From 45946fc75d5bf9525807e5cbc04e5c4c8da0f6e0 Mon Sep 17 00:00:00 2001
From: Ian Douglas Scott <idscott@system76.com>
Date: Wed, 27 Dec 2023 19:17:13 -0800
Subject: [PATCH] Add `map_to_output` input option for touch devices

---
 cosmic-comp-config/src/input.rs |  2 ++
 src/config/input_config.rs      |  1 +
 src/config/mod.rs               | 10 +++++++
 src/input/mod.rs                | 46 +++++++++++++++++++++++++++++----
 4 files changed, 54 insertions(+), 5 deletions(-)

diff --git a/cosmic-comp-config/src/input.rs b/cosmic-comp-config/src/input.rs
index 90f49c24..5ac4889e 100644
--- a/cosmic-comp-config/src/input.rs
+++ b/cosmic-comp-config/src/input.rs
@@ -27,6 +27,8 @@ pub struct InputConfig {
     pub scroll_config: Option<ScrollConfig>,
     #[serde(skip_serializing_if = "Option::is_none", default)]
     pub tap_config: Option<TapConfig>,
+    #[serde(skip_serializing_if = "Option::is_none", default)]
+    pub map_to_output: Option<String>,
 }
 
 #[derive(Clone, Debug, Default, PartialEq, Deserialize, Serialize)]
diff --git a/src/config/input_config.rs b/src/config/input_config.rs
index 063e80cf..6371a23b 100644
--- a/src/config/input_config.rs
+++ b/src/config/input_config.rs
@@ -79,6 +79,7 @@ pub fn for_device(device: &InputDevice) -> InputConfig {
         } else {
             None
         },
+        map_to_output: None,
     }
 }
 
diff --git a/src/config/mod.rs b/src/config/mod.rs
index fff0340e..a81ae6fd 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -426,6 +426,16 @@ impl Config {
         .map_or(1.0, |x| x.0)
     }
 
+    pub fn map_to_output(&self, device: &InputDevice) -> Option<&str> {
+        let (device_config, default_config) = self.get_device_config(device);
+        Some(
+            input_config::get_config(device_config, default_config, |x| {
+                x.map_to_output.as_deref()
+            })?
+            .0,
+        )
+    }
+
     fn get_device_config(&self, device: &InputDevice) -> (Option<&InputConfig>, &InputConfig) {
         let default_config = if device.config_tap_finger_count() > 0 {
             &self.input_touchpad
diff --git a/src/input/mod.rs b/src/input/mod.rs
index dcec5b6c..50580d10 100644
--- a/src/input/mod.rs
+++ b/src/input/mod.rs
@@ -41,7 +41,12 @@ use smithay::{
         Seat, SeatState,
     },
     output::Output,
-    reexports::wayland_server::DisplayHandle,
+    reexports::{
+        input::event::touch::{
+            TouchDownEvent as LibinputTouchDownEvent, TouchMotionEvent as LibinputTouchMotionEvent,
+        },
+        wayland_server::DisplayHandle,
+    },
     utils::{Point, Serial, SERIAL_COUNTER},
     wayland::{
         keyboard_shortcuts_inhibit::KeyboardShortcutsInhibitorSeat,
@@ -217,6 +222,8 @@ impl State {
         needs_key_repetition: bool,
     ) where
         <B as InputBackend>::PointerAxisEvent: 'static,
+        <B as InputBackend>::TouchDownEvent: 'static,
+        <B as InputBackend>::TouchMotionEvent: 'static,
     {
         use smithay::backend::input::Event;
         match event {
@@ -1167,9 +1174,23 @@ impl State {
             }
             InputEvent::TouchDown { event, .. } => {
                 if let Some(seat) = self.common.seat_with_device(&event.device()).cloned() {
-                    // TODO: Configuration option for mapping touch device to output
-                    // Is it possible to determine mapping for external touchscreen?
-                    let Some(output) = self.common.shell.builtin_output().cloned() else {
+                    // TODO Is it possible to determine mapping for external touchscreen?
+                    let map_to_output = if let Some(event) =
+                        <dyn Any>::downcast_ref::<LibinputTouchDownEvent>(&event)
+                    {
+                        self.common
+                            .config
+                            .map_to_output(&event.device())
+                            .and_then(|name| {
+                                self.common
+                                    .shell
+                                    .outputs()
+                                    .find(|output| output.name() == name)
+                            })
+                    } else {
+                        None
+                    };
+                    let Some(output) = map_to_output.or_else(|| self.common.shell.builtin_output()).cloned() else {
                         return;
                     };
 
@@ -1209,7 +1230,22 @@ impl State {
             }
             InputEvent::TouchMotion { event, .. } => {
                 if let Some(seat) = self.common.seat_with_device(&event.device()).cloned() {
-                    let Some(output) = self.common.shell.builtin_output().cloned() else {
+                    let map_to_output = if let Some(event) =
+                        <dyn Any>::downcast_ref::<LibinputTouchMotionEvent>(&event)
+                    {
+                        self.common
+                            .config
+                            .map_to_output(&event.device())
+                            .and_then(|name| {
+                                self.common
+                                    .shell
+                                    .outputs()
+                                    .find(|output| output.name() == name)
+                            })
+                    } else {
+                        None
+                    };
+                    let Some(output) = map_to_output.or_else(|| self.common.shell.builtin_output()).cloned() else {
                         return;
                     };