1 files changed, 44 insertions, 0 deletions
diff --git a/seqmatcher.h b/seqmatcher.h
new file mode 100644
index 0000000..7ce6bf4
--- /dev/null
+++ b/seqmatcher.h
@@ -0,0 +1,44 @@
+#pragma once
+
+#include <functional>
+#include <vector>
+#include <variant>
+#include <unordered_map>
+#include <memory>
+#include "xutil.h"
+
+
+class SeqMatcher {
+public:
+	using Callback = std::function<void()>;
+
+	struct SymSequence {
+		std::vector<x::Keysym> syms;
+		Callback callback;
+	};
+
+	SeqMatcher(Display *dpy);
+
+	// Initialise with an initial list of sequences.
+	SeqMatcher(Display *dpy, std::vector<SymSequence> seqs);
+
+	// Register a key sequence
+	void addSequence(const std::vector<x::Keysym> &syms, Callback callback);
+
+	// Returns bel()-running callback if unrecognised sequence is given
+	std::optional<Callback> observe(const XKeyEvent &ev);
+
+	// Cancel any running sequence and restart from the beginning
+	void reset();
+
+private:
+	struct Node;
+	using NodeMap = std::unordered_map<x::Keycode, std::unique_ptr<Node>>;
+	struct Node {
+		std::variant<NodeMap, Callback> v;
+	};
+
+	Display *const dpy;
+	Node rootNode;
+	Node *curNode = &rootNode;
+};