Source/WebCore/accessibility/atk/WebKitAccessibleUtil.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2008 Nuanti Ltd.
  * Copyright (C) 2009 Jan Alonzo
  * Copyright (C) 2009, 2010, 2012 Igalia S.L.
  *
  * Portions from Mozilla a11y, copyright as follows:
  *
  * The Original Code is mozilla.org code.
  *
  * The Initial Developer of the Original Code is
  * Sun Microsystems, Inc.
  * Portions created by the Initial Developer are Copyright (C) 2002
  * the Initial Developer. All Rights Reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */

 #include "config.h"
 #include "WebKitAccessibleUtil.h"

 #if ENABLE(ACCESSIBILITY) && USE(ATK)

 #include "AXObjectCache.h"
 #include "AccessibilityObject.h"
 #include "FrameView.h"
 #include "IntRect.h"
 #include "Node.h"
 #include "Range.h"
 #include "RenderObject.h"
 #include "TextIterator.h"
 #include "VisibleSelection.h"

 #include <wtf/text/AtomString.h>
 #include <wtf/text/CString.h>

 using namespace WebCore;

 AtkAttributeSet* addToAtkAttributeSet(AtkAttributeSet* attributeSet, const char* name, const char* value)
 {
     AtkAttribute* attribute = static_cast<AtkAttribute*>(g_malloc(sizeof(AtkAttribute)));
     attribute->name = g_strdup(name);
     attribute->value = g_strdup(value);
     attributeSet = g_slist_prepend(attributeSet, attribute);
     return attributeSet;
 }

 void contentsRelativeToAtkCoordinateType(AccessibilityObject* coreObject, AtkCoordType coordType, IntRect rect, gint* x, gint* y, gint* width, gint* height)
 {
     FrameView* frameView = coreObject->documentFrameView();

     if (frameView) {
         switch (coordType) {
         case ATK_XY_WINDOW:
             rect = frameView->contentsToWindow(rect);
             break;
         case ATK_XY_SCREEN:
             rect = frameView->contentsToScreen(rect);
             break;
 #if ATK_CHECK_VERSION(2, 30, 0)
         case ATK_XY_PARENT:
             RELEASE_ASSERT_NOT_REACHED();
 #endif
         }
     }

     if (x)
         *x = rect.x();
     if (y)
         *y = rect.y();
     if (width)
         *width = rect.width();
     if (height)
         *height = rect.height();
 }

 // FIXME: Different kinds of elements are putting the title tag to use
 // in different AX fields. This might not be 100% correct but we will
 // keep it now in order to achieve consistency with previous behavior.
 static bool titleTagShouldBeUsedInDescriptionField(AccessibilityObject* coreObject)
 {
     return (coreObject->isLink() && !coreObject->isImageMapLink()) || coreObject->isImage();
 }

 // This should be the "visible" text that's actually on the screen if possible.
 // If there's alternative text, that can override the title.
 String accessibilityTitle(AccessibilityObject* coreObject)
 {
     Vector<AccessibilityText> textOrder;
     coreObject->accessibilityText(textOrder);

     for (const AccessibilityText& text : textOrder) {
         // Once we encounter visible text, or the text from our children that should be used foremost.
         if (text.textSource == AccessibilityTextSource::Visible || text.textSource == AccessibilityTextSource::Children)
             return text.text;

         // If there's an element that labels this object and it's not exposed, then we should use
         // that text as our title.
         if (text.textSource == AccessibilityTextSource::LabelByElement && !coreObject->titleUIElement())
             return text.text;

         // Elements of role AccessibilityRole::Toolbar will return its title as AccessibilityTextSource::Alternative.
         if (coreObject->roleValue() == AccessibilityRole::Toolbar && text.textSource == AccessibilityTextSource::Alternative)
             return text.text;

