Source/WebCore/accessibility/mac/WebAccessibilityObjectWrapperBase.mm - WebKit - Git at Google

 /*
  * Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  *     its contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #import "config.h"
 #import "WebAccessibilityObjectWrapperBase.h"

 #if HAVE(ACCESSIBILITY)

 #import "AXObjectCache.h"
 #import "AccessibilityARIAGridRow.h"
 #import "AccessibilityList.h"
 #import "AccessibilityListBox.h"
 #import "AccessibilityRenderObject.h"
 #import "AccessibilityScrollView.h"
 #import "AccessibilitySpinButton.h"
 #import "AccessibilityTable.h"
 #import "AccessibilityTableCell.h"
 #import "AccessibilityTableColumn.h"
 #import "AccessibilityTableRow.h"
 #import "Chrome.h"
 #import "ChromeClient.h"
 #import "ColorMac.h"
 #import "ContextMenuController.h"
 #import "Font.h"
 #import "Frame.h"
 #import "FrameLoaderClient.h"
 #import "FrameSelection.h"
 #import "HTMLAnchorElement.h"
 #import "HTMLAreaElement.h"
 #import "HTMLFrameOwnerElement.h"
 #import "HTMLImageElement.h"
 #import "HTMLInputElement.h"
 #import "HTMLNames.h"
 #import "HTMLTextAreaElement.h"
 #import "LocalizedStrings.h"
 #import "Page.h"
 #import "RenderTextControl.h"
 #import "RenderView.h"
 #import "RenderWidget.h"
 #import "ScrollView.h"
 #import "SimpleFontData.h"
 #import "TextCheckerClient.h"
 #import "TextCheckingHelper.h"
 #import "TextIterator.h"
 #import "WebCoreFrameView.h"
 #import "WebCoreObjCExtras.h"
 #import "WebCoreSystemInterface.h"
 #import "htmlediting.h"
 #import "visible_units.h"

 using namespace WebCore;
 using namespace HTMLNames;
 using namespace std;

 @implementation WebAccessibilityObjectWrapperBase

 - (id)initWithAccessibilityObject:(AccessibilityObject*)axObject
 {
     if (!(self = [super init]))
         return nil;

     m_object = axObject;
     return self;
 }

 - (void)detach
 {
     m_object = 0;
 }

 - (BOOL)updateObjectBackingStore
 {
     // Calling updateBackingStore() can invalidate this element so self must be retained.
     // If it does become invalidated, m_object will be nil.
     [[self retain] autorelease];

     if (!m_object)
         return NO;

     m_object->updateBackingStore();
     if (!m_object)
         return NO;

     return YES;
 }

 - (id)attachmentView
 {
     return nil;
 }

 - (AccessibilityObject*)accessibilityObject
 {
     return m_object;
 }

 // FIXME: Different kinds of elements are putting the title tag to use in different
 // AX fields. This should be rectified, but in the initial patch I want to achieve
 // parity with existing behavior.
 - (BOOL)titleTagShouldBeUsedInDescriptionField
 {
     return (m_object->isLink() && !m_object->isImageMapLink()) || m_object->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.
 - (NSString *)accessibilityTitle
 {
     // Static text objects should not have a title. Its content is communicated in its AXValue.
     if (m_object->roleValue() == StaticTextRole)
         return [NSString string];

     // A file upload button presents a challenge because it has button text and a value, but the
     // API doesn't support this paradigm.
     // The compromise is to return the button type in the role description and the value of the file path in the title
     if (m_object->isFileUploadButton())
         return m_object->stringValue();

     Vector<AccessibilityText> textOrder;
     m_object->accessibilityText(textOrder);

     unsigned length = textOrder.size();
     for (unsigned k = 0; k < length; k++) {
         const AccessibilityText& text = textOrder[k];

         // If we have alternative text, then we should not expose a title.
         if (text.textSource == AlternativeText)
             break;

         // Once we encounter visible text, or the text from our children that should be used foremost.
         if (text.textSource == VisibleText || text.textSource == ChildrenText)
             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 == LabelByElementText && !m_object->exposesTitleUIElement())
             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 == TitleTagText && ![self titleTagShouldBeUsedInDescriptionField])
             return text.text;
     }

     return [NSString string];
 }

 - (NSString *)accessibilityDescription
 {
     // Static text objects should not have a description. Its content is communicated in its AXValue.
     // One exception is the media control labels that have a value and a description. Those are set programatically.
     if (m_object->roleValue() == StaticTextRole && !m_object->isMediaControlLabel())
         return [NSString string];

