1 files changed, 259 insertions, 0 deletions
diff --git a/dom/html/HTMLMeterElement.cpp b/dom/html/HTMLMeterElement.cpp
new file mode 100644
index 0000000000..3bc025de5a
--- /dev/null
+++ b/dom/html/HTMLMeterElement.cpp
@@ -0,0 +1,259 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "HTMLMeterElement.h"
+#include "mozilla/dom/HTMLMeterElementBinding.h"
+
+NS_IMPL_NS_NEW_HTML_ELEMENT(Meter)
+
+namespace mozilla::dom {
+
+static const double kDefaultValue = 0.0;
+static const double kDefaultMin = 0.0;
+static const double kDefaultMax = 1.0;
+
+HTMLMeterElement::HTMLMeterElement(
+    already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo)
+    : nsGenericHTMLElement(std::move(aNodeInfo)) {}
+
+HTMLMeterElement::~HTMLMeterElement() = default;
+
+NS_IMPL_ELEMENT_CLONE(HTMLMeterElement)
+
+static bool IsInterestingAttr(int32_t aNamespaceID, nsAtom* aAttribute) {
+  if (aNamespaceID != kNameSpaceID_None) {
+    return false;
+  }
+  return aAttribute == nsGkAtoms::value || aAttribute == nsGkAtoms::max ||
+         aAttribute == nsGkAtoms::min || aAttribute == nsGkAtoms::low ||
+         aAttribute == nsGkAtoms::high || aAttribute == nsGkAtoms::optimum;
+}
+
+bool HTMLMeterElement::ParseAttribute(int32_t aNamespaceID, nsAtom* aAttribute,
+                                      const nsAString& aValue,
+                                      nsIPrincipal* aMaybeScriptedPrincipal,
+                                      nsAttrValue& aResult) {
+  if (IsInterestingAttr(aNamespaceID, aAttribute)) {
+    return aResult.ParseDoubleValue(aValue);
+  }
+  return nsGenericHTMLElement::ParseAttribute(aNamespaceID, aAttribute, aValue,
+                                              aMaybeScriptedPrincipal, aResult);
+}
+
+void HTMLMeterElement::AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
+                                    const nsAttrValue* aValue,
+                                    const nsAttrValue* aOldValue,
+                                    nsIPrincipal* aSubjectPrincipal,
+                                    bool aNotify) {
+  if (IsInterestingAttr(aNameSpaceID, aName)) {
+    UpdateOptimumState(aNotify);
+  }
+  nsGenericHTMLElement::AfterSetAttr(aNameSpaceID, aName, aValue, aOldValue,
+                                     aSubjectPrincipal, aNotify);
+}
+
+void HTMLMeterElement::UpdateOptimumState(bool aNotify) {
+  AutoStateChangeNotifier notifier(*this, aNotify);
+  RemoveStatesSilently(ElementState::METER_OPTIMUM_STATES);
+  AddStatesSilently(GetOptimumState());
+}
+
+double HTMLMeterElement::Min() const {
+  /**
+   * If the attribute min is defined, the minimum is this value.
+   * Otherwise, the minimum is the default value.
+   */
+  const nsAttrValue* attrMin = mAttrs.GetAttr(nsGkAtoms::min);
+  if (attrMin && attrMin->Type() == nsAttrValue::eDoubleValue) {
+    return attrMin->GetDoubleValue();
+  }
+  return kDefaultMin;
+}
+
+double HTMLMeterElement::Max() const {
+  /**
+   * If the attribute max is defined, the maximum is this value.
+   * Otherwise, the maximum is the default value.
+   * If the maximum value is less than the minimum value,
+   * the maximum value is the same as the minimum value.
+   */
+  double max;
+
+  const nsAttrValue* attrMax = mAttrs.GetAttr(nsGkAtoms::max);
+  if (attrMax && attrMax->Type() == nsAttrValue::eDoubleValue) {
+    max = attrMax->GetDoubleValue();
+  } else {
+    max = kDefaultMax;
+  }
+
+  return std::max(max, Min());
+}
+
+double HTMLMeterElement::Value() const {
+  /**
+   * If the attribute value is defined, the actual value is this value.
+   * Otherwise, the actual value is the default value.
+   * If the actual value is less than the minimum value,
+   * the actual value is the same as the minimum value.
+   * If the actual value is greater than the maximum value,
+   * the actual value is the same as the maximum value.
