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      1 /*
      2  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      3  *           (C) 1999 Antti Koivisto (koivisto (at) kde.org)
      4  *           (C) 2001 Dirk Mueller (mueller (at) kde.org)
      5  *           (C) 2006 Alexey Proskuryakov (ap (at) webkit.org)
      6  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
      7  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
      8  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
      9  * Copyright (C) 2012-2013 Intel Corporation. All rights reserved.
     10  *
     11  * This library is free software; you can redistribute it and/or
     12  * modify it under the terms of the GNU Library General Public
     13  * License as published by the Free Software Foundation; either
     14  * version 2 of the License, or (at your option) any later version.
     15  *
     16  * This library is distributed in the hope that it will be useful,
     17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     19  * Library General Public License for more details.
     20  *
     21  * You should have received a copy of the GNU Library General Public License
     22  * along with this library; see the file COPYING.LIB.  If not, write to
     23  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     24  * Boston, MA 02110-1301, USA.
     25  *
     26  */
     27 
     28 #include "config.h"
     29 #include "core/dom/ViewportDescription.h"
     30 
     31 #include "core/dom/Document.h"
     32 #include "core/frame/FrameHost.h"
     33 #include "core/frame/FrameView.h"
     34 #include "core/frame/LocalFrame.h"
     35 #include "core/frame/Settings.h"
     36 #include "platform/weborigin/KURL.h"
     37 #include "public/platform/Platform.h"
     38 
     39 namespace WebCore {
     40 
     41 static const float& compareIgnoringAuto(const float& value1, const float& value2, const float& (*compare) (const float&, const float&))
     42 {
     43     if (value1 == ViewportDescription::ValueAuto)
     44         return value2;
     45 
     46     if (value2 == ViewportDescription::ValueAuto)
     47         return value1;
     48 
     49     return compare(value1, value2);
     50 }
     51 
     52 float ViewportDescription::resolveViewportLength(const Length& length, const FloatSize& initialViewportSize, Direction direction)
     53 {
     54     if (length.isAuto())
     55         return ViewportDescription::ValueAuto;
     56 
     57     if (length.isFixed())
     58         return length.getFloatValue();
     59 
     60     if (length.type() == ExtendToZoom)
     61         return ViewportDescription::ValueExtendToZoom;
     62 
     63     if (length.type() == Percent && direction == Horizontal)
     64         return initialViewportSize.width() * length.getFloatValue() / 100.0f;
     65 
     66     if (length.type() == Percent && direction == Vertical)
     67         return initialViewportSize.height() * length.getFloatValue() / 100.0f;
     68 
     69     if (length.type() == DeviceWidth)
     70         return initialViewportSize.width();
     71 
     72     if (length.type() == DeviceHeight)
     73         return initialViewportSize.height();
     74 
     75     ASSERT_NOT_REACHED();
     76     return ViewportDescription::ValueAuto;
     77 }
     78 
     79 PageScaleConstraints ViewportDescription::resolve(const FloatSize& initialViewportSize, Length legacyFallbackWidth) const
     80 {
     81     float resultWidth = ValueAuto;
     82 
     83     Length copyMaxWidth = maxWidth;
     84     Length copyMinWidth = minWidth;
     85     // In case the width (used for min- and max-width) is undefined.
     86     if (isLegacyViewportType() && maxWidth.isAuto()) {
     87         // The width viewport META property is translated into 'width' descriptors, setting
     88         // the 'min' value to 'extend-to-zoom' and the 'max' value to the intended length.
     89         // In case the UA-defines a min-width, use that as length.
     90         if (zoom == ViewportDescription::ValueAuto) {
     91             copyMinWidth = Length(ExtendToZoom);
     92             copyMaxWidth = legacyFallbackWidth;
     93         } else if (maxHeight.isAuto()) {
     94             copyMinWidth = Length(ExtendToZoom);
     95             copyMaxWidth = Length(ExtendToZoom);
     96         }
     97     }
     98 
     99     float resultMaxWidth = resolveViewportLength(copyMaxWidth, initialViewportSize, Horizontal);
    100     float resultMinWidth = resolveViewportLength(copyMinWidth, initialViewportSize, Horizontal);
    101 
    102     float resultHeight = ValueAuto;
    103     float resultMaxHeight = resolveViewportLength(maxHeight, initialViewportSize, Vertical);
    104     float resultMinHeight = resolveViewportLength(minHeight, initialViewportSize, Vertical);
    105 
    106     float resultZoom = zoom;
    107     float resultMinZoom = minZoom;
    108     float resultMaxZoom = maxZoom;
    109     bool resultUserZoom = userZoom;
    110 
    111     // 1. Resolve min-zoom and max-zoom values.
