1 files changed, 29 insertions, 98 deletions

diff --git a/Source/WebCore/rendering/LayoutState.cpp b/Source/WebCore/rendering/LayoutState.cpp
index bed4756e2..fc80183ec 100644
--- a/Source/WebCore/rendering/LayoutState.cpp
+++ b/Source/WebCore/rendering/LayoutState.cpp
@@ -26,21 +26,16 @@
 #include "config.h"
 #include "LayoutState.h"
 
-#include "ColumnInfo.h"
 #include "RenderFlowThread.h"
 #include "RenderInline.h"
 #include "RenderLayer.h"
+#include "RenderMultiColumnFlowThread.h"
 #include "RenderView.h"
 
 namespace WebCore {
 
-LayoutState::LayoutState(std::unique_ptr<LayoutState> next, RenderBox* renderer, const LayoutSize& offset, LayoutUnit pageLogicalHeight, bool pageLogicalHeightChanged, ColumnInfo* columnInfo)
-    : m_columnInfo(columnInfo)
-    , m_lineGrid(0)
-    , m_next(std::move(next))
-#if ENABLE(CSS_SHAPES)
-    , m_shapeInsideInfo(nullptr)
-#endif
+LayoutState::LayoutState(std::unique_ptr<LayoutState> next, RenderBox* renderer, const LayoutSize& offset, LayoutUnit pageLogicalHeight, bool pageLogicalHeightChanged)
+    : m_next(WTFMove(next))
 #ifndef NDEBUG
     , m_renderer(renderer)
 #endif
@@ -57,8 +52,8 @@ LayoutState::LayoutState(std::unique_ptr<LayoutState> next, RenderBox* renderer,
 
     if (renderer->isOutOfFlowPositioned() && !fixed) {
         if (RenderElement* container = renderer->container()) {
-            if (container->isInFlowPositioned() && container->isRenderInline())
-                m_paintOffset += toRenderInline(container)->offsetForInFlowPositionedInline(renderer);
+            if (container->isInFlowPositioned() && is<RenderInline>(*container))
+                m_paintOffset += downcast<RenderInline>(*container).offsetForInFlowPositionedInline(renderer);
         }
     }
 
@@ -72,7 +67,7 @@ LayoutState::LayoutState(std::unique_ptr<LayoutState> next, RenderBox* renderer,
         m_clipRect = m_next->m_clipRect;
 
     if (renderer->hasOverflowClip()) {
-        LayoutRect clipRect(toPoint(m_paintOffset) + renderer->view().layoutDelta(), renderer->cachedSizeForOverflowClip());
+        LayoutRect clipRect(toLayoutPoint(m_paintOffset) + renderer->view().layoutDelta(), renderer->cachedSizeForOverflowClip());
         if (m_clipped)
             m_clipRect.intersect(clipRect);
         else {
@@ -80,17 +75,18 @@ LayoutState::LayoutState(std::unique_ptr<LayoutState> next, RenderBox* renderer,
             m_clipped = true;
         }
 
-        m_paintOffset -= renderer->scrolledContentOffset();
+        m_paintOffset -= toLayoutSize(renderer->scrollPosition());
     }
 
     // If we establish a new page height, then cache the offset to the top of the first page.
     // We can compare this later on to figure out what part of the page we're actually on,
-    if (pageLogicalHeight || m_columnInfo || renderer->isRenderFlowThread()) {
+    if (pageLogicalHeight || renderer->isRenderFlowThread()) {
         m_pageLogicalHeight = pageLogicalHeight;
         bool isFlipped = renderer->style().isFlippedBlocksWritingMode();
         m_pageOffset = LayoutSize(m_layoutOffset.width() + (!isFlipped ? renderer->borderLeft() + renderer->paddingLeft() : renderer->borderRight() + renderer->paddingRight()),
                                m_layoutOffset.height() + (!isFlipped ? renderer->borderTop() + renderer->paddingTop() : renderer->borderBottom() + renderer->paddingBottom()));
         m_pageLogicalHeightChanged = pageLogicalHeightChanged;
+        m_isPaginated = true;
     } else {
         // If we don't establish a new page height, then propagate the old page height and offset down.
         m_pageLogicalHeight = m_next->m_pageLogicalHeight;
@@ -99,39 +95,28 @@ LayoutState::LayoutState(std::unique_ptr<LayoutState> next, RenderBox* renderer,
         
