Move viewport unit resolution to style recalc time

Source/core/rendering/RenderView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 302 matching lines @@
     bool relayoutChildren = !shouldUsePrintingLayout() && (!m_frameView || width() != viewWidth() || height() != viewHeight());
     if (relayoutChildren) {
         layoutScope.setChildNeedsLayout(this);
         for (RenderObject* child = firstChild(); child; child = child->nextSibling()) {
             if (child->isSVGRoot())
                 continue;
 
             if ((child->isBox() && toRenderBox(child)->hasRelativeLogicalHeight())
                     || child->style()->logicalHeight().isPercent()
                     || child->style()->logicalMinHeight().isPercent()
-                    || child->style()->logicalMaxHeight().isPercent()
-                    || child->style()->logicalHeight().isViewportPercentage()
-                    || child->style()->logicalMinHeight().isViewportPercentage()
-                    || child->style()->logicalMaxHeight().isViewportPercentage())
+                    || child->style()->logicalMaxHeight().isPercent())
                 layoutScope.setChildNeedsLayout(child);
         }
 
         if (document().svgExtensions())
             document().accessSVGExtensions()->invalidateSVGRootsWithRelativeLengthDescendents(&layoutScope);
     }
 
     ASSERT(!m_layoutState);
     if (!needsLayout())
         return;
@@ skipping 869 matching lines @@
 
 bool RenderView::backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const
 {
     // FIXME: Remove this main frame check. Same concept applies to subframes too.
     if (!m_frameView || !m_frameView->isMainFrame())
         return false;
 
     return m_frameView->hasOpaqueBackground();
 }
 
-LayoutUnit RenderView::viewportPercentageWidth(float percentage) const
+double RenderView::viewportWidthPercent() const

[johnme, 2013/12/18 12:04:15]

1. This doesn't seem to return a percentage?

2. Is this the initial viewport (window width in DIPs, affected only by page
zoom), layout viewport (also affected by @viewport and meta viewport) or actual
viewport (also affected by pinch zoom)? Since viewWidth uses
FrameView::layoutSize, which is set by WebViewImpl::setFixedLayoutSize, it seems
that this is probably the layout viewport size.

Consider renaming this to layoutViewportWidth (similarly below, and in
CSSToLengthConversionData).

[Timothy Loh, 2013/12/23 06:28:16]

See comment (message) above.

 {
-    return viewLogicalWidth(ScrollableArea::IncludeScrollbars) * percentage / 100.f;
+    float scale = m_frameView ? m_frameView->frame().pageZoomFactor() : 1;
+    return viewWidth(ScrollableArea::IncludeScrollbars) / scale / 100.f;

[johnme, 2013/12/18 12:04:15]

According to http://www.w3.org/TR/css3-values/#viewport-relative-lengths, vw et
al are relative to the size of the initial containing block, whose "size is
affected by the presence of scrollbars on the viewport". Since the size depends
on the presence of scrollbars, shouldn't this be using ExcludeScrollbars
instead?

[Timothy Loh, 2013/12/23 06:28:16]

Possibly; but that would have to be a separate patch (I'm just trying to move
resolution to style time in this patch).

 }
 
-LayoutUnit RenderView::viewportPercentageHeight(float percentage) const
+double RenderView::viewportHeightPercent() const
 {
-    return viewLogicalHeight(ScrollableArea::IncludeScrollbars) * percentage / 100.f;
+    float scale = m_frameView ? m_frameView->frame().pageZoomFactor() : 1;
+    return viewHeight(ScrollableArea::IncludeScrollbars) / scale / 100.f;
 }
 
-LayoutUnit RenderView::viewportPercentageMin(float percentage) const
+double RenderView::viewportMinPercent() const
 {
-    return std::min(viewLogicalWidth(ScrollableArea::IncludeScrollbars), viewLogicalHeight(ScrollableArea::IncludeScrollbars))
-        * percentage / 100.f;
+    return std::min(viewportWidthPercent(), viewportHeightPercent());
 }
 
-LayoutUnit RenderView::viewportPercentageMax(float percentage) const
+double RenderView::viewportMaxPercent() const
 {
-    return std::max(viewLogicalWidth(ScrollableArea::IncludeScrollbars), viewLogicalHeight(ScrollableArea::IncludeScrollbars))
-        * percentage / 100.f;
+    return std::max(viewportWidthPercent(), viewportHeightPercent());
 }
 
 FragmentationDisabler::FragmentationDisabler(RenderObject* root)
 {
     RenderView* renderView = root->view();
     ASSERT(renderView);
 
     LayoutState* layoutState = renderView->layoutState();
 
     m_root = root;
@@ skipping 21 matching lines @@
 #endif
 
     if (layoutState)
         layoutState->m_isPaginated = m_fragmenting;
 
     if (m_flowThreadState != RenderObject::NotInsideFlowThread)
         m_root->setFlowThreadStateIncludingDescendants(m_flowThreadState);
 }
 
 } // namespace WebCore