1 files changed, 74 insertions, 0 deletions
diff --git a/dungeon/src/msg.rs b/dungeon/src/msg.rs
new file mode 100644
index 0000000..68a6cbd
--- /dev/null
+++ b/dungeon/src/msg.rs
@@ -0,0 +1,74 @@
+//! The `msg` crate contains the core functionality for
+//! the on screen message.
+
+use std::time::{Duration, Instant};
+
+use crate::player_input::PlayerInput;
+
+/// Duration between each character printed
+const DURATION_PER: Duration = Duration::from_millis(100);
+
+#[derive(Debug, Clone)]
+pub struct Message {
+	text: Option<Vec<u8>>,
+	end: usize,
+	waiting: bool,
+	last: Instant,
+}
+impl Message {
+	/// Returns the default empty message
+	pub fn empty() -> Self {
+		Self {
+			text: None,
+			end: 0,
+			waiting: false,
+			last: Instant::now(),
+		}
+	}
+
+	/// Sets string as the current onscreen message
+	pub fn set_message(&mut self, msg: &str) {
+		let bytes = msg.bytes().collect();
+		self.text = Some(bytes);
+		self.end = 0;
+	}
+
+	/// Attempts to update the message on screen.
+	/// Returns true if a character was printed
+	pub fn update(&mut self, input: PlayerInput) -> bool {
+		let Some(text) = &self.text else { return false };
+
+		if self.end >= text.len() {
+			if input.interact {
+				self.text = None;
+			}
+			return false;
+		}
+
+		if self.waiting && !input.interact {
+			return false;
+		}
+
+		if self.last.elapsed() < DURATION_PER {
+			return false;
+		}
+		self.last = Instant::now();
+
+		if text[self.end] == b'.' {
+			self.waiting = true;
+		}
+
+		self.end += 1;
+		true
+	}
+
+	/// Returns the current ascii message (if exists)
+	pub fn current(&self) -> Option<&[u8]> {
+		self.text.as_ref().map(|text| &text[..self.end])
+	}
+
+	/// Returns if the message box is visible
+	pub const fn visible(&self) -> bool {
+		self.text.is_some()
+	}
+}