flutter_flutter/sky/engine/core/rendering/HitTestLocation.cpp

/*
 * Copyright (C) 2006, 2008, 2011 Apple Inc. All rights reserved.
 * Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#include "flutter/sky/engine/core/rendering/HitTestLocation.h"

namespace blink {

HitTestLocation::HitTestLocation()
    : m_isRectBased(false), m_isRectilinear(true) {}

HitTestLocation::HitTestLocation(const LayoutPoint& point)
    : m_point(point),
      m_boundingBox(rectForPoint(point, 0, 0, 0, 0)),
      m_transformedPoint(point),
      m_transformedRect(m_boundingBox),
      m_isRectBased(false),
      m_isRectilinear(true) {}

HitTestLocation::HitTestLocation(const FloatPoint& point)
    : m_point(flooredLayoutPoint(point)),
      m_boundingBox(rectForPoint(m_point, 0, 0, 0, 0)),
      m_transformedPoint(point),
      m_transformedRect(m_boundingBox),
      m_isRectBased(false),
      m_isRectilinear(true) {}

HitTestLocation::HitTestLocation(const FloatPoint& point, const FloatQuad& quad)
    : m_transformedPoint(point), m_transformedRect(quad), m_isRectBased(true) {
  m_point = flooredLayoutPoint(point);
  m_boundingBox = enclosingIntRect(quad.boundingBox());
  m_isRectilinear = quad.isRectilinear();
}

HitTestLocation::HitTestLocation(const LayoutPoint& centerPoint,
                                 unsigned topPadding,
                                 unsigned rightPadding,
                                 unsigned bottomPadding,
                                 unsigned leftPadding)
    : m_point(centerPoint),
      m_boundingBox(rectForPoint(centerPoint,
                                 topPadding,
                                 rightPadding,
                                 bottomPadding,
                                 leftPadding)),
      m_transformedPoint(centerPoint),
      m_isRectBased(topPadding || rightPadding || bottomPadding || leftPadding),
      m_isRectilinear(true) {
  m_transformedRect = FloatQuad(m_boundingBox);
}

HitTestLocation::HitTestLocation(const HitTestLocation& other,
                                 const LayoutSize& offset)
    : m_point(other.m_point),
      m_boundingBox(other.m_boundingBox),
      m_transformedPoint(other.m_transformedPoint),
      m_transformedRect(other.m_transformedRect),
      m_isRectBased(other.m_isRectBased),
      m_isRectilinear(other.m_isRectilinear) {
  move(offset);
}

HitTestLocation::HitTestLocation(const HitTestLocation& other)
    : m_point(other.m_point),
      m_boundingBox(other.m_boundingBox),
      m_transformedPoint(other.m_transformedPoint),
      m_transformedRect(other.m_transformedRect),
      m_isRectBased(other.m_isRectBased),
      m_isRectilinear(other.m_isRectilinear) {}

HitTestLocation::~HitTestLocation() {}

HitTestLocation& HitTestLocation::operator=(const HitTestLocation& other) {
  m_point = other.m_point;
  m_boundingBox = other.m_boundingBox;
  m_transformedPoint = other.m_transformedPoint;
  m_transformedRect = other.m_transformedRect;
  m_isRectBased = other.m_isRectBased;
  m_isRectilinear = other.m_isRectilinear;

  return *this;
}

void HitTestLocation::move(const LayoutSize& offset) {
  m_point.move(offset);
  m_transformedPoint.move(offset);
  m_transformedRect.move(offset);
  m_boundingBox = enclosingIntRect(m_transformedRect.boundingBox());
}

template <typename RectType>
bool HitTestLocation::intersectsRect(const RectType& rect) const {
  // FIXME: When the hit test is not rect based we should use
  // rect.contains(m_point). That does change some corner case tests though.

  // First check if rect even intersects our bounding box.
  if (!rect.intersects(m_boundingBox))
    return false;

  // If the transformed rect is rectilinear the bounding box intersection was
  // accurate.
  if (m_isRectilinear)
    return true;

  // If rect fully contains our bounding box, we are also sure of an
  // intersection.
  if (rect.contains(m_boundingBox))
    return true;

  // Otherwise we need to do a slower quad based intersection test.
  return m_transformedRect.intersectsRect(rect);
}

bool HitTestLocation::intersects(const LayoutRect& rect) const {
  return intersectsRect(rect);
}

bool HitTestLocation::intersects(const FloatRect& rect) const {
  return intersectsRect(rect);
}

bool HitTestLocation::intersects(const RoundedRect& rect) const {
  return rect.intersectsQuad(m_transformedRect);
}

bool HitTestLocation::containsPoint(const FloatPoint& point) const {
  return m_transformedRect.containsPoint(point);
}

IntRect HitTestLocation::rectForPoint(const LayoutPoint& point,
                                      unsigned topPadding,
                                      unsigned rightPadding,
                                      unsigned bottomPadding,
                                      unsigned leftPadding) {
  IntPoint actualPoint(flooredIntPoint(point));
  actualPoint -= IntSize(leftPadding, topPadding);

  IntSize actualPadding(leftPadding + rightPadding, topPadding + bottomPadding);
  // As IntRect is left inclusive and right exclusive (seeing
  // IntRect::contains(x, y)), adding "1".
  // FIXME: Remove this once non-rect based hit-detection stops using
  // IntRect:intersects.
  actualPadding += IntSize(1, 1);

  return IntRect(actualPoint, actualPadding);
}

}  // namespace blink