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      1 /*
      2  * Copyright (C) 2012 Google Inc.  All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #include "config.h"
     27 #include "core/rendering/RenderThemeChromiumFontProvider.h"
     28 
     29 #include "core/CSSValueKeywords.h"
     30 #include "platform/fonts/FontDescription.h"
     31 #include "platform/win/HWndDC.h"
     32 #include "platform/win/SystemInfo.h"
     33 #include "wtf/text/WTFString.h"
     34 #include <windows.h>
     35 
     36 #define SIZEOF_STRUCT_WITH_SPECIFIED_LAST_MEMBER(structName, member) \
     37     offsetof(structName, member) + \
     38     (sizeof static_cast<structName*>(0)->member)
     39 #define NONCLIENTMETRICS_SIZE_PRE_VISTA \
     40     SIZEOF_STRUCT_WITH_SPECIFIED_LAST_MEMBER(NONCLIENTMETRICS, lfMessageFont)
     41 
     42 namespace blink {
     43 
     44 static FontDescription& smallSystemFont()
     45 {
     46     DEFINE_STATIC_LOCAL(FontDescription, font, ());
     47     return font;
     48 }
     49 
     50 static FontDescription& menuFont()
     51 {
     52     DEFINE_STATIC_LOCAL(FontDescription, font, ());
     53     return font;
     54 }
     55 
     56 static FontDescription& labelFont()
     57 {
     58     DEFINE_STATIC_LOCAL(FontDescription, font, ());
     59     return font;
     60 }
     61 
     62 // Converts |points| to pixels. One point is 1/72 of an inch.
     63 static float pointsToPixels(float points)
     64 {
     65     static float pixelsPerInch = 0.0f;
     66     if (!pixelsPerInch) {
     67         HWndDC hdc(0); // What about printing? Is this the right DC?
     68         if (hdc) // Can this ever actually be 0?
     69             pixelsPerInch = GetDeviceCaps(hdc, LOGPIXELSY);
     70         else
     71             pixelsPerInch = 96.0f;
     72     }
     73 
     74     static const float pointsPerInch = 72.0f;
     75     return points / pointsPerInch * pixelsPerInch;
     76 }
     77 
     78 static void getNonClientMetrics(NONCLIENTMETRICS* metrics)
     79 {
     80     static UINT size = isWindowsVistaOrGreater() ?
     81         sizeof(NONCLIENTMETRICS) : NONCLIENTMETRICS_SIZE_PRE_VISTA;
     82     metrics->cbSize = size;
     83     bool success = !!SystemParametersInfo(SPI_GETNONCLIENTMETRICS, size, metrics, 0);
     84     ASSERT(success);
     85 }
     86 
     87 // Return the height of system font |font| in pixels. We use this size by
     88 // default for some non-form-control elements.
     89 static float systemFontSize(const LOGFONT& font)
     90 {
     91     float size = -font.lfHeight;
     92     if (size < 0) {
     93         HFONT hFont = CreateFontIndirect(&font);
     94         if (hFont) {
     95             HWndDC hdc(0); // What about printing? Is this the right DC?
     96             if (hdc) {
     97                 HGDIOBJ hObject = SelectObject(hdc, hFont);
     98                 TEXTMETRIC tm;
     99                 GetTextMetrics(hdc, &tm);
    100                 SelectObject(hdc, hObject);
    101                 size = tm.tmAscent;
    102             }
    103             DeleteObject(hFont);
    104         }
    105     }
    106 
    107     // The "codepage 936" bit here is from Gecko; apparently this helps make
    108     // fonts more legible in Simplified Chinese where the default font size is
    109     // too small.
    110     //
    111     // FIXME: http://b/1119883 Since this is only used for "small caption",
    112     // "menu", and "status bar" objects, I'm not sure how much this even
    113     // matters. Plus the Gecko patch went in back in 2002, and maybe this
    114     // isn't even relevant anymore. We should investigate whether this should
    115     // be removed, or perhaps broadened to be "any CJK locale".
    116     //
    117     return ((size < 12.0f) && (GetACP() == 936)) ? 12.0f : size;
    118 }
    119 
    120 // static
    121 void RenderThemeChromiumFontProvider::systemFont(CSSValueID valueID, FontDescription& fontDescription)
    122 {
    123     // This logic owes much to RenderThemeSafari.cpp.
    124     FontDescription* cachedDesc = 0;
    125     AtomicString faceName;
    126     float fontSize = 0;
    127     switch (valueID) {
    128     case CSSValueSmallCaption:
    129         cachedDesc = &smallSystemFont();
    130         if (!smallSystemFont().isAbsoluteSize()) {
    131             NONCLIENTMETRICS metrics;
    132             getNonClientMetrics(&metrics);
    133             faceName = AtomicString(metrics.lfSmCaptionFont.lfFaceName, wcslen(metrics.lfSmCaptionFont.lfFaceName));
    134             fontSize = systemFontSize(metrics.lfSmCaptionFont);
    135         }
    136         break;
    137     case CSSValueMenu:
    138         cachedDesc = &menuFont();
    139         if (!menuFont().isAbsoluteSize()) {
    140             NONCLIENTMETRICS metrics;
    141             getNonClientMetrics(&metrics);
    142             faceName = AtomicString(metrics.lfMenuFont.lfFaceName, wcslen(metrics.lfMenuFont.lfFaceName));
    143             fontSize = systemFontSize(metrics.lfMenuFont);
    144         }
    145         break;
    146     case CSSValueStatusBar:
    147         cachedDesc = &labelFont();
    148         if (!labelFont().isAbsoluteSize()) {
    149             NONCLIENTMETRICS metrics;
    150             getNonClientMetrics(&metrics);
    151             faceName = metrics.lfStatusFont.lfFaceName;
    152             fontSize = systemFontSize(metrics.lfStatusFont);
    153         }
    154         break;
    155     case CSSValueWebkitMiniControl:
    156     case CSSValueWebkitSmallControl:
    157     case CSSValueWebkitControl:
    158         faceName = defaultGUIFont();
    159         // Why 2 points smaller? Because that's what Gecko does.
    160         fontSize = s_defaultFontSize - pointsToPixels(2);
    161         break;
    162     default:
    163         faceName = defaultGUIFont();
    164         fontSize = s_defaultFontSize;
    165         break;
    166     }
    167 
    168     if (!cachedDesc)
    169         cachedDesc = &fontDescription;
    170 
    171     if (fontSize) {
    172         cachedDesc->firstFamily().setFamily(faceName);
    173         cachedDesc->setIsAbsoluteSize(true);
    174         cachedDesc->setGenericFamily(FontDescription::NoFamily);
    175         cachedDesc->setSpecifiedSize(fontSize);
    176         cachedDesc->setWeight(FontWeightNormal);
    177         cachedDesc->setStyle(FontStyleNormal);
    178     }
    179     fontDescription = *cachedDesc;
    180 }
    181 
    182 // static
    183 void RenderThemeChromiumFontProvider::setDefaultFontSize(int fontSize)
    184 {
    185     s_defaultFontSize = static_cast<float>(fontSize);
    186 
    187     // Reset cached fonts.
    188     smallSystemFont() = menuFont() = labelFont() = FontDescription();
    189 }
    190 
    191 } // namespace blink
    192