third_party/blink/renderer/core/html/forms/html_label_element.cc - 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 "third_party/blink/renderer/core/html/forms/html_label_element.h"

 #include "third_party/blink/renderer/core/dom/document.h"
 #include "third_party/blink/renderer/core/dom/element_traversal.h"
 #include "third_party/blink/renderer/core/editing/editing_utilities.h"
 #include "third_party/blink/renderer/core/editing/frame_selection.h"
 #include "third_party/blink/renderer/core/editing/selection_controller.h"
 #include "third_party/blink/renderer/core/editing/visible_selection.h"
 #include "third_party/blink/renderer/core/events/mouse_event.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
 #include "third_party/blink/renderer/core/frame/use_counter.h"
 #include "third_party/blink/renderer/core/html/custom/element_internals.h"
 #include "third_party/blink/renderer/core/html/forms/html_form_control_element.h"
 #include "third_party/blink/renderer/core/html/forms/listed_element.h"
 #include "third_party/blink/renderer/core/html_names.h"
 #include "third_party/blink/renderer/core/input/event_handler.h"
 #include "third_party/blink/renderer/core/layout/layout_object.h"

 namespace blink {

 using namespace html_names;

 inline HTMLLabelElement::HTMLLabelElement(Document& document)
     : HTMLElement(kLabelTag, document), processing_click_(false) {}

 HTMLLabelElement* HTMLLabelElement::Create(Document& document) {
   return MakeGarbageCollected<HTMLLabelElement>(document);
 }

 HTMLElement* HTMLLabelElement::control() const {
   // https://html.spec.whatwg.org/multipage/forms.html#labeled-control
   const AtomicString& control_id = getAttribute(kForAttr);
   if (control_id.IsNull()) {
     // "If the for attribute is not specified, but the label element has a
     // labelable element descendant, then the first such descendant in tree
     // order is the label element's labeled control."
     for (HTMLElement& element : Traversal<HTMLElement>::DescendantsOf(*this)) {
       if (element.IsLabelable()) {
         if (!element.IsFormControlElement()) {
           UseCounter::Count(
               GetDocument(),
               WebFeature::kHTMLLabelElementControlForNonFormAssociatedElement);
         }
         return &element;
       }
     }
     return nullptr;
   }

   if (!IsInTreeScope())
     return nullptr;

   if (Element* element = GetTreeScope().getElementById(control_id)) {
     if (auto* html_element = ToHTMLElementOrNull(*element)) {
       if (html_element->IsLabelable()) {
         if (!html_element->IsFormControlElement()) {
           UseCounter::Count(
               GetDocument(),
               WebFeature::kHTMLLabelElementControlForNonFormAssociatedElement);
         }
         return html_element;
       }
     }
   }

   return nullptr;
 }

 HTMLFormElement* HTMLLabelElement::form() const {
   if (HTMLElement* control = this->control()) {
     if (auto* form_control_element = ToHTMLFormControlElementOrNull(control))
       return form_control_element->Form();
     if (control->IsFormAssociatedCustomElement())
       return control->EnsureElementInternals().Form();
   }
   return nullptr;
 }

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

   // Also update our corresponding control.
   HTMLElement* control_element = control();
   if (control_element && control_element->IsActive() != IsActive())
     control_element->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() == event_type_names::kClick && !processing_click_) {
     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 is_label_text_selected = 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 = GetDocument().GetFrame()) {
         // Check if there is a selection and click is not on the
         // selection.
         if (GetLayoutObject() && GetLayoutObject()->IsSelectable() &&
             frame->Selection()
                 .ComputeVisibleSelectionInDOMTreeDeprecated()
                 .IsRange() &&
             !frame->GetEventHandler()
                  .GetSelectionController()
                  .MouseDownWasSingleClickInSelection() &&
             evt.target()->ToNode()->CanStartSelection())
           is_label_text_selected = 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 (is_label_text_selected && ToMouseEvent(evt).ClickCount() == 1)
           return;
       }
     }

     processing_click_ = true;

     GetDocument().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 (!is_label_text_selected) {
         element->focus(FocusParams(SelectionBehaviorOnFocus::kRestore,
                                    kWebFocusTypeMouse, nullptr));
       }
     }

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

     processing_click_ = false;

     evt.SetDefaultHandled();
   }

   HTMLElement::DefaultEventHandler(evt);
 }

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

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

   return HTMLElement::WillRespondToMouseClickEvents();
 }

 void HTMLLabelElement::focus(const FocusParams& params) {
   GetDocument().UpdateStyleAndLayoutTreeForNode(this);
   if (IsFocusable()) {
     HTMLElement::focus(params);
     return;
   }
   // To match other browsers, always restore previous selection.
   if (HTMLElement* element = control()) {
     element->focus(FocusParams(SelectionBehaviorOnFocus::kRestore, params.type,
                                params.source_capabilities, params.options));
   }
 }

