third_party/WebKit/Source/core/html/HTMLLabelElement.cpp - chromium/src - Git at Google

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * 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 "core/html/HTMLLabelElement.h"

 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/editing/FrameSelection.h"
 #include "core/editing/SelectionController.h"
 #include "core/events/MouseEvent.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/UseCounter.h"
 #include "core/html/FormAssociatedElement.h"
 #include "core/html/HTMLFormControlElement.h"
 #include "core/input/EventHandler.h"
 #include "core/layout/LayoutObject.h"

 namespace blink {

 using namespace HTMLNames;

 inline HTMLLabelElement::HTMLLabelElement(Document& document)
     : HTMLElement(labelTag, document), m_processingClick(false) {}

 HTMLLabelElement* HTMLLabelElement::create(Document& document) {
   return new HTMLLabelElement(document);
 }

 LabelableElement* HTMLLabelElement::control() const {
   const AtomicString& controlId = getAttribute(forAttr);
   if (controlId.isNull()) {
     // Search the children and descendants of the label element for a form
     // element.
     // per http://dev.w3.org/html5/spec/Overview.html#the-label-element
     // the form element must be "labelable form-associated element".
     for (LabelableElement& element :
          Traversal<LabelableElement>::descendantsOf(*this)) {
       if (element.supportLabels()) {
         if (!element.isFormControlElement())
           UseCounter::count(
               document(),
               UseCounter::HTMLLabelElementControlForNonFormAssociatedElement);
         return &element;
       }
     }
     return nullptr;
   }

   if (Element* element = treeScope().getElementById(controlId)) {
     if (isLabelableElement(*element) &&
         toLabelableElement(*element).supportLabels()) {
       if (!element->isFormControlElement())
         UseCounter::count(
             document(),
             UseCounter::HTMLLabelElementControlForNonFormAssociatedElement);
       return toLabelableElement(element);
     }
   }

   return nullptr;
 }

 HTMLFormElement* HTMLLabelElement::form() const {
   if (LabelableElement* control = this->control())
     return control->isFormControlElement()
                ? toHTMLFormControlElement(control)->form()
                : nullptr;
   return nullptr;
 }

 void HTMLLabelElement::setActive(bool down) {
   if (down != isActive()) {
     // Update our status first.
     HTMLElement::setActive(down);
   }

   // Also update our corresponding control.
   HTMLElement* controlElement = control();
   if (controlElement && controlElement->isActive() != isActive())
     controlElement->setActive(isActive());
 }

 void HTMLLabelElement::setHovered(bool over) {
   if (over != isHovered()) {
     // Update our status first.
     HTMLElement::setHovered(over);
   }

   // Also update our corresponding control.
   HTMLElement* element = control();
   if (element && element->isHovered() != isHovered())
     element->setHovered(isHovered());
 }

 bool HTMLLabelElement::isInteractiveContent() const {
   return true;
 }

 bool HTMLLabelElement::isInInteractiveContent(Node* node) const {
   if (!isShadowIncludingInclusiveAncestorOf(node))
     return false;
   while (node && this != node) {
     if (node->isHTMLElement() && toHTMLElement(node)->isInteractiveContent())
       return true;
     node = node->parentOrShadowHostNode();
   }
   return false;
 }

 void HTMLLabelElement::defaultEventHandler(Event* evt) {
   if (evt->type() == EventTypeNames::click && !m_processingClick) {
     HTMLElement* element = control();

     // If we can't find a control or if the control received the click
     // event, then there's no need for us to do anything.
     if (!element || (evt->target() &&
                      element->isShadowIncludingInclusiveAncestorOf(
                          evt->target()->toNode())))
       return;

     if (evt->target() && isInInteractiveContent(evt->target()->toNode()))
       return;

     //   Behaviour of label element is as follows:
     //     - If there is double click, two clicks will be passed to control
     //       element. Control element will *not* be focused.
     //     - If there is selection of label element by dragging, no click
     //       event is passed. Also, no focus on control element.
     //     - If there is already a selection on label element and then label
     //       is clicked, then click event is passed to control element and
     //       control element is focused.

     bool isLabelTextSelected = false;