         // Disable pagination for objects we don't support. For now this includes overflow:scroll/auto, inline blocks and
         // writing mode roots.
-        if (renderer->isUnsplittableForPagination())
+        if (renderer->isUnsplittableForPagination()) {
             m_pageLogicalHeight = 0;
+            m_isPaginated = false;
+        } else
+            m_isPaginated = m_pageLogicalHeight || renderer->flowThreadContainingBlock();
     }
     
     // Propagate line grid information.
     propagateLineGridInfo(renderer);
 
-    if (!m_columnInfo)
-        m_columnInfo = m_next->m_columnInfo;
-
-#if ENABLE(CSS_SHAPES)
-    if (renderer->isRenderBlock()) {
-        const RenderBlock* renderBlock = toRenderBlock(renderer);
-        m_shapeInsideInfo = renderBlock->shapeInsideInfo();
-        if (!m_shapeInsideInfo && m_next->m_shapeInsideInfo && renderBlock->allowsShapeInsideInfoSharing())
-            m_shapeInsideInfo = m_next->m_shapeInsideInfo;
-    }
-#endif
-
     m_layoutDelta = m_next->m_layoutDelta;
-#if !ASSERT_DISABLED && ENABLE(SATURATED_LAYOUT_ARITHMETIC)
+#if !ASSERT_DISABLED
     m_layoutDeltaXSaturated = m_next->m_layoutDeltaXSaturated;
     m_layoutDeltaYSaturated = m_next->m_layoutDeltaYSaturated;
 #endif
-    
-    m_isPaginated = m_pageLogicalHeight || m_columnInfo || renderer->isRenderFlowThread();
 
-    if (lineGrid() && renderer->hasColumns() && renderer->style().hasInlineColumnAxis())
-        computeLineGridPaginationOrigin(renderer);
+    if (lineGrid() && (lineGrid()->style().writingMode() == renderer->style().writingMode()) && is<RenderMultiColumnFlowThread>(*renderer))
+        downcast<RenderMultiColumnFlowThread>(*renderer).computeLineGridPaginationOrigin(*this);
 
     // If we have a new grid to track, then add it to our set.
-    if (renderer->style().lineGrid() != RenderStyle::initialLineGrid() && renderer->isRenderBlockFlow())
-        establishLineGrid(toRenderBlockFlow(renderer));
+    if (renderer->style().lineGrid() != RenderStyle::initialLineGrid() && is<RenderBlockFlow>(*renderer))
+        establishLineGrid(downcast<RenderBlockFlow>(renderer));
 
     // FIXME: <http://bugs.webkit.org/show_bug.cgi?id=13443> Apply control clip if present.
 }
@@ -140,36 +125,31 @@ LayoutState::LayoutState(RenderObject& root)
     : m_clipped(false)
     , m_isPaginated(false)
     , m_pageLogicalHeightChanged(false)
-#if !ASSERT_DISABLED && ENABLE(SATURATED_LAYOUT_ARITHMETIC)
+#if !ASSERT_DISABLED
     , m_layoutDeltaXSaturated(false)
     , m_layoutDeltaYSaturated(false)
 #endif    
-    , m_columnInfo(0)
-    , m_lineGrid(0)
-#if ENABLE(CSS_SHAPES)
-    , m_shapeInsideInfo(nullptr)
-#endif
-    , m_pageLogicalHeight(0)
 #ifndef NDEBUG
     , m_renderer(&root)
 #endif
 {
-    RenderElement* container = root.container();
-    FloatPoint absContentPoint = container->localToAbsolute(FloatPoint(), UseTransforms);
-    m_paintOffset = LayoutSize(absContentPoint.x(), absContentPoint.y());
+    if (RenderElement* container = root.container()) {
+        FloatPoint absContentPoint = container->localToAbsolute(FloatPoint(), UseTransforms);
+        m_paintOffset = LayoutSize(absContentPoint.x(), absContentPoint.y());
 
