Track/cache button state and mods state

src/input/mouse.zig

@@ -0,0 +1,38 @@
+/// The state of a mouse button.
+pub const MouseButtonState = enum(u1) {
+    release = 0,
+    press = 1,
+};
+
+/// Possible mouse buttons. We only track up to 11 because thats the maximum
+/// button input that terminal mouse tracking handles without becoming
+/// ambiguous.
+///
+/// Its a bit silly to name numbers like this but given its a restricted
+/// set, it feels better than passing around raw numeric literals.
+pub const MouseButton = enum(u4) {
+    const Self = @This();
+
+    /// The maximum value in this enum. This can be used to create a densely
+    /// packed array, for example.
+    pub const max = max: {
+        var cur = 0;
+        for (@typeInfo(Self).Enum.fields) |field| {
+            if (field.value > cur) cur = field.value;
+        }
+
+        break :max cur;
+    };
+
+    left = 1,
+    right = 2,
+    middle = 3,
+    four = 4,
+    five = 5,
+    six = 6,
+    seven = 7,
+    eight = 8,
+    nine = 9,
+    ten = 10,
+    eleven = 11,
+};