gecko-dev/accessible/base/nsCoreUtils.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsCoreUtils.h"

#include "nsIAccessibleTypes.h"

#include "nsIBaseWindow.h"
#include "nsIDocShellTreeOwner.h"
#include "mozilla/dom/Document.h"
#include "nsRange.h"
#include "nsXULElement.h"
#include "nsIDocShell.h"
#include "nsIObserverService.h"
#include "nsPresContext.h"
#include "nsIScrollableFrame.h"
#include "nsISelectionController.h"
#include "nsISimpleEnumerator.h"
#include "mozilla/dom/TouchEvent.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/EventListenerManager.h"
#include "mozilla/EventStateManager.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/PresShell.h"
#include "mozilla/TouchEvents.h"
#include "nsView.h"
#include "nsGkAtoms.h"

#include "nsComponentManagerUtils.h"

#include "XULTreeElement.h"
#include "nsTreeColumns.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/HTMLLabelElement.h"
#include "mozilla/dom/MouseEventBinding.h"
#include "mozilla/dom/Selection.h"

using namespace mozilla;

////////////////////////////////////////////////////////////////////////////////
// nsCoreUtils
////////////////////////////////////////////////////////////////////////////////

bool nsCoreUtils::IsLabelWithControl(nsIContent *aContent) {
  dom::HTMLLabelElement *label = dom::HTMLLabelElement::FromNode(aContent);
  if (label && label->GetControl()) return true;

  return false;
}

bool nsCoreUtils::HasClickListener(nsIContent *aContent) {
  NS_ENSURE_TRUE(aContent, false);
  EventListenerManager *listenerManager =
      aContent->GetExistingListenerManager();

  return listenerManager &&
         (listenerManager->HasListenersFor(nsGkAtoms::onclick) ||
          listenerManager->HasListenersFor(nsGkAtoms::onmousedown) ||
          listenerManager->HasListenersFor(nsGkAtoms::onmouseup));
}

void nsCoreUtils::DispatchClickEvent(XULTreeElement *aTree, int32_t aRowIndex,
                                     nsTreeColumn *aColumn,
                                     const nsAString &aPseudoElt) {
  RefPtr<dom::Element> tcElm = aTree->GetTreeBody();
  if (!tcElm) return;

  Document *document = tcElm->GetUncomposedDoc();
  if (!document) return;

  RefPtr<PresShell> presShell = document->GetPresShell();
  if (!presShell) {
    return;
  }

  // Ensure row is visible.
  aTree->EnsureRowIsVisible(aRowIndex);

  // Calculate x and y coordinates.
  nsresult rv;
  nsIntRect rect =
      aTree->GetCoordsForCellItem(aRowIndex, aColumn, aPseudoElt, rv);
  if (NS_FAILED(rv)) {
    return;
  }

  RefPtr<DOMRect> treeBodyRect = tcElm->GetBoundingClientRect();
  int32_t tcX = (int32_t)treeBodyRect->X();
  int32_t tcY = (int32_t)treeBodyRect->Y();

  // Dispatch mouse events.
  AutoWeakFrame tcFrame = tcElm->GetPrimaryFrame();
  nsIFrame *rootFrame = presShell->GetRootFrame();

  nsPoint offset;
  nsCOMPtr<nsIWidget> rootWidget =
      rootFrame->GetView()->GetNearestWidget(&offset);

  RefPtr<nsPresContext> presContext = presShell->GetPresContext();

  int32_t cnvdX = presContext->CSSPixelsToDevPixels(tcX + int32_t(rect.x) + 1) +
                  presContext->AppUnitsToDevPixels(offset.x);
  int32_t cnvdY = presContext->CSSPixelsToDevPixels(tcY + int32_t(rect.y) + 1) +
                  presContext->AppUnitsToDevPixels(offset.y);

  // XUL is just desktop, so there is no real reason for senfing touch events.
  DispatchMouseEvent(eMouseDown, cnvdX, cnvdY, tcElm, tcFrame, presShell,
                     rootWidget);

