input: add click method and middle button emulation

jay-config/src/input/clickmethod.rs

@@ -0,0 +1,18 @@
+//! Constants determining the click method of a device.
+//!
+//! See the libinput documentation for details.
+
+use serde::{Deserialize, Serialize};
+
+/// The click method of a device.
+#[derive(Serialize, Deserialize, Copy, Clone, Debug, Hash, Eq, PartialEq)]
+pub struct ClickMethod(pub u32);
+
+/// No click method handling
+pub const CLICK_METHOD_NONE: ClickMethod = ClickMethod(0);
+
+/// Button area
+pub const CLICK_METHOD_BUTTON_AREAS: ClickMethod = ClickMethod(1 << 0);
+
+/// Clickfinger
+pub const CLICK_METHOD_CLICKFINGER: ClickMethod = ClickMethod(1 << 1);