From b1f8fc88a10d6b47583019cc1f7f57858c34e38b Mon Sep 17 00:00:00 2001
From: Keenan Wresch <keenan.wresch@gmail.com>
Date: Thu, 4 Jul 2024 10:22:42 -0400
Subject: [PATCH] Allow Shift + Scroll to Horizontally Scroll in X11 and
 Wayland (#13676)

Release Notes:

- Allows shift + scroll horizontal scrolling on X11 and Wayland.

[Screencast from 2024-06-29
17-17-59.webm](https://github.com/zed-industries/zed/assets/14155062/2cac77b9-ecc8-4ddb-b08d-b5d964c8dc84)
---
 crates/gpui/src/platform/linux/wayland/client.rs | 15 +++++++++++++++
 crates/gpui/src/platform/linux/x11/client.rs     |  7 ++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/crates/gpui/src/platform/linux/wayland/client.rs b/crates/gpui/src/platform/linux/wayland/client.rs
index 2728a141ee..dd645e959b 100644
--- a/crates/gpui/src/platform/linux/wayland/client.rs
+++ b/crates/gpui/src/platform/linux/wayland/client.rs
@@ -1508,6 +1508,11 @@ impl Dispatch<wl_pointer::WlPointer, ()> for WaylandClientStatePtr {
                 if state.axis_source == AxisSource::Wheel {
                     return;
                 }
+                let axis = if state.modifiers.shift {
+                    wl_pointer::Axis::HorizontalScroll
+                } else {
+                    axis
+                };
                 let axis_modifier = match axis {
                     wl_pointer::Axis::VerticalScroll => state.vertical_modifier,
                     wl_pointer::Axis::HorizontalScroll => state.horizontal_modifier,
@@ -1533,6 +1538,11 @@ impl Dispatch<wl_pointer::WlPointer, ()> for WaylandClientStatePtr {
                 discrete,
             } => {
                 