gecko/accessible/base/nsAccUtils.cpp

424 lines
11 KiB
C++

/* -*- 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 "nsAccUtils.h"
#include "Accessible-inl.h"
#include "ARIAMap.h"
#include "nsAccessibilityService.h"
#include "nsCoreUtils.h"
#include "DocAccessible.h"
#include "HyperTextAccessible.h"
#include "nsIAccessibleTypes.h"
#include "Role.h"
#include "States.h"
#include "TextLeafAccessible.h"
#include "nsIDOMXULContainerElement.h"
#include "nsIPersistentProperties2.h"
#include "mozilla/dom/Element.h"
using namespace mozilla;
using namespace mozilla::a11y;
void
nsAccUtils::GetAccAttr(nsIPersistentProperties *aAttributes,
nsIAtom *aAttrName, nsAString& aAttrValue)
{
aAttrValue.Truncate();
aAttributes->GetStringProperty(nsAtomCString(aAttrName), aAttrValue);
}
void
nsAccUtils::SetAccAttr(nsIPersistentProperties *aAttributes,
nsIAtom *aAttrName, const nsAString& aAttrValue)
{
nsAutoString oldValue;
aAttributes->SetStringProperty(nsAtomCString(aAttrName), aAttrValue, oldValue);
}
void
nsAccUtils::SetAccAttr(nsIPersistentProperties *aAttributes,
nsIAtom* aAttrName, nsIAtom* aAttrValue)
{
nsAutoString oldValue;
aAttributes->SetStringProperty(nsAtomCString(aAttrName),
nsAtomString(aAttrValue), oldValue);
}
void
nsAccUtils::SetAccGroupAttrs(nsIPersistentProperties *aAttributes,
int32_t aLevel, int32_t aSetSize,
int32_t aPosInSet)
{
nsAutoString value;
if (aLevel) {
value.AppendInt(aLevel);
SetAccAttr(aAttributes, nsGkAtoms::level, value);
}
if (aSetSize && aPosInSet) {
value.Truncate();
value.AppendInt(aPosInSet);
SetAccAttr(aAttributes, nsGkAtoms::posinset, value);
value.Truncate();
value.AppendInt(aSetSize);
SetAccAttr(aAttributes, nsGkAtoms::setsize, value);
}
}
int32_t
nsAccUtils::GetDefaultLevel(Accessible* aAccessible)
{
roles::Role role = aAccessible->Role();
if (role == roles::OUTLINEITEM)
return 1;
if (role == roles::ROW) {
Accessible* parent = aAccessible->Parent();
// It is a row inside flatten treegrid. Group level is always 1 until it
// is overriden by aria-level attribute.
if (parent && parent->Role() == roles::TREE_TABLE)
return 1;
}
return 0;
}
int32_t
nsAccUtils::GetARIAOrDefaultLevel(Accessible* aAccessible)
{
int32_t level = 0;
nsCoreUtils::GetUIntAttr(aAccessible->GetContent(),
nsGkAtoms::aria_level, &level);
if (level != 0)
return level;
return GetDefaultLevel(aAccessible);
}
int32_t
nsAccUtils::GetLevelForXULContainerItem(nsIContent *aContent)
{
nsCOMPtr<nsIDOMXULContainerItemElement> item(do_QueryInterface(aContent));
if (!item)
return 0;
nsCOMPtr<nsIDOMXULContainerElement> container;
item->GetParentContainer(getter_AddRefs(container));
if (!container)
return 0;
// Get level of the item.
