scrollcontainer.cpp

hl2 source code. Do not use it illegal.

/*----------------------------------------------------------------------
Copyright (c) 1998 Gipsysoft. All Rights Reserved.
Please see the file "licence.txt" for licencing details.

File:	ScrollContainer.cpp
Owner:	[e-mail]
Purpose:	General purpose scroll container
----------------------------------------------------------------------*/
#include "stdafx.h"
#include <math.h>
#include "ScrollContainer.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CScrollContainer::CScrollContainer( CParentSection *psect )
	: CParentSection( psect )
{
	Reset( 0, 0 );
}


CScrollContainer::~CScrollContainer()
{

}


void CScrollContainer::Reset( int nMaxWidth, int nMaxHeight )
{
	m_nLastScrollPos = m_nScrollPos = 0;
	m_nMaxHeight = nMaxHeight;
	m_nLastScrollPosH = m_nScrollPosH = 0;
	m_nMaxWidth = nMaxWidth;
}


void CScrollContainer::OnLayout( const CRect &rc )
{
	CSectionABC::OnLayout( rc );

	m_nLastScrollPos = max( (m_nMaxHeight - Height()), 0 );
	if( m_nScrollPos > m_nLastScrollPos )
		m_nScrollPos = m_nLastScrollPos;

	m_nLastScrollPosH = max((m_nMaxWidth - Width()), 0);
	if (m_nScrollPosH > m_nLastScrollPosH )
		m_nScrollPosH = m_nLastScrollPosH;
}


void CScrollContainer::OnDraw( CDrawContext &dc )
{
	//
	//	Get a clip rectangle that *only* encompasses this section.
	//	This helps to restrict drawing to just the parts that are visible
	const CRect &rcDCClip = dc.GetClipRect();
	CRect rcClip( max( rcDCClip.left, left )
							, max( rcDCClip.top, top )
							, min( rcDCClip.right, right)
							, min( rcDCClip.bottom, bottom ) );

	dc.SetClipRect( *this);
	const UINT uSize = m_arrSections.GetSize();
	for( UINT n = 0; n < uSize; n++ )
	{
		CSectionABC *psect = m_arrSections[ n ];
		if( rcClip.Intersect( *psect ) )
		{
			psect->OnDraw( dc );
		}
	}

	dc.RemoveClipRect();
}


void CScrollContainer::InternalScroll( int cx, int cy, bool bScroll )
{
	int nOldPos = m_nScrollPos;
	int nOldPosH = m_nScrollPosH;

	m_nScrollPos += cy;
	m_nScrollPosH += cx;

	m_nScrollPos = max( 0, min( m_nScrollPos, m_nLastScrollPos ) );
	m_nScrollPosH = max( 0, min( m_nScrollPosH, m_nLastScrollPosH ) );

	int nDeltaY = nOldPos - m_nScrollPos;
	int nDeltaX = nOldPosH - m_nScrollPosH;

	DoInternalScroll( nDeltaX, nDeltaY, bScroll );
}


void CScrollContainer::InternalScrollAbsolute( int cx, int cy, bool bScroll )
{
	//	Ignores extrema!
	int nOldPos = m_nScrollPos;
	int nOldPosH = m_nScrollPosH;

	m_nScrollPos += cy;
	m_nScrollPosH += cx;

	int nDeltaY = nOldPos - m_nScrollPos;
	int nDeltaX = nOldPosH - m_nScrollPosH;

	DoInternalScroll( nDeltaX, nDeltaY, bScroll );
}


void CScrollContainer::DoInternalScroll( int nDeltaX, int nDeltaY, bool bScroll )
{
	if( nDeltaY || nDeltaX )
	{
		const UINT uSize = m_arrSections.GetSize();
		for( UINT n = 0; n < uSize; n++ )
		{
			m_arrSections[ n ]->Offset( nDeltaX, nDeltaY );
		}
		if( (abs( nDeltaY ) < Height() || abs( nDeltaX ) < Width() ) && bScroll )
		{
			Scroll( nDeltaX, nDeltaY, *this );
		}
	}
}



void CScrollContainer::ScrollV( int nAmount )
{
	if( m_bUseScroll )
	{
		InternalScroll( 0, nAmount, true );
	}
	else
	{
		InternalScroll( 0, nAmount, false );
		ForceRedraw();
	}
}


void CScrollContainer::ScrollH( int nAmount )
{
	if( m_bUseScroll )
	{
		InternalScroll( nAmount, 0, true );
	}
	else
	{
		InternalScroll( nAmount, 0, false );
		ForceRedraw();
	}
}


int CScrollContainer::GetScrollPos() const
{
	return m_nScrollPos;
}


int CScrollContainer::GetScrollPosH() const
{
	return m_nScrollPosH;
}


void CScrollContainer::SetPos( int nPos )
{
	InternalScroll( 0, nPos - m_nScrollPos, false );
}


void CScrollContainer::SetPosH( int nPos )
{
	InternalScroll( nPos - m_nScrollPosH, 0, false );
}

void CScrollContainer::SetPosAbsolute( int nHPos, int nVPos )
{
	InternalScrollAbsolute( nHPos - m_nScrollPosH, nVPos - m_nScrollPos, false );
}

bool CScrollContainer::CanScrollUp() const
{
	return m_nScrollPos == 0 ? false : true;
}


bool CScrollContainer::CanScrollDown() const
{
	return m_nScrollPos == m_nLastScrollPos || Height() > m_nMaxHeight ? false : true;
}

bool CScrollContainer::CanScrollLeft() const
{
	return m_nScrollPosH == 0 ? false : true;
}


bool CScrollContainer::CanScrollRight() const
{
	return m_nScrollPosH == m_nLastScrollPosH || Width() > m_nMaxWidth ? false : true;
}