1/*
2 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB.  If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 *
19 */
20
21#include "config.h"
22
23#include "core/html/HTMLMeterElement.h"
24
25#include "bindings/core/v8/ExceptionMessages.h"
26#include "bindings/core/v8/ExceptionState.h"
27#include "bindings/core/v8/ExceptionStatePlaceholder.h"
28#include "core/HTMLNames.h"
29#include "core/dom/ExceptionCode.h"
30#include "core/dom/shadow/ShadowRoot.h"
31#include "core/frame/UseCounter.h"
32#include "core/html/parser/HTMLParserIdioms.h"
33#include "core/html/shadow/MeterShadowElement.h"
34#include "core/rendering/RenderMeter.h"
35#include "core/rendering/RenderTheme.h"
36
37namespace blink {
38
39using namespace HTMLNames;
40
41HTMLMeterElement::HTMLMeterElement(Document& document)
42    : LabelableElement(meterTag, document)
43{
44    UseCounter::count(document, UseCounter::MeterElement);
45}
46
47HTMLMeterElement::~HTMLMeterElement()
48{
49}
50
51PassRefPtrWillBeRawPtr<HTMLMeterElement> HTMLMeterElement::create(Document& document)
52{
53    RefPtrWillBeRawPtr<HTMLMeterElement> meter = adoptRefWillBeNoop(new HTMLMeterElement(document));
54    meter->ensureUserAgentShadowRoot();
55    return meter.release();
56}
57
58RenderObject* HTMLMeterElement::createRenderer(RenderStyle* style)
59{
60    if (hasAuthorShadowRoot() || !RenderTheme::theme().supportsMeter(style->appearance()))
61        return RenderObject::createObject(this, style);
62
63    return new RenderMeter(this);
64}
65
66void HTMLMeterElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
67{
68    if (name == valueAttr || name == minAttr || name == maxAttr || name == lowAttr || name == highAttr || name == optimumAttr)
69        didElementStateChange();
70    else
71        LabelableElement::parseAttribute(name, value);
72}
73
74double HTMLMeterElement::value() const
75{
76    double value = getFloatingPointAttribute(valueAttr, 0);
77    return std::min(std::max(value, min()), max());
78}
79
80void HTMLMeterElement::setValue(double value)
81{
82    setFloatingPointAttribute(valueAttr, value);
83}
84
85double HTMLMeterElement::min() const
86{
87    return getFloatingPointAttribute(minAttr, 0);
88}
89
90void HTMLMeterElement::setMin(double min)
91{
92    setFloatingPointAttribute(minAttr, min);
93}
94
95double HTMLMeterElement::max() const
96{
97    return std::max(getFloatingPointAttribute(maxAttr, std::max(1.0, min())), min());
98}
99
100void HTMLMeterElement::setMax(double max)
101{
102    setFloatingPointAttribute(maxAttr, max);
103}
104
105double HTMLMeterElement::low() const
106{
107    double low = getFloatingPointAttribute(lowAttr, min());
108    return std::min(std::max(low, min()), max());
109}
110
111void HTMLMeterElement::setLow(double low)
112{
113    setFloatingPointAttribute(lowAttr, low);
114}
115
116double HTMLMeterElement::high() const
117{
118    double high = getFloatingPointAttribute(highAttr, max());
119    return std::min(std::max(high, low()), max());
120}
121
122void HTMLMeterElement::setHigh(double high)
123{
124    setFloatingPointAttribute(highAttr, high);
125}
126
127double HTMLMeterElement::optimum() const
128{
129    double optimum = getFloatingPointAttribute(optimumAttr, (max() + min()) / 2);
130    return std::min(std::max(optimum, min()), max());
131}
132
133void HTMLMeterElement::setOptimum(double optimum)
134{
135    setFloatingPointAttribute(optimumAttr, optimum);
136}
137
138HTMLMeterElement::GaugeRegion HTMLMeterElement::gaugeRegion() const
139{
140    double lowValue = low();
141    double highValue = high();
142    double theValue = value();
143    double optimumValue = optimum();
144
145    if (optimumValue < lowValue) {
146        // The optimum range stays under low
147        if (theValue <= lowValue)
148            return GaugeRegionOptimum;
149        if (theValue <= highValue)
150            return GaugeRegionSuboptimal;
151        return GaugeRegionEvenLessGood;
152    }
153
154    if (highValue < optimumValue) {
155        // The optimum range stays over high
156        if (highValue <= theValue)
157            return GaugeRegionOptimum;
158        if (lowValue <= theValue)
159            return GaugeRegionSuboptimal;
160        return GaugeRegionEvenLessGood;
161    }
162
163    // The optimum range stays between high and low.
164    // According to the standard, <meter> never show GaugeRegionEvenLessGood in this case
165    // because the value is never less or greater than min or max.
166    if (lowValue <= theValue && theValue <= highValue)
167        return GaugeRegionOptimum;
168    return GaugeRegionSuboptimal;
169}
170
171double HTMLMeterElement::valueRatio() const
172{
173    double min = this->min();
174    double max = this->max();
175    double value = this->value();
176
177    if (max <= min)
178        return 0;
179    return (value - min) / (max - min);
180}
181
182void HTMLMeterElement::didElementStateChange()
183{
184    m_value->setWidthPercentage(valueRatio()*100);
185    m_value->updatePseudo();
186    if (RenderMeter* render = renderMeter())
187        render->updateFromElement();
188}
189
190RenderMeter* HTMLMeterElement::renderMeter() const
191{
192    if (renderer() && renderer()->isMeter())
193        return toRenderMeter(renderer());
194
195    RenderObject* renderObject = userAgentShadowRoot()->firstChild()->renderer();
196    return toRenderMeter(renderObject);
197}
198
199void HTMLMeterElement::didAddUserAgentShadowRoot(ShadowRoot& root)
200{
201    ASSERT(!m_value);
202
203    RefPtrWillBeRawPtr<MeterInnerElement> inner = MeterInnerElement::create(document());
204    root.appendChild(inner);
205
206    RefPtrWillBeRawPtr<MeterBarElement> bar = MeterBarElement::create(document());
207    m_value = MeterValueElement::create(document());
208    m_value->setWidthPercentage(0);
209    m_value->updatePseudo();
210    bar->appendChild(m_value);
211
212    inner->appendChild(bar);
213}
214
215void HTMLMeterElement::trace(Visitor* visitor)
216{
217    visitor->trace(m_value);
218    LabelableElement::trace(visitor);
219}
220
221} // namespace
222