| /* |
| * 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 "DragScrollTimer.h" |
| |
| #include "FrameView.h" |
| |
| using namespace WebCore; |
| |
| namespace WebKit { |
| |
| // Computes the distance from a point outside a rect to the nearest edge of the rect. |
| static IntSize distanceToRect(const IntPoint& point, const IntRect& rect) |
| { |
| int dx = 0, dy = 0; |
| if (point.x() < rect.x()) |
| dx = point.x() - rect.x(); |
| else if (rect.maxX() < point.x()) |
| dx = point.x() - rect.maxX(); |
| if (point.y() < rect.y()) |
| dy = point.y() - rect.y(); |
| else if (rect.maxY() < point.y()) |
| dy = point.y() - rect.maxY(); |
| return IntSize(dx, dy); |
| } |
| |
| DragScrollTimer::DragScrollTimer() |
| : m_timer(this, &DragScrollTimer::fired) |
| , m_view(0) |
| , m_scrolling(false) |
| { |
| } |
| |
| DragScrollTimer::~DragScrollTimer() |
| { |
| // We do this for detecting dead object earlier |
| stop(); |
| } |
| |
| void DragScrollTimer::stop() |
| { |
| m_timer.stop(); |
| m_view = 0; |
| m_scrolling = false; |
| } |
| |
| void DragScrollTimer::scroll() |
| { |
| m_view->scrollBy(m_lastDistance); |
| m_scrolling = true; |
| } |
| |
| void DragScrollTimer::update() |
| { |
| if (shouldScroll()) |
| scroll(); |
| else |
| stop(); |
| } |
| |
| void DragScrollTimer::triggerScroll(FrameView* view, const WebPoint& location) |
| { |
| if (!view) |
| return; |
| |
| // Approximates Safari |
| static const double scrollStartDelay = 0.2; |
| |
| m_view = view; |
| m_lastDistance = scrollDistanceFor(view, location); |
| |
| if (m_scrolling) |
| update(); |
| else if (shouldScroll() && !m_timer.isActive()) |
| m_timer.startOneShot(scrollStartDelay); |
| } |
| |
| IntSize DragScrollTimer::scrollDistanceFor(FrameView* view, const WebPoint& location) const |
| { |
| static const int scrollMargin = 30; |
| |
| IntRect bounds(0, 0, view->visibleWidth(), view->visibleHeight()); |
| if (!bounds.contains(location)) |
| return IntSize(0, 0); // The location is outside the border belt. |
| |
| bounds.setY(bounds.y() + scrollMargin); |
| bounds.setHeight(bounds.height() - scrollMargin * 2); |
| bounds.setX(bounds.x() + scrollMargin); |
| bounds.setWidth(bounds.width() - scrollMargin * 2); |
| |
| if (bounds.contains(location)) |
| return IntSize(0, 0); // The location is inside the border belt. |
| |
| // The location is over the border belt. |
| return distanceToRect(location, bounds); |
| } |
| |
| } // namespace WebKit |