aboutsummaryrefslogtreecommitdiffstats
path: root/src
diff options
context:
space:
mode:
authorMax Kellermann <max@duempel.org>2014-08-28 06:28:14 +0200
committerMax Kellermann <max@duempel.org>2014-08-28 06:42:04 +0200
commitc2001a725978b665f0b22a4ad3865293754efd38 (patch)
treefe6a1cdf3c3d53c7aabf93dccfba3f9a8ab91815 /src
parent78f911ac1911e0ebdab3afd26683653d416c08f0 (diff)
downloadmpd-c2001a725978b665f0b22a4ad3865293754efd38.tar.gz
mpd-c2001a725978b665f0b22a4ad3865293754efd38.tar.xz
mpd-c2001a725978b665f0b22a4ad3865293754efd38.zip
Chrono: add class SignedSongTime
Diffstat (limited to '')
-rw-r--r--src/Chrono.hxx64
1 files changed, 64 insertions, 0 deletions
diff --git a/src/Chrono.hxx b/src/Chrono.hxx
index f20edaf59..9832a680f 100644
--- a/src/Chrono.hxx
+++ b/src/Chrono.hxx
@@ -83,4 +83,68 @@ public:
}
};
+/**
+ * A variant of #SongTime that is based on a signed integer. It can
+ * be used for relative values.
+ */
+class SignedSongTime : public std::chrono::duration<std::int32_t, std::milli> {
+ typedef std::chrono::duration<std::int32_t, std::milli> Base;
+ typedef Base::rep rep;
+
+public:
+ SignedSongTime() = default;
+
+ template<typename T>
+ explicit constexpr SignedSongTime(T t):Base(t) {}
+
+ /**
+ * This constructor allows implicit conversion from the base
+ * class to this class. It is necessary because all of
+ * std::chrono::duration's operators return another
+ * std::chrono::duration and not an instance of this class.
+ */
+ constexpr SignedSongTime(Base b):Base(b) {}
+
+ static constexpr SignedSongTime FromS(int s) {
+ return SignedSongTime(rep(s) * 1000);
+ }
+
+ static constexpr SignedSongTime FromS(float s) {
+ return SignedSongTime(rep(s * 1000));
+ }
+
+ static constexpr SignedSongTime FromS(double s) {
+ return SignedSongTime(rep(s * 1000));
+ }
+
+ static constexpr SignedSongTime FromMS(rep ms) {
+ return SignedSongTime(ms);
+ }
+
+ constexpr rep ToMS() const {
+ return count();
+ }
+
+ template<typename T=rep>
+ constexpr T ToScale(unsigned base) const {
+ return count() * T(base) / 1000;
+ }
+
+ constexpr double ToDoubleS() const {
+ return double(count()) / 1000.;
+ };
+
+ constexpr bool IsZero() const {
+ return count() == 0;
+ }
+
+ constexpr bool IsPositive() const {
+ return count() > 0;
+ }
+
+ constexpr bool IsNegative() const {
+ return count() < 0;
+ }
+};
+
#endif