Chromium HTML Input 类型radio 对应c++

一、单选按钮（Radio Buttons）

<input type="radio"> 标签定义了表单的单选框选项:

<form action="">
<input type="radio" name="sex" value="male">男<br>
<input type="radio" name="sex" value="female">女
</form>

二、 radio c++接口定义：

third_party\blink\renderer\core\html\forms\radio_input_type.h

third_party\blink\renderer\core\html\forms\radio_input_type.cc

namespace blink {

class RadioInputType final : public BaseCheckableInputType {
 public:
  CORE_EXPORT static HTMLInputElement* NextRadioButtonInGroup(HTMLInputElement*,
                                                              bool forward);

  RadioInputType(HTMLInputElement& element)
      : BaseCheckableInputType(Type::kRadio, element) {}
  bool ValueMissing(const String&) const;

 private:
  void CountUsage() override;
  ControlPart AutoAppearance() const override;
  void WillUpdateCheckedness(bool new_checked) override;
  String ValueMissingText() const override;
  void HandleClickEvent(MouseEvent&) override;
  void HandleKeydownEvent(KeyboardEvent&) override;
  void HandleKeyupEvent(KeyboardEvent&) override;
  bool IsKeyboardFocusable(
      Element::UpdateBehavior update_behavior =
          Element::UpdateBehavior::kStyleAndLayout) const override;
  bool ShouldSendChangeEventAfterCheckedChanged() override;
  ClickHandlingState* WillDispatchClick() override;
  void DidDispatchClick(Event&, const ClickHandlingState&) override;
  bool ShouldAppearIndeterminate() const override;

  HTMLInputElement* FindNextFocusableRadioButtonInGroup(HTMLInputElement*,
                                                        bool);
  HTMLInputElement* CheckedRadioButtonForGroup() const;
};

template <>
struct DowncastTraits<RadioInputType> {
  static bool AllowFrom(const InputType& type) {
    return type.IsRadioInputType();
  }
};

}  // namespace blink