     // If the click is not simulated and the text of the label element
     // is selected by dragging over it, then return without passing the
     // click event to control element.
     // Note: check if it is a MouseEvent because a click event may
     // not be an instance of a MouseEvent if created by document.createEvent().
     if (evt->isMouseEvent() && toMouseEvent(evt)->hasPosition()) {
       if (LocalFrame* frame = document().frame()) {
         // Check if there is a selection and click is not on the
         // selection.
         if (layoutObject() && layoutObject()->isSelectable() &&
             frame->selection().isRange() &&
             !frame->eventHandler()
                  .selectionController()
                  .mouseDownWasSingleClickInSelection())
           isLabelTextSelected = true;
         // If selection is there and is single click i.e. text is
         // selected by dragging over label text, then return.
         // Click count >=2, meaning double click or triple click,
         // should pass click event to control element.
         // Only in case of drag, *neither* we pass the click event,
         // *nor* we focus the control element.
         if (isLabelTextSelected && toMouseEvent(evt)->clickCount() == 1)
           return;
       }
     }

     m_processingClick = true;

     document().updateStyleAndLayoutIgnorePendingStylesheets();
     if (element->isMouseFocusable()) {
       // If the label is *not* selected, or if the click happened on
       // selection of label, only then focus the control element.
       // In case of double click or triple click, selection will be there,
       // so do not focus the control element.
       if (!isLabelTextSelected)
         element->focus(FocusParams(SelectionBehaviorOnFocus::Restore,
                                    WebFocusTypeMouse, nullptr));
     }

     // Click the corresponding control.
     element->dispatchSimulatedClick(evt);

     m_processingClick = false;

     evt->setDefaultHandled();
   }

   HTMLElement::defaultEventHandler(evt);
 }

 bool HTMLLabelElement::willRespondToMouseClickEvents() {
   if (control() && control()->willRespondToMouseClickEvents())
     return true;

   return HTMLElement::willRespondToMouseClickEvents();
 }

 void HTMLLabelElement::focus(const FocusParams& params) {
   document().updateStyleAndLayoutTreeForNode(this);
   if (isFocusable()) {
     HTMLElement::focus(params);
     return;
   }
   // To match other browsers, always restore previous selection.
   if (HTMLElement* element = control())
     element->focus(FocusParams(SelectionBehaviorOnFocus::Restore, params.type,
                                params.sourceCapabilities));
 }

 void HTMLLabelElement::accessKeyAction(bool sendMouseEvents) {
   if (HTMLElement* element = control())
     element->accessKeyAction(sendMouseEvents);
   else
     HTMLElement::accessKeyAction(sendMouseEvents);
 }

 }  // namespace blink
	/*
	* Copyright (C) 1999 Lars Knoll (knoll@kde.org)
	* (C) 1999 Antti Koivisto (koivisto@kde.org)
	* (C) 2001 Dirk Mueller (mueller@kde.org)
	* Copyright (C) 2004, 2005, 2006, 2007, 2010 Apple Inc. All rights reserved.
	* (C) 2006 Alexey Proskuryakov (ap@nypop.com)
	*
	* 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 "core/html/HTMLLabelElement.h"

	#include "core/HTMLNames.h"
	#include "core/dom/Document.h"
	#include "core/dom/ElementTraversal.h"
	#include "core/editing/EditingUtilities.h"
	#include "core/editing/FrameSelection.h"
	#include "core/editing/SelectionController.h"
	#include "core/events/MouseEvent.h"
	#include "core/frame/LocalFrame.h"
	#include "core/frame/UseCounter.h"
	#include "core/html/FormAssociatedElement.h"
	#include "core/html/HTMLFormControlElement.h"
	#include "core/input/EventHandler.h"
	#include "core/layout/LayoutObject.h"

	namespace blink {

	using namespace HTMLNames;

	inline HTMLLabelElement::HTMLLabelElement(Document& document)
	: HTMLElement(labelTag, document), m_processingClick(false) {}

	HTMLLabelElement* HTMLLabelElement::create(Document& document) {
	return new HTMLLabelElement(document);
	}

	LabelableElement* HTMLLabelElement::control() const {
	const AtomicString& controlId = getAttribute(forAttr);
	if (controlId.isNull()) {
	// Search the children and descendants of the label element for a form
	// element.
	// per http://dev.w3.org/html5/spec/Overview.html#the-label-element
	// the form element must be "labelable form-associated element".
	for (LabelableElement& element :
	Traversal<LabelableElement>::descendantsOf(*this)) {
	if (element.supportLabels()) {
	if (!element.isFormControlElement())
	UseCounter::count(
	document(),
	UseCounter::HTMLLabelElementControlForNonFormAssociatedElement);
	return &element;
	}
	}
	return nullptr;
	}

	if (Element* element = treeScope().getElementById(controlId)) {
	if (isLabelableElement(*element) &&
	toLabelableElement(*element).supportLabels()) {
	if (!element->isFormControlElement())
	UseCounter::count(
	document(),
	UseCounter::HTMLLabelElementControlForNonFormAssociatedElement);
	return toLabelableElement(element);
	}
	}

	return nullptr;
	}

	HTMLFormElement* HTMLLabelElement::form() const {
	if (LabelableElement* control = this->control())
	return control->isFormControlElement()
	? toHTMLFormControlElement(control)->form()
	: nullptr;
	return nullptr;
	}

	void HTMLLabelElement::setActive(bool down) {
	if (down != isActive()) {
	// Update our status first.
	HTMLElement::setActive(down);
	}