         // FIXME: The title tag is used in certain cases for the title. This usage should
         // probably be in the description field since it's not "visible".
         if (text.textSource == AccessibilityTextSource::TitleTag && !titleTagShouldBeUsedInDescriptionField(coreObject))
             return text.text;
     }

     return String();
 }

 String accessibilityDescription(AccessibilityObject* coreObject)
 {
     Vector<AccessibilityText> textOrder;
     coreObject->accessibilityText(textOrder);

     bool visibleTextAvailable = false;
     for (const AccessibilityText& text : textOrder) {
         if (text.textSource == AccessibilityTextSource::Alternative)
             return text.text;

         switch (text.textSource) {
         case AccessibilityTextSource::Visible:
         case AccessibilityTextSource::Children:
         case AccessibilityTextSource::LabelByElement:
             visibleTextAvailable = true;
         default:
             break;
         }

         if (text.textSource == AccessibilityTextSource::TitleTag && !visibleTextAvailable)
             return text.text;
     }

     return String();
 }

 bool selectionBelongsToObject(AccessibilityObject* coreObject, VisibleSelection& selection)
 {
     if (!coreObject || !coreObject->isAccessibilityRenderObject())
         return false;

     auto range = selection.firstRange();
     return range && intersects<ComposedTree>(*range, *coreObject->node());
 }

 AXCoreObject* objectFocusedAndCaretOffsetUnignored(AXCoreObject* referenceObject, int& offset)
 {
     // Indication that something bogus has transpired.
     offset = -1;

     Document* document = referenceObject->document();
     if (!document)
         return nullptr;

     Node* focusedNode = referenceObject->selection().end().containerNode();
     if (!focusedNode)
         return nullptr;

     RenderObject* focusedRenderer = focusedNode->renderer();
     if (!focusedRenderer)
         return nullptr;

     AccessibilityObject* focusedObject = document->axObjectCache()->getOrCreate(focusedRenderer);
     if (!focusedObject)
         return nullptr;

     // Look for the actual (not ignoring accessibility) selected object.
     AXCoreObject* firstUnignoredParent = focusedObject;
     if (firstUnignoredParent->accessibilityIsIgnored())
         firstUnignoredParent = firstUnignoredParent->parentObjectUnignored();
     if (!firstUnignoredParent)
         return nullptr;

     // Don't ignore links if the offset is being requested for a link
     // or if the link is a block.
     if (!referenceObject->isLink() && firstUnignoredParent->isLink()
         && !(firstUnignoredParent->renderer() && !firstUnignoredParent->renderer()->isInline()))
         firstUnignoredParent = firstUnignoredParent->parentObjectUnignored();
     if (!firstUnignoredParent)
         return nullptr;

     // The reference object must either coincide with the focused
     // object being considered, or be a descendant of it.
     if (referenceObject->isDescendantOfObject(firstUnignoredParent))
         referenceObject = firstUnignoredParent;

     Node* startNode = nullptr;
     if (firstUnignoredParent != referenceObject || firstUnignoredParent->isTextControl()) {
         // We need to use the first child's node of the reference
         // object as the start point to calculate the caret offset
         // because we want it to be relative to the object of
         // reference, not just to the focused object (which could have
         // previous siblings which should be taken into account too).
         AXCoreObject* axFirstChild = referenceObject->firstChild();
         if (axFirstChild)
             startNode = axFirstChild->node();
     }
     // Getting the Position of a PseudoElement now triggers an assertion.
     // This can occur when clicking on empty space in a render block.
     if (!startNode || startNode->isPseudoElement())
         startNode = firstUnignoredParent->node();

     // Check if the node for the first parent object not ignoring
     // accessibility is null again before using it. This might happen
     // with certain kind of accessibility objects, such as the root
     // one (the scroller containing the webArea object).
     if (!startNode)
         return nullptr;

     VisiblePosition startPosition = VisiblePosition(positionBeforeNode(startNode));
     VisiblePosition endPosition = firstUnignoredParent->selection().visibleEnd();

     if (startPosition == endPosition)
         offset = 0;
     else if (!isStartOfLine(endPosition)) {
         auto range = makeSimpleRange(startPosition, endPosition.previous());
         offset = (range ? characterCount(*range, TextIteratorBehavior::EmitsCharactersBetweenAllVisiblePositions) : 0) + 1;
     } else {
         auto range = makeSimpleRange(startPosition, endPosition);
         offset = range ? characterCount(*range, TextIteratorBehavior::EmitsCharactersBetweenAllVisiblePositions) : 0;
     }

