a tooltip-window. If you have a look at the source code you’ll find out that it was quite easy to implement. The code itself is self-explanatory…
HOW TO USE
To use the ScrollViewPageCounter-Object you have to perform the following steps:1. Add the files ScrollViewPageCounter.h and ScrollViewPageCounter.cpp to your project.
2. Add a new member m_pScrollViewPageCounter to your scroll view class.
Of course your have to include the corresponding header file here as well:
CScrollViewPageCounter*
m_pScrollViewPageCounter;
#include “ScrollViewPageCounter.h”
3. Create the page counter object in CYourScrollView::OnInitialUpdate()
BOOL CYourScrollView::PreCreateWindow(CREATESTRUCT& cs)
{
CScrollView::OnInitialUpdate();// Instantiate the counter object
m_pScrollViewPageCounter = new CScrollViewPageCounter( this );
}
4. Add a command handler for the message WM_VSCROLL:
void CYourScrollView::OnVScroll(UINT SBCode, UINT nPos, CScrollBar* pScrollBar)That’s it.
{
if ( nSBCode == SB_THUMBTRACK )
{
// calculate page number (insert your algorithm here)
UINT uiPageNumber = (UINT) (nPos / 10) + 1;// display page number
m_pScrollViewPageCounter->DisplayPageNumber( uiPageNumber );
}// when scrolling is finished we have to hide the page counter
if ( nSBCode == SB_ENDSCROLL )
m_pScrollViewPageCounter->Reset();CScrollView::OnVScroll(nSBCode, nPos, pScrollBar);
}
Now compile and enjoy…
Date Last Updated: April 16, 1999
