MyGameFramework/lib/gwen/controls/gwen_horizontalscrollbar.cpp

/*
	GWEN
	Copyright (c) 2010 Facepunch Studios
	See license in Gwen.h
*/


#include "gwen_scrollbar.h"
#include "gwen_horizontalscrollbar.h"

using namespace Gwen;
using namespace Gwen::Controls;

GWEN_CONTROL_CONSTRUCTOR( HorizontalScrollBar )
{
	m_Bar->SetHorizontal();

	m_ScrollButton[SCROLL_BUTTON_LEFT]->SetDirectionLeft();
	m_ScrollButton[SCROLL_BUTTON_LEFT]->onPress.Add( this, &HorizontalScrollBar::NudgeLeft );

	m_ScrollButton[SCROLL_BUTTON_RIGHT]->SetDirectionRight();
	m_ScrollButton[SCROLL_BUTTON_RIGHT]->onPress.Add( this, &HorizontalScrollBar::NudgeRight );

	m_Bar->onDragged.Add( this, &HorizontalScrollBar::OnBarMoved );
}

void HorizontalScrollBar::Layout( Skin::Base* skin )
{
	BaseClass::Layout( skin );

	m_ScrollButton[SCROLL_BUTTON_LEFT]->SetWidth( Height() );
	m_ScrollButton[SCROLL_BUTTON_LEFT]->Dock(Pos::Left);

	m_ScrollButton[SCROLL_BUTTON_RIGHT]->SetWidth( Height() );
	m_ScrollButton[SCROLL_BUTTON_RIGHT]->Dock(Pos::Right);

	m_Bar->SetHeight( GetButtonSize() );
	m_Bar->SetPadding( Padding( GetButtonSize(), 0, GetButtonSize(), 0 ) );

	float barWidth = (m_fViewableContentSize / m_fContentSize) * (Width() - GetButtonSize());

	if ( barWidth < GetButtonSize() * 0.5 )
		barWidth = GetButtonSize() * 0.5;

	m_Bar->SetWidth( barWidth );
	m_Bar->SetHidden( Width() - (GetButtonSize() * 2) <= barWidth );

	//Based on our last scroll amount, produce a position for the bar
	if ( !m_Bar->IsDepressed() )
	{
		SetScrolledAmount( GetScrolledAmount(), true );
	}
}

void HorizontalScrollBar::NudgeLeft( Base* /*control*/ )
{
	if ( !IsDisabled() )
		SetScrolledAmount( GetScrolledAmount() - GetNudgeAmount(), true);
}

void HorizontalScrollBar::NudgeRight( Base* /*control*/ )
{
	if ( !IsDisabled() )
		SetScrolledAmount( GetScrolledAmount() + GetNudgeAmount(), true);
}

void HorizontalScrollBar::ScrollToLeft()
{
	SetScrolledAmount( 0, true);
}
void HorizontalScrollBar::ScrollToRight()
{
	SetScrolledAmount( 1, true);
}

float HorizontalScrollBar::GetNudgeAmount()
{
	if ( m_bDepressed ) 
		return m_fViewableContentSize / m_fContentSize;
	else			 
		return BaseClass::GetNudgeAmount();
}



void HorizontalScrollBar::OnMouseClickLeft( int x, int y, bool bDown )
{
	if ( bDown )
	{
		m_bDepressed = true;
		Gwen::MouseFocus = this;
	}
	else
	{
		Gwen::Point clickPos = CanvasPosToLocal( Gwen::Point( x, y ) );
		if ( clickPos.x < m_Bar->X() )
			NudgeLeft( this );
		else if ( clickPos.x > m_Bar->X() + m_Bar->Width() )
			NudgeRight( this );

		m_bDepressed = false;
		Gwen::MouseFocus = NULL;
	}
}

float HorizontalScrollBar::CalculateScrolledAmount()
{
	return (float)(m_Bar->X() - GetButtonSize()) / (float)(Width() - m_Bar->Width() - (GetButtonSize() * 2 ));
}

bool HorizontalScrollBar::SetScrolledAmount( float amount, bool forceUpdate )
{
	amount = Gwen::Clamp( amount, 0, 1 );

	if  ( !BaseClass::SetScrolledAmount( amount, forceUpdate ) )
		return false;

	if ( forceUpdate )
	{
		int newX = GetButtonSize() + (amount * ((Width() - m_Bar->Width()) - (GetButtonSize()*2)));
		m_Bar->MoveTo( newX, m_Bar->Y() );
	}

	return true;
}

void HorizontalScrollBar::OnBarMoved( Controls::Base* control )
{
	if ( m_Bar->IsDepressed() )
	{
		SetScrolledAmount( CalculateScrolledAmount(), false );
		BaseClass::OnBarMoved(control);
	}
	else
		InvalidateParent();
}