int32_t level = -1;
while (container) {
level++;
nsCOMPtr<nsIDOMXULContainerElement> parentContainer;
container->GetParentContainer(getter_AddRefs(parentContainer));
parentContainer.swap(container);
}
return level;
}
void
nsAccUtils::SetLiveContainerAttributes(nsIPersistentProperties *aAttributes,
nsIContent *aStartContent,
nsIContent *aTopContent)
{
nsAutoString live, relevant, busy;
nsIContent *ancestor = aStartContent;
while (ancestor) {
// container-relevant attribute
if (relevant.IsEmpty() &&
HasDefinedARIAToken(ancestor, nsGkAtoms::aria_relevant) &&
ancestor->GetAttr(kNameSpaceID_None, nsGkAtoms::aria_relevant, relevant))
SetAccAttr(aAttributes, nsGkAtoms::containerRelevant, relevant);
// container-live, and container-live-role attributes
if (live.IsEmpty()) {
nsRoleMapEntry* role = aria::GetRoleMap(ancestor);
if (HasDefinedARIAToken(ancestor, nsGkAtoms::aria_live)) {
ancestor->GetAttr(kNameSpaceID_None, nsGkAtoms::aria_live,
live);
} else if (role) {
GetLiveAttrValue(role->liveAttRule, live);
}
if (!live.IsEmpty()) {
SetAccAttr(aAttributes, nsGkAtoms::containerLive, live);
if (role) {
SetAccAttr(aAttributes, nsGkAtoms::containerLiveRole,
role->ARIARoleString());
}
}
}
// container-atomic attribute
if (ancestor->AttrValueIs(kNameSpaceID_None, nsGkAtoms::aria_atomic,
nsGkAtoms::_true, eCaseMatters)) {
SetAccAttr(aAttributes, nsGkAtoms::containerAtomic,
NS_LITERAL_STRING("true"));
}
// container-busy attribute
if (busy.IsEmpty() &&
HasDefinedARIAToken(ancestor, nsGkAtoms::aria_busy) &&
ancestor->GetAttr(kNameSpaceID_None, nsGkAtoms::aria_busy, busy))
SetAccAttr(aAttributes, nsGkAtoms::containerBusy, busy);
if (ancestor == aTopContent)
break;
ancestor = ancestor->GetParent();
if (!ancestor)
ancestor = aTopContent; // Use <body>/<frameset>
}
}
bool
nsAccUtils::HasDefinedARIAToken(nsIContent *aContent, nsIAtom *aAtom)
{
NS_ASSERTION(aContent, "aContent is null in call to HasDefinedARIAToken!");
if (!aContent->HasAttr(kNameSpaceID_None, aAtom) ||
aContent->AttrValueIs(kNameSpaceID_None, aAtom,
nsGkAtoms::_empty, eCaseMatters) ||
aContent->AttrValueIs(kNameSpaceID_None, aAtom,
nsGkAtoms::_undefined, eCaseMatters)) {
return false;
}
return true;
}
nsIAtom*
nsAccUtils::GetARIAToken(dom::Element* aElement, nsIAtom* aAttr)
{
if (!HasDefinedARIAToken(aElement, aAttr))
return nsGkAtoms::_empty;
static nsIContent::AttrValuesArray tokens[] =
{ &nsGkAtoms::_false, &nsGkAtoms::_true,
&nsGkAtoms::mixed, nullptr};
int32_t idx = aElement->FindAttrValueIn(kNameSpaceID_None,
aAttr, tokens, eCaseMatters);
if (idx >= 0)
return *(tokens[idx]);
return nullptr;
}
Accessible*
nsAccUtils::GetSelectableContainer(Accessible* aAccessible, uint64_t aState)
{
if (!aAccessible)
return nullptr;
if (!(aState & states::SELECTABLE))
return nullptr;
Accessible* parent = aAccessible;
while ((parent = parent->Parent()) && !parent->IsSelect()) {
if (parent->Role() == roles::PANE)
return nullptr;
}
return parent;
}
bool
nsAccUtils::IsARIASelected(Accessible* aAccessible)
{
return aAccessible->GetContent()->
AttrValueIs(kNameSpaceID_None, nsGkAtoms::aria_selected,
nsGkAtoms::_true, eCaseMatters);
}
HyperTextAccessible*
nsAccUtils::GetTextContainer(nsINode* aNode)
{
// Get text accessible containing the result node.
