Translate viewport related meta tags into @viewport descriptors as suggested by the CSS Device Adap…

Source/core/dom/ViewportArguments.cpp

Index: Source/core/dom/ViewportArguments.cpp
diff --git a/Source/core/dom/ViewportArguments.cpp b/Source/core/dom/ViewportArguments.cpp
index d6a56f98c46bba374558a2660e04ae2d3157e406..23cb1d2ec7eff392527eda560b7c125d1bcb36dc 100644
--- a/Source/core/dom/ViewportArguments.cpp
+++ b/Source/core/dom/ViewportArguments.cpp
@@ -6,7 +6,7 @@
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
- * Copyright (C) 2012 Intel Corporation. All rights reserved.
+ * Copyright (C) 2012-2013 Intel Corporation. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -37,8 +37,6 @@ namespace WebCore {
 
 static const float& compareIgnoringAuto(const float& value1, const float& value2, const float& (*compare) (const float&, const float&))
 {
-    ASSERT(value1 != ViewportArguments::ValueAuto || value2 != ViewportArguments::ValueAuto);
-
     if (value1 == ViewportArguments::ValueAuto)
         return value2;
 
@@ -48,354 +46,95 @@ static const float& compareIgnoringAuto(const float& value1, const float& value2
     return compare(value1, value2);
 }
 
-static inline float clampLengthValue(float value)
-{
-    ASSERT(value != ViewportArguments::ValueDeviceWidth);
-    ASSERT(value != ViewportArguments::ValueDeviceHeight);
-
-    // Limits as defined in the css-device-adapt spec.
-    if (value != ViewportArguments::ValueAuto)
-        return min(float(10000), max(value, float(1)));
-    return value;
-}
-
-static inline float clampScaleValue(float value)
+PageScaleConstraints ViewportArguments::resolve(const FloatSize& initialViewportSize) const
 {
-    ASSERT(value != ViewportArguments::ValueDeviceWidth);
-    ASSERT(value != ViewportArguments::ValueDeviceHeight);
-
-    // Limits as defined in the css-device-adapt spec.
-    if (value != ViewportArguments::ValueAuto)
-        return min(float(10), max(value, float(0.1)));
-    return value;
-}
-
-PageScaleConstraints ViewportArguments::resolve(const FloatSize& initialViewportSize, const FloatSize& deviceSize, int defaultWidth) const
-{
-    float resultWidth = width;
+    float resultWidth = ViewportArguments::ValueAuto;
     float resultMaxWidth = maxWidth;
     float resultMinWidth = minWidth;
-    float resultHeight = height;
+
+    float resultHeight = ViewportArguments::ValueAuto;
     float resultMinHeight = minHeight;
     float resultMaxHeight = maxHeight;
+
     float resultZoom = zoom;
     float resultMinZoom = minZoom;
     float resultMaxZoom = maxZoom;
     float resultUserZoom = userZoom;
 
-    switch (int(resultWidth)) {
-    case ViewportArguments::ValueDeviceWidth:
-        resultWidth = deviceSize.width();
-        break;
-    case ViewportArguments::ValueDeviceHeight:
-        resultWidth = deviceSize.height();
-        break;
-    }
+    // 1. Resolve min-zoom and max-zoom values.
+    if (resultMinZoom != ViewportArguments::ValueAuto && resultMaxZoom != ViewportArguments::ValueAuto)
+        resultMaxZoom = max(resultMinZoom, resultMaxZoom);
 
-    switch (int(resultHeight)) {
-    case ViewportArguments::ValueDeviceWidth:
-        resultHeight = deviceSize.width();
-        break;
-    case ViewportArguments::ValueDeviceHeight:
-        resultHeight = deviceSize.height();
-        break;
-    }
+    // 2. Constrain zoom value to the [min-zoom, max-zoom] range.
+    if (resultZoom != ViewportArguments::ValueAuto)
+        resultZoom = compareIgnoringAuto(resultMinZoom, compareIgnoringAuto(resultMaxZoom, resultZoom, min), max);
 
-    if (type == ViewportArguments::CSSDeviceAdaptation) {
+    float extendZoom = compareIgnoringAuto(resultZoom, resultMaxZoom, min);
 
