accessible/src/base/SelectionManager.cpp

   1 /* -*- Mode: C++; tab-width: 4; 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/a11y/SelectionManager.h"
   7
   8 #include "DocAccessible-inl.h"
   9 #include "nsAccessibilityService.h"
  10 #include "nsAccUtils.h"
  11 #include "nsCoreUtils.h"
  12 #include "nsIAccessibleEvent.h"
  13 #include "RootAccessible.h"
  14
  15 #include "nsCaret.h"
  16 #include "nsIDOMDocument.h"
  17 #include "nsIDOMHTMLAnchorElement.h"
  18 #include "nsIDOMHTMLTextAreaElement.h"
  19 #include "nsIFrame.h"
  20 #include "nsIPresShell.h"
  21 #include "nsISelectionPrivate.h"
  22 #include "nsServiceManagerUtils.h"
  23 #include "mozilla/Selection.h"
  24
  25 using namespace mozilla;
  26 using namespace mozilla::a11y;
  27
  28 void
  29 SelectionManager::Shutdown()
  30 {
  31   ClearControlSelectionListener();
  32   mLastTextAccessible = nullptr;
  33   mLastUsedSelection = nullptr;
  34 }
  35
  36 void
  37 SelectionManager::ClearControlSelectionListener()
  38 {
  39   if (!mCurrCtrlFrame)
  40     return;
  41
  42   const nsFrameSelection* frameSel = mCurrCtrlFrame->GetConstFrameSelection();
  43   NS_ASSERTION(frameSel, "No frame selection for the element!");
  44
  45   mCurrCtrlFrame = nullptr;
  46   if (!frameSel)
  47     return;
  48
  49   // Remove 'this' registered as selection listener for the normal selection.
  50   Selection* normalSel =
  51     frameSel->GetSelection(nsISelectionController::SELECTION_NORMAL);
  52   normalSel->RemoveSelectionListener(this);
  53
  54   // Remove 'this' registered as selection listener for the spellcheck
  55   // selection.
  56   Selection* spellSel =
  57     frameSel->GetSelection(nsISelectionController::SELECTION_SPELLCHECK);
  58   spellSel->RemoveSelectionListener(this);
  59 }
  60
  61 void
  62 SelectionManager::SetControlSelectionListener(dom::Element* aFocusedElm)
  63 {
  64   // When focus moves such that the caret is part of a new frame selection
  65   // this removes the old selection listener and attaches a new one for
  66   // the current focus.
  67   ClearControlSelectionListener();
  68
  69   mLastTextAccessible = nullptr;
  70
  71   mCurrCtrlFrame = aFocusedElm->GetPrimaryFrame();
  72   if (!mCurrCtrlFrame)
  73     return;
  74
  75   const nsFrameSelection* frameSel = mCurrCtrlFrame->GetConstFrameSelection();
  76   NS_ASSERTION(frameSel, "No frame selection for focused element!");
  77   if (!frameSel)
  78     return;
  79
  80   // Register 'this' as selection listener for the normal selection.
  81   Selection* normalSel =
  82     frameSel->GetSelection(nsISelectionController::SELECTION_NORMAL);
  83   normalSel->AddSelectionListener(this);
  84
  85   // Register 'this' as selection listener for the spell check selection.
  86   Selection* spellSel =
  87     frameSel->GetSelection(nsISelectionController::SELECTION_SPELLCHECK);
  88   spellSel->AddSelectionListener(this);
  89 }
  90
  91 void
  92 SelectionManager::AddDocSelectionListener(nsIPresShell* aPresShell)
  93 {
  94   const nsFrameSelection* frameSel = aPresShell->ConstFrameSelection();
  95
  96   // Register 'this' as selection listener for the normal selection.
  97   Selection* normalSel =
  98     frameSel->GetSelection(nsISelectionController::SELECTION_NORMAL);
  99   normalSel->AddSelectionListener(this);
 100
 101   // Register 'this' as selection listener for the spell check selection.
