C++ (Cpp) ScrollOffset::setX示例

示例#1

void Frame::scrollOverflowLayer(RenderLayer* layer, const IntRect& visibleRect, const IntRect& exposeRect)
{
    if (!layer)
        return;

    RenderBox* box = layer->renderBox();
    if (!box)
        return;

    if (visibleRect.intersects(exposeRect))
        return;

    // FIXME: Why isn't this just calling RenderLayer::scrollRectToVisible()?
    ScrollOffset scrollOffset = layer->scrollOffset();
    int exposeLeft = exposeRect.x();
    int exposeRight = exposeLeft + exposeRect.width();
    int clientWidth = roundToInt(box->clientWidth());
    if (exposeLeft <= 0)
        scrollOffset.setX(std::max(0, scrollOffset.x() + exposeLeft - clientWidth / 2));
    else if (exposeRight >= clientWidth)
        scrollOffset.setX(std::min(box->scrollWidth() - clientWidth, scrollOffset.x() + clientWidth / 2));

    int exposeTop = exposeRect.y();
    int exposeBottom = exposeTop + exposeRect.height();
    int clientHeight = roundToInt(box->clientHeight());
    if (exposeTop <= 0)
        scrollOffset.setY(std::max(0, scrollOffset.y() + exposeTop - clientHeight / 2));
    else if (exposeBottom >= clientHeight)
        scrollOffset.setY(std::min(box->scrollHeight() - clientHeight, scrollOffset.y() + clientHeight / 2));

    layer->scrollToOffset(scrollOffset);
    selection().setCaretRectNeedsUpdate();
    selection().updateAppearance();
}