  DispatchMouseEvent(eMouseUp, cnvdX, cnvdY, tcElm, tcFrame, presShell,
                     rootWidget);
}

void nsCoreUtils::DispatchMouseEvent(EventMessage aMessage, int32_t aX,
                                     int32_t aY, nsIContent *aContent,
                                     nsIFrame *aFrame, PresShell *aPresShell,
                                     nsIWidget *aRootWidget) {
  WidgetMouseEvent event(true, aMessage, aRootWidget, WidgetMouseEvent::eReal,
                         WidgetMouseEvent::eNormal);

  event.mRefPoint = LayoutDeviceIntPoint(aX, aY);

  event.mClickCount = 1;
  event.mButton = MouseButton::eLeft;
  event.mTime = PR_IntervalNow();
  event.mInputSource = dom::MouseEvent_Binding::MOZ_SOURCE_UNKNOWN;

  nsEventStatus status = nsEventStatus_eIgnore;
  aPresShell->HandleEventWithTarget(&event, aFrame, aContent, &status);
}

void nsCoreUtils::DispatchTouchEvent(EventMessage aMessage, int32_t aX,
                                     int32_t aY, nsIContent *aContent,
                                     nsIFrame *aFrame, PresShell *aPresShell,
                                     nsIWidget *aRootWidget) {
  nsIDocShell *docShell = nullptr;
  if (aPresShell->GetDocument()) {
    docShell = aPresShell->GetDocument()->GetDocShell();
  }
  if (!dom::TouchEvent::PrefEnabled(docShell)) {
    return;
  }

  WidgetTouchEvent event(true, aMessage, aRootWidget);

  event.mTime = PR_IntervalNow();

  // XXX: Touch has an identifier of -1 to hint that it is synthesized.
  RefPtr<dom::Touch> t = new dom::Touch(-1, LayoutDeviceIntPoint(aX, aY),
                                        LayoutDeviceIntPoint(1, 1), 0.0f, 1.0f);
  t->SetTouchTarget(aContent);
  event.mTouches.AppendElement(t);
  nsEventStatus status = nsEventStatus_eIgnore;
  aPresShell->HandleEventWithTarget(&event, aFrame, aContent, &status);
}

uint32_t nsCoreUtils::GetAccessKeyFor(nsIContent *aContent) {
  // Accesskeys are registered by @accesskey attribute only. At first check
  // whether it is presented on the given element to avoid the slow
  // EventStateManager::GetRegisteredAccessKey() method.
  if (!aContent->IsElement() ||
      !aContent->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::accesskey))
    return 0;

  nsPresContext *presContext = aContent->OwnerDoc()->GetPresContext();
  if (!presContext) return 0;

  EventStateManager *esm = presContext->EventStateManager();
  if (!esm) return 0;

  return esm->GetRegisteredAccessKey(aContent->AsElement());
}

nsIContent *nsCoreUtils::GetDOMElementFor(nsIContent *aContent) {
  if (aContent->IsElement()) return aContent;

  if (aContent->IsText()) return aContent->GetFlattenedTreeParent();

  return nullptr;
}

nsINode *nsCoreUtils::GetDOMNodeFromDOMPoint(nsINode *aNode, uint32_t aOffset) {
  if (aNode && aNode->IsElement()) {
    uint32_t childCount = aNode->GetChildCount();
    NS_ASSERTION(aOffset <= childCount, "Wrong offset of the DOM point!");

    // The offset can be after last child of container node that means DOM point
    // is placed immediately after the last child. In this case use the DOM node
    // from the given DOM point is used as result node.
    if (aOffset != childCount) return aNode->GetChildAt_Deprecated(aOffset);
  }

  return aNode;
}

bool nsCoreUtils::IsAncestorOf(nsINode *aPossibleAncestorNode,
                               nsINode *aPossibleDescendantNode,
                               nsINode *aRootNode) {
  NS_ENSURE_TRUE(aPossibleAncestorNode && aPossibleDescendantNode, false);

  nsINode *parentNode = aPossibleDescendantNode;
  while ((parentNode = parentNode->GetParentNode()) &&
         parentNode != aRootNode) {
    if (parentNode == aPossibleAncestorNode) return true;
  }

  return false;
}

nsresult nsCoreUtils::ScrollSubstringTo(nsIFrame *aFrame, nsRange *aRange,
                                        uint32_t aScrollType) {
  nsIPresShell::ScrollAxis vertical, horizontal;
  ConvertScrollTypeToPercents(aScrollType, &vertical, &horizontal);

  return ScrollSubstringTo(aFrame, aRange, vertical, horizontal);
}

nsresult nsCoreUtils::ScrollSubstringTo(nsIFrame *aFrame, nsRange *aRange,
                                        nsIPresShell::ScrollAxis aVertical,
                                        nsIPresShell::ScrollAxis aHorizontal) {
  if (!aFrame || !aRange) {
    return NS_ERROR_FAILURE;
  }

  nsPresContext *presContext = aFrame->PresContext();

  nsCOMPtr<nsISelectionController> selCon;
  aFrame->GetSelectionController(presContext, getter_AddRefs(selCon));
  NS_ENSURE_TRUE(selCon, NS_ERROR_FAILURE);

