Source/WebCore/editing/DeleteButtonController.cpp - platform/external/webkit - Git at Google

 /*
  * Copyright (C) 2006, 2008, 2009 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.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 COMPUTER, INC. OR
  * 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.
  */

 #include "config.h"
 #include "DeleteButtonController.h"

 #include "CachedImage.h"
 #include "CSSMutableStyleDeclaration.h"
 #include "CSSPrimitiveValue.h"
 #include "CSSPropertyNames.h"
 #include "CSSValueKeywords.h"
 #include "DeleteButton.h"
 #include "Document.h"
 #include "Editor.h"
 #include "Frame.h"
 #include "htmlediting.h"
 #include "HTMLDivElement.h"
 #include "HTMLNames.h"
 #include "Image.h"
 #include "Node.h"
 #include "Range.h"
 #include "RemoveNodeCommand.h"
 #include "RenderBox.h"
 #include "SelectionController.h"

 namespace WebCore {

 using namespace HTMLNames;

 const char* const DeleteButtonController::containerElementIdentifier = "WebKit-Editing-Delete-Container";
 const char* const DeleteButtonController::buttonElementIdentifier = "WebKit-Editing-Delete-Button";
 const char* const DeleteButtonController::outlineElementIdentifier = "WebKit-Editing-Delete-Outline";

 DeleteButtonController::DeleteButtonController(Frame* frame)
     : m_frame(frame)
     , m_wasStaticPositioned(false)
     , m_wasAutoZIndex(false)
     , m_disableStack(0)
 {
 }

 static bool isDeletableElement(const Node* node)
 {
     if (!node || !node->isHTMLElement() || !node->inDocument() || !node->rendererIsEditable())
         return false;

     // In general we want to only draw the UI around object of a certain area, but we still keep the min width/height to
     // make sure we don't end up with very thin or very short elements getting the UI.
     const int minimumArea = 2500;
     const int minimumWidth = 48;
     const int minimumHeight = 16;
     const unsigned minimumVisibleBorders = 1;

     RenderObject* renderer = node->renderer();
     if (!renderer || !renderer->isBox())
         return false;

     // Disallow the body element since it isn't practical to delete, and the deletion UI would be clipped.
     if (node->hasTagName(bodyTag))
         return false;

     // Disallow elements with any overflow clip, since the deletion UI would be clipped as well. <rdar://problem/6840161>
     if (renderer->hasOverflowClip())
         return false;

     // Disallow Mail blockquotes since the deletion UI would get in the way of editing for these.
     if (isMailBlockquote(node))
         return false;

     RenderBox* box = toRenderBox(renderer);
     IntRect borderBoundingBox = box->borderBoundingBox();
     if (borderBoundingBox.width() < minimumWidth || borderBoundingBox.height() < minimumHeight)
         return false;

     if ((borderBoundingBox.width() * borderBoundingBox.height()) < minimumArea)
         return false;

     if (renderer->isTable())
         return true;

     if (node->hasTagName(ulTag) || node->hasTagName(olTag) || node->hasTagName(iframeTag))
         return true;

     if (renderer->isPositioned())
         return true;

     if (renderer->isRenderBlock() && !renderer->isTableCell()) {
         RenderStyle* style = renderer->style();
         if (!style)
             return false;

         // Allow blocks that have background images
         if (style->hasBackgroundImage()) {
             for (const FillLayer* background = style->backgroundLayers(); background; background = background->next()) {
                 if (background->image() && background->image()->canRender(1))
                     return true;
             }
         }

         // Allow blocks with a minimum number of non-transparent borders
         unsigned visibleBorders = style->borderTop().isVisible() + style->borderBottom().isVisible() + style->borderLeft().isVisible() + style->borderRight().isVisible();
         if (visibleBorders >= minimumVisibleBorders)
             return true;

         // Allow blocks that have a different background from it's parent
         ContainerNode* parentNode = node->parentNode();
         if (!parentNode)
             return false;

         RenderObject* parentRenderer = parentNode->renderer();
         if (!parentRenderer)
             return false;