-        // device-width/device-height not supported for @viewport.
-        ASSERT(resultMinWidth != ViewportArguments::ValueDeviceWidth);
-        ASSERT(resultMinWidth != ViewportArguments::ValueDeviceHeight);
-        ASSERT(resultMaxWidth != ViewportArguments::ValueDeviceWidth);
-        ASSERT(resultMaxWidth != ViewportArguments::ValueDeviceHeight);
-        ASSERT(resultMinHeight != ViewportArguments::ValueDeviceWidth);
-        ASSERT(resultMinHeight != ViewportArguments::ValueDeviceHeight);
-        ASSERT(resultMaxHeight != ViewportArguments::ValueDeviceWidth);
-        ASSERT(resultMaxHeight != ViewportArguments::ValueDeviceHeight);
+    // 3. Resolve non-"auto" lengths to pixel lengths.
+    if (extendZoom == ViewportArguments::ValueAuto) {
+        if (resultMaxWidth == ViewportArguments::ValueExtendToZoom)
+            resultMaxWidth = ViewportArguments::ValueAuto;
 
-        if (resultMinWidth != ViewportArguments::ValueAuto || resultMaxWidth != ViewportArguments::ValueAuto)
-            resultWidth = compareIgnoringAuto(resultMinWidth, compareIgnoringAuto(resultMaxWidth, initialViewportSize.width(), min), max);
+        if (resultMaxHeight == ViewportArguments::ValueExtendToZoom)
+            resultMaxHeight = ViewportArguments::ValueAuto;
 
-        if (resultMinHeight != ViewportArguments::ValueAuto || resultMaxHeight != ViewportArguments::ValueAuto)
-            resultHeight = compareIgnoringAuto(resultMinHeight, compareIgnoringAuto(resultMaxHeight, initialViewportSize.height(), min), max);
+        if (resultMinWidth == ViewportArguments::ValueExtendToZoom)
+            resultMinWidth = resultMaxWidth;
 
-        if (resultMinZoom != ViewportArguments::ValueAuto && resultMaxZoom != ViewportArguments::ValueAuto)
-            resultMaxZoom = max(resultMinZoom, resultMaxZoom);
+        if (resultMinHeight == ViewportArguments::ValueExtendToZoom)
+            resultMinHeight = resultMaxHeight;
+    } else {
+        float extendWidth = initialViewportSize.width() / extendZoom;
+        float extendHeight = initialViewportSize.height() / extendZoom;
 
-        if (resultZoom != ViewportArguments::ValueAuto)
-            resultZoom = compareIgnoringAuto(resultMinZoom, compareIgnoringAuto(resultMaxZoom, resultZoom, min), max);
+        if (resultMaxWidth == ViewportArguments::ValueExtendToZoom)
+            resultMaxWidth = extendWidth;
 
-        if (resultWidth == ViewportArguments::ValueAuto && (resultHeight == ViewportArguments::ValueAuto || !initialViewportSize.height()))
-            resultWidth = initialViewportSize.width();
+        if (resultMaxHeight == ViewportArguments::ValueExtendToZoom)
+            resultMaxHeight = extendHeight;
 
-        if (resultWidth == ViewportArguments::ValueAuto) {
-            ASSERT(initialViewportSize.height()); // If height is 0, resultWidth should be resolved above.
-            resultWidth = resultHeight * initialViewportSize.width() / initialViewportSize.height();
-        }
-
-        if (resultHeight == ViewportArguments::ValueAuto) {
-            if (!initialViewportSize.width())
-                resultHeight = initialViewportSize.height();
-            else
-                resultHeight = resultWidth * initialViewportSize.height() / initialViewportSize.width();
-        }
-    }
+        if (resultMinWidth == ViewportArguments::ValueExtendToZoom)
+            resultMinWidth = compareIgnoringAuto(extendWidth, resultMaxWidth, max);
 
