layout/style/nsCSSValue.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /* representation of simple property values within CSS declarations */
   8
   9 #include "nsCSSValue.h"
  10
  11 #include "mozilla/CORSMode.h"
  12 #include "mozilla/FontPropertyTypes.h"
  13 #include "mozilla/ServoBindings.h"
  14 #include "mozilla/ServoStyleSet.h"
  15 #include "mozilla/ServoTypes.h"
  16 #include "mozilla/StyleSheetInlines.h"
  17 #include "mozilla/Likely.h"
  18 #include "mozilla/MemoryReporting.h"
  19 #include "mozilla/css/ImageLoader.h"
  20 #include "gfxFontConstants.h"
  21 #include "imgRequestProxy.h"
  22 #include "mozilla/dom/Document.h"
  23 #include "nsCSSProps.h"
  24 #include "nsNetUtil.h"
  25 #include "nsPresContext.h"
  26 #include "nsStyleUtil.h"
  27 #include "nsDeviceContext.h"
  28 #include "nsContentUtils.h"
  29
  30 using namespace mozilla;
  31 using namespace mozilla::css;
  32 using namespace mozilla::dom;
  33
  34 nsCSSValue::nsCSSValue(float aValue, nsCSSUnit aUnit) : mUnit(aUnit) {
  35   MOZ_ASSERT(eCSSUnit_Null == aUnit, "not a float value");
  36   mValue = aValue;
  37   MOZ_ASSERT(!std::isnan(mValue));
  38 }
  39
  40 nsCSSValue::nsCSSValue(const nsCSSValue& aCopy) : mUnit(aCopy.mUnit) {
  41   if (eCSSUnit_Null != mUnit) {
  42     mValue = aCopy.mValue;
  43     MOZ_ASSERT(!std::isnan(mValue));
  44   } else {
  45     MOZ_ASSERT_UNREACHABLE("unknown unit");
  46   }
  47 }
  48
  49 nsCSSValue& nsCSSValue::operator=(const nsCSSValue& aCopy) {
  50   if (this != &aCopy) {
  51     this->~nsCSSValue();
  52     new (this) nsCSSValue(aCopy);
  53   }
  54   return *this;
  55 }
  56
  57 nsCSSValue& nsCSSValue::operator=(nsCSSValue&& aOther) {
  58   MOZ_ASSERT(this != &aOther, "Self assigment with rvalue reference");
  59
  60   Reset();
  61   mUnit = aOther.mUnit;
  62   mValue = aOther.mValue;
  63   aOther.mUnit = eCSSUnit_Null;
  64
  65   return *this;
  66 }
  67
  68 bool nsCSSValue::operator==(const nsCSSValue& aOther) const {
  69   if (mUnit != aOther.mUnit) {
  70     return false;
  71   }
  72   return mValue == aOther.mValue;
  73 }
  74
  75 nscoord nsCSSValue::GetPixelLength() const {
  76   MOZ_ASSERT(IsPixelLengthUnit(), "not a fixed length unit");
  77
  78   double scaleFactor;
  79   switch (mUnit) {
  80     case eCSSUnit_Pixel:
  81       return nsPresContext::CSSPixelsToAppUnits(mValue);
  82     case eCSSUnit_Pica:
  83       scaleFactor = 16.0;
  84       break;
  85     case eCSSUnit_Point:
  86       scaleFactor = 4 / 3.0;
  87       break;
  88     case eCSSUnit_Inch:
  89       scaleFactor = 96.0;
  90       break;
  91     case eCSSUnit_Millimeter:
  92       scaleFactor = 96 / 25.4;
  93       break;
  94     case eCSSUnit_Centimeter:
  95       scaleFactor = 96 / 2.54;
  96       break;
  97     case eCSSUnit_Quarter:
  98       scaleFactor = 96 / 101.6;
  99       break;
 100     default:
 101       NS_ERROR("should never get here");
 102       return 0;
 103   }
 104   return nsPresContext::CSSPixelsToAppUnits(float(mValue * scaleFactor));
 105 }
 106
 107 void nsCSSValue::SetPercentValue(float aValue) {
 108   Reset();
 109   mUnit = eCSSUnit_Percent;
 110   mValue = aValue;
 111   MOZ_ASSERT(!std::isnan(mValue));
 112 }
 113
 114 void nsCSSValue::SetFloatValue(float aValue, nsCSSUnit aUnit) {
 115   MOZ_ASSERT(IsFloatUnit(aUnit), "not a float value");
 116   Reset();
 117   if (IsFloatUnit(aUnit)) {
 118     mUnit = aUnit;
 119     mValue = aValue;
 120     MOZ_ASSERT(!std::isnan(mValue));
 121   }
 122 }