         RenderStyle* parentStyle = parentRenderer->style();
         if (!parentStyle)
             return false;

         if (renderer->hasBackground() && (!parentRenderer->hasBackground() || style->visitedDependentColor(CSSPropertyBackgroundColor) != parentStyle->visitedDependentColor(CSSPropertyBackgroundColor)))
             return true;
     }

     return false;
 }

 static HTMLElement* enclosingDeletableElement(const VisibleSelection& selection)
 {
     if (!selection.isContentEditable())
         return 0;

     RefPtr<Range> range = selection.toNormalizedRange();
     if (!range)
         return 0;

     ExceptionCode ec = 0;
     Node* container = range->commonAncestorContainer(ec);
     ASSERT(container);
     ASSERT(ec == 0);

     // The enclosingNodeOfType function only works on nodes that are editable
     // (which is strange, given its name).
     if (!container->rendererIsEditable())
         return 0;

     Node* element = enclosingNodeOfType(firstPositionInNode(container), &isDeletableElement);
     return element && element->isHTMLElement() ? toHTMLElement(element) : 0;
 }

 void DeleteButtonController::respondToChangedSelection(const VisibleSelection& oldSelection)
 {
     if (!enabled())
         return;

     HTMLElement* oldElement = enclosingDeletableElement(oldSelection);
     HTMLElement* newElement = enclosingDeletableElement(m_frame->selection()->selection());
     if (oldElement == newElement)
         return;

     // If the base is inside a deletable element, give the element a delete widget.
     if (newElement)
         show(newElement);
     else
         hide();
 }

 void DeleteButtonController::createDeletionUI()
 {
     RefPtr<HTMLDivElement> container = HTMLDivElement::create(m_target->document());
     container->setIdAttribute(containerElementIdentifier);

     CSSMutableStyleDeclaration* style = container->getInlineStyleDecl();
     style->setProperty(CSSPropertyWebkitUserDrag, CSSValueNone);
     style->setProperty(CSSPropertyWebkitUserSelect, CSSValueNone);
     style->setProperty(CSSPropertyWebkitUserModify, CSSValueReadOnly);
     style->setProperty(CSSPropertyVisibility, CSSValueHidden);
     style->setProperty(CSSPropertyPosition, CSSValueAbsolute);
     style->setProperty(CSSPropertyCursor, CSSValueDefault);
     style->setProperty(CSSPropertyTop, "0");
     style->setProperty(CSSPropertyRight, "0");
     style->setProperty(CSSPropertyBottom, "0");
     style->setProperty(CSSPropertyLeft, "0");

     RefPtr<HTMLDivElement> outline = HTMLDivElement::create(m_target->document());
     outline->setIdAttribute(outlineElementIdentifier);

     const int borderWidth = 4;
     const int borderRadius = 6;

     style = outline->getInlineStyleDecl();
     style->setProperty(CSSPropertyPosition, CSSValueAbsolute);
     style->setProperty(CSSPropertyZIndex, String::number(-1000000));
     style->setProperty(CSSPropertyTop, String::number(-borderWidth - m_target->renderBox()->borderTop()) + "px");
     style->setProperty(CSSPropertyRight, String::number(-borderWidth - m_target->renderBox()->borderRight()) + "px");
     style->setProperty(CSSPropertyBottom, String::number(-borderWidth - m_target->renderBox()->borderBottom()) + "px");
     style->setProperty(CSSPropertyLeft, String::number(-borderWidth - m_target->renderBox()->borderLeft()) + "px");
     style->setProperty(CSSPropertyBorder, String::number(borderWidth) + "px solid rgba(0, 0, 0, 0.6)");
     style->setProperty(CSSPropertyWebkitBorderRadius, String::number(borderRadius) + "px");
     style->setProperty(CSSPropertyVisibility, CSSValueVisible);

     ExceptionCode ec = 0;
     container->appendChild(outline.get(), ec);
     ASSERT(ec == 0);
     if (ec)
         return;

