flutter_flutter/engine/platform/Widget.cpp

/*
 * Copyright (C) 2004, 2005, 2006, 2010 Apple Inc. All rights reserved.
 * Copyright (C) 2013 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "platform/Widget.h"


#include "wtf/Assertions.h"

namespace blink {

Widget::Widget()
    : m_parent(0)
{
}

Widget::~Widget()
{
    ASSERT(!parent());
}

Widget* Widget::root() const
{
    const Widget* top = this;
    while (top->parent())
        top = top->parent();
    if (top->isFrameView())
        return const_cast<Widget*>(static_cast<const Widget*>(top));
    return 0;
}

IntRect Widget::convertFromRootView(const IntRect& rootRect) const
{
    if (const Widget* parentWidget = parent()) {
        IntRect parentRect = parentWidget->convertFromRootView(rootRect);
        return convertFromContainingView(parentRect);
    }
    return rootRect;
}

IntRect Widget::convertToRootView(const IntRect& localRect) const
{
    if (const Widget* parentWidget = parent()) {
        IntRect parentRect = convertToContainingView(localRect);
        return parentWidget->convertToRootView(parentRect);
    }
    return localRect;
}

IntPoint Widget::convertFromRootView(const IntPoint& rootPoint) const
{
    if (const Widget* parentWidget = parent()) {
        IntPoint parentPoint = parentWidget->convertFromRootView(rootPoint);
        return convertFromContainingView(parentPoint);
    }
    return rootPoint;
}

IntPoint Widget::convertToRootView(const IntPoint& localPoint) const
{
    if (const Widget* parentWidget = parent()) {
        IntPoint parentPoint = convertToContainingView(localPoint);
        return parentWidget->convertToRootView(parentPoint);
    }
    return localPoint;
}

IntRect Widget::convertFromContainingWindow(const IntRect& windowRect) const
{
    if (const Widget* parentWidget = parent()) {
        IntRect parentRect = parentWidget->convertFromContainingWindow(windowRect);
        return convertFromContainingView(parentRect);
    }
    return windowRect;
}

IntRect Widget::convertToContainingWindow(const IntRect& localRect) const
{
    if (const Widget* parentWidget = parent()) {
        IntRect parentRect = convertToContainingView(localRect);
        return parentWidget->convertToContainingWindow(parentRect);
    }
    return localRect;
}

IntPoint Widget::convertFromContainingWindow(const IntPoint& windowPoint) const
{
    if (const Widget* parentWidget = parent()) {
        IntPoint parentPoint = parentWidget->convertFromContainingWindow(windowPoint);
        return convertFromContainingView(parentPoint);
    }
    return windowPoint;
}


FloatPoint Widget::convertFromContainingWindow(const FloatPoint& windowPoint) const
{
    // Widgets / windows are required to be IntPoint aligned, but we may need to convert
    // FloatPoint values within them (eg. for event co-ordinates).
    IntPoint flooredPoint = flooredIntPoint(windowPoint);
    FloatPoint parentPoint = this->convertFromContainingWindow(flooredPoint);
    FloatSize windowFraction = windowPoint - flooredPoint;
    // Use linear interpolation handle any fractional value (eg. for iframes subject to a transform
    // beyond just a simple translation).
    // FIXME: Add FloatPoint variants of all co-ordinate space conversion APIs.
    if (!windowFraction.isEmpty()) {
        const int kFactor = 1000;
        IntPoint parentLineEnd = this->convertFromContainingWindow(flooredPoint + roundedIntSize(windowFraction.scaledBy(kFactor)));
        FloatSize parentFraction = (parentLineEnd - parentPoint).scaledBy(1.0f / kFactor);
        parentPoint.move(parentFraction);
    }
    return parentPoint;
}

IntPoint Widget::convertToContainingWindow(const IntPoint& localPoint) const
{
    if (const Widget* parentWidget = parent()) {
        IntPoint parentPoint = convertToContainingView(localPoint);
        return parentWidget->convertToContainingWindow(parentPoint);
    }
    return localPoint;
}

IntRect Widget::convertToContainingView(const IntRect& localRect) const
{
    return localRect;
}

IntRect Widget::convertFromContainingView(const IntRect& parentRect) const
{
    return parentRect;
}

IntPoint Widget::convertToContainingView(const IntPoint& localPoint) const
{
    return localPoint;
}

IntPoint Widget::convertFromContainingView(const IntPoint& parentPoint) const
{
    return parentPoint;
}

} // namespace blink