[FastTextAutosizer] Incorporate accessibility and device scale factors

Source/core/rendering/FastTextAutosizer.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 29 matching lines @@
 #include "core/rendering/RenderBlock.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/TextAutosizer.h"
 
 using namespace std;
 
 namespace WebCore {
 
 FastTextAutosizer::FastTextAutosizer(Document* document)
     : m_document(document)
+#ifndef NDEBUG
+    , m_renderViewInfoPrepared(false)
+#endif
 {
 }
 
 void FastTextAutosizer::record(RenderBlock* block)
 {
     if (!enabled())
         return;
 
     if (!shouldBeClusterRoot(block))
         return;
 
     AtomicString fingerprint = computeFingerprint(block);
     if (fingerprint.isNull())
         return;
 
     m_fingerprintMapper.add(block, fingerprint);
 }
 
 void FastTextAutosizer::destroy(RenderBlock* block)
 {
     m_fingerprintMapper.remove(block);
 }
 
 void FastTextAutosizer::beginLayout(RenderBlock* block)
 {
     if (!enabled())
         return;
 
     if (block->isRenderView())
-        prepareWindowInfo(toRenderView(block));
+        prepareRenderViewInfo(toRenderView(block));
 
     if (shouldBeClusterRoot(block))
         m_clusterStack.append(getOrCreateCluster(block));
 }
 
 void FastTextAutosizer::inflate(RenderBlock* block)
 {
     if (m_clusterStack.isEmpty())
         return;
     Cluster* cluster = m_clusterStack.last();
@@ skipping 21 matching lines @@
 }
 
 bool FastTextAutosizer::enabled()
 {
     return m_document->settings()
         && m_document->settings()->textAutosizingEnabled()
         && !m_document->printing()
         && m_document->page();
 }
 
-void FastTextAutosizer::prepareWindowInfo(RenderView* renderView)
+void FastTextAutosizer::prepareRenderViewInfo(RenderView* renderView)
 {
     bool horizontalWritingMode = isHorizontalWritingMode(renderView->style()->writingMode());
 
     Frame* mainFrame = m_document->page()->mainFrame();
     IntSize windowSize = m_document->settings()->textAutosizingWindowSizeOverride();
     if (windowSize.isEmpty())
         windowSize = mainFrame->view()->unscaledVisibleContentSize(ScrollableArea::IncludeScrollbars);
     m_windowWidth = horizontalWritingMode ? windowSize.width() : windowSize.height();
 
     IntSize layoutSize = m_document->page()->mainFrame()->view()->layoutSize();
     m_layoutWidth = horizontalWritingMode ? layoutSize.width() : layoutSize.height();
+
+    // Compute the base font scale multiplier based on device and accessibility settings.
+    m_baseMultiplier = m_document->settings()->accessibilityFontScaleFactor();
+    // If the page has a meta viewport or @viewport, don't apply the device scale adjustment.
+    const ViewportDescription& viewportDescription = m_document->page()->mainFrame()->document()->viewportDescription();
+    if (!viewportDescription.isSpecifiedByAuthor())
+        m_baseMultiplier *= m_document->settings()->deviceScaleAdjustment();
+#ifndef NDEBUG
+    m_renderViewInfoPrepared = true;
+#endif
 }
 
 bool FastTextAutosizer::shouldBeClusterRoot(RenderBlock* block)
 {
     // FIXME: move the logic out of TextAutosizer.cpp into this class.
     return block->isRenderView()
         || (TextAutosizer::isAutosizingContainer(block)
             && TextAutosizer::isIndependentDescendant(block));
 }
 
@@ skipping 63 matching lines @@
             if (ancestors.count(block) == blocks.size())
                 return block;
         }
     }
     ASSERT_NOT_REACHED();
     return 0;
 }
 
 float FastTextAutosizer::computeMultiplier(RenderBlock* block)
 {
+#ifndef NDEBUG
+    ASSERT(m_renderViewInfoPrepared);
+#endif
     // Block width, in CSS pixels.
     float blockWidth = block->contentLogicalWidth();
 
-    // FIXME(crbug.com/333124): incorporate font scale factor.
-    // FIXME(crbug.com/333124): incorporate device scale adjustment.
-    return max(min(blockWidth, (float) m_layoutWidth) / m_windowWidth, 1.0f);
+    float multiplier = min(blockWidth, static_cast<float>(m_layoutWidth)) / m_windowWidth;
+    return max(m_baseMultiplier * multiplier, 1.0f);
 }
 
 void FastTextAutosizer::applyMultiplier(RenderObject* renderer, float multiplier)
 {
     RenderStyle* currentStyle = renderer->style();
     if (currentStyle->textAutosizingMultiplier() == multiplier)
         return;
 
     // We need to clone the render style to avoid breaking style sharing.
     RefPtr<RenderStyle> style = RenderStyle::clone(currentStyle);
@@ skipping 29 matching lines @@
 {
     return m_fingerprints.get(block);
 }
 
 FastTextAutosizer::BlockSet& FastTextAutosizer::FingerprintMapper::getBlocks(AtomicString fingerprint)
 {
     return *m_blocksForFingerprint.get(fingerprint);
 }
 
 } // namespace WebCore