     RefPtr<DeleteButton> button = DeleteButton::create(m_target->document());
     button->setIdAttribute(buttonElementIdentifier);

     const int buttonWidth = 30;
     const int buttonHeight = 30;
     const int buttonBottomShadowOffset = 2;

     style = button->getInlineStyleDecl();
     style->setProperty(CSSPropertyPosition, CSSValueAbsolute);
     style->setProperty(CSSPropertyZIndex, String::number(1000000));
     style->setProperty(CSSPropertyTop, String::number((-buttonHeight / 2) - m_target->renderBox()->borderTop() - (borderWidth / 2) + buttonBottomShadowOffset) + "px");
     style->setProperty(CSSPropertyLeft, String::number((-buttonWidth / 2) - m_target->renderBox()->borderLeft() - (borderWidth / 2)) + "px");
     style->setProperty(CSSPropertyWidth, String::number(buttonWidth) + "px");
     style->setProperty(CSSPropertyHeight, String::number(buttonHeight) + "px");
     style->setProperty(CSSPropertyVisibility, CSSValueVisible);

     RefPtr<Image> buttonImage = Image::loadPlatformResource("deleteButton");
     if (buttonImage->isNull())
         return;

     button->setCachedImage(new CachedImage(buttonImage.get()));

     container->appendChild(button.get(), ec);
     ASSERT(ec == 0);
     if (ec)
         return;

     m_containerElement = container.release();
     m_outlineElement = outline.release();
     m_buttonElement = button.release();
 }

 void DeleteButtonController::show(HTMLElement* element)
 {
     hide();

     if (!enabled() || !element || !element->inDocument() || !isDeletableElement(element))
         return;

     if (!m_frame->editor()->shouldShowDeleteInterface(toHTMLElement(element)))
         return;

     // we rely on the renderer having current information, so we should update the layout if needed
     m_frame->document()->updateLayoutIgnorePendingStylesheets();

     m_target = element;

     if (!m_containerElement) {
         createDeletionUI();
         if (!m_containerElement) {
             hide();
             return;
         }
     }

     ExceptionCode ec = 0;
     m_target->appendChild(m_containerElement.get(), ec);
     ASSERT(ec == 0);
     if (ec) {
         hide();
         return;
     }

     if (m_target->renderer()->style()->position() == StaticPosition) {
         m_target->getInlineStyleDecl()->setProperty(CSSPropertyPosition, CSSValueRelative);
         m_wasStaticPositioned = true;
     }

     if (m_target->renderer()->style()->hasAutoZIndex()) {
         m_target->getInlineStyleDecl()->setProperty(CSSPropertyZIndex, "0");
         m_wasAutoZIndex = true;
     }
 }

 void DeleteButtonController::hide()
 {
     m_outlineElement = 0;
     m_buttonElement = 0;

     ExceptionCode ec = 0;
     if (m_containerElement && m_containerElement->parentNode())
         m_containerElement->parentNode()->removeChild(m_containerElement.get(), ec);

     if (m_target) {
         if (m_wasStaticPositioned)
             m_target->getInlineStyleDecl()->setProperty(CSSPropertyPosition, CSSValueStatic);
         if (m_wasAutoZIndex)
             m_target->getInlineStyleDecl()->setProperty(CSSPropertyZIndex, CSSValueAuto);
     }

     m_wasStaticPositioned = false;
     m_wasAutoZIndex = false;
 }

 void DeleteButtonController::enable()
 {
     ASSERT(m_disableStack > 0);
     if (m_disableStack > 0)
         m_disableStack--;
     if (enabled()) {
         // Determining if the element is deletable currently depends on style
         // because whether something is editable depends on style, so we need
         // to recalculate style before calling enclosingDeletableElement.
         m_frame->document()->updateStyleIfNeeded();
         show(enclosingDeletableElement(m_frame->selection()->selection()));
     }
 }

 void DeleteButtonController::disable()
 {
     if (enabled())
         hide();
     m_disableStack++;
 }

 void DeleteButtonController::deleteTarget()
 {
     if (!enabled() || !m_target)
         return;

     RefPtr<Node> element = m_target;
     hide();

     // Because the deletion UI only appears when the selection is entirely
     // within the target, we unconditionally update the selection to be
     // a caret where the target had been.
     Position pos = positionInParentBeforeNode(element.get());
     applyCommand(RemoveNodeCommand::create(element.release()));
     m_frame->selection()->setSelection(VisiblePosition(pos));
 }