	// Also update our corresponding control.
	HTMLElement* controlElement = control();
	if (controlElement && controlElement->isActive() != isActive())
	controlElement->setActive(isActive());
	}

	void HTMLLabelElement::setHovered(bool over) {
	if (over != isHovered()) {
	// Update our status first.
	HTMLElement::setHovered(over);
	}

	// Also update our corresponding control.
	HTMLElement* element = control();
	if (element && element->isHovered() != isHovered())
	element->setHovered(isHovered());
	}

	bool HTMLLabelElement::isInteractiveContent() const {
	return true;
	}

	bool HTMLLabelElement::isInInteractiveContent(Node* node) const {
	if (!isShadowIncludingInclusiveAncestorOf(node))
	return false;
	while (node && this != node) {
	if (node->isHTMLElement() && toHTMLElement(node)->isInteractiveContent())
	return true;
	node = node->parentOrShadowHostNode();
	}
	return false;
	}

	void HTMLLabelElement::defaultEventHandler(Event* evt) {
	if (evt->type() == EventTypeNames::click && !m_processingClick) {
	HTMLElement* element = control();

	// If we can't find a control or if the control received the click
	// event, then there's no need for us to do anything.
	if (!element \|\| (evt->target() &&
	element->isShadowIncludingInclusiveAncestorOf(
	evt->target()->toNode())))
	return;

	if (evt->target() && isInInteractiveContent(evt->target()->toNode()))
	return;

	// Behaviour of label element is as follows:
	// - If there is double click, two clicks will be passed to control
	// element. Control element will not be focused.
	// - If there is selection of label element by dragging, no click
	// event is passed. Also, no focus on control element.
	// - If there is already a selection on label element and then label
	// is clicked, then click event is passed to control element and
	// control element is focused.

	bool isLabelTextSelected = false;

	// If the click is not simulated and the text of the label element
	// is selected by dragging over it, then return without passing the
	// click event to control element.
	// Note: check if it is a MouseEvent because a click event may
	// not be an instance of a MouseEvent if created by document.createEvent().
	if (evt->isMouseEvent() && toMouseEvent(evt)->hasPosition()) {
	if (LocalFrame* frame = document().frame()) {
	// Check if there is a selection and click is not on the
	// selection.
	if (layoutObject() && layoutObject()->isSelectable() &&
	frame->selection().isRange() &&
	!frame->eventHandler()
	.selectionController()
	.mouseDownWasSingleClickInSelection())
	isLabelTextSelected = true;
	// If selection is there and is single click i.e. text is
	// selected by dragging over label text, then return.
	// Click count >=2, meaning double click or triple click,
	// should pass click event to control element.
	// Only in case of drag, neither we pass the click event,
	// nor we focus the control element.
	if (isLabelTextSelected && toMouseEvent(evt)->clickCount() == 1)
	return;
	}
	}

	m_processingClick = true;

	document().updateStyleAndLayoutIgnorePendingStylesheets();
	if (element->isMouseFocusable()) {
	// If the label is not selected, or if the click happened on
	// selection of label, only then focus the control element.
	// In case of double click or triple click, selection will be there,
	// so do not focus the control element.
	if (!isLabelTextSelected)
	element->focus(FocusParams(SelectionBehaviorOnFocus::Restore,
	WebFocusTypeMouse, nullptr));
	}

	// Click the corresponding control.
	element->dispatchSimulatedClick(evt);

	m_processingClick = false;

	evt->setDefaultHandled();
	}

	HTMLElement::defaultEventHandler(evt);
	}

	bool HTMLLabelElement::willRespondToMouseClickEvents() {
	if (control() && control()->willRespondToMouseClickEvents())
	return true;

	return HTMLElement::willRespondToMouseClickEvents();
	}

	void HTMLLabelElement::focus(const FocusParams& params) {
	document().updateStyleAndLayoutTreeForNode(this);
	if (isFocusable()) {
	HTMLElement::focus(params);
	return;
	}
	// To match other browsers, always restore previous selection.
	if (HTMLElement* element = control())
	element->focus(FocusParams(SelectionBehaviorOnFocus::Restore, params.type,
	params.sourceCapabilities));
	}

	void HTMLLabelElement::accessKeyAction(bool sendMouseEvents) {
	if (HTMLElement* element = control())
	element->accessKeyAction(sendMouseEvents);
	else
	HTMLElement::accessKeyAction(sendMouseEvents);
	}

	} // namespace blink