If no 'mappings.dkmap' file is found, use default mappings

If a mappings file is found but is empty, no mappings will be set. Hmm,
that sounds wrong. We still want to keep the defaults even if only some
button triggers are mapped. Making buttons do nothing is what `<Nop>` is
for, not this behaviour. Darn.

2 files changed, 61 insertions, 6 deletions

diff --git a/src/ffi.rs b/src/ffi.rs
index 55b0998..4d71334 100644
--- a/src/ffi.rs
+++ b/src/ffi.rs
@@ -50,13 +50,13 @@ pub extern "C" fn dome_key_state_free(ptr: *mut State) {
 pub extern "C" fn dome_key_state_load_map_group(ptr: *mut State) {
     match xdg::BaseDirectories::with_prefix("dome-key") {
         Ok(xdg_dirs) => {
+            let state = unsafe {
+                assert!(!ptr.is_null());
+                &mut *ptr
+            };
+
             match xdg_dirs.find_config_file("mappings.dkmap") {
                 Some(mapping_file) => {
-                    let state = unsafe {
-                        assert!(!ptr.is_null());
-                        &mut *ptr
-                    };
-
                     let dkmap = fs::read_to_string(mapping_file)
                         .expect("Failed to read 'mappings.dkmap'");
 
@@ -67,10 +67,13 @@ pub extern "C" fn dome_key_state_load_map_group(ptr: *mut State) {
                     state.map_group = Some(map_group);
                 },
                 None => {
+                    state.map_group = Some(MapGroup::default());
+
                     match xdg_dirs.get_config_home().to_str() {
                         Some(config_home) => {
                             error!(
-                                "No mapping file found at '{}{}'",
+                                "No mapping file found at '{}{}'.
+                                Using default mappings.",
                                 config_home,
                                 "mappings.dkmap"
                             )
diff --git a/src/parser.rs b/src/parser.rs
index fe56fca..8314e0d 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -203,6 +203,58 @@ impl MapGroup {
     }
 }
 
+/// Default headphone button mappings:
+///
+/// * Up → Volume up
+/// * Middle → Play
+/// * Down → Volume down
+impl Default for MapGroup {
+    fn default() -> Self {
+        let mut default_maps: MapCollection = HashMap::new();
+        default_maps.insert(
+            vec![HeadphoneButton::Up],
+            MapAction {
+                action: Action::Map(
+                    vec![KeyboardKeyWithModifiers::new(
+                        KeyboardKey::NXKey(key_code::NX_KEYTYPE_SOUND_UP),
+                        vec![],
+                    )]
+                ),
+                kind: MapKind::Map,
+            },
+        );
+        default_maps.insert(
+            vec![HeadphoneButton::Play],
+            MapAction {
+                action: Action::Map(
+                    vec![KeyboardKeyWithModifiers::new(
+                        KeyboardKey::NXKey(key_code::NX_KEYTYPE_PLAY),
+                        vec![],
+                    )]
+                ),
+                kind: MapKind::Map,
+            },
+        );
+        default_maps.insert(
+            vec![HeadphoneButton::Down],
+            MapAction {
+                action: Action::Map(
+                    vec![KeyboardKeyWithModifiers::new(
+                        KeyboardKey::NXKey(key_code::NX_KEYTYPE_SOUND_DOWN),
+                        vec![],
+                    )]
+                ),
+                kind: MapKind::Map,
+            },
+        );
+
+        MapGroup {
+            maps: default_maps,
+            modes: HashMap::new(),
+        }
+    }
+}
+
 
 fn string_case_insensitive<I>(
     s: &'static str