+   */
+  double value;
+
+  const nsAttrValue* attrValue = mAttrs.GetAttr(nsGkAtoms::value);
+  if (attrValue && attrValue->Type() == nsAttrValue::eDoubleValue) {
+    value = attrValue->GetDoubleValue();
+  } else {
+    value = kDefaultValue;
+  }
+
+  double min = Min();
+
+  if (value <= min) {
+    return min;
+  }
+
+  return std::min(value, Max());
+}
+
+double HTMLMeterElement::Position() const {
+  const double max = Max();
+  const double min = Min();
+  const double value = Value();
+
+  double range = max - min;
+  return range != 0.0 ? (value - min) / range : 1.0;
+}
+
+double HTMLMeterElement::Low() const {
+  /**
+   * If the low value is defined, the low value is this value.
+   * Otherwise, the low value is the minimum value.
+   * If the low value is less than the minimum value,
+   * the low value is the same as the minimum value.
+   * If the low value is greater than the maximum value,
+   * the low value is the same as the maximum value.
+   */
+
+  double min = Min();
+
+  const nsAttrValue* attrLow = mAttrs.GetAttr(nsGkAtoms::low);
+  if (!attrLow || attrLow->Type() != nsAttrValue::eDoubleValue) {
+    return min;
+  }
+
+  double low = attrLow->GetDoubleValue();
+
+  if (low <= min) {
+    return min;
+  }
+
+  return std::min(low, Max());
+}
+
+double HTMLMeterElement::High() const {
+  /**
+   * If the high value is defined, the high value is this value.
+   * Otherwise, the high value is the maximum value.
+   * If the high value is less than the low value,
+   * the high value is the same as the low value.
+   * If the high value is greater than the maximum value,
+   * the high value is the same as the maximum value.
+   */
+
+  double max = Max();
+
+  const nsAttrValue* attrHigh = mAttrs.GetAttr(nsGkAtoms::high);
+  if (!attrHigh || attrHigh->Type() != nsAttrValue::eDoubleValue) {
+    return max;
+  }
+
+  double high = attrHigh->GetDoubleValue();
+
+  if (high >= max) {
+    return max;
+  }
+
+  return std::max(high, Low());
+}
+
+double HTMLMeterElement::Optimum() const {
+  /**
+   * If the optimum value is defined, the optimum value is this value.
+   * Otherwise, the optimum value is the midpoint between
+   * the minimum value and the maximum value :
+   * min + (max - min)/2 = (min + max)/2
+   * If the optimum value is less than the minimum value,
+   * the optimum value is the same as the minimum value.
+   * If the optimum value is greater than the maximum value,
+   * the optimum value is the same as the maximum value.
+   */
+
+  double max = Max();
+
+  double min = Min();
+
+  const nsAttrValue* attrOptimum = mAttrs.GetAttr(nsGkAtoms::optimum);
+  if (!attrOptimum || attrOptimum->Type() != nsAttrValue::eDoubleValue) {
+    return (min + max) / 2.0;
+  }
+
+  double optimum = attrOptimum->GetDoubleValue();
+
+  if (optimum <= min) {
+    return min;
+  }
+
+  return std::min(optimum, max);
+}
+
+ElementState HTMLMeterElement::GetOptimumState() const {
+  /*
+   * If the optimum value is in [minimum, low[,
+   *     return if the value is in optimal, suboptimal or sub-suboptimal region
+   *
+   * If the optimum value is in [low, high],
+   *     return if the value is in optimal or suboptimal region
+   *
+   * If the optimum value is in ]high, maximum],
+   *     return if the value is in optimal, suboptimal or sub-suboptimal region
+   */
+  double value = Value();
+  double low = Low();
+  double high = High();
+  double optimum = Optimum();
+
+  if (optimum < low) {
+    if (value < low) {
+      return ElementState::OPTIMUM;
+    }
+    if (value <= high) {
+      return ElementState::SUB_OPTIMUM;
+    }
+    return ElementState::SUB_SUB_OPTIMUM;
+  }
+  if (optimum > high) {
+    if (value > high) {
+      return ElementState::OPTIMUM;
+    }
+    if (value >= low) {
+      return ElementState::SUB_OPTIMUM;
+    }
+    return ElementState::SUB_SUB_OPTIMUM;
+  }
+  // optimum in [low, high]
+  if (value >= low && value <= high) {
+    return ElementState::OPTIMUM;
+  }
+  return ElementState::SUB_OPTIMUM;
+}
+
+JSObject* HTMLMeterElement::WrapNode(JSContext* aCx,
+                                     JS::Handle<JSObject*> aGivenProto) {
+  return HTMLMeterElement_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+}  // namespace mozilla::dom