IntRect TileController::boundsForSize(const FloatSize& size) const
{
IntPoint boundsOriginIncludingMargin(-leftMarginWidth(), -topMarginHeight());
IntSize boundsSizeIncludingMargin = expandedIntSize(size);
boundsSizeIncludingMargin.expand(leftMarginWidth() + rightMarginWidth(), topMarginHeight() + bottomMarginHeight());
return IntRect(boundsOriginIncludingMargin, boundsSizeIncludingMargin);
}
IntRect TileController::boundsAtLastRevalidateWithoutMargin() const
{
IntRect boundsWithoutMargin = IntRect(IntPoint(), m_boundsAtLastRevalidate.size());
boundsWithoutMargin.contract(IntSize(leftMarginWidth() + rightMarginWidth(), topMarginHeight() + bottomMarginHeight()));
return boundsWithoutMargin;
}
FloatRect TileController::computeTileCoverageRect(const FloatSize& newSize, const FloatRect& previousVisibleRect, const FloatRect& visibleRect, float contentsScale) const
{
// If the page is not in a window (for example if it's in a background tab), we limit the tile coverage rect to the visible rect.
if (!m_isInWindow)
return visibleRect;
#if PLATFORM(IOS)
// FIXME: unify the iOS and Mac code.
UNUSED_PARAM(previousVisibleRect);
if (m_tileCoverage == CoverageForVisibleArea || MemoryPressureHandler::singleton().isUnderMemoryPressure())
return visibleRect;
double horizontalMargin = tileSize().width() / contentsScale;
double verticalMargin = tileSize().height() / contentsScale;
double currentTime = monotonicallyIncreasingTime();
double timeDelta = currentTime - m_velocity.lastUpdateTime;
FloatRect futureRect = visibleRect;
futureRect.setLocation(FloatPoint(
futureRect.location().x() + timeDelta * m_velocity.horizontalVelocity,
futureRect.location().y() + timeDelta * m_velocity.verticalVelocity));
if (m_velocity.horizontalVelocity) {
futureRect.setWidth(futureRect.width() + horizontalMargin);
if (m_velocity.horizontalVelocity < 0)
futureRect.setX(futureRect.x() - horizontalMargin);
}
if (m_velocity.verticalVelocity) {
futureRect.setHeight(futureRect.height() + verticalMargin);
if (m_velocity.verticalVelocity < 0)
futureRect.setY(futureRect.y() - verticalMargin);
}
if (!m_velocity.horizontalVelocity && !m_velocity.verticalVelocity) {
if (m_velocity.scaleChangeRate > 0)
return visibleRect;
futureRect.setWidth(futureRect.width() + horizontalMargin);
futureRect.setHeight(futureRect.height() + verticalMargin);
futureRect.setX(futureRect.x() - horizontalMargin / 2);
futureRect.setY(futureRect.y() - verticalMargin / 2);
}
// Can't use m_tileCacheLayer->bounds() here, because the size of the underlying platform layer
// hasn't been updated for the current commit.
IntSize contentSize = expandedIntSize(newSize);
if (futureRect.maxX() > contentSize.width())
futureRect.setX(contentSize.width() - futureRect.width());
if (futureRect.maxY() > contentSize.height())
futureRect.setY(contentSize.height() - futureRect.height());
if (futureRect.x() < 0)
futureRect.setX(0);
if (futureRect.y() < 0)
futureRect.setY(0);
return futureRect;
#else
UNUSED_PARAM(contentsScale);
// FIXME: look at how far the document can scroll in each dimension.
float coverageHorizontalSize = visibleRect.width();
float coverageVerticalSize = visibleRect.height();
bool largeVisibleRectChange = !previousVisibleRect.isEmpty() && !visibleRect.intersects(previousVisibleRect);
// Inflate the coverage rect so that it covers 2x of the visible width and 3x of the visible height.
// These values were chosen because it's more common to have tall pages and to scroll vertically,
// so we keep more tiles above and below the current area.
if (m_tileCoverage & CoverageForHorizontalScrolling && !largeVisibleRectChange)
coverageHorizontalSize *= 2;
if (m_tileCoverage & CoverageForVerticalScrolling && !largeVisibleRectChange)
coverageVerticalSize *= 3;
coverageVerticalSize += topMarginHeight() + bottomMarginHeight();
coverageHorizontalSize += leftMarginWidth() + rightMarginWidth();
// Can't use m_tileCacheLayer->bounds() here, because the size of the underlying platform layer
// hasn't been updated for the current commit.
FloatRect coverageBounds = boundsForSize(newSize);
float coverageLeft = visibleRect.x() - (coverageHorizontalSize - visibleRect.width()) / 2;
coverageLeft = std::min(coverageLeft, coverageBounds.maxX() - coverageHorizontalSize);
coverageLeft = std::max(coverageLeft, coverageBounds.x());
float coverageTop = visibleRect.y() - (coverageVerticalSize - visibleRect.height()) / 2;
coverageTop = std::min(coverageTop, coverageBounds.maxY() - coverageVerticalSize);
coverageTop = std::max(coverageTop, coverageBounds.y());
return FloatRect(coverageLeft, coverageTop, coverageHorizontalSize, coverageVerticalSize);
#endif
}