1/*
2 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
4 *           (C) 2001 Dirk Mueller (mueller@kde.org)
5 * Copyright (C) 2004, 2005, 2006, 2007, 2010 Apple Inc. All rights reserved.
6 *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Library General Public License for more details.
17 *
18 * You should have received a copy of the GNU Library General Public License
19 * along with this library; see the file COPYING.LIB.  If not, write to
20 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
22 *
23 */
24
25#include "config.h"
26#include "HTMLLabelElement.h"
27
28#include "Document.h"
29#include "Event.h"
30#include "EventNames.h"
31#include "HTMLFormControlElement.h"
32#include "HTMLFormElement.h"
33#include "HTMLNames.h"
34
35namespace WebCore {
36
37using namespace HTMLNames;
38
39static HTMLFormControlElement* nodeAsLabelableFormControl(Node* node)
40{
41    if (!node || !node->isElementNode() || !static_cast<Element*>(node)->isFormControlElement())
42        return 0;
43
44    HTMLFormControlElement* formControlElement = static_cast<HTMLFormControlElement*>(node);
45    if (!formControlElement->isLabelable())
46        return 0;
47
48    return formControlElement;
49}
50
51inline HTMLLabelElement::HTMLLabelElement(const QualifiedName& tagName, Document* document)
52    : HTMLElement(tagName, document)
53{
54    ASSERT(hasTagName(labelTag));
55}
56
57PassRefPtr<HTMLLabelElement> HTMLLabelElement::create(const QualifiedName& tagName, Document* document)
58{
59    return adoptRef(new HTMLLabelElement(tagName, document));
60}
61
62bool HTMLLabelElement::isFocusable() const
63{
64    return false;
65}
66
67HTMLFormControlElement* HTMLLabelElement::control()
68{
69    const AtomicString& controlId = getAttribute(forAttr);
70    if (controlId.isNull()) {
71        // Search the children and descendants of the label element for a form element.
72        // per http://dev.w3.org/html5/spec/Overview.html#the-label-element
73        // the form element must be "labelable form-associated element".
74        Node* node = this;
75        while ((node = node->traverseNextNode(this))) {
76            if (HTMLFormControlElement* formControlElement = nodeAsLabelableFormControl(node))
77                return formControlElement;
78        }
79        return 0;
80    }
81
82    // Find the first element whose id is controlId. If it is found and it is a labelable form control,
83    // return it, otherwise return 0.
84    return nodeAsLabelableFormControl(document()->getElementById(controlId));
85}
86
87void HTMLLabelElement::setActive(bool down, bool pause)
88{
89    if (down == active())
90        return;
91
92    // Update our status first.
93    HTMLElement::setActive(down, pause);
94
95    // Also update our corresponding control.
96    if (HTMLElement* element = control())
97        element->setActive(down, pause);
98}
99
100void HTMLLabelElement::setHovered(bool over)
101{
102    if (over == hovered())
103        return;
104
105    // Update our status first.
106    HTMLElement::setHovered(over);
107
108    // Also update our corresponding control.
109    if (HTMLElement* element = control())
110        element->setHovered(over);
111}
112
113void HTMLLabelElement::defaultEventHandler(Event* evt)
114{
115    static bool processingClick = false;
116
117    if (evt->type() == eventNames().clickEvent && !processingClick) {
118        RefPtr<HTMLElement> element = control();
119
120        // If we can't find a control or if the control received the click
121        // event, then there's no need for us to do anything.
122        if (!element || (evt->target() && element->containsIncludingShadowDOM(evt->target()->toNode())))
123            return;
124
125        processingClick = true;
126
127        // Click the corresponding control.
128        element->dispatchSimulatedClick(evt);
129
130        // If the control can be focused via the mouse, then do that too.
131        if (element->isMouseFocusable())
132            element->focus();
133
134        processingClick = false;
135
136        evt->setDefaultHandled();
137    }
138
139    HTMLElement::defaultEventHandler(evt);
140}
141
142void HTMLLabelElement::focus(bool)
143{
144    // to match other browsers, always restore previous selection
145    if (HTMLElement* element = control())
146        element->focus();
147}
148
149void HTMLLabelElement::accessKeyAction(bool sendToAnyElement)
150{
151    if (HTMLElement* element = control())
152        element->accessKeyAction(sendToAnyElement);
153    else
154        HTMLElement::accessKeyAction(sendToAnyElement);
155}
156
157void HTMLLabelElement::parseMappedAttribute(Attribute* attribute)
158{
159    if (attribute->name() == forAttr) {
160        // htmlFor attribute change affects other nodes than this.
161        // Clear the caches to ensure that the labels caches are cleared.
162        if (document())
163            document()->notifyLocalNodeListsLabelChanged();
164    } else
165        HTMLElement::parseMappedAttribute(attribute);
166}
167
168} // namespace
169