void DrawingBuffer::setSize(const IntSize& size) {
if (m_size == size)
return;
s_currentResourceUsePixels += pixelDelta(size);
m_size = size;
}
IntSize DrawingBuffer::adjustSize(const IntSize& size) {
IntSize adjustedSize = size;
// Clamp if the desired size is greater than the maximum texture size for the device.
if (adjustedSize.height() > m_maxTextureSize)
adjustedSize.setHeight(m_maxTextureSize);
if (adjustedSize.width() > m_maxTextureSize)
adjustedSize.setWidth(m_maxTextureSize);
// Try progressively smaller sizes until we find a size that fits or reach a scale limit.
int scaleAttempts = 0;
while ((s_currentResourceUsePixels + pixelDelta(adjustedSize)) > s_maximumResourceUsePixels) {
scaleAttempts++;
if (scaleAttempts > s_maxScaleAttempts)
return IntSize();
adjustedSize.scale(s_resourceAdjustedRatio);
if (adjustedSize.isEmpty())
return IntSize();
}
return adjustedSize;
}
ScrollResult RootFrameViewport::userScroll(ScrollGranularity granularity,
const FloatSize& delta) {
// TODO(bokan/ymalik): Once smooth scrolling is permanently enabled we
// should be able to remove this method override and use the base class
// version: ScrollableArea::userScroll.
updateScrollAnimator();
// Distribute the scroll between the visual and layout viewport.
float stepX = scrollStep(granularity, HorizontalScrollbar);
float stepY = scrollStep(granularity, VerticalScrollbar);
FloatSize pixelDelta(delta);
pixelDelta.scale(stepX, stepY);
// Precompute the amount of possible scrolling since, when animated,
// ScrollAnimator::userScroll will report having consumed the total given
// scroll delta, regardless of how much will actually scroll, but we need to
// know how much to leave for the layout viewport.
FloatSize visualConsumedDelta =
visualViewport().scrollAnimator().computeDeltaToConsume(pixelDelta);
// Split the remaining delta between scrollable and unscrollable axes of the
// layout viewport. We only pass a delta to the scrollable axes and remember
// how much was held back so we can add it to the unused delta in the
// result.
FloatSize layoutDelta = pixelDelta - visualConsumedDelta;
FloatSize scrollableAxisDelta(
layoutViewport().userInputScrollable(HorizontalScrollbar)
? layoutDelta.width()
: 0,
layoutViewport().userInputScrollable(VerticalScrollbar)
? layoutDelta.height()
: 0);
// If there won't be any scrolling, bail early so we don't produce any side
// effects like cancelling existing animations.
if (visualConsumedDelta.isZero() && scrollableAxisDelta.isZero()) {
return ScrollResult(false, false, pixelDelta.width(), pixelDelta.height());
}
cancelProgrammaticScrollAnimation();
// TODO(bokan): Why do we call userScroll on the animators directly and
// not through the ScrollableAreas?
ScrollResult visualResult = visualViewport().scrollAnimator().userScroll(
granularity, visualConsumedDelta);
if (visualConsumedDelta == pixelDelta)
return visualResult;
ScrollResult layoutResult = layoutViewport().scrollAnimator().userScroll(
granularity, scrollableAxisDelta);
// Remember to add any delta not used because of !userInputScrollable to the
// unusedScrollDelta in the result.
FloatSize unscrollableAxisDelta = layoutDelta - scrollableAxisDelta;
return ScrollResult(
visualResult.didScrollX || layoutResult.didScrollX,
visualResult.didScrollY || layoutResult.didScrollY,
layoutResult.unusedScrollDeltaX + unscrollableAxisDelta.width(),
layoutResult.unusedScrollDeltaY + unscrollableAxisDelta.height());
}