DocAccessible* doc =
GetAccService()->GetDocAccessible(aNode->OwnerDoc());
Accessible* accessible =
doc ? doc->GetAccessibleOrContainer(aNode) : nullptr;
if (!accessible)
return nullptr;
do {
HyperTextAccessible* textAcc = accessible->AsHyperText();
if (textAcc)
return textAcc;
accessible = accessible->Parent();
} while (accessible);
return nullptr;
}
nsIntPoint
nsAccUtils::ConvertToScreenCoords(int32_t aX, int32_t aY,
uint32_t aCoordinateType,
Accessible* aAccessible)
{
nsIntPoint coords(aX, aY);
switch (aCoordinateType) {
case nsIAccessibleCoordinateType::COORDTYPE_SCREEN_RELATIVE:
break;
case nsIAccessibleCoordinateType::COORDTYPE_WINDOW_RELATIVE:
{
coords += nsCoreUtils::GetScreenCoordsForWindow(aAccessible->GetNode());
break;
}
case nsIAccessibleCoordinateType::COORDTYPE_PARENT_RELATIVE:
{
coords += GetScreenCoordsForParent(aAccessible);
break;
}
default:
NS_NOTREACHED("invalid coord type!");
}
return coords;
}
void
nsAccUtils::ConvertScreenCoordsTo(int32_t *aX, int32_t *aY,
uint32_t aCoordinateType,
Accessible* aAccessible)
{
switch (aCoordinateType) {
case nsIAccessibleCoordinateType::COORDTYPE_SCREEN_RELATIVE:
break;
case nsIAccessibleCoordinateType::COORDTYPE_WINDOW_RELATIVE:
{
nsIntPoint coords = nsCoreUtils::GetScreenCoordsForWindow(aAccessible->GetNode());
*aX -= coords.x;
*aY -= coords.y;
break;
}
case nsIAccessibleCoordinateType::COORDTYPE_PARENT_RELATIVE:
{
nsIntPoint coords = GetScreenCoordsForParent(aAccessible);
*aX -= coords.x;
*aY -= coords.y;
break;
}
default:
NS_NOTREACHED("invalid coord type!");
}
}
nsIntPoint
nsAccUtils::GetScreenCoordsForParent(Accessible* aAccessible)
{
Accessible* parent = aAccessible->Parent();
if (!parent)
return nsIntPoint(0, 0);
nsIFrame *parentFrame = parent->GetFrame();
if (!parentFrame)
return nsIntPoint(0, 0);
nsRect rect = parentFrame->GetScreenRectInAppUnits();
return nsPoint(rect.x, rect.y).
ToNearestPixels(parentFrame->PresContext()->AppUnitsPerDevPixel());
}
bool
nsAccUtils::GetLiveAttrValue(uint32_t aRule, nsAString& aValue)
{
switch (aRule) {
case eOffLiveAttr:
aValue = NS_LITERAL_STRING("off");
return true;
case ePoliteLiveAttr:
aValue = NS_LITERAL_STRING("polite");
return true;
}
return false;
}
#ifdef DEBUG
bool
nsAccUtils::IsTextInterfaceSupportCorrect(Accessible* aAccessible)
{
// Don't test for accessible docs, it makes us create accessibles too
// early and fire mutation events before we need to
if (aAccessible->IsDoc())
return true;
bool foundText = false;
uint32_t childCount = aAccessible->ChildCount();
for (uint32_t childIdx = 0; childIdx < childCount; childIdx++) {
Accessible* child = aAccessible->GetChildAt(childIdx);
if (!IsEmbeddedObject(child)) {
foundText = true;
break;
}
}
return !foundText || aAccessible->IsHyperText();
}
#endif
uint32_t
nsAccUtils::TextLength(Accessible* aAccessible)
{
if (IsEmbeddedObject(aAccessible))
return 1;
TextLeafAccessible* textLeaf = aAccessible->AsTextLeaf();
if (textLeaf)
return textLeaf->Text().Length();
// For list bullets (or anything other accessible which would compute its own
// text. They don't have their own frame.
// XXX In the future, list bullets may have frame and anon content, so
// we should be able to remove this at that point
nsAutoString text;
aAccessible->AppendTextTo(text); // Get all the text
return text.Length();
}
bool
nsAccUtils::MustPrune(Accessible* aAccessible)
{
roles::Role role = aAccessible->Role();
// Don't prune the tree for certain roles if the tree is more complex than
// a single text leaf.
return
(role == roles::MENUITEM ||
role == roles::COMBOBOX_OPTION ||
role == roles::OPTION ||
role == roles::ENTRY ||
role == roles::FLAT_EQUATION ||
role == roles::PASSWORD_TEXT ||
role == roles::PUSHBUTTON ||
role == roles::TOGGLE_BUTTON ||
role == roles::GRAPHIC ||
role == roles::SLIDER ||
role == roles::PROGRESSBAR ||
role == roles::SEPARATOR) &&
aAccessible->ContentChildCount() == 1 &&
aAccessible->ContentChildAt(0)->IsTextLeaf();
}