Clean up handling of autosizing state changes.

Source/core/rendering/FastTextAutosizer.cpp

Index: Source/core/rendering/FastTextAutosizer.cpp
diff --git a/Source/core/rendering/FastTextAutosizer.cpp b/Source/core/rendering/FastTextAutosizer.cpp
index 5cbbf1bd02c399e5b79e4b740fb5611d8b3f28eb..5fda6e47f68ff5c9ad794e1404d1569b00bcae93 100644
--- a/Source/core/rendering/FastTextAutosizer.cpp
+++ b/Source/core/rendering/FastTextAutosizer.cpp
@@ -234,10 +234,11 @@ FastTextAutosizer::FastTextAutosizer(const Document* document)
     , m_frameWidth(0)
     , m_layoutWidth(0)
     , m_baseMultiplier(0)
-    , m_pageAutosizingStatus(PageAutosizingStatusUnknown)
+    , m_pageNeedsAutosizing(false)
+    , m_previouslyAutosized(false)
+    , m_updatePageInfoDeferred(false)
     , m_firstBlock(0)
 #ifndef NDEBUG
-    , m_renderViewInfoPrepared(false)
     , m_blocksThatHaveBegunLayout()
 #endif
     , m_superclusters()
@@ -290,7 +291,7 @@ void FastTextAutosizer::prepareClusterStack(const RenderObject* renderer)
 
 void FastTextAutosizer::beginLayout(RenderBlock* block)
 {
-    ASSERT(enabled() && m_pageAutosizingStatus == PageNeedsAutosizing);
+    ASSERT(enabled() && m_pageNeedsAutosizing);
 #ifndef NDEBUG
     m_blocksThatHaveBegunLayout.add(block);
 #endif
@@ -316,7 +317,7 @@ void FastTextAutosizer::beginLayout(RenderBlock* block)
 
 void FastTextAutosizer::inflateListItem(RenderListItem* listItem, RenderListMarker* listItemMarker)
 {
-    if (!enabled() || m_pageAutosizingStatus != PageNeedsAutosizing)
+    if (!enabled() || !m_pageNeedsAutosizing)
         return;
     ASSERT(listItem && listItemMarker);
 #ifndef NDEBUG
@@ -379,11 +380,10 @@ void FastTextAutosizer::inflateTable(RenderTable* table)
 
 void FastTextAutosizer::endLayout(RenderBlock* block)
 {
-    ASSERT(enabled() && m_pageAutosizingStatus == PageNeedsAutosizing);
+    ASSERT(enabled() && m_pageNeedsAutosizing);
 
     if (block == m_firstBlock) {
         m_firstBlock = 0;
-        m_pageAutosizingStatus = PageAutosizingStatusUnknown;
         m_clusterStack.clear();
         m_superclusters.clear();
 #ifndef NDEBUG
@@ -425,8 +425,28 @@ bool FastTextAutosizer::enabled()
     return m_document->settings()->textAutosizingEnabled();
 }
 
-void FastTextAutosizer::updateRenderViewInfo()
+void FastTextAutosizer::updatePageInfoInAllFrames()
 {
+    if (!enabled())
+        return;
+
+    ASSERT(m_document->frame()->isMainFrame());
+
+    for (LocalFrame* frame = m_document->frame(); frame; frame = frame->tree().traverseNext()) {
+        if (FastTextAutosizer* textAutosizer = frame->document()->fastTextAutosizer())
+            textAutosizer->updatePageInfo();
+    }
+}
+
+void FastTextAutosizer::updatePageInfo()
+{
+    if (!enabled() || m_updatePageInfoDeferred)
+        return;
+
+    int previousFrameWidth = m_frameWidth;
+    int previousLayoutWidth = m_layoutWidth;
+    float previousBaseMultiplier = m_baseMultiplier;
+
     RenderView* renderView = toRenderView(m_document->renderer());
     bool horizontalWritingMode = isHorizontalWritingMode(renderView->style()->writingMode());
 
@@ -448,12 +468,42 @@ void FastTextAutosizer::updateRenderViewInfo()
         m_baseMultiplier *= deviceScaleAdjustment;
     }
 