     Vector<AccessibilityText> textOrder;
     m_object->accessibilityText(textOrder);

     unsigned length = textOrder.size();
     for (unsigned k = 0; k < length; k++) {
         const AccessibilityText& text = textOrder[k];

         if (text.textSource == AlternativeText)
             return text.text;

         if (text.textSource == TitleTagText && [self titleTagShouldBeUsedInDescriptionField])
             return text.text;
     }

     return [NSString string];
 }

 - (NSString *)accessibilityHelpText
 {
     Vector<AccessibilityText> textOrder;
     m_object->accessibilityText(textOrder);

     unsigned length = textOrder.size();
     bool descriptiveTextAvailable = false;
     for (unsigned k = 0; k < length; k++) {
         const AccessibilityText& text = textOrder[k];

         if (text.textSource == HelpText || text.textSource == SummaryText)
             return text.text;

         // If an element does NOT have other descriptive text the title tag should be used as its descriptive text.
         // But, if those ARE available, then the title tag should be used for help text instead.
         switch (text.textSource) {
         case AlternativeText:
         case VisibleText:
         case ChildrenText:
         case LabelByElementText:
             descriptiveTextAvailable = true;
         default:
             break;
         }

         if (text.textSource == TitleTagText && descriptiveTextAvailable)
             return text.text;
     }

     return [NSString string];
 }

 // This is set by DRT when it wants to listen for notifications.
 static BOOL accessibilityShouldRepostNotifications;
 + (void)accessibilitySetShouldRepostNotifications:(BOOL)repost
 {
     accessibilityShouldRepostNotifications = repost;
 }

 - (void)accessibilityPostedNotification:(NSString *)notificationName
 {
     if (accessibilityShouldRepostNotifications) {
         NSDictionary* userInfo = [NSDictionary dictionaryWithObjectsAndKeys:notificationName, @"notificationName", nil];
         [[NSNotificationCenter defaultCenter] postNotificationName:@"AXDRTNotification" object:self userInfo:userInfo];
     }
 }

 @end

 #endif // HAVE(ACCESSIBILITY)
	/*
	* Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	*
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
	* its contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#import "config.h"
	#import "WebAccessibilityObjectWrapperBase.h"

	#if HAVE(ACCESSIBILITY)

	#import "AXObjectCache.h"
	#import "AccessibilityARIAGridRow.h"
	#import "AccessibilityList.h"
	#import "AccessibilityListBox.h"
	#import "AccessibilityRenderObject.h"
	#import "AccessibilityScrollView.h"
	#import "AccessibilitySpinButton.h"
	#import "AccessibilityTable.h"
	#import "AccessibilityTableCell.h"
	#import "AccessibilityTableColumn.h"
	#import "AccessibilityTableRow.h"
	#import "Chrome.h"
	#import "ChromeClient.h"
	#import "ColorMac.h"
	#import "ContextMenuController.h"
	#import "Font.h"
	#import "Frame.h"
	#import "FrameLoaderClient.h"
	#import "FrameSelection.h"
	#import "HTMLAnchorElement.h"
	#import "HTMLAreaElement.h"
	#import "HTMLFrameOwnerElement.h"
	#import "HTMLImageElement.h"
	#import "HTMLInputElement.h"
	#import "HTMLNames.h"
	#import "HTMLTextAreaElement.h"
	#import "LocalizedStrings.h"
	#import "Page.h"
	#import "RenderTextControl.h"
	#import "RenderView.h"
	#import "RenderWidget.h"
	#import "ScrollView.h"
	#import "SimpleFontData.h"
	#import "TextCheckerClient.h"
	#import "TextCheckingHelper.h"
	#import "TextIterator.h"
	#import "WebCoreFrameView.h"
	#import "WebCoreObjCExtras.h"
	#import "WebCoreSystemInterface.h"
	#import "htmlediting.h"
	#import "visible_units.h"

	using namespace WebCore;
	using namespace HTMLNames;
	using namespace std;