     return firstUnignoredParent;
 }

 #endif
	/*
	* Copyright (C) 2008 Nuanti Ltd.
	* Copyright (C) 2009 Jan Alonzo
	* Copyright (C) 2009, 2010, 2012 Igalia S.L.
	*
	* Portions from Mozilla a11y, copyright as follows:
	*
	* The Original Code is mozilla.org code.
	*
	* The Initial Developer of the Original Code is
	* Sun Microsystems, Inc.
	* Portions created by the Initial Developer are Copyright (C) 2002
	* the Initial Developer. All Rights Reserved.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Library General Public
	* License as published by the Free Software Foundation; either
	* version 2 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Library General Public License for more details.
	*
	* You should have received a copy of the GNU Library General Public License
	* along with this library; see the file COPYING.LIB. If not, write to
	* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
	* Boston, MA 02110-1301, USA.
	*/

	#include "config.h"
	#include "WebKitAccessibleUtil.h"

	#if ENABLE(ACCESSIBILITY) && USE(ATK)

	#include "AXObjectCache.h"
	#include "AccessibilityObject.h"
	#include "FrameView.h"
	#include "IntRect.h"
	#include "Node.h"
	#include "Range.h"
	#include "RenderObject.h"
	#include "TextIterator.h"
	#include "VisibleSelection.h"

	#include <wtf/text/AtomString.h>
	#include <wtf/text/CString.h>

	using namespace WebCore;

	AtkAttributeSet* addToAtkAttributeSet(AtkAttributeSet* attributeSet, const char* name, const char* value)
	{
	AtkAttribute* attribute = static_cast<AtkAttribute*>(g_malloc(sizeof(AtkAttribute)));
	attribute->name = g_strdup(name);
	attribute->value = g_strdup(value);
	attributeSet = g_slist_prepend(attributeSet, attribute);
	return attributeSet;
	}

	void contentsRelativeToAtkCoordinateType(AccessibilityObject* coreObject, AtkCoordType coordType, IntRect rect, gint* x, gint* y, gint* width, gint* height)
	{
	FrameView* frameView = coreObject->documentFrameView();

	if (frameView) {
	switch (coordType) {
	case ATK_XY_WINDOW:
	rect = frameView->contentsToWindow(rect);
	break;
	case ATK_XY_SCREEN:
	rect = frameView->contentsToScreen(rect);
	break;
	#if ATK_CHECK_VERSION(2, 30, 0)
	case ATK_XY_PARENT:
	RELEASE_ASSERT_NOT_REACHED();
	#endif
	}
	}

	if (x)
	*x = rect.x();
	if (y)
	*y = rect.y();
	if (width)
	*width = rect.width();
	if (height)
	*height = rect.height();
	}

	// FIXME: Different kinds of elements are putting the title tag to use
	// in different AX fields. This might not be 100% correct but we will
	// keep it now in order to achieve consistency with previous behavior.
	static bool titleTagShouldBeUsedInDescriptionField(AccessibilityObject* coreObject)
	{
	return (coreObject->isLink() && !coreObject->isImageMapLink()) \|\| coreObject->isImage();
	}

	// This should be the "visible" text that's actually on the screen if possible.
	// If there's alternative text, that can override the title.
	String accessibilityTitle(AccessibilityObject* coreObject)
	{
	Vector<AccessibilityText> textOrder;
	coreObject->accessibilityText(textOrder);

	for (const AccessibilityText& text : textOrder) {
	// Once we encounter visible text, or the text from our children that should be used foremost.
	if (text.textSource == AccessibilityTextSource::Visible \|\| text.textSource == AccessibilityTextSource::Children)
	return text.text;

	// If there's an element that labels this object and it's not exposed, then we should use
	// that text as our title.
	if (text.textSource == AccessibilityTextSource::LabelByElement && !coreObject->titleUIElement())
	return text.text;

	// Elements of role AccessibilityRole::Toolbar will return its title as AccessibilityTextSource::Alternative.
	if (coreObject->roleValue() == AccessibilityRole::Toolbar && text.textSource == AccessibilityTextSource::Alternative)
	return text.text;