-    m_pageAutosizingStatus = m_frameWidth && (m_baseMultiplier * (static_cast<float>(m_layoutWidth) / m_frameWidth) > 1.0f)
-        ? PageNeedsAutosizing : PageDoesNotNeedAutosizing;
+    m_pageNeedsAutosizing = !!m_frameWidth
+        && (m_baseMultiplier * (static_cast<float>(m_layoutWidth) / m_frameWidth) > 1.0f);
 
-#ifndef NDEBUG
-    m_renderViewInfoPrepared = true;
-#endif
+    if (!m_pageNeedsAutosizing && m_previouslyAutosized)
+        resetMultipliers();
+
+    if (m_pageNeedsAutosizing
+        && (m_frameWidth != previousFrameWidth
+            || m_layoutWidth != previousLayoutWidth
+            || m_baseMultiplier != previousBaseMultiplier))
+        invalidateMultipliers();
+}
+
+void FastTextAutosizer::resetMultipliers()
+{
+    RenderObject* renderer = m_document->renderer();
+    while (renderer) {
+        if (RenderStyle* style = renderer->style()) {
+            if (style->textAutosizingMultiplier() != 1)
+                applyMultiplier(renderer, 1);

[pdr., 2014/03/24 01:03:18]

Do we need to setNeedsLayout here? Normally, applyMultiplier is called while in
layout where the height changing doesn't matter. When it's called outside of
layout, it can cause the renderobject to need layout because the height can
change.

I suspect applyMultiplier should assert that the renderobject needs layout.

[skobes, 2014/03/25 01:23:24]

You're right, applyMultiplier assumes it is inside layout by using
setStyleInternal instead of setStyle.  I've updated it to take a param to
distinguish this case.

+        }
+        renderer = renderer->nextInPreOrder();
+    }
+    m_previouslyAutosized = false;
+}
+
+void FastTextAutosizer::invalidateMultipliers()

[timvolodine, 2014/03/24 15:24:27]

nit: the name seems a bit confusing, it is not directly clear what the
difference is between invalidateMultipliers and resetMultipliers. maybe
setAllTextNeedsLayout() is a better name?

[skobes, 2014/03/25 01:23:24]

Done.

+{
+    RenderObject* renderer = m_document->renderer();
+    while (renderer) {
+        if (renderer->isText()) {
+            renderer->setNeedsLayout();
+            renderer->parent()->setNeedsLayout();

[pdr., 2014/03/24 01:03:18]

setNeedsLayout already walks up the parent chain so I don't think this parent
one is needed.

[skobes, 2014/03/25 01:23:24]

Done. (This was an unsuccessful initial attempt to fix the line height bug.)

+        }
+        renderer = renderer->nextInPreOrder();
+    }
 }
 
 bool FastTextAutosizer::clusterWouldHaveEnoughTextToAutosize(const RenderBlock* root, const RenderBlock* widthProvider)
@@ -626,7 +676,6 @@ const RenderBlock* FastTextAutosizer::deepestCommonAncestor(BlockSet& blocks)
 
 float FastTextAutosizer::clusterMultiplier(Cluster* cluster)
 {
-    ASSERT(m_renderViewInfoPrepared);
     if (!cluster->m_multiplier) {
         if (cluster->m_root->isTable()
             || isIndependentDescendant(cluster->m_root)
@@ -807,6 +856,9 @@ void FastTextAutosizer::applyMultiplier(RenderObject* renderer, float multiplier
     style->setTextAutosizingMultiplier(multiplier);
     style->setUnique();
     renderer->setStyleInternal(style.release());
+
+    if (multiplier != 1)
+        m_previouslyAutosized = true;
 }
 
 bool FastTextAutosizer::isWiderOrNarrowerDescendant(Cluster* cluster)
@@ -917,15 +969,7 @@ FastTextAutosizer::LayoutScope::LayoutScope(RenderBlock* block)
     if (!m_textAutosizer)
         return;
 
-    if (!m_textAutosizer->enabled()) {
-        m_textAutosizer = 0;
-        return;
-    }
-
-    if (m_textAutosizer->m_pageAutosizingStatus == PageAutosizingStatusUnknown)
-        m_textAutosizer->updateRenderViewInfo();
-
-    if (m_textAutosizer->m_pageAutosizingStatus == PageNeedsAutosizing)
+    if (m_textAutosizer->enabled() && m_textAutosizer->m_pageNeedsAutosizing)
         m_textAutosizer->beginLayout(m_block);
     else
         m_textAutosizer = 0;