 102   Selection* spellSel =
 103     frameSel->GetSelection(nsISelectionController::SELECTION_SPELLCHECK);
 104   spellSel->AddSelectionListener(this);
 105 }
 106
 107 void
 108 SelectionManager::RemoveDocSelectionListener(nsIPresShell* aPresShell)
 109 {
 110   const nsFrameSelection* frameSel = aPresShell->ConstFrameSelection();
 111
 112   // Remove 'this' registered as selection listener for the normal selection.
 113   Selection* normalSel =
 114     frameSel->GetSelection(nsISelectionController::SELECTION_NORMAL);
 115   normalSel->RemoveSelectionListener(this);
 116
 117   // Remove 'this' registered as selection listener for the spellcheck
 118   // selection.
 119   Selection* spellSel =
 120     frameSel->GetSelection(nsISelectionController::SELECTION_SPELLCHECK);
 121   spellSel->RemoveSelectionListener(this);
 122 }
 123
 124 NS_IMETHODIMP
 125 SelectionManager::NotifySelectionChanged(nsIDOMDocument* aDOMDocument,
 126                                          nsISelection* aSelection,
 127                                          int16_t aReason)
 128 {
 129   NS_ENSURE_ARG(aDOMDocument);
 130
 131   nsCOMPtr<nsIDocument> documentNode(do_QueryInterface(aDOMDocument));
 132   DocAccessible* document = GetAccService()->GetDocAccessible(documentNode);
 133
 134 #ifdef A11Y_LOG
 135   if (logging::IsEnabled(logging::eSelection))
 136     logging::SelChange(aSelection, document);
 137 #endif
 138
 139   // Don't fire events until document is loaded.
 140   if (document && document->IsContentLoaded()) {
 141     // Selection manager has longer lifetime than any document accessible,
 142     // so that we are guaranteed that the notification is processed before
 143     // the selection manager is destroyed.
 144     document->HandleNotification<SelectionManager, nsISelection>
 145       (this, &SelectionManager::ProcessSelectionChanged, aSelection);
 146   }
 147
 148   return NS_OK;
 149 }
 150
 151 void
 152 SelectionManager::ProcessSelectionChanged(nsISelection* aSelection)
 153 {
 154   nsCOMPtr<nsISelectionPrivate> privSel(do_QueryInterface(aSelection));
 155
 156   int16_t type = 0;
 157   privSel->GetType(&type);
 158
 159   if (type == nsISelectionController::SELECTION_NORMAL)
 160     NormalSelectionChanged(aSelection);
 161
 162   else if (type == nsISelectionController::SELECTION_SPELLCHECK)
 163     SpellcheckSelectionChanged(aSelection);
 164 }
 165
 166 void
 167 SelectionManager::NormalSelectionChanged(nsISelection* aSelection)
 168 {
 169   mLastUsedSelection = do_GetWeakReference(aSelection);
 170
 171   int32_t rangeCount = 0;
 172   aSelection->GetRangeCount(&rangeCount);
 173   if (rangeCount == 0) {
 174     mLastTextAccessible = nullptr;
 175     return; // No selection
 176   }
 177
 178   HyperTextAccessible* textAcc =
 179     nsAccUtils::GetTextAccessibleFromSelection(aSelection);
 180   if (!textAcc)
 181     return;
 182
 183   int32_t caretOffset = -1;
 184   nsresult rv = textAcc->GetCaretOffset(&caretOffset);
 185   if (NS_FAILED(rv))
 186     return;
 187
 188   if (textAcc == mLastTextAccessible && caretOffset == mLastCaretOffset) {
 189     int32_t selectionCount = 0;
 190     textAcc->GetSelectionCount(&selectionCount);   // Don't swallow similar events when selecting text
 191     if (!selectionCount)
 192       return;  // Swallow duplicate caret event
 193   }
 194
 195   mLastCaretOffset = caretOffset;
 196   mLastTextAccessible = textAcc;
 197
 198   nsRefPtr<AccEvent> event = new AccCaretMoveEvent(mLastTextAccessible);
 199   mLastTextAccessible->Document()->FireDelayedEvent(event);
 200 }
 201
 202 void
 203 SelectionManager::SpellcheckSelectionChanged(nsISelection* aSelection)
 204 {
 205   // XXX: fire an event for accessible of focus node of the selection. If
 206   // spellchecking is enabled then we will fire the number of events for
 207   // the same accessible for newly appended range of the selection (for every
 208   // misspelled word). If spellchecking is disabled (for example,
 209   // @spellcheck="false" on html:body) then we won't fire any event.
