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 f1195baa9161fcfc5566801607b1cfdc9a0dd18a..be15bc3e36036063f654f749d86308408a57f604 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 +468,43 @@ 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 we are no longer autosizing the page, we won't do anything during the next layout.
+    // Set all the multipliers back to 1 now.
+    if (!m_pageNeedsAutosizing && m_previouslyAutosized)
+        resetMultipliers();
+
+    // If page info has changed, multipliers may have changed. Force a layout to recompute them.
+    if (m_pageNeedsAutosizing
+        && (m_frameWidth != previousFrameWidth
+            || m_layoutWidth != previousLayoutWidth
+            || m_baseMultiplier != previousBaseMultiplier))
+        setAllTextNeedsLayout();
+}
+
+void FastTextAutosizer::resetMultipliers()
+{
+    RenderObject* renderer = m_document->renderer();
+    while (renderer) {
+        if (RenderStyle* style = renderer->style()) {
+            if (style->textAutosizingMultiplier() != 1)
+                applyMultiplier(renderer, 1, true /* relayout */);
+        }
+        renderer = renderer->nextInPreOrder();
+    }
+    m_previouslyAutosized = false;
+}
+
+void FastTextAutosizer::setAllTextNeedsLayout()
+{
+    RenderObject* renderer = m_document->renderer();
+    while (renderer) {
+        if (renderer->isText())
+            renderer->setNeedsLayout();
+        renderer = renderer->nextInPreOrder();
+    }
 }
 
 bool FastTextAutosizer::clusterWouldHaveEnoughTextToAutosize(const RenderBlock* root, const RenderBlock* widthProvider)
@@ -621,7 +672,6 @@ 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)
@@ -790,7 +840,7 @@ const RenderObject* FastTextAutosizer::findTextLeaf(const RenderObject* parent,
     return 0;
 }
 
-void FastTextAutosizer::applyMultiplier(RenderObject* renderer, float multiplier)
+void FastTextAutosizer::applyMultiplier(RenderObject* renderer, float multiplier, bool relayout)
 {
     ASSERT(renderer);
     RenderStyle* currentStyle = renderer->style();
@@ -801,10 +851,17 @@ void FastTextAutosizer::applyMultiplier(RenderObject* renderer, float multiplier
     RefPtr<RenderStyle> style = RenderStyle::clone(currentStyle);
     style->setTextAutosizingMultiplier(multiplier);
     style->setUnique();
-    renderer->setStyleInternal(style.release());
 
-    if (renderer->isRenderBlock())
-        toRenderBlock(renderer)->invalidateLineHeight();
+    if (relayout) {
+        renderer->setStyle(style.release());

[pdr., 2014/03/25 04:23:41]

This can cause us to go back through quite a bit of extra code, including
styleDidChange and FTA::record. Is that intended?

I expected this to just setNeedsLayout or adjust the layout triggers in
RenderStyle.

[skobes, 2014/03/25 18:25:26]

There's no way for setStyleInternal to trigger a layout, it's literally just
setting a RefPtr.

We could setNeedsLayout manually but it seems safer to use setStyle when we are
touching style outside of layout.  That way RenderObject is responsible for the
logic to mark the block as needing layout.  For example, setStyle will mark the
pref widths dirty.  FTA has some issues with pref widths, but at least we can
make sure they are correct when we resetMultipliers. :)

Also note that the old autosizer does all multiplier changes with setStyle.

+    } else {
+        renderer->setStyleInternal(style.release());
+        if (renderer->isRenderBlock())
+            toRenderBlock(renderer)->invalidateLineHeight();

[pdr., 2014/03/25 04:23:41]

Is this lineheight change supposed to be part of this patch?

[skobes, 2014/03/25 18:25:26]

This patch is branched from the lineheight change.

+    }
+
+    if (multiplier != 1)
+        m_previouslyAutosized = true;
 }
 
 bool FastTextAutosizer::isWiderOrNarrowerDescendant(Cluster* cluster)
@@ -915,15 +972,7 @@ 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;