  RefPtr<dom::Selection> selection =
      selCon->GetSelection(nsISelectionController::SELECTION_ACCESSIBILITY);

  selection->RemoveAllRanges(IgnoreErrors());
  selection->AddRange(*aRange, IgnoreErrors());

  selection->ScrollIntoView(nsISelectionController::SELECTION_ANCHOR_REGION,
                            aVertical, aHorizontal,
                            Selection::SCROLL_SYNCHRONOUS);

  selection->CollapseToStart(IgnoreErrors());

  return NS_OK;
}

void nsCoreUtils::ScrollFrameToPoint(nsIFrame *aScrollableFrame,
                                     nsIFrame *aFrame,
                                     const nsIntPoint &aPoint) {
  nsIScrollableFrame *scrollableFrame = do_QueryFrame(aScrollableFrame);
  if (!scrollableFrame) return;

  nsPoint point =
      ToAppUnits(aPoint, aFrame->PresContext()->AppUnitsPerDevPixel());
  nsRect frameRect = aFrame->GetScreenRectInAppUnits();
  nsPoint deltaPoint = point - frameRect.TopLeft();

  nsPoint scrollPoint = scrollableFrame->GetScrollPosition();
  scrollPoint -= deltaPoint;

  scrollableFrame->ScrollTo(scrollPoint, ScrollMode::eInstant);
}

void nsCoreUtils::ConvertScrollTypeToPercents(
    uint32_t aScrollType, nsIPresShell::ScrollAxis *aVertical,
    nsIPresShell::ScrollAxis *aHorizontal) {
  int16_t whereY, whereX;
  nsIPresShell::WhenToScroll whenY, whenX;
  switch (aScrollType) {
    case nsIAccessibleScrollType::SCROLL_TYPE_TOP_LEFT:
      whereY = nsIPresShell::SCROLL_TOP;
      whenY = nsIPresShell::SCROLL_ALWAYS;
      whereX = nsIPresShell::SCROLL_LEFT;
      whenX = nsIPresShell::SCROLL_ALWAYS;
      break;
    case nsIAccessibleScrollType::SCROLL_TYPE_BOTTOM_RIGHT:
      whereY = nsIPresShell::SCROLL_BOTTOM;
      whenY = nsIPresShell::SCROLL_ALWAYS;
      whereX = nsIPresShell::SCROLL_RIGHT;
      whenX = nsIPresShell::SCROLL_ALWAYS;
      break;
    case nsIAccessibleScrollType::SCROLL_TYPE_TOP_EDGE:
      whereY = nsIPresShell::SCROLL_TOP;
      whenY = nsIPresShell::SCROLL_ALWAYS;
      whereX = nsIPresShell::SCROLL_MINIMUM;
      whenX = nsIPresShell::SCROLL_IF_NOT_FULLY_VISIBLE;
      break;
    case nsIAccessibleScrollType::SCROLL_TYPE_BOTTOM_EDGE:
      whereY = nsIPresShell::SCROLL_BOTTOM;
      whenY = nsIPresShell::SCROLL_ALWAYS;
      whereX = nsIPresShell::SCROLL_MINIMUM;
      whenX = nsIPresShell::SCROLL_IF_NOT_FULLY_VISIBLE;
      break;
    case nsIAccessibleScrollType::SCROLL_TYPE_LEFT_EDGE:
      whereY = nsIPresShell::SCROLL_MINIMUM;
      whenY = nsIPresShell::SCROLL_IF_NOT_FULLY_VISIBLE;
      whereX = nsIPresShell::SCROLL_LEFT;
      whenX = nsIPresShell::SCROLL_ALWAYS;
      break;
    case nsIAccessibleScrollType::SCROLL_TYPE_RIGHT_EDGE:
      whereY = nsIPresShell::SCROLL_MINIMUM;
      whenY = nsIPresShell::SCROLL_IF_NOT_FULLY_VISIBLE;
      whereX = nsIPresShell::SCROLL_RIGHT;
      whenX = nsIPresShell::SCROLL_ALWAYS;
      break;
    default:
      whereY = nsIPresShell::SCROLL_MINIMUM;
      whenY = nsIPresShell::SCROLL_IF_NOT_FULLY_VISIBLE;
      whereX = nsIPresShell::SCROLL_MINIMUM;
      whenX = nsIPresShell::SCROLL_IF_NOT_FULLY_VISIBLE;
  }
  *aVertical = nsIPresShell::ScrollAxis(whereY, whenY);
  *aHorizontal = nsIPresShell::ScrollAxis(whereX, whenX);
}