 } // namespace WebCore
	/*
	* Copyright (C) 2006, 2008, 2009 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.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 COMPUTER, INC. OR
	* 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.
	*/

	#include "config.h"
	#include "DeleteButtonController.h"

	#include "CachedImage.h"
	#include "CSSMutableStyleDeclaration.h"
	#include "CSSPrimitiveValue.h"
	#include "CSSPropertyNames.h"
	#include "CSSValueKeywords.h"
	#include "DeleteButton.h"
	#include "Document.h"
	#include "Editor.h"
	#include "Frame.h"
	#include "htmlediting.h"
	#include "HTMLDivElement.h"
	#include "HTMLNames.h"
	#include "Image.h"
	#include "Node.h"
	#include "Range.h"
	#include "RemoveNodeCommand.h"
	#include "RenderBox.h"
	#include "SelectionController.h"

	namespace WebCore {

	using namespace HTMLNames;

	const char* const DeleteButtonController::containerElementIdentifier = "WebKit-Editing-Delete-Container";
	const char* const DeleteButtonController::buttonElementIdentifier = "WebKit-Editing-Delete-Button";
	const char* const DeleteButtonController::outlineElementIdentifier = "WebKit-Editing-Delete-Outline";

	DeleteButtonController::DeleteButtonController(Frame* frame)
	: m_frame(frame)
	, m_wasStaticPositioned(false)
	, m_wasAutoZIndex(false)
	, m_disableStack(0)
	{
	}

	static bool isDeletableElement(const Node* node)
	{
	if (!node \|\| !node->isHTMLElement() \|\| !node->inDocument() \|\| !node->rendererIsEditable())
	return false;

	// In general we want to only draw the UI around object of a certain area, but we still keep the min width/height to
	// make sure we don't end up with very thin or very short elements getting the UI.
	const int minimumArea = 2500;
	const int minimumWidth = 48;
	const int minimumHeight = 16;
	const unsigned minimumVisibleBorders = 1;

	RenderObject* renderer = node->renderer();
	if (!renderer \|\| !renderer->isBox())
	return false;

	// Disallow the body element since it isn't practical to delete, and the deletion UI would be clipped.
	if (node->hasTagName(bodyTag))
	return false;

	// Disallow elements with any overflow clip, since the deletion UI would be clipped as well. <rdar://problem/6840161>
	if (renderer->hasOverflowClip())
	return false;

	// Disallow Mail blockquotes since the deletion UI would get in the way of editing for these.
	if (isMailBlockquote(node))
	return false;

	RenderBox* box = toRenderBox(renderer);
	IntRect borderBoundingBox = box->borderBoundingBox();
	if (borderBoundingBox.width() < minimumWidth \|\| borderBoundingBox.height() < minimumHeight)
	return false;

	if ((borderBoundingBox.width() * borderBoundingBox.height()) < minimumArea)
	return false;

	if (renderer->isTable())
	return true;

	if (node->hasTagName(ulTag) \|\| node->hasTagName(olTag) \|\| node->hasTagName(iframeTag))
	return true;

	if (renderer->isPositioned())
	return true;

	if (renderer->isRenderBlock() && !renderer->isTableCell()) {
	RenderStyle* style = renderer->style();
	if (!style)
	return false;

	// Allow blocks that have background images
	if (style->hasBackgroundImage()) {
	for (const FillLayer* background = style->backgroundLayers(); background; background = background->next()) {
	if (background->image() && background->image()->canRender(1))
	return true;
	}
	}

	// Allow blocks with a minimum number of non-transparent borders
	unsigned visibleBorders = style->borderTop().isVisible() + style->borderBottom().isVisible() + style->borderLeft().isVisible() + style->borderRight().isVisible();
	if (visibleBorders >= minimumVisibleBorders)
	return true;

	// Allow blocks that have a different background from it's parent
	ContainerNode* parentNode = node->parentNode();
	if (!parentNode)
	return false;

	RenderObject* parentRenderer = parentNode->renderer();
	if (!parentRenderer)
	return false;