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

 }  // 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 "third_party/blink/renderer/core/html/forms/html_label_element.h"

	#include "third_party/blink/renderer/core/dom/document.h"
	#include "third_party/blink/renderer/core/dom/element_traversal.h"
	#include "third_party/blink/renderer/core/editing/editing_utilities.h"
	#include "third_party/blink/renderer/core/editing/frame_selection.h"
	#include "third_party/blink/renderer/core/editing/selection_controller.h"
	#include "third_party/blink/renderer/core/editing/visible_selection.h"
	#include "third_party/blink/renderer/core/events/mouse_event.h"
	#include "third_party/blink/renderer/core/frame/local_frame.h"
	#include "third_party/blink/renderer/core/frame/use_counter.h"
	#include "third_party/blink/renderer/core/html/custom/element_internals.h"
	#include "third_party/blink/renderer/core/html/forms/html_form_control_element.h"
	#include "third_party/blink/renderer/core/html/forms/listed_element.h"
	#include "third_party/blink/renderer/core/html_names.h"
	#include "third_party/blink/renderer/core/input/event_handler.h"
	#include "third_party/blink/renderer/core/layout/layout_object.h"

	namespace blink {

	using namespace html_names;

	inline HTMLLabelElement::HTMLLabelElement(Document& document)
	: HTMLElement(kLabelTag, document), processing_click_(false) {}

	HTMLLabelElement* HTMLLabelElement::Create(Document& document) {
	return MakeGarbageCollected<HTMLLabelElement>(document);
	}

	HTMLElement* HTMLLabelElement::control() const {
	// https://html.spec.whatwg.org/multipage/forms.html#labeled-control
	const AtomicString& control_id = getAttribute(kForAttr);
	if (control_id.IsNull()) {
	// "If the for attribute is not specified, but the label element has a
	// labelable element descendant, then the first such descendant in tree
	// order is the label element's labeled control."
	for (HTMLElement& element : Traversal<HTMLElement>::DescendantsOf(*this)) {
	if (element.IsLabelable()) {
	if (!element.IsFormControlElement()) {
	UseCounter::Count(
	GetDocument(),
	WebFeature::kHTMLLabelElementControlForNonFormAssociatedElement);
	}
	return &element;
	}
	}
	return nullptr;
	}

	if (!IsInTreeScope())
	return nullptr;

	if (Element* element = GetTreeScope().getElementById(control_id)) {
	if (auto* html_element = ToHTMLElementOrNull(*element)) {
	if (html_element->IsLabelable()) {
	if (!html_element->IsFormControlElement()) {
	UseCounter::Count(
	GetDocument(),
	WebFeature::kHTMLLabelElementControlForNonFormAssociatedElement);
	}
	return html_element;
	}
	}
	}

	return nullptr;
	}

	HTMLFormElement* HTMLLabelElement::form() const {
	if (HTMLElement* control = this->control()) {
	if (auto* form_control_element = ToHTMLFormControlElementOrNull(control))
	return form_control_element->Form();
	if (control->IsFormAssociatedCustomElement())
	return control->EnsureElementInternals().Form();
	}
	return nullptr;
	}

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

	// Also update our corresponding control.
	HTMLElement* control_element = control();
	if (control_element && control_element->IsActive() != IsActive())
	control_element->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() == event_type_names::kClick && !processing_click_) {
	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 is_label_text_selected = 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 = GetDocument().GetFrame()) {
	// Check if there is a selection and click is not on the
	// selection.
	if (GetLayoutObject() && GetLayoutObject()->IsSelectable() &&
	frame->Selection()
	.ComputeVisibleSelectionInDOMTreeDeprecated()
	.IsRange() &&
	!frame->GetEventHandler()
	.GetSelectionController()
	.MouseDownWasSingleClickInSelection() &&
	evt.target()->ToNode()->CanStartSelection())
	is_label_text_selected = 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 (is_label_text_selected && ToMouseEvent(evt).ClickCount() == 1)
	return;
	}
	}

	processing_click_ = true;

	GetDocument().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 (!is_label_text_selected) {
	element->focus(FocusParams(SelectionBehaviorOnFocus::kRestore,
	kWebFocusTypeMouse, nullptr));
	}
	}

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

	processing_click_ = false;

	evt.SetDefaultHandled();
	}

	HTMLElement::DefaultEventHandler(evt);
	}

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

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

	return HTMLElement::WillRespondToMouseClickEvents();
	}

	void HTMLLabelElement::focus(const FocusParams& params) {
	GetDocument().UpdateStyleAndLayoutTreeForNode(this);
	if (IsFocusable()) {
	HTMLElement::focus(params);
	return;
	}
	// To match other browsers, always restore previous selection.
	if (HTMLElement* element = control()) {
	element->focus(FocusParams(SelectionBehaviorOnFocus::kRestore, params.type,
	params.source_capabilities, params.options));
	}
	}

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

	} // namespace blink