nsIntPoint nsCoreUtils::GetScreenCoordsForWindow(nsINode *aNode) {
  nsIntPoint coords(0, 0);
  nsCOMPtr<nsIDocShellTreeItem> treeItem(GetDocShellFor(aNode));
  if (!treeItem) return coords;

  nsCOMPtr<nsIDocShellTreeOwner> treeOwner;
  treeItem->GetTreeOwner(getter_AddRefs(treeOwner));
  if (!treeOwner) return coords;

  nsCOMPtr<nsIBaseWindow> baseWindow = do_QueryInterface(treeOwner);
  if (baseWindow)
    baseWindow->GetPosition(&coords.x, &coords.y);  // in device pixels

  return coords;
}

already_AddRefed<nsIDocShell> nsCoreUtils::GetDocShellFor(nsINode *aNode) {
  if (!aNode) return nullptr;

  nsCOMPtr<nsIDocShell> docShell = aNode->OwnerDoc()->GetDocShell();
  return docShell.forget();
}

bool nsCoreUtils::IsRootDocument(Document *aDocument) {
  nsCOMPtr<nsIDocShellTreeItem> docShellTreeItem = aDocument->GetDocShell();
  NS_ASSERTION(docShellTreeItem, "No document shell for document!");

  nsCOMPtr<nsIDocShellTreeItem> parentTreeItem;
  docShellTreeItem->GetParent(getter_AddRefs(parentTreeItem));

  return !parentTreeItem;
}

bool nsCoreUtils::IsContentDocument(Document *aDocument) {
  nsCOMPtr<nsIDocShellTreeItem> docShellTreeItem = aDocument->GetDocShell();
  NS_ASSERTION(docShellTreeItem, "No document shell tree item for document!");

  return (docShellTreeItem->ItemType() == nsIDocShellTreeItem::typeContent);
}

bool nsCoreUtils::IsTabDocument(Document *aDocumentNode) {
  nsCOMPtr<nsIDocShellTreeItem> treeItem(aDocumentNode->GetDocShell());

  nsCOMPtr<nsIDocShellTreeItem> parentTreeItem;
  treeItem->GetParent(getter_AddRefs(parentTreeItem));

  // Tab document running in own process doesn't have parent.
  if (XRE_IsContentProcess()) return !parentTreeItem;

  // Parent of docshell for tab document running in chrome process is root.
  nsCOMPtr<nsIDocShellTreeItem> rootTreeItem;
  treeItem->GetRootTreeItem(getter_AddRefs(rootTreeItem));

  return parentTreeItem == rootTreeItem;
}

bool nsCoreUtils::IsErrorPage(Document *aDocument) {
  nsIURI *uri = aDocument->GetDocumentURI();
  bool isAboutScheme = false;
  uri->SchemeIs("about", &isAboutScheme);
  if (!isAboutScheme) return false;

  nsAutoCString path;
  uri->GetPathQueryRef(path);

  NS_NAMED_LITERAL_CSTRING(neterror, "neterror");
  NS_NAMED_LITERAL_CSTRING(certerror, "certerror");

  return StringBeginsWith(path, neterror) || StringBeginsWith(path, certerror);
}

bool nsCoreUtils::GetID(nsIContent *aContent, nsAString &aID) {
  return aContent->IsElement() &&
         aContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::id, aID);
}

bool nsCoreUtils::GetUIntAttr(nsIContent *aContent, nsAtom *aAttr,
                              int32_t *aUInt) {
  nsAutoString value;
  if (!aContent->IsElement()) {
    return false;
  }
  aContent->AsElement()->GetAttr(kNameSpaceID_None, aAttr, value);
  if (!value.IsEmpty()) {
    nsresult error = NS_OK;
    int32_t integer = value.ToInteger(&error);
    if (NS_SUCCEEDED(error) && integer > 0) {
      *aUInt = integer;
      return true;
    }
  }

  return false;
}

void nsCoreUtils::GetLanguageFor(nsIContent *aContent, nsIContent *aRootContent,
                                 nsAString &aLanguage) {
  aLanguage.Truncate();

  nsIContent *walkUp = aContent;
  while (walkUp && walkUp != aRootContent &&
         (!walkUp->IsElement() ||
          !walkUp->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::lang,
                                        aLanguage)))
    walkUp = walkUp->GetParent();
}