	// FIXME: The title tag is used in certain cases for the title. This usage should
	// probably be in the description field since it's not "visible".
	if (text.textSource == AccessibilityTextSource::TitleTag && !titleTagShouldBeUsedInDescriptionField(coreObject))
	return text.text;
	}

	return String();
	}

	String accessibilityDescription(AccessibilityObject* coreObject)
	{
	Vector<AccessibilityText> textOrder;
	coreObject->accessibilityText(textOrder);

	bool visibleTextAvailable = false;
	for (const AccessibilityText& text : textOrder) {
	if (text.textSource == AccessibilityTextSource::Alternative)
	return text.text;

	switch (text.textSource) {
	case AccessibilityTextSource::Visible:
	case AccessibilityTextSource::Children:
	case AccessibilityTextSource::LabelByElement:
	visibleTextAvailable = true;
	default:
	break;
	}

	if (text.textSource == AccessibilityTextSource::TitleTag && !visibleTextAvailable)
	return text.text;
	}

	return String();
	}

	bool selectionBelongsToObject(AccessibilityObject* coreObject, VisibleSelection& selection)
	{
	if (!coreObject \|\| !coreObject->isAccessibilityRenderObject())
	return false;

	auto range = selection.firstRange();
	return range && intersects<ComposedTree>(range, coreObject->node());
	}

	AXCoreObject* objectFocusedAndCaretOffsetUnignored(AXCoreObject* referenceObject, int& offset)
	{
	// Indication that something bogus has transpired.
	offset = -1;

	Document* document = referenceObject->document();
	if (!document)
	return nullptr;

	Node* focusedNode = referenceObject->selection().end().containerNode();
	if (!focusedNode)
	return nullptr;

	RenderObject* focusedRenderer = focusedNode->renderer();
	if (!focusedRenderer)
	return nullptr;

	AccessibilityObject* focusedObject = document->axObjectCache()->getOrCreate(focusedRenderer);
	if (!focusedObject)
	return nullptr;

	// Look for the actual (not ignoring accessibility) selected object.
	AXCoreObject* firstUnignoredParent = focusedObject;
	if (firstUnignoredParent->accessibilityIsIgnored())
	firstUnignoredParent = firstUnignoredParent->parentObjectUnignored();
	if (!firstUnignoredParent)
	return nullptr;

	// Don't ignore links if the offset is being requested for a link
	// or if the link is a block.
	if (!referenceObject->isLink() && firstUnignoredParent->isLink()
	&& !(firstUnignoredParent->renderer() && !firstUnignoredParent->renderer()->isInline()))
	firstUnignoredParent = firstUnignoredParent->parentObjectUnignored();
	if (!firstUnignoredParent)
	return nullptr;

	// The reference object must either coincide with the focused
	// object being considered, or be a descendant of it.
	if (referenceObject->isDescendantOfObject(firstUnignoredParent))
	referenceObject = firstUnignoredParent;

	Node* startNode = nullptr;
	if (firstUnignoredParent != referenceObject \|\| firstUnignoredParent->isTextControl()) {
	// We need to use the first child's node of the reference
	// object as the start point to calculate the caret offset
	// because we want it to be relative to the object of
	// reference, not just to the focused object (which could have
	// previous siblings which should be taken into account too).
	AXCoreObject* axFirstChild = referenceObject->firstChild();
	if (axFirstChild)
	startNode = axFirstChild->node();
	}
	// Getting the Position of a PseudoElement now triggers an assertion.
	// This can occur when clicking on empty space in a render block.
	if (!startNode \|\| startNode->isPseudoElement())
	startNode = firstUnignoredParent->node();

	// Check if the node for the first parent object not ignoring
	// accessibility is null again before using it. This might happen
	// with certain kind of accessibility objects, such as the root
	// one (the scroller containing the webArea object).
	if (!startNode)
	return nullptr;

	VisiblePosition startPosition = VisiblePosition(positionBeforeNode(startNode));
	VisiblePosition endPosition = firstUnignoredParent->selection().visibleEnd();

	if (startPosition == endPosition)
	offset = 0;
	else if (!isStartOfLine(endPosition)) {
	auto range = makeSimpleRange(startPosition, endPosition.previous());
	offset = (range ? characterCount(*range, TextIteratorBehavior::EmitsCharactersBetweenAllVisiblePositions) : 0) + 1;
	} else {
	auto range = makeSimpleRange(startPosition, endPosition);
	offset = range ? characterCount(*range, TextIteratorBehavior::EmitsCharactersBetweenAllVisiblePositions) : 0;
	}

	return firstUnignoredParent;
	}

	#endif