cpp: Add getters for the attributes of a trust signature

* lang/cpp/src/key.h (TrustSignatureTrust): New enum.
* lang/cpp/src/key.h, lang/cpp/src/key.cpp
(UserID::Signature::isTrustSignature): New.
(UserID::Signature::trustValue): New.
(UserID::Signature::trustDepth): New.
(UserID::Signature::trustScope): New.
--

GnuPG-bug-id: 5245, 5420

NEWS

@@ -4,6 +4,10 @@ Noteworthy changes in version 1.15.2 (unreleased)
 
  * Interface changes relative to the 1.15.1 release:
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ cpp: UserID::Signature::isTrustSignature   NEW.
+ cpp: UserID::Signature::trustValue         NEW.
+ cpp: UserID::Signature::trustDepth         NEW.
+ cpp: UserID::Signature::trustScope         NEW.
  gpgme_key_sig_t                       EXTENDED: New field 'trust_depth'.
  gpgme_key_sig_t                       EXTENDED: New field 'trust_value'.
  gpgme_key_sig_t                       EXTENDED: New field 'trust_scope'.

lang/cpp/src/key.cpp

@@ -1083,6 +1083,29 @@ const char *UserID::Signature::policyURL() const
     return nullptr;
 }
 
+bool UserID::Signature::isTrustSignature() const
+{
+    return sig && sig->trust_depth > 0;
+}
+
+TrustSignatureTrust UserID::Signature::trustValue() const
+{
+    if (!sig || !isTrustSignature()) {
+        return TrustSignatureTrust::None;
+    }
+    return sig->trust_value >= 120 ? TrustSignatureTrust::Complete : TrustSignatureTrust::Partial;
+}
+
+unsigned int UserID::Signature::trustDepth() const
+{
+    return sig ? sig->trust_depth : 0;
+}
+
+const char *UserID::Signature::trustScope() const
+{
+    return sig ? sig->trust_scope : nullptr;
+}
+
 std::string UserID::addrSpecFromString(const char *userid)
 {
     if (!userid) {

lang/cpp/src/key.h

@@ -47,6 +47,12 @@ class TofuInfo;
 
 typedef std::shared_ptr< std::remove_pointer<gpgme_key_t>::type > shared_gpgme_key_t;
 
+enum class TrustSignatureTrust : char {
+    None = 0,
+    Partial,
+    Complete,
+};
+
 //
 // class Key
 //
@@ -514,6 +520,11 @@ public:
     GpgME::Notation notation(unsigned int idx) const;
     std::vector<GpgME::Notation> notations() const;
 
+    bool isTrustSignature() const;
+    TrustSignatureTrust trustValue() const;
+    unsigned int trustDepth() const;
+    const char *trustScope() const;
+
 private:
     shared_gpgme_key_t key;
     gpgme_user_id_t uid;