	@implementation WebAccessibilityObjectWrapperBase

	- (id)initWithAccessibilityObject:(AccessibilityObject*)axObject
	{
	if (!(self = [super init]))
	return nil;

	m_object = axObject;
	return self;
	}

	- (void)detach
	{
	m_object = 0;
	}

	- (BOOL)updateObjectBackingStore
	{
	// Calling updateBackingStore() can invalidate this element so self must be retained.
	// If it does become invalidated, m_object will be nil.
	[[self retain] autorelease];

	if (!m_object)
	return NO;

	m_object->updateBackingStore();
	if (!m_object)
	return NO;

	return YES;
	}

	- (id)attachmentView
	{
	return nil;
	}

	- (AccessibilityObject*)accessibilityObject
	{
	return m_object;
	}

	// FIXME: Different kinds of elements are putting the title tag to use in different
	// AX fields. This should be rectified, but in the initial patch I want to achieve
	// parity with existing behavior.
	- (BOOL)titleTagShouldBeUsedInDescriptionField
	{
	return (m_object->isLink() && !m_object->isImageMapLink()) \|\| m_object->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.
	- (NSString *)accessibilityTitle
	{
	// Static text objects should not have a title. Its content is communicated in its AXValue.
	if (m_object->roleValue() == StaticTextRole)
	return [NSString string];

	// A file upload button presents a challenge because it has button text and a value, but the
	// API doesn't support this paradigm.
	// The compromise is to return the button type in the role description and the value of the file path in the title
	if (m_object->isFileUploadButton())
	return m_object->stringValue();

	Vector<AccessibilityText> textOrder;
	m_object->accessibilityText(textOrder);

	unsigned length = textOrder.size();
	for (unsigned k = 0; k < length; k++) {
	const AccessibilityText& text = textOrder[k];

	// If we have alternative text, then we should not expose a title.
	if (text.textSource == AlternativeText)
	break;

	// Once we encounter visible text, or the text from our children that should be used foremost.
	if (text.textSource == VisibleText \|\| text.textSource == ChildrenText)
	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 == LabelByElementText && !m_object->exposesTitleUIElement())
	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 == TitleTagText && ![self titleTagShouldBeUsedInDescriptionField])
	return text.text;
	}

	return [NSString string];
	}

	- (NSString *)accessibilityDescription
	{
	// Static text objects should not have a description. Its content is communicated in its AXValue.
	// One exception is the media control labels that have a value and a description. Those are set programatically.
	if (m_object->roleValue() == StaticTextRole && !m_object->isMediaControlLabel())
	return [NSString string];

	Vector<AccessibilityText> textOrder;
	m_object->accessibilityText(textOrder);

	unsigned length = textOrder.size();
	for (unsigned k = 0; k < length; k++) {
	const AccessibilityText& text = textOrder[k];

	if (text.textSource == AlternativeText)
	return text.text;

	if (text.textSource == TitleTagText && [self titleTagShouldBeUsedInDescriptionField])
	return text.text;
	}

	return [NSString string];
	}

	- (NSString *)accessibilityHelpText
	{
	Vector<AccessibilityText> textOrder;
	m_object->accessibilityText(textOrder);

	unsigned length = textOrder.size();
	bool descriptiveTextAvailable = false;
	for (unsigned k = 0; k < length; k++) {
	const AccessibilityText& text = textOrder[k];

	if (text.textSource == HelpText \|\| text.textSource == SummaryText)
	return text.text;

	// If an element does NOT have other descriptive text the title tag should be used as its descriptive text.
	// But, if those ARE available, then the title tag should be used for help text instead.
	switch (text.textSource) {
	case AlternativeText:
	case VisibleText:
	case ChildrenText:
	case LabelByElementText:
	descriptiveTextAvailable = true;
	default:
	break;
	}

	if (text.textSource == TitleTagText && descriptiveTextAvailable)
	return text.text;
	}

	return [NSString string];
	}

	// This is set by DRT when it wants to listen for notifications.
	static BOOL accessibilityShouldRepostNotifications;
	+ (void)accessibilitySetShouldRepostNotifications:(BOOL)repost
	{
	accessibilityShouldRepostNotifications = repost;
	}

	- (void)accessibilityPostedNotification:(NSString *)notificationName
	{
	if (accessibilityShouldRepostNotifications) {
	NSDictionary* userInfo = [NSDictionary dictionaryWithObjectsAndKeys:notificationName, @"notificationName", nil];
	[[NSNotificationCenter defaultCenter] postNotificationName:@"AXDRTNotification" object:self userInfo:userInfo];
	}
	}

	@end

	#endif // HAVE(ACCESSIBILITY)