	RenderStyle* parentStyle = parentRenderer->style();
	if (!parentStyle)
	return false;

	if (renderer->hasBackground() && (!parentRenderer->hasBackground() \|\| style->visitedDependentColor(CSSPropertyBackgroundColor) != parentStyle->visitedDependentColor(CSSPropertyBackgroundColor)))
	return true;
	}

	return false;
	}

	static HTMLElement* enclosingDeletableElement(const VisibleSelection& selection)
	{
	if (!selection.isContentEditable())
	return 0;

	RefPtr<Range> range = selection.toNormalizedRange();
	if (!range)
	return 0;

	ExceptionCode ec = 0;
	Node* container = range->commonAncestorContainer(ec);
	ASSERT(container);
	ASSERT(ec == 0);

	// The enclosingNodeOfType function only works on nodes that are editable
	// (which is strange, given its name).
	if (!container->rendererIsEditable())
	return 0;

	Node* element = enclosingNodeOfType(firstPositionInNode(container), &isDeletableElement);
	return element && element->isHTMLElement() ? toHTMLElement(element) : 0;
	}

	void DeleteButtonController::respondToChangedSelection(const VisibleSelection& oldSelection)
	{
	if (!enabled())
	return;

	HTMLElement* oldElement = enclosingDeletableElement(oldSelection);
	HTMLElement* newElement = enclosingDeletableElement(m_frame->selection()->selection());
	if (oldElement == newElement)
	return;

	// If the base is inside a deletable element, give the element a delete widget.
	if (newElement)
	show(newElement);
	else
	hide();
	}

	void DeleteButtonController::createDeletionUI()
	{
	RefPtr<HTMLDivElement> container = HTMLDivElement::create(m_target->document());
	container->setIdAttribute(containerElementIdentifier);

	CSSMutableStyleDeclaration* style = container->getInlineStyleDecl();
	style->setProperty(CSSPropertyWebkitUserDrag, CSSValueNone);
	style->setProperty(CSSPropertyWebkitUserSelect, CSSValueNone);
	style->setProperty(CSSPropertyWebkitUserModify, CSSValueReadOnly);
	style->setProperty(CSSPropertyVisibility, CSSValueHidden);
	style->setProperty(CSSPropertyPosition, CSSValueAbsolute);
	style->setProperty(CSSPropertyCursor, CSSValueDefault);
	style->setProperty(CSSPropertyTop, "0");
	style->setProperty(CSSPropertyRight, "0");
	style->setProperty(CSSPropertyBottom, "0");
	style->setProperty(CSSPropertyLeft, "0");

	RefPtr<HTMLDivElement> outline = HTMLDivElement::create(m_target->document());
	outline->setIdAttribute(outlineElementIdentifier);

	const int borderWidth = 4;
	const int borderRadius = 6;

	style = outline->getInlineStyleDecl();
	style->setProperty(CSSPropertyPosition, CSSValueAbsolute);
	style->setProperty(CSSPropertyZIndex, String::number(-1000000));
	style->setProperty(CSSPropertyTop, String::number(-borderWidth - m_target->renderBox()->borderTop()) + "px");
	style->setProperty(CSSPropertyRight, String::number(-borderWidth - m_target->renderBox()->borderRight()) + "px");
	style->setProperty(CSSPropertyBottom, String::number(-borderWidth - m_target->renderBox()->borderBottom()) + "px");
	style->setProperty(CSSPropertyLeft, String::number(-borderWidth - m_target->renderBox()->borderLeft()) + "px");
	style->setProperty(CSSPropertyBorder, String::number(borderWidth) + "px solid rgba(0, 0, 0, 0.6)");
	style->setProperty(CSSPropertyWebkitBorderRadius, String::number(borderRadius) + "px");
	style->setProperty(CSSPropertyVisibility, CSSValueVisible);

	ExceptionCode ec = 0;
	container->appendChild(outline.get(), ec);
	ASSERT(ec == 0);
	if (ec)
	return;

