Partial commit toward IV/seq implementation!

1 files changed, 72 insertions, 0 deletions

diff --git a/src/seq/file/iv.rs b/src/seq/file/iv.rs
new file mode 100644
index 0000000..27d468f
--- /dev/null
+++ b/src/seq/file/iv.rs
@@ -0,0 +1,72 @@
+use std::io;
+use std::collections::HashMap;
+use std::borrow::Borrow;
+
+use xml::reader;
+use xml::reader::{EventReader, XmlEvent};
+use xml::attribute::OwnedAttribute;
+
+use super::*;
+
+struct AttrMapping(HashMap<String, String>);
+
+impl AttrMapping {
+    pub fn make(attrs: Vec<OwnedAttribute>) -> AttrMapping {
+        let mut output = HashMap::new();
+
+        for attr in attrs {
+            output.insert(attr.name.local_name.clone(), attr.value.clone());
+        }
+
+        AttrMapping(output)
+    }
+
+    pub fn get_str<'a, 'b, 'c: 'a, Q>(&'a self, key: &'b Q, default: &'c str) -> &'a str where String: Borrow<Q> {
+        self.0.get(key).or(default)
+    }
+}
+
+pub fn read<R: io::Read>(source: R) -> reader::Result<IV> {
+    let mut output: IV = Default::default();
+    let mut event_reader = EventReader::new(source);
+
+    #[derive(Debug)]
+    enum ReadState<'a> {
+        Idle,
+        InStreams,
+        InBPMs,
+        InNoteStream(&'a mut NoteStream),
+        InAuxStream(&'a mut AuxStream),
+    }
+
+    let mut state = ReadState::Idle;
+
+    for ev in event_reader {
+        match ev? {
+            XmlEvent::StartElement{name, attributes, ..} => {
+                let attrmap = AttrMapping::make(attributes);
+
+                match (name.local_name.as_ref(), &state) {
+                    ("bpms", &ReadState::Idle) => { state = ReadState::InBPMs; },
+                    ("bpm", &ReadState::InBPMs) => {
+                        let entry = BPMEntry {
+                            abstick: 0,
+                            bpm: BPM(0.0),
+                            realtime: Some(Seconds(0.0)),
+                        };
+                    },
+                    ("streams", &ReadState::Idle) => { state = ReadState::InStreams; },
+                    _ => (),
+                }
+            },
+            XmlEvent::EndElement{name} => match (name.local_name.as_ref(), &state) {
+                ("bpms", _) => { state = ReadState::Idle; },
+                ("streams", _) => { state = ReadState::Idle; },
+                _ => (),
+            },
+            _ => (),
+        }
+    }
+
+    Ok(output)
+}