    112     if (resultMinZoom != ViewportDescription::ValueAuto && resultMaxZoom != ViewportDescription::ValueAuto)
    113         resultMaxZoom = std::max(resultMinZoom, resultMaxZoom);
    114 
    115     // 2. Constrain zoom value to the [min-zoom, max-zoom] range.
    116     if (resultZoom != ViewportDescription::ValueAuto)
    117         resultZoom = compareIgnoringAuto(resultMinZoom, compareIgnoringAuto(resultMaxZoom, resultZoom, std::min), std::max);
    118 
    119     float extendZoom = compareIgnoringAuto(resultZoom, resultMaxZoom, std::min);
    120 
    121     // 3. Resolve non-"auto" lengths to pixel lengths.
    122     if (extendZoom == ViewportDescription::ValueAuto) {
    123         if (resultMaxWidth == ViewportDescription::ValueExtendToZoom)
    124             resultMaxWidth = ViewportDescription::ValueAuto;
    125 
    126         if (resultMaxHeight == ViewportDescription::ValueExtendToZoom)
    127             resultMaxHeight = ViewportDescription::ValueAuto;
    128 
    129         if (resultMinWidth == ViewportDescription::ValueExtendToZoom)
    130             resultMinWidth = resultMaxWidth;
    131 
    132         if (resultMinHeight == ViewportDescription::ValueExtendToZoom)
    133             resultMinHeight = resultMaxHeight;
    134     } else {
    135         float extendWidth = initialViewportSize.width() / extendZoom;
    136         float extendHeight = initialViewportSize.height() / extendZoom;
    137 
    138         if (resultMaxWidth == ViewportDescription::ValueExtendToZoom)
    139             resultMaxWidth = extendWidth;
    140 
    141         if (resultMaxHeight == ViewportDescription::ValueExtendToZoom)
    142             resultMaxHeight = extendHeight;
    143 
    144         if (resultMinWidth == ViewportDescription::ValueExtendToZoom)
    145             resultMinWidth = compareIgnoringAuto(extendWidth, resultMaxWidth, std::max);
    146 
    147         if (resultMinHeight == ViewportDescription::ValueExtendToZoom)
    148             resultMinHeight = compareIgnoringAuto(extendHeight, resultMaxHeight, std::max);
    149     }
    150 
    151     // 4. Resolve initial width from min/max descriptors.
    152     if (resultMinWidth != ViewportDescription::ValueAuto || resultMaxWidth != ViewportDescription::ValueAuto)
    153         resultWidth = compareIgnoringAuto(resultMinWidth, compareIgnoringAuto(resultMaxWidth, initialViewportSize.width(), std::min), std::max);
    154 
    155     // 5. Resolve initial height from min/max descriptors.
    156     if (resultMinHeight != ViewportDescription::ValueAuto || resultMaxHeight != ViewportDescription::ValueAuto)
    157         resultHeight = compareIgnoringAuto(resultMinHeight, compareIgnoringAuto(resultMaxHeight, initialViewportSize.height(), std::min), std::max);
    158 
    159     // 6-7. Resolve width value.
    160     if (resultWidth == ViewportDescription::ValueAuto) {
    161         if (resultHeight == ViewportDescription::ValueAuto || !initialViewportSize.height())
    162             resultWidth = initialViewportSize.width();
    163         else
    164             resultWidth = resultHeight * (initialViewportSize.width() / initialViewportSize.height());
    165     }
    166 
    167     // 8. Resolve height value.
    168     if (resultHeight == ViewportDescription::ValueAuto) {
    169         if (!initialViewportSize.width())
    170             resultHeight = initialViewportSize.height();
    171         else
    172             resultHeight = resultWidth * initialViewportSize.height() / initialViewportSize.width();
    173     }
    174 
    175     // Resolve initial-scale value.