	RefPtr<DeleteButton> button = DeleteButton::create(m_target->document());
	button->setIdAttribute(buttonElementIdentifier);

	const int buttonWidth = 30;
	const int buttonHeight = 30;
	const int buttonBottomShadowOffset = 2;

	style = button->getInlineStyleDecl();
	style->setProperty(CSSPropertyPosition, CSSValueAbsolute);
	style->setProperty(CSSPropertyZIndex, String::number(1000000));
	style->setProperty(CSSPropertyTop, String::number((-buttonHeight / 2) - m_target->renderBox()->borderTop() - (borderWidth / 2) + buttonBottomShadowOffset) + "px");
	style->setProperty(CSSPropertyLeft, String::number((-buttonWidth / 2) - m_target->renderBox()->borderLeft() - (borderWidth / 2)) + "px");
	style->setProperty(CSSPropertyWidth, String::number(buttonWidth) + "px");
	style->setProperty(CSSPropertyHeight, String::number(buttonHeight) + "px");
	style->setProperty(CSSPropertyVisibility, CSSValueVisible);

	RefPtr<Image> buttonImage = Image::loadPlatformResource("deleteButton");
	if (buttonImage->isNull())
	return;

	button->setCachedImage(new CachedImage(buttonImage.get()));

	container->appendChild(button.get(), ec);
	ASSERT(ec == 0);
	if (ec)
	return;

	m_containerElement = container.release();
	m_outlineElement = outline.release();
	m_buttonElement = button.release();
	}

	void DeleteButtonController::show(HTMLElement* element)
	{
	hide();

	if (!enabled() \|\| !element \|\| !element->inDocument() \|\| !isDeletableElement(element))
	return;

	if (!m_frame->editor()->shouldShowDeleteInterface(toHTMLElement(element)))
	return;

	// we rely on the renderer having current information, so we should update the layout if needed
	m_frame->document()->updateLayoutIgnorePendingStylesheets();

	m_target = element;

	if (!m_containerElement) {
	createDeletionUI();
	if (!m_containerElement) {
	hide();
	return;
	}
	}

	ExceptionCode ec = 0;
	m_target->appendChild(m_containerElement.get(), ec);
	ASSERT(ec == 0);
	if (ec) {
	hide();
	return;
	}

	if (m_target->renderer()->style()->position() == StaticPosition) {
	m_target->getInlineStyleDecl()->setProperty(CSSPropertyPosition, CSSValueRelative);
	m_wasStaticPositioned = true;
	}

	if (m_target->renderer()->style()->hasAutoZIndex()) {
	m_target->getInlineStyleDecl()->setProperty(CSSPropertyZIndex, "0");
	m_wasAutoZIndex = true;
	}
	}

	void DeleteButtonController::hide()
	{
	m_outlineElement = 0;
	m_buttonElement = 0;

	ExceptionCode ec = 0;
	if (m_containerElement && m_containerElement->parentNode())
	m_containerElement->parentNode()->removeChild(m_containerElement.get(), ec);

	if (m_target) {
	if (m_wasStaticPositioned)
	m_target->getInlineStyleDecl()->setProperty(CSSPropertyPosition, CSSValueStatic);
	if (m_wasAutoZIndex)
	m_target->getInlineStyleDecl()->setProperty(CSSPropertyZIndex, CSSValueAuto);
	}

	m_wasStaticPositioned = false;
	m_wasAutoZIndex = false;
	}

	void DeleteButtonController::enable()
	{
	ASSERT(m_disableStack > 0);
	if (m_disableStack > 0)
	m_disableStack--;
	if (enabled()) {
	// Determining if the element is deletable currently depends on style
	// because whether something is editable depends on style, so we need
	// to recalculate style before calling enclosingDeletableElement.
	m_frame->document()->updateStyleIfNeeded();
	show(enclosingDeletableElement(m_frame->selection()->selection()));
	}
	}

	void DeleteButtonController::disable()
	{
	if (enabled())
	hide();
	m_disableStack++;
	}

	void DeleteButtonController::deleteTarget()
	{
	if (!enabled() \|\| !m_target)
	return;

	RefPtr<Node> element = m_target;
	hide();

	// Because the deletion UI only appears when the selection is entirely
	// within the target, we unconditionally update the selection to be
	// a caret where the target had been.
	Position pos = positionInParentBeforeNode(element.get());
	applyCommand(RemoveNodeCommand::create(element.release()));
	m_frame->selection()->setSelection(VisiblePosition(pos));
	}

	} // namespace WebCore