dom/base/DOMRect.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "mozilla/dom/DOMRect.h"
   7
   8 #include "nsPresContext.h"
   9 #include "mozilla/dom/DOMRectListBinding.h"
  10 #include "mozilla/dom/DOMRectBinding.h"
  11
  12 using namespace mozilla;
  13 using namespace mozilla::dom;
  14
  15 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DOMRectReadOnly, mParent)
  16 NS_IMPL_CYCLE_COLLECTING_ADDREF(DOMRectReadOnly)
  17 NS_IMPL_CYCLE_COLLECTING_RELEASE(DOMRectReadOnly)
  18 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DOMRectReadOnly)
  19   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  20   NS_INTERFACE_MAP_ENTRY(nsISupports)
  21 NS_INTERFACE_MAP_END
  22
  23 JSObject*
  24 DOMRectReadOnly::WrapObject(JSContext* aCx)
  25 {
  26   MOZ_ASSERT(mParent);
  27   return DOMRectReadOnlyBinding::Wrap(aCx, this);
  28 }
  29
  30 // -----------------------------------------------------------------------------
  31
  32 NS_IMPL_ISUPPORTS_INHERITED(DOMRect, DOMRectReadOnly, nsIDOMClientRect)
  33
  34 #define FORWARD_GETTER(_name)                                                   \
  35   NS_IMETHODIMP                                                                 \
  36   DOMRect::Get ## _name(float* aResult)                                         \
  37   {                                                                             \
  38     *aResult = float(_name());                                                  \
  39     return NS_OK;                                                               \
  40   }
  41
  42 FORWARD_GETTER(Left)
  43 FORWARD_GETTER(Top)
  44 FORWARD_GETTER(Right)
  45 FORWARD_GETTER(Bottom)
  46 FORWARD_GETTER(Width)
  47 FORWARD_GETTER(Height)
  48
  49 JSObject*
  50 DOMRect::WrapObject(JSContext* aCx)
  51 {
  52   MOZ_ASSERT(mParent);
  53   return DOMRectBinding::Wrap(aCx, this);
  54 }
  55
  56 already_AddRefed<DOMRect>
  57 DOMRect::Constructor(const GlobalObject& aGlobal, ErrorResult& aRV)
  58 {
  59   nsRefPtr<DOMRect> obj =
  60     new DOMRect(aGlobal.GetAsSupports(), 0.0, 0.0, 0.0, 0.0);
  61   return obj.forget();
  62 }
  63
  64 already_AddRefed<DOMRect>
  65 DOMRect::Constructor(const GlobalObject& aGlobal, double aX, double aY,
  66                      double aWidth, double aHeight, ErrorResult& aRV)
  67 {
  68   nsRefPtr<DOMRect> obj =
  69     new DOMRect(aGlobal.GetAsSupports(), aX, aY, aWidth, aHeight);
  70   return obj.forget();
  71 }
  72
  73 // -----------------------------------------------------------------------------
  74
  75 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DOMRectList, mParent, mArray)
  76
  77 NS_INTERFACE_TABLE_HEAD(DOMRectList)
  78   NS_WRAPPERCACHE_INTERFACE_TABLE_ENTRY
  79   NS_INTERFACE_TABLE(DOMRectList, nsIDOMClientRectList)
  80   NS_INTERFACE_TABLE_TO_MAP_SEGUE_CYCLE_COLLECTION(DOMRectList)
  81 NS_INTERFACE_MAP_END
  82
  83 NS_IMPL_CYCLE_COLLECTING_ADDREF(DOMRectList)
  84 NS_IMPL_CYCLE_COLLECTING_RELEASE(DOMRectList)
  85
  86
  87 NS_IMETHODIMP
  88 DOMRectList::GetLength(uint32_t* aLength)
  89 {
  90   *aLength = Length();
  91   return NS_OK;
  92 }
  93
  94 NS_IMETHODIMP
  95 DOMRectList::Item(uint32_t aIndex, nsIDOMClientRect** aReturn)
  96 {
  97   NS_IF_ADDREF(*aReturn = Item(aIndex));
  98   return NS_OK;
  99 }
 100
 101 JSObject*
 102 DOMRectList::WrapObject(JSContext *cx)
 103 {
 104   return mozilla::dom::DOMRectListBinding::Wrap(cx, this);
 105 }
 106
 107 static double
 108 RoundFloat(double aValue)
 109 {
 110   return floor(aValue + 0.5);
 111 }
 112
 113 void
 114 DOMRect::SetLayoutRect(const nsRect& aLayoutRect)
 115 {
 116   double scale = 65536.0;
 117   // Round to the nearest 1/scale units. We choose scale so it can be represented
 118   // exactly by machine floating point.
 119   double scaleInv = 1/scale;
 120   double t2pScaled = scale/nsPresContext::AppUnitsPerCSSPixel();
 121   double x = RoundFloat(aLayoutRect.x*t2pScaled)*scaleInv;
 122   double y = RoundFloat(aLayoutRect.y*t2pScaled)*scaleInv;
 123   SetRect(x, y, RoundFloat(aLayoutRect.XMost()*t2pScaled)*scaleInv - x,
 124           RoundFloat(aLayoutRect.YMost()*t2pScaled)*scaleInv - y);
 125 }