-    if (container->hasOverflowClip()) {
-        m_clipped = true;
-        RenderBox* containerBox = toRenderBox(container);
-        m_clipRect = LayoutRect(toPoint(m_paintOffset), containerBox->cachedSizeForOverflowClip());
-        m_paintOffset -= containerBox->scrolledContentOffset();
+        if (container->hasOverflowClip()) {
+            m_clipped = true;
+            auto& containerBox = downcast<RenderBox>(*container);
+            m_clipRect = LayoutRect(toLayoutPoint(m_paintOffset), containerBox.cachedSizeForOverflowClip());
+            m_paintOffset -= toLayoutSize(containerBox.scrollPosition());
+        }
     }
 }
+
 void LayoutState::clearPaginationInformation()
 {
     m_pageLogicalHeight = m_next->m_pageLogicalHeight;
     m_pageOffset = m_next->m_pageOffset;
-    m_columnInfo = m_next->m_columnInfo;
 }
 
 LayoutUnit LayoutState::pageLogicalOffset(RenderBox* child, LayoutUnit childLogicalOffset) const
@@ -179,13 +159,6 @@ LayoutUnit LayoutState::pageLogicalOffset(RenderBox* child, LayoutUnit childLogi
     return m_layoutOffset.width() + childLogicalOffset - m_pageOffset.width();
 }
 
-void LayoutState::addForcedColumnBreak(RenderBox* child, LayoutUnit childLogicalOffset)
-{
-    if (!m_columnInfo || m_columnInfo->columnHeight())
-        return;
-    m_columnInfo->addForcedBreak(pageLogicalOffset(child, childLogicalOffset));
-}
-
 void LayoutState::propagateLineGridInfo(RenderBox* renderer)
 {
     // Disable line grids for objects we don't support. For now this includes overflow:scroll/auto, inline blocks and
@@ -224,46 +197,4 @@ void LayoutState::establishLineGrid(RenderBlockFlow* block)
     m_lineGridOffset = m_layoutOffset; 
 }
 
-void LayoutState::computeLineGridPaginationOrigin(RenderBox* renderer)
-{
-    // We need to cache a line grid pagination origin so that we understand how to reset the line grid
-    // at the top of each column.
-    // Get the current line grid and offset.
-    if (!lineGrid() || lineGrid()->style().writingMode() != renderer->style().writingMode())
-        return;
-
-    // Get the hypothetical line box used to establish the grid.
-    RootInlineBox* lineGridBox = lineGrid()->lineGridBox();
-    if (!lineGridBox)
-        return;
-    
-    bool isHorizontalWritingMode = lineGrid()->isHorizontalWritingMode();
-
-    LayoutUnit lineGridBlockOffset = isHorizontalWritingMode ? lineGridOffset().height() : lineGridOffset().width();
-
-    // Now determine our position on the grid. Our baseline needs to be adjusted to the nearest baseline multiple
-    // as established by the line box.
-    // FIXME: Need to handle crazy line-box-contain values that cause the root line box to not be considered. I assume
-    // the grid should honor line-box-contain.
-    LayoutUnit gridLineHeight = lineGridBox->lineBottomWithLeading() - lineGridBox->lineTopWithLeading();
-    if (!gridLineHeight)
-        return;
-
-    LayoutUnit firstLineTopWithLeading = lineGridBlockOffset + lineGridBox->lineTopWithLeading();
-    
-    if (isPaginated() && pageLogicalHeight()) {
-        LayoutUnit pageLogicalTop = renderer->isHorizontalWritingMode() ? m_pageOffset.height() : m_pageOffset.width();
-        if (pageLogicalTop > firstLineTopWithLeading) {
-            // Shift to the next highest line grid multiple past the page logical top. Cache the delta
-            // between this new value and the page logical top as the pagination origin.
-            LayoutUnit remainder = roundToInt(pageLogicalTop - firstLineTopWithLeading) % roundToInt(gridLineHeight);
-            LayoutUnit paginationDelta = gridLineHeight - remainder;
-            if (isHorizontalWritingMode)
-                m_lineGridPaginationOrigin.setHeight(paginationDelta);
-            else
-                m_lineGridPaginationOrigin.setWidth(paginationDelta);
-        }
-    }
-}
-
 } // namespace WebCore