-    if (type != ViewportArguments::CSSDeviceAdaptation && type != ViewportArguments::Implicit) {
-        // Clamp values to a valid range, but not for @viewport since is
-        // not mandated by the specification.
-        resultWidth = clampLengthValue(resultWidth);
-        resultHeight = clampLengthValue(resultHeight);
-        resultZoom = clampScaleValue(resultZoom);
-        resultMinZoom = clampScaleValue(resultMinZoom);
-        resultMaxZoom = clampScaleValue(resultMaxZoom);
+        if (resultMinHeight == ViewportArguments::ValueExtendToZoom)
+            resultMinHeight = compareIgnoringAuto(extendHeight, resultMaxHeight, max);
     }
 
-    PageScaleConstraints result;
-
-    // Resolve minimum-scale and maximum-scale values according to spec.
-    if (resultMinZoom == ViewportArguments::ValueAuto)
-        result.minimumScale = float(0.25);
-    else
-        result.minimumScale = resultMinZoom;
-
-    if (resultMaxZoom == ViewportArguments::ValueAuto) {
-        result.maximumScale = float(5.0);
-        result.minimumScale = min(float(5.0), result.minimumScale);
-    } else
-        result.maximumScale = resultMaxZoom;
-    result.maximumScale = max(result.minimumScale, result.maximumScale);
+    // 4. Resolve initial width from min/max descriptors.
+    if (resultMinWidth != ViewportArguments::ValueAuto || resultMaxWidth != ViewportArguments::ValueAuto)
+        resultWidth = compareIgnoringAuto(resultMinWidth, compareIgnoringAuto(resultMaxWidth, initialViewportSize.width(), min), max);
 
-    // Resolve initial-scale value.
-    result.initialScale = resultZoom;
-    if (resultZoom == ViewportArguments::ValueAuto) {
-        result.initialScale = initialViewportSize.width() / defaultWidth;
-        if (resultWidth != ViewportArguments::ValueAuto && resultWidth > 0)
-            result.initialScale = initialViewportSize.width() / resultWidth;
-        if (resultHeight != ViewportArguments::ValueAuto && resultHeight > 0) {
-            // if 'auto', the initial-scale will be negative here and thus ignored.
-            result.initialScale = max<float>(result.initialScale, initialViewportSize.height() / resultHeight);
-        }
-    }
 
-    // Constrain initial-scale value to minimum-scale/maximum-scale range.
-    result.initialScale = min(result.maximumScale, max(result.minimumScale, result.initialScale));
+    // 5. Resolve initial height from min/max descriptors.
+    if (resultMinHeight != ViewportArguments::ValueAuto || resultMaxHeight != ViewportArguments::ValueAuto)
+        resultHeight = compareIgnoringAuto(resultMinHeight, compareIgnoringAuto(resultMaxHeight, initialViewportSize.height(), min), max);
 
-    // Resolve width value.
+    // 6-7. Resolve width value.
     if (resultWidth == ViewportArguments::ValueAuto) {
-        if (resultZoom == ViewportArguments::ValueAuto)
-            resultWidth = defaultWidth;
-        else if (resultHeight != ViewportArguments::ValueAuto)
-            resultWidth = resultHeight * (initialViewportSize.width() / initialViewportSize.height());
+        if (resultHeight == ViewportArguments::ValueAuto || !initialViewportSize.height())
+            resultWidth = initialViewportSize.width();
         else
-            resultWidth = initialViewportSize.width() / result.initialScale;
+            resultWidth = resultHeight * (initialViewportSize.width() / initialViewportSize.height());
     }
 
-    // Resolve height value.
-    if (resultHeight == ViewportArguments::ValueAuto)
-        resultHeight = resultWidth * (initialViewportSize.height() / initialViewportSize.width());
-
-    if (type == ViewportArguments::ViewportMeta) {
-        // Extend width and height to fill the visual viewport for the resolved initial-scale.
-        resultWidth = max<float>(resultWidth, initialViewportSize.width() / result.initialScale);
-        resultHeight = max<float>(resultHeight, initialViewportSize.height() / result.initialScale);
+    // 8. Resolve height value.
+    if (resultHeight == ViewportArguments::ValueAuto) {
+        if (!initialViewportSize.width())
+            resultHeight = initialViewportSize.height();
+        else
+            resultHeight = resultWidth * (initialViewportSize.height() / initialViewportSize.width());
     }
 
