src/views/SkScrollBarView.cpp

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "SkScrollBarView.h"
#include "SkAnimator.h"
#include "SkWidgetViews.h"
#include "SkSystemEventTypes.h"
#include "SkTime.h"

//see SkProgressBarView.cpp
//#include "SkWidgetViews.cpp"

SkScrollBarView::SkScrollBarView()
{
	fAnim.setHostEventSink(this);
	init_skin_anim(kScroll_SkinEnum, &fAnim);

	fTotalLength = 0;
	fStartPoint = 0;
	fShownLength = 0;

	this->adjust();
}

void SkScrollBarView::setStart(unsigned start)
{
	if ((int)start < 0)
		start = 0;
	
	if (fStartPoint != start)
	{
		fStartPoint = start;
		this->adjust();
	}
}

void SkScrollBarView::setShown(unsigned shown)
{
	if ((int)shown < 0)
		shown = 0;

	if (fShownLength != shown)
	{
		fShownLength = shown;
		this->adjust();
	}
}

void SkScrollBarView::setTotal(unsigned total)
{
	if ((int)total < 0)
		total = 0;

	if (fTotalLength != total)
	{
		fTotalLength = total;
		this->adjust();
	}
}

/* virtual */ void SkScrollBarView::onInflate(const SkDOM& dom, const SkDOM::Node* node)
{
	this->INHERITED::onInflate(dom, node);
	
	int32_t value;
	if (dom.findS32(node, "total", &value))
		this->setTotal(value);
	if (dom.findS32(node, "shown", &value))
		this->setShown(value);
}

/*virtual*/ void SkScrollBarView::onSizeChange()
{
	this->INHERITED::onSizeChange();
	SkEvent evt("user");
	evt.setString("id", "setDim");
	evt.setScalar("dimX", this->width());
	evt.setScalar("dimY", this->height());
	fAnim.doUserEvent(evt);
}

/*virtual*/ void SkScrollBarView::onDraw(SkCanvas* canvas)
{
	SkPaint						paint;		
	SkAnimator::DifferenceType	diff = fAnim.draw(canvas, &paint, SkTime::GetMSecs());
	
	if (diff == SkAnimator::kDifferent)
		this->inval(NULL);
	else if (diff == SkAnimator::kPartiallyDifferent)
	{
		SkRect	bounds;
		fAnim.getInvalBounds(&bounds);
		this->inval(&bounds);
	}
}

/*virtual*/ bool SkScrollBarView::onEvent(const SkEvent& evt)
{
	if (evt.isType(SK_EventType_Inval))
	{
		this->inval(NULL);
		return true;
	}
	if (evt.isType("recommendDim"))
	{
		SkScalar	width;
		
		if (evt.findScalar("x", &width))
			this->setWidth(width);
		return true;
	}

	return this->INHERITED::onEvent(evt);
}

void SkScrollBarView::adjust()
{
	int total = fTotalLength;
	int start = fStartPoint;
	int shown = fShownLength;
	int hideBar = 0;
	
	if (total <= 0 || shown <= 0 || shown >= total)	// no bar to show
	{
		total = 1;		// avoid divide-by-zero. should be done by skin/script
		hideBar = 1;	// signal we don't want a thumb
	}
	else
	{
		if (start + shown > total)
			start = total - shown;
	}
	
	SkEvent e("user");
	e.setString("id", "adjustScrollBar");
	e.setScalar("_totalLength", SkIntToScalar(total));
	e.setScalar("_startPoint", SkIntToScalar(start));
	e.setScalar("_shownLength", SkIntToScalar(shown));
//	e.setS32("hideBar", hideBar);
	fAnim.doUserEvent(e);
}