accessible/src/msaa/CAccessibleComponent.cpp

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   4 /* ***** BEGIN LICENSE BLOCK *****
   5  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   6  *
   7  * The contents of this file are subject to the Mozilla Public License Version
   8  * 1.1 (the "License"); you may not use this file except in compliance with
   9  * the License. You may obtain a copy of the License at
  10  * http://www.mozilla.org/MPL/
  11  *
  12  * Software distributed under the License is distributed on an "AS IS" basis,
  13  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  14  * for the specific language governing rights and limitations under the
  15  * License.
  16  *
  17  * The Original Code is mozilla.org code.
  18  *
  19  * The Initial Developer of the Original Code is
  20  * Mozilla Foundation.
  21  * Portions created by the Initial Developer are Copyright (C) 2007
  22  * the Initial Developer. All Rights Reserved.
  23  *
  24  * Contributor(s):
  25  *   Alexander Surkov <surkov.alexander@gmail.com> (original author)
  26  *
  27  * Alternatively, the contents of this file may be used under the terms of
  28  * either the GNU General Public License Version 2 or later (the "GPL"), or
  29  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  30  * in which case the provisions of the GPL or the LGPL are applicable instead
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  36  * the provisions above, a recipient may use your version of this file under
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  38  *
  39  * ***** END LICENSE BLOCK ***** */
  40
  41 #include "CAccessibleComponent.h"
  42
  43 #include "AccessibleComponent_i.c"
  44
  45 #include "nsIAccessNode.h"
  46 #include "nsIAccessible.h"
  47 #include "nsIAccessibleStates.h"
  48 #include "nsAccessNodeWrap.h"
  49
  50 #include "nsCOMPtr.h"
  51 #include "nsString.h"
  52
  53 #include "nsIDOMCSSPrimitiveValue.h"
  54 #include "nsIDOMNSRGBAColor.h"
  55
  56 enum {
  57   IA2AlphaShift = 24,
  58   IA2RedShift = 16,
  59   IA2GreenShift = 8,
  60   IA2BlueShift = 0
  61 };
  62
  63 // IUnknown
  64
  65 STDMETHODIMP
  66 CAccessibleComponent::QueryInterface(REFIID iid, void** ppv)
  67 {
  68   *ppv = NULL;
  69
  70   if (IID_IAccessibleComponent == iid) {
  71     *ppv = static_cast<IAccessibleComponent*>(this);
  72     (reinterpret_cast<IUnknown*>(*ppv))->AddRef();
  73     return S_OK;
  74   }
  75
  76   return E_NOINTERFACE;
  77 }
  78
  79 // IAccessibleComponent
  80
  81 STDMETHODIMP
  82 CAccessibleComponent::get_locationInParent(long *aX, long *aY)
  83 {
  84 __try {
  85   *aX = 0;
  86   *aY = 0;
  87
  88   nsCOMPtr<nsIAccessible> acc(do_QueryInterface(this));
  89   if (!acc)
  90     return E_FAIL;
  91
  92   // If the object is not on any screen the returned position is (0,0).
  93   PRUint32 states = 0;
  94   nsresult rv = acc->GetFinalState(&states, nsnull);
  95   if (NS_FAILED(rv))
  96     return GetHRESULT(rv);
  97
  98   if (states & nsIAccessibleStates::STATE_INVISIBLE)
  99     return S_OK;
 100
 101   PRInt32 x = 0, y = 0, width = 0, height = 0;
 102   rv = acc->GetBounds(&x, &y, &width, &height);
 103   if (NS_FAILED(rv))
 104     return GetHRESULT(rv);
 105
 106   nsCOMPtr<nsIAccessible> parentAcc;
 107   rv = acc->GetParent(getter_AddRefs(parentAcc));
 108   if (NS_FAILED(rv))
 109     return GetHRESULT(rv);
 110
 111   // The coordinates of the returned position are relative to this object's
 112   // parent or relative to the screen on which this object is rendered if it
 113   // has no parent.
 114   if (!parentAcc) {
 115     *aX = x;
 116     *aY = y;
 117     return S_OK;
 118   }
 119
 120   // The coordinates of the bounding box are given relative to the parent's
 121   // coordinate system.
 122   PRInt32 parentx = 0, parenty = 0;
 123   rv = acc->GetBounds(&parentx, &parenty, &width, &height);
 124   if (NS_FAILED(rv))
 125     return GetHRESULT(rv);
 126
 127   *aX = x - parentx;
 128   *aY = y - parenty;
 129   return S_OK;
 130
 131 } __except(nsAccessNodeWrap::FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
 132   return E_FAIL;
 133 }
 134
 135 STDMETHODIMP
 136 CAccessibleComponent::get_foreground(IA2Color *aForeground)
 137 {
 138 __try {
 139   return GetARGBValueFromCSSProperty(NS_LITERAL_STRING("color"), aForeground);
 140 } __except(nsAccessNodeWrap::FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
 141
 142   return E_FAIL;
 143 }
 144
 145 STDMETHODIMP
 146 CAccessibleComponent::get_background(IA2Color *aBackground)
 147 {
 148 __try {
 149   return GetARGBValueFromCSSProperty(NS_LITERAL_STRING("background-color"),
 150                                      aBackground);
 151 } __except(nsAccessNodeWrap::FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
 152
 153   return E_FAIL;
 154 }
 155
 156 HRESULT
 157 CAccessibleComponent::GetARGBValueFromCSSProperty(const nsAString& aPropName,
 158                                                   IA2Color *aColorValue)
 159 {
 160 __try {
 161   *aColorValue = 0;
 162
 163   nsCOMPtr<nsIAccessNode> acc(do_QueryInterface(this));
 164   if (!acc)
 165     return E_FAIL;
 166
 167   nsCOMPtr<nsIDOMCSSPrimitiveValue> cssValue;
 168   nsresult rv = acc->GetComputedStyleCSSValue(EmptyString(), aPropName,
 169                                               getter_AddRefs(cssValue));
 170   if (NS_FAILED(rv) || !cssValue)
 171     return GetHRESULT(rv);
 172
 173   nsCOMPtr<nsIDOMRGBColor> rgbColor;
 174   rv = cssValue->GetRGBColorValue(getter_AddRefs(rgbColor));
 175   if (NS_FAILED(rv) || !rgbColor)
 176     return GetHRESULT(rv);
 177
 178   nsCOMPtr<nsIDOMNSRGBAColor> rgbaColor(do_QueryInterface(rgbColor));
 179   if (!rgbaColor)
 180     return GetHRESULT(rv);
 181
 182   // get alpha
 183   nsCOMPtr<nsIDOMCSSPrimitiveValue> alphaValue;
 184   rv = rgbaColor->GetAlpha(getter_AddRefs(alphaValue));
 185   if (NS_FAILED(rv) || !alphaValue)
 186     return GetHRESULT(rv);
 187
 188   float alpha = 0.0;
 189   rv = alphaValue->GetFloatValue(nsIDOMCSSPrimitiveValue::CSS_NUMBER, &alpha);
 190   if (NS_FAILED(rv))
 191     return GetHRESULT(rv);
 192
 193   // get red
 194   nsCOMPtr<nsIDOMCSSPrimitiveValue> redValue;
 195   rv = rgbaColor->GetRed(getter_AddRefs(redValue));
 196   if (NS_FAILED(rv) || !redValue)
 197     return GetHRESULT(rv);
 198
 199   float red = 0.0;
 200   rv = redValue->GetFloatValue(nsIDOMCSSPrimitiveValue::CSS_NUMBER, &red);
 201   if (NS_FAILED(rv))
 202     return GetHRESULT(rv);
 203
 204   // get green
 205   nsCOMPtr<nsIDOMCSSPrimitiveValue> greenValue;
 206   rv = rgbaColor->GetGreen(getter_AddRefs(greenValue));
 207   if (NS_FAILED(rv) || !greenValue)
 208     return GetHRESULT(rv);
 209
 210   float green = 0.0;
 211   rv = greenValue->GetFloatValue(nsIDOMCSSPrimitiveValue::CSS_NUMBER, &green);
 212   if (NS_FAILED(rv))
 213     return GetHRESULT(rv);
 214
 215   // get blue
 216   nsCOMPtr<nsIDOMCSSPrimitiveValue> blueValue;
 217   rv = rgbaColor->GetBlue(getter_AddRefs(blueValue));
 218   if (NS_FAILED(rv) || !blueValue)
 219     return GetHRESULT(rv);
 220
 221   float blue = 0.0;
 222   rv = blueValue->GetFloatValue(nsIDOMCSSPrimitiveValue::CSS_NUMBER, &blue);
 223   if (NS_FAILED(rv))
 224     return GetHRESULT(rv);
 225
 226   // compose ARGB value
 227   *aColorValue = (((IA2Color) blue) << IA2BlueShift) |
 228                  (((IA2Color) green) << IA2GreenShift) |
 229                  (((IA2Color) red) << IA2RedShift) |
 230                  (((IA2Color) (alpha * 0xff)) << IA2AlphaShift);
 231   return S_OK;
 232
 233 } __except(nsAccessNodeWrap::FilterA11yExceptions(::GetExceptionCode(), GetExceptionInformation())) { }
 234   return E_FAIL;
 235 }
 236