 210
 211   HyperTextAccessible* hyperText =
 212     nsAccUtils::GetTextAccessibleFromSelection(aSelection);
 213   if (hyperText) {
 214     hyperText->Document()->
 215       FireDelayedEvent(nsIAccessibleEvent::EVENT_TEXT_ATTRIBUTE_CHANGED,
 216                        hyperText);
 217   }
 218 }
 219
 220 nsIntRect
 221 SelectionManager::GetCaretRect(nsIWidget** aWidget)
 222 {
 223   nsIntRect caretRect;
 224   NS_ENSURE_TRUE(aWidget, caretRect);
 225   *aWidget = nullptr;
 226
 227   if (!mLastTextAccessible) {
 228     return caretRect;    // Return empty rect
 229   }
 230
 231   nsINode *lastNodeWithCaret = mLastTextAccessible->GetNode();
 232   NS_ENSURE_TRUE(lastNodeWithCaret, caretRect);
 233
 234   nsIPresShell *presShell = nsCoreUtils::GetPresShellFor(lastNodeWithCaret);
 235   NS_ENSURE_TRUE(presShell, caretRect);
 236
 237   nsRefPtr<nsCaret> caret = presShell->GetCaret();
 238   NS_ENSURE_TRUE(caret, caretRect);
 239
 240   nsCOMPtr<nsISelection> caretSelection(do_QueryReferent(mLastUsedSelection));
 241   NS_ENSURE_TRUE(caretSelection, caretRect);
 242
 243   bool isVisible;
 244   caret->GetCaretVisible(&isVisible);
 245   if (!isVisible) {
 246     return nsIntRect();  // Return empty rect
 247   }
 248
 249   nsRect rect;
 250   nsIFrame* frame = caret->GetGeometry(caretSelection, &rect);
 251   if (!frame || rect.IsEmpty()) {
 252     return nsIntRect(); // Return empty rect
 253   }
 254
 255   nsPoint offset;
 256   // Offset from widget origin to the frame origin, which includes chrome
 257   // on the widget.
 258   *aWidget = frame->GetNearestWidget(offset);
 259   NS_ENSURE_TRUE(*aWidget, nsIntRect());
 260   rect.MoveBy(offset);
 261
 262   caretRect = rect.ToOutsidePixels(frame->PresContext()->AppUnitsPerDevPixel());
 263   // ((content screen origin) - (content offset in the widget)) = widget origin on the screen
 264   caretRect.MoveBy((*aWidget)->WidgetToScreenOffset() - (*aWidget)->GetClientOffset());
 265
 266   // Correct for character size, so that caret always matches the size of the character
 267   // This is important for font size transitions, and is necessary because the Gecko caret uses the
 268   // previous character's size as the user moves forward in the text by character.
 269   int32_t charX, charY, charWidth, charHeight;
 270   if (NS_SUCCEEDED(mLastTextAccessible->GetCharacterExtents(mLastCaretOffset, &charX, &charY,
 271                                                             &charWidth, &charHeight,
 272                                                             nsIAccessibleCoordinateType::COORDTYPE_SCREEN_RELATIVE))) {
 273     caretRect.height -= charY - caretRect.y;
 274     caretRect.y = charY;
 275   }
 276
 277   return caretRect;
 278 }