add state which is shared with the lua environment

1 files changed, 36 insertions, 0 deletions

diff --git a/src/state/mod.rs b/src/state/mod.rs
new file mode 100644
index 0000000..5efd770
--- /dev/null
+++ b/src/state/mod.rs
@@ -0,0 +1,36 @@
+use std::sync::{RwLock, RwLockReadGuard, RwLockWriteGuard};
+
+use mlua::{UserData, UserDataFields};
+
+
+pub mod sheetview;
+
+#[derive(Debug, Default)]
+pub struct GlobalState {
+    pub sheetview: sheetview::SheetViewState,
+}
+
+static GLOBAL_STATE: RwLock<GlobalState> = RwLock::new(GlobalState::new());
+const DUMMY_STATE: GlobalState = GlobalState::new();
+
+impl GlobalState {
+    const fn new() -> Self {
+        Self {
+            sheetview: sheetview::SheetViewState::new()
+        }
+    }
+
+    pub fn instance() -> RwLockReadGuard<'static, Self> {
+        GLOBAL_STATE.read().unwrap()
+    }
+
+    pub fn instance_mut() -> RwLockWriteGuard<'static, Self> {
+        GLOBAL_STATE.write().unwrap()
+    }
+}
+
+impl UserData for GlobalState {
+    fn add_fields<'lua, F: UserDataFields<'lua, Self>>(fields: &mut F) {
+        fields.add_field_function_get("sheetview", |_, _| Ok(DUMMY_STATE.sheetview))
+    }
+}