    176     if (resultZoom == ViewportDescription::ValueAuto) {
    177         if (resultWidth != ViewportDescription::ValueAuto && resultWidth > 0)
    178             resultZoom = initialViewportSize.width() / resultWidth;
    179         if (resultHeight != ViewportDescription::ValueAuto && resultHeight > 0) {
    180             // if 'auto', the initial-scale will be negative here and thus ignored.
    181             resultZoom = std::max<float>(resultZoom, initialViewportSize.height() / resultHeight);
    182         }
    183     }
    184 
    185     // If user-scalable = no, lock the min/max scale to the computed initial
    186     // scale.
    187     if (!resultUserZoom)
    188         resultMinZoom = resultMaxZoom = resultZoom;
    189 
    190     // Only set initialScale to a value if it was explicitly set.
    191     if (zoom == ViewportDescription::ValueAuto)
    192         resultZoom = ViewportDescription::ValueAuto;
    193 
    194     PageScaleConstraints result;
    195     result.minimumScale = resultMinZoom;
    196     result.maximumScale = resultMaxZoom;
    197     result.initialScale = resultZoom;
    198     result.layoutSize.setWidth(resultWidth);
    199     result.layoutSize.setHeight(resultHeight);
    200     return result;
    201 }
    202 
    203 void ViewportDescription::reportMobilePageStats(const LocalFrame* mainFrame) const
    204 {
    205 #if OS(ANDROID)
    206     enum ViewportUMAType {
    207         NoViewportTag,
    208         DeviceWidth,
    209         ConstantWidth,
    210         MetaWidthOther,
    211         MetaHandheldFriendly,
    212         MetaMobileOptimized,
    213         XhtmlMobileProfile,
    214         TypeCount
    215     };
    216 
    217     if (!mainFrame || !mainFrame->host() || !mainFrame->view() || !mainFrame->document())
    218         return;
    219 
    220     // Avoid chrome:// pages like the new-tab page (on Android new tab is non-http).
    221     if (!mainFrame->document()->url().protocolIsInHTTPFamily())
    222         return;
    223 
    224     if (!isSpecifiedByAuthor()) {
    225         if (mainFrame->document()->isMobileDocument())
    226             blink::Platform::current()->histogramEnumeration("Viewport.MetaTagType", XhtmlMobileProfile, TypeCount);
    227         else
    228             blink::Platform::current()->histogramEnumeration("Viewport.MetaTagType", NoViewportTag, TypeCount);
    229 
    230         return;
    231     }
    232 
    233     if (isMetaViewportType()) {
    234         if (maxWidth.type() == WebCore::Fixed) {
    235             blink::Platform::current()->histogramEnumeration("Viewport.MetaTagType", ConstantWidth, TypeCount);
    236 
    237             if (mainFrame->view()) {
    238                 // To get an idea of how "far" the viewport is from the device's ideal width, we
    239                 // report the zoom level that we'd need to be at for the entire page to be visible.
    240                 int viewportWidth = maxWidth.intValue();
    241                 int windowWidth = mainFrame->document()->settings()->pinchVirtualViewportEnabled()
    242                     ? mainFrame->host()->pinchViewport().size().width()
    243                     : mainFrame->view()->frameRect().width();
    244                 int overviewZoomPercent = 100 * windowWidth / static_cast<float>(viewportWidth);
    245                 blink::Platform::current()->histogramSparse("Viewport.OverviewZoom", overviewZoomPercent);
    246             }
    247 
    248         } else if (maxWidth.type() == WebCore::DeviceWidth || maxWidth.type() == WebCore::ExtendToZoom) {
    249             blink::Platform::current()->histogramEnumeration("Viewport.MetaTagType", DeviceWidth, TypeCount);
    250         } else {
    251             // Overflow bucket for cases we may be unaware of.
    252             blink::Platform::current()->histogramEnumeration("Viewport.MetaTagType", MetaWidthOther, TypeCount);
    253         }
    254     } else if (type == ViewportDescription::HandheldFriendlyMeta) {
    255         blink::Platform::current()->histogramEnumeration("Viewport.MetaTagType", MetaHandheldFriendly, TypeCount);
    256     } else if (type == ViewportDescription::MobileOptimizedMeta) {
    257         blink::Platform::current()->histogramEnumeration("Viewport.MetaTagType", MobileOptimizedMeta, TypeCount);
    258     }
    259 #endif
    260 }
    261 
    262 } // namespace WebCore
    263