+    PageScaleConstraints result;
+
+    result.minimumScale = resultMinZoom;
+    result.maximumScale = resultMaxZoom;
+    result.initialScale = resultZoom;
     result.layoutSize.setWidth(resultWidth);
     result.layoutSize.setHeight(resultHeight);
 
-    // If user-scalable = no, lock the min/max scale to the computed initial
-    // scale.
-    if (!resultUserZoom)
-        result.maximumScale = result.minimumScale = result.initialScale;
-
-    // Only set initialScale to a value if it was explicitly set.
-    if (resultZoom == ViewportArguments::ValueAuto)
-        result.initialScale = ViewportArguments::ValueAuto;
-
     return result;
 }
 
-static float numericPrefix(const String& keyString, const String& valueString, Document* document, bool* ok = 0)
-{
-    size_t parsedLength;
-    float value;
-    if (valueString.is8Bit())
-        value = charactersToFloat(valueString.characters8(), valueString.length(), parsedLength);
-    else
-        value = charactersToFloat(valueString.characters16(), valueString.length(), parsedLength);
-    if (!parsedLength) {
-        reportViewportWarning(document, UnrecognizedViewportArgumentValueError, valueString, keyString);
-        if (ok)
-            *ok = false;
-        return 0;
-    }
-    if (parsedLength < valueString.length())
-        reportViewportWarning(document, TruncatedViewportArgumentValueError, valueString, keyString);
-    if (ok)
-        *ok = true;
-    return value;
-}
-
-static float findSizeValue(const String& keyString, const String& valueString, Document* document)
-{
-    // 1) Non-negative number values are translated to px lengths.
-    // 2) Negative number values are translated to auto.
-    // 3) device-width and device-height are used as keywords.
-    // 4) Other keywords and unknown values translate to 0.0.
-
-    if (equalIgnoringCase(valueString, "device-width"))
-        return ViewportArguments::ValueDeviceWidth;
-    if (equalIgnoringCase(valueString, "device-height"))
-        return ViewportArguments::ValueDeviceHeight;
-
-    float value = numericPrefix(keyString, valueString, document);
-
-    if (value < 0)
-        return ViewportArguments::ValueAuto;
-
-    return value;
-}
-
-static float findScaleValue(const String& keyString, const String& valueString, Document* document)
-{
-    // 1) Non-negative number values are translated to <number> values.
-    // 2) Negative number values are translated to auto.
-    // 3) yes is translated to 1.0.
-    // 4) device-width and device-height are translated to 10.0.
-    // 5) no and unknown values are translated to 0.0
-
-    if (equalIgnoringCase(valueString, "yes"))
-        return 1;
-    if (equalIgnoringCase(valueString, "no"))
-        return 0;
-    if (equalIgnoringCase(valueString, "device-width"))
-        return 10;
-    if (equalIgnoringCase(valueString, "device-height"))
-        return 10;
-
-    float value = numericPrefix(keyString, valueString, document);
-
-    if (value < 0)
-        return ViewportArguments::ValueAuto;
-
-    if (value > 10.0)
-        reportViewportWarning(document, MaximumScaleTooLargeError, String(), String());
-
-    return value;
-}
-
-static float findUserScalableValue(const String& keyString, const String& valueString, Document* document)
-{
-    // yes and no are used as keywords.
-    // Numbers >= 1, numbers <= -1, device-width and device-height are mapped to yes.
-    // Numbers in the range <-1, 1>, and unknown values, are mapped to no.
-
-    if (equalIgnoringCase(valueString, "yes"))
-        return 1;
-    if (equalIgnoringCase(valueString, "no"))
-        return 0;
-    if (equalIgnoringCase(valueString, "device-width"))
-        return 1;
-    if (equalIgnoringCase(valueString, "device-height"))
-        return 1;
-
-    float value = numericPrefix(keyString, valueString, document);
-
-    if (fabs(value) < 1)
-        return 0;
-
-    return 1;
-}
-
-static float findTargetDensityDPIValue(const String& keyString, const String& valueString, Document* document)
-{
-    if (equalIgnoringCase(valueString, "device-dpi"))
-        return ViewportArguments::ValueDeviceDPI;
-    if (equalIgnoringCase(valueString, "low-dpi"))
-        return ViewportArguments::ValueLowDPI;
-    if (equalIgnoringCase(valueString, "medium-dpi"))
-        return ViewportArguments::ValueMediumDPI;
-    if (equalIgnoringCase(valueString, "high-dpi"))
-        return ViewportArguments::ValueHighDPI;
-
-    bool ok;
-    float value = numericPrefix(keyString, valueString, document, &ok);
-    if (!ok || value < 70 || value > 400)
-        return ViewportArguments::ValueAuto;
-
-    return value;
-}
-
-void setViewportFeature(const String& keyString, const String& valueString, Document* document, void* data)
-{
-    ViewportArguments* arguments = static_cast<ViewportArguments*>(data);
-
-    if (keyString == "width")
-        arguments->width = findSizeValue(keyString, valueString, document);
-    else if (keyString == "height")
-        arguments->height = findSizeValue(keyString, valueString, document);
-    else if (keyString == "initial-scale")
-        arguments->zoom = findScaleValue(keyString, valueString, document);
-    else if (keyString == "minimum-scale")
-        arguments->minZoom = findScaleValue(keyString, valueString, document);
-    else if (keyString == "maximum-scale")
-        arguments->maxZoom = findScaleValue(keyString, valueString, document);
-    else if (keyString == "user-scalable")
-        arguments->userZoom = findUserScalableValue(keyString, valueString, document);
-    else if (keyString == "target-densitydpi") {
-        arguments->deprecatedTargetDensityDPI = findTargetDensityDPIValue(keyString, valueString, document);
-        reportViewportWarning(document, TargetDensityDpiUnsupported, String(), String());
-    } else
-        reportViewportWarning(document, UnrecognizedViewportArgumentKeyError, keyString, String());
-}
-
-static const char* viewportErrorMessageTemplate(ViewportErrorCode errorCode)
-{
-    static const char* const errors[] = {
-        "Viewport argument key \"%replacement1\" not recognized and ignored.",
-        "Viewport argument value \"%replacement1\" for key \"%replacement2\" is invalid, and has been ignored.",
-        "Viewport argument value \"%replacement1\" for key \"%replacement2\" was truncated to its numeric prefix.",
-        "Viewport maximum-scale cannot be larger than 10.0. The maximum-scale will be set to 10.0.",
-        "Viewport target-densitydpi is not supported.",
-    };
-
-    return errors[errorCode];
-}
-
-static MessageLevel viewportErrorMessageLevel(ViewportErrorCode errorCode)
-{
-    switch (errorCode) {
-    case TruncatedViewportArgumentValueError:
-    case TargetDensityDpiUnsupported:
-        return WarningMessageLevel;
-    case UnrecognizedViewportArgumentKeyError:
-    case UnrecognizedViewportArgumentValueError:
-    case MaximumScaleTooLargeError:
-        return ErrorMessageLevel;
-    }
-
-    ASSERT_NOT_REACHED();
-    return ErrorMessageLevel;
-}
-
-void reportViewportWarning(Document* document, ViewportErrorCode errorCode, const String& replacement1, const String& replacement2)
-{
-    Frame* frame = document->frame();
-    if (!frame)
-        return;
-
-    String message = viewportErrorMessageTemplate(errorCode);
-    if (!replacement1.isNull())
-        message.replace("%replacement1", replacement1);
-    if (!replacement2.isNull())
-        message.replace("%replacement2", replacement2);
-
-    if ((errorCode == UnrecognizedViewportArgumentValueError || errorCode == TruncatedViewportArgumentValueError) && replacement1.find(';') != WTF::notFound)
-        message.append(" Note that ';' is not a separator in viewport values. The list should be comma-separated.");
-
-    // FIXME: This message should be moved off the console once a solution to https://bugs.webkit.org/show_bug.cgi?id=103274 exists.
-    document->addConsoleMessage(RenderingMessageSource, viewportErrorMessageLevel(errorCode), message);
-}
-
 } // namespace WebCore