XULTreeElement *nsCoreUtils::GetTree(nsIContent *aContent) {
  // Find DOMNode's parents recursively until reach the <tree> tag
  nsIContent *currentContent = aContent;
  while (currentContent) {
    if (currentContent->NodeInfo()->Equals(nsGkAtoms::tree, kNameSpaceID_XUL)) {
      return XULTreeElement::FromNode(currentContent);
    }
    currentContent = currentContent->GetFlattenedTreeParent();
  }

  return nullptr;
}

already_AddRefed<nsTreeColumn> nsCoreUtils::GetFirstSensibleColumn(
    XULTreeElement *aTree) {
  RefPtr<nsTreeColumns> cols = aTree->GetColumns();
  if (!cols) return nullptr;

  RefPtr<nsTreeColumn> column = cols->GetFirstColumn();
  if (column && IsColumnHidden(column)) return GetNextSensibleColumn(column);

  return column.forget();
}

uint32_t nsCoreUtils::GetSensibleColumnCount(XULTreeElement *aTree) {
  uint32_t count = 0;

  RefPtr<nsTreeColumns> cols = aTree->GetColumns();
  if (!cols) return count;

  nsTreeColumn *column = cols->GetFirstColumn();

  while (column) {
    if (!IsColumnHidden(column)) count++;

    column = column->GetNext();
  }

  return count;
}

already_AddRefed<nsTreeColumn> nsCoreUtils::GetSensibleColumnAt(
    XULTreeElement *aTree, uint32_t aIndex) {
  uint32_t idx = aIndex;

  nsCOMPtr<nsTreeColumn> column = GetFirstSensibleColumn(aTree);
  while (column) {
    if (idx == 0) return column.forget();

    idx--;
    column = GetNextSensibleColumn(column);
  }

  return nullptr;
}

already_AddRefed<nsTreeColumn> nsCoreUtils::GetNextSensibleColumn(
    nsTreeColumn *aColumn) {
  RefPtr<nsTreeColumn> nextColumn = aColumn->GetNext();

  while (nextColumn && IsColumnHidden(nextColumn)) {
    nextColumn = nextColumn->GetNext();
  }

  return nextColumn.forget();
}

already_AddRefed<nsTreeColumn> nsCoreUtils::GetPreviousSensibleColumn(
    nsTreeColumn *aColumn) {
  RefPtr<nsTreeColumn> prevColumn = aColumn->GetPrevious();

  while (prevColumn && IsColumnHidden(prevColumn)) {
    prevColumn = prevColumn->GetPrevious();
  }

  return prevColumn.forget();
}

bool nsCoreUtils::IsColumnHidden(nsTreeColumn *aColumn) {
  Element *element = aColumn->Element();
  return element->AttrValueIs(kNameSpaceID_None, nsGkAtoms::hidden,
                              nsGkAtoms::_true, eCaseMatters);
}

void nsCoreUtils::ScrollTo(PresShell *aPresShell, nsIContent *aContent,
                           uint32_t aScrollType) {
  nsIPresShell::ScrollAxis vertical, horizontal;
  ConvertScrollTypeToPercents(aScrollType, &vertical, &horizontal);
  aPresShell->ScrollContentIntoView(aContent, vertical, horizontal,
                                    nsIPresShell::SCROLL_OVERFLOW_HIDDEN);
}

bool nsCoreUtils::IsWhitespaceString(const nsAString &aString) {
  nsAString::const_char_iterator iterBegin, iterEnd;

  aString.BeginReading(iterBegin);
  aString.EndReading(iterEnd);

  while (iterBegin != iterEnd && IsWhitespace(*iterBegin)) ++iterBegin;

  return iterBegin == iterEnd;
}

bool nsCoreUtils::AccEventObserversExist() {
  nsCOMPtr<nsIObserverService> obsService = services::GetObserverService();
  NS_ENSURE_TRUE(obsService, false);

  nsCOMPtr<nsISimpleEnumerator> observers;
  obsService->EnumerateObservers(NS_ACCESSIBLE_EVENT_TOPIC,
                                 getter_AddRefs(observers));
  NS_ENSURE_TRUE(observers, false);

  bool hasObservers = false;
  observers->HasMoreElements(&hasObservers);

  return hasObservers;
}

void nsCoreUtils::DispatchAccEvent(RefPtr<nsIAccessibleEvent> event) {
  nsCOMPtr<nsIObserverService> obsService = services::GetObserverService();
  NS_ENSURE_TRUE_VOID(obsService);

  obsService->NotifyObservers(event, NS_ACCESSIBLE_EVENT_TOPIC, nullptr);
}