accessible/atk/nsMaiInterfaceComponent.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=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 #include "InterfaceInitFuncs.h"
   8
   9 #include "LocalAccessible-inl.h"
  10 #include "AccessibleWrap.h"
  11 #include "nsAccUtils.h"
  12 #include "nsMai.h"
  13 #include "nsWindow.h"
  14 #include "mozilla/Likely.h"
  15 #include "mozilla/a11y/DocAccessibleParent.h"
  16 #include "mozilla/a11y/RemoteAccessible.h"
  17 #include "mozilla/dom/BrowserParent.h"
  18 #include "mozilla/dom/Document.h"
  19 #include "nsAccessibilityService.h"
  20
  21 using namespace mozilla;
  22 using namespace mozilla::a11y;
  23
  24 extern "C" {
  25
  26 static AtkObject* refAccessibleAtPointCB(AtkComponent* aComponent, gint aAccX,
  27                                          gint aAccY, AtkCoordType aCoordType) {
  28   return refAccessibleAtPointHelper(ATK_OBJECT(aComponent), aAccX, aAccY,
  29                                     aCoordType);
  30 }
  31
  32 static void getExtentsCB(AtkComponent* aComponent, gint* aX, gint* aY,
  33                          gint* aWidth, gint* aHeight, AtkCoordType aCoordType) {
  34   getExtentsHelper(ATK_OBJECT(aComponent), aX, aY, aWidth, aHeight, aCoordType);
  35 }
  36
  37 static gboolean grabFocusCB(AtkComponent* aComponent) {
  38   AtkObject* atkObject = ATK_OBJECT(aComponent);
  39   Accessible* acc = GetInternalObj(atkObject);
  40   if (acc) {
  41     acc->TakeFocus();
  42     return TRUE;
  43   }
  44   return FALSE;
  45 }
  46
  47 // ScrollType is compatible
  48 MOZ_CAN_RUN_SCRIPT_BOUNDARY
  49 static gboolean scrollToCB(AtkComponent* aComponent, AtkScrollType type) {
  50   AtkObject* atkObject = ATK_OBJECT(aComponent);
  51   if (Accessible* acc = GetInternalObj(atkObject)) {
  52     acc->ScrollTo(type);
  53     return TRUE;
  54   }
  55
  56   return FALSE;
  57 }
  58
  59 // CoordType is compatible
  60 static gboolean scrollToPointCB(AtkComponent* aComponent, AtkCoordType coords,
  61                                 gint x, gint y) {
  62   AtkObject* atkObject = ATK_OBJECT(aComponent);
  63   AccessibleWrap* accWrap = GetAccessibleWrap(atkObject);
  64   if (accWrap) {
  65     accWrap->ScrollToPoint(coords, x, y);
  66     return TRUE;
  67   }
  68
  69   RemoteAccessible* proxy = GetProxy(atkObject);
  70   if (proxy) {
  71     proxy->ScrollToPoint(coords, x, y);
  72     return TRUE;
  73   }
  74
  75   return FALSE;
  76 }
  77 }
  78
  79 AtkObject* refAccessibleAtPointHelper(AtkObject* aAtkObj, gint aX, gint aY,
  80                                       AtkCoordType aCoordType) {
  81   Accessible* acc = GetInternalObj(aAtkObj);
  82   if (!acc) {
  83     return nullptr;
  84   }
  85
  86   // Accessible::ChildAtPoint(x,y) is in screen pixels.
  87   if (aCoordType == ATK_XY_WINDOW) {
  88     mozilla::LayoutDeviceIntPoint winCoords =
  89         nsAccUtils::GetScreenCoordsForWindow(acc);
  90     aX += winCoords.x;
  91     aY += winCoords.y;
  92   }
  93
  94   Accessible* accAtPoint =
  95       acc->ChildAtPoint(aX, aY, Accessible::EWhichChildAtPoint::DeepestChild);
  96   if (!accAtPoint) {
  97     return nullptr;
  98   }
  99   roles::Role role = accAtPoint->Role();
 100   if (role == roles::TEXT_LEAF || role == roles::STATICTEXT) {
 101     // We don't include text leaf nodes in the ATK tree, so return the parent.
 102     accAtPoint = accAtPoint->Parent();
 103     MOZ_ASSERT(accAtPoint, "Text leaf should always have a parent");
 104   }
 105   AtkObject* atkObj = GetWrapperFor(accAtPoint);
 106   if (atkObj) {
 107     g_object_ref(atkObj);
 108   }
 109   return atkObj;
 110 }
 111
 112 static double getScaleFactor(Accessible* aAccessible) {
 113   DocAccessible* docAcc = nullptr;
 114   if (LocalAccessible* localAcc = aAccessible->AsLocal()) {
 115     docAcc = localAcc->Document();
 116   } else {
 117     RemoteAccessible* remote = aAccessible->AsRemote();
 118     LocalAccessible* outerDoc = remote->OuterDocOfRemoteBrowser();
 119     if (outerDoc) {
 120       docAcc = outerDoc->Document();
 121     }
 122   }
 123
 124   if (!docAcc || !docAcc->DocumentNode()) {
 125     return 1.0;
 126   }
 127
 128   nsCOMPtr<nsIWidget> rootWidget =
 129       nsContentUtils::WidgetForDocument(docAcc->DocumentNode());
 130   if (!rootWidget) {
 131     return 1.0;
 132   }
 133
 134   if (RefPtr<nsWindow> window =
 135           static_cast<nsWindow*>(rootWidget->GetTopLevelWidget())) {
 136     return window->FractionalScaleFactor();
 137   }
 138
 139   return 1.0;
 140 }
 141
 142 void getExtentsHelper(AtkObject* aAtkObj, gint* aX, gint* aY, gint* aWidth,
 143                       gint* aHeight, AtkCoordType aCoordType) {
 144   *aX = *aY = *aWidth = *aHeight = -1;
 145
 146   Accessible* acc = GetInternalObj(aAtkObj);
 147   if (!acc) {
 148     return;
 149   }
 150
 151   mozilla::LayoutDeviceIntRect screenRect = acc->Bounds();
 152   if (screenRect.IsEmpty()) {
 153     return;
 154   }
 155
 156   if (aCoordType == ATK_XY_WINDOW) {
 157     mozilla::LayoutDeviceIntPoint winCoords =
 158         nsAccUtils::GetScreenCoordsForWindow(acc);
 159     screenRect.x -= winCoords.x;
 160     screenRect.y -= winCoords.y;
 161   }
 162
 163   double scaleFactor = getScaleFactor(acc);
 164
 165   *aX = screenRect.x / scaleFactor;
 166   *aY = screenRect.y / scaleFactor;
 167   *aWidth = screenRect.width / scaleFactor;
 168   *aHeight = screenRect.height / scaleFactor;
 169 }
 170
 171 void componentInterfaceInitCB(AtkComponentIface* aIface) {
 172   NS_ASSERTION(aIface, "Invalid Interface");
 173   if (MOZ_UNLIKELY(!aIface)) return;
 174
 175   /*
 176    * Use default implementation in atk for contains, get_position,
 177    * and get_size
 178    */
 179   aIface->ref_accessible_at_point = refAccessibleAtPointCB;
 180   aIface->get_extents = getExtentsCB;
 181   aIface->grab_focus = grabFocusCB;
 182   if (IsAtkVersionAtLeast(2, 30)) {
 183     aIface->scroll_to = scrollToCB;
 184     aIface->scroll_to_point = scrollToPointCB;
 185   }
 186 }