| /* |
| * Copyright (c) 2010, 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: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * 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. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "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 THE COPYRIGHT |
| * OWNER 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 "core/platform/ScrollAnimator.h" |
| |
| #include "core/platform/ScrollableArea.h" |
| #include "platform/geometry/FloatPoint.h" |
| #include "wtf/PassOwnPtr.h" |
| #include <algorithm> |
| |
| using namespace std; |
| |
| namespace WebCore { |
| |
| ScrollAnimator::ScrollAnimator(ScrollableArea* scrollableArea) |
| : m_scrollableArea(scrollableArea) |
| , m_currentPosX(0) |
| , m_currentPosY(0) |
| { |
| } |
| |
| ScrollAnimator::~ScrollAnimator() |
| { |
| } |
| |
| bool ScrollAnimator::scroll(ScrollbarOrientation orientation, ScrollGranularity, float step, float multiplier) |
| { |
| float* currentPos = (orientation == HorizontalScrollbar) ? &m_currentPosX : &m_currentPosY; |
| float newPos = clampScrollPosition(orientation, *currentPos + step * multiplier); |
| float delta = *currentPos - newPos; |
| if (*currentPos == newPos) |
| return false; |
| *currentPos = newPos; |
| |
| notifyPositionChanged(orientation == HorizontalScrollbar ? FloatSize(delta, 0) : FloatSize(0, delta)); |
| |
| return true; |
| } |
| |
| void ScrollAnimator::scrollToOffsetWithoutAnimation(const FloatPoint& offset) |
| { |
| FloatSize delta = FloatSize(offset.x() - m_currentPosX, offset.y() - m_currentPosY); |
| m_currentPosX = offset.x(); |
| m_currentPosY = offset.y(); |
| notifyPositionChanged(delta); |
| } |
| |
| bool ScrollAnimator::handleWheelEvent(const PlatformWheelEvent& e) |
| { |
| bool canScrollX = m_scrollableArea->userInputScrollable(HorizontalScrollbar); |
| bool canScrollY = m_scrollableArea->userInputScrollable(VerticalScrollbar); |
| |
| // Accept the event if we are scrollable in that direction and can still |
| // scroll any further. |
| float deltaX = canScrollX ? e.deltaX() : 0; |
| float deltaY = canScrollY ? e.deltaY() : 0; |
| |
| bool handled = false; |
| |
| #if !OS(MACOSX) |
| ScrollGranularity granularity = e.hasPreciseScrollingDeltas() ? ScrollByPrecisePixel : ScrollByPixel; |
| #else |
| ScrollGranularity granularity = ScrollByPixel; |
| #endif |
| |
| IntSize maxForwardScrollDelta = m_scrollableArea->maximumScrollPosition() - m_scrollableArea->scrollPosition(); |
| IntSize maxBackwardScrollDelta = m_scrollableArea->scrollPosition() - m_scrollableArea->minimumScrollPosition(); |
| if ((deltaX < 0 && maxForwardScrollDelta.width() > 0) |
| || (deltaX > 0 && maxBackwardScrollDelta.width() > 0) |
| || (deltaY < 0 && maxForwardScrollDelta.height() > 0) |
| || (deltaY > 0 && maxBackwardScrollDelta.height() > 0)) { |
| handled = true; |
| |
| if (deltaY) { |
| if (e.granularity() == ScrollByPageWheelEvent) { |
| bool negative = deltaY < 0; |
| deltaY = m_scrollableArea->pageStep(VerticalScrollbar); |
| if (negative) |
| deltaY = -deltaY; |
| } |
| |
| scroll(VerticalScrollbar, granularity, m_scrollableArea->pixelStep(VerticalScrollbar), -deltaY); |
| } |
| |
| if (deltaX) { |
| if (e.granularity() == ScrollByPageWheelEvent) { |
| bool negative = deltaX < 0; |
| deltaX = m_scrollableArea->pageStep(HorizontalScrollbar); |
| if (negative) |
| deltaX = -deltaX; |
| } |
| |
| scroll(HorizontalScrollbar, granularity, m_scrollableArea->pixelStep(HorizontalScrollbar), -deltaX); |
| } |
| } |
| return handled; |
| } |
| |
| void ScrollAnimator::setCurrentPosition(const FloatPoint& position) |
| { |
| m_currentPosX = position.x(); |
| m_currentPosY = position.y(); |
| } |
| |
| FloatPoint ScrollAnimator::currentPosition() const |
| { |
| return FloatPoint(m_currentPosX, m_currentPosY); |
| } |
| |
| void ScrollAnimator::notifyPositionChanged(const FloatSize& delta) |
| { |
| UNUSED_PARAM(delta); |
| m_scrollableArea->setScrollOffsetFromAnimation(IntPoint(m_currentPosX, m_currentPosY)); |
| } |
| |
| float ScrollAnimator::clampScrollPosition(ScrollbarOrientation orientation, float pos) |
| { |
| float maxScrollPos = m_scrollableArea->maximumScrollPosition(orientation); |
| float minScrollPos = m_scrollableArea->minimumScrollPosition(orientation); |
| return std::max(std::min(pos, maxScrollPos), minScrollPos); |
| } |
| |
| } // namespace WebCore |