[Android WebView] Add a legacy quirk for 'user-scalable=no' case

Source/web/PageScaleConstraintsSet.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 105 matching lines @@
     else if (description.deprecatedTargetDensityDPI != ViewportDescription::ValueAuto)
         targetDPI = description.deprecatedTargetDensityDPI;
     return targetDPI > 0 ? 160.0f / targetDPI : 1.0f;
 }
 
 static float getLayoutWidthForNonWideViewport(const FloatSize& deviceSize, float initialScale)
 {
     return initialScale == -1 ? deviceSize.width() : deviceSize.width() / initialScale;
 }
 
-void PageScaleConstraintsSet::adjustForAndroidWebViewQuirks(const ViewportDescription& description, IntSize viewSize, int layoutFallbackWidth, float deviceScaleFactor, bool supportTargetDensityDPI, bool wideViewportQuirkEnabled, bool useWideViewport, bool loadWithOverviewMode)
+void PageScaleConstraintsSet::adjustForAndroidWebViewQuirks(const ViewportDescription& description, IntSize viewSize, int layoutFallbackWidth, float deviceScaleFactor, bool supportTargetDensityDPI, bool wideViewportQuirkEnabled, bool useWideViewport, bool loadWithOverviewMode, bool nonUserScalableQuirkEnabled)
 {
-    if (!supportTargetDensityDPI && !wideViewportQuirkEnabled && loadWithOverviewMode)
+    if (!supportTargetDensityDPI && !wideViewportQuirkEnabled && loadWithOverviewMode && !nonUserScalableQuirkEnabled)
         return;
 
     const float oldInitialScale = m_pageDefinedConstraints.initialScale;
     if (!loadWithOverviewMode) {
         bool resetInitialScale = false;
         if (description.zoom == -1) {
             if (description.maxWidth.isAuto())
                 resetInitialScale = true;
             if (useWideViewport || !description.maxWidth.isFixed())
                 resetInitialScale = true;
         }
         if (resetInitialScale)
             m_pageDefinedConstraints.initialScale = 1.0f;
     }
+    if (nonUserScalableQuirkEnabled && !description.userZoom) {
+        m_pageDefinedConstraints.initialScale = 1.0f;
+        m_pageDefinedConstraints.minimumScale = 1.0f;
+        m_pageDefinedConstraints.maximumScale = 1.0f;
+    }
 
     float adjustedLayoutSizeWidth = m_pageDefinedConstraints.layoutSize.width();
     float targetDensityDPIFactor = 1.0f;
 
     if (supportTargetDensityDPI) {
         targetDensityDPIFactor = computeDeprecatedTargetDensityDPIFactor(description, deviceScaleFactor);
         if (m_pageDefinedConstraints.initialScale != -1)
             m_pageDefinedConstraints.initialScale *= targetDensityDPIFactor;
         m_pageDefinedConstraints.minimumScale *= targetDensityDPIFactor;
         m_pageDefinedConstraints.maximumScale *= targetDensityDPIFactor;
         if (wideViewportQuirkEnabled && (!useWideViewport || !description.maxWidth.isFixed()))
             adjustedLayoutSizeWidth /= targetDensityDPIFactor;
     }
 
     if (wideViewportQuirkEnabled) {
-        if (useWideViewport && (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom != 1.0f) {
+        const bool nonUserScalable = nonUserScalableQuirkEnabled && !description.userZoom;
+        if (useWideViewport && (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom != 1.0f && !nonUserScalable) {
             adjustedLayoutSizeWidth = layoutFallbackWidth;
-        } else if (!useWideViewport) {
-            const float nonWideScale = description.zoom < 1 && !description.maxWidth.isViewportPercentage() ? -1 : oldInitialScale;
+        } else if (!useWideViewport || (nonUserScalable && (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom || !description.maxWidth.isFixed()))) {
+            const float nonWideScale = nonUserScalable || (description.zoom < 1 && !description.maxWidth.isViewportPercentage()) ? -1 : oldInitialScale;
             adjustedLayoutSizeWidth = getLayoutWidthForNonWideViewport(viewSize, nonWideScale) / targetDensityDPIFactor;
-            if (description.zoom < 1) {
+            if (nonUserScalable || description.zoom < 1) {
                 m_pageDefinedConstraints.initialScale = targetDensityDPIFactor;
                 m_pageDefinedConstraints.minimumScale = std::min<float>(m_pageDefinedConstraints.minimumScale, m_pageDefinedConstraints.initialScale);
                 m_pageDefinedConstraints.maximumScale = std::max<float>(m_pageDefinedConstraints.maximumScale, m_pageDefinedConstraints.initialScale);
             }
         }
     }
 

[aelias_OOO_until_Jul13, 2013/11/01 23:58:00]

The logic inside wideViewportQuirkEnabled is too tangled.  Could you delete all
the changes above and just have a block at this point that says:

if (nonUserScalableQuirkEnabled) {
    if (!description.userZoom) {
        m_pageDefinedConstraints.initialScale = targetDensityDPIFactor;
        if (description.maxWidth.isAuto() || description.maxWidth.type() ==
ExtendToZoom || !description.maxWidth.isFixed())))
            adjustedLayoutSizeWidth = viewSize.width() / targetDensityDPIFactor;

    }
}

if (!description.userZoom) {
    m_pageDefinedConstraints.minimumScale =
m_pageDefinedConstraints.initialScale;
    m_pageDefinedConstraints.maximumScale =
m_pageDefinedConstraints.initialScale;
}

I think that's equivalent (except that it actually disallows scaling in all
cases with "user-scalable:no" which is a bugfix anyway).

[mnaganov (inactive), 2013/11/05 11:01:38]

OK, thanks for the suggestion! Rewritten.

     if (oldInitialScale != m_pageDefinedConstraints.initialScale && m_pageDefinedConstraints.initialScale != -1)
         setNeedsReset(true);
 
     if (adjustedLayoutSizeWidth != m_pageDefinedConstraints.layoutSize.width()) {
         ASSERT(m_pageDefinedConstraints.layoutSize.width() > 0);
         float adjustedLayoutSizeHeight = (adjustedLayoutSizeWidth * m_pageDefinedConstraints.layoutSize.height()) / m_pageDefinedConstraints.layoutSize.width();
         m_pageDefinedConstraints.layoutSize.setWidth(adjustedLayoutSizeWidth);
         m_pageDefinedConstraints.layoutSize.setHeight(adjustedLayoutSizeHeight);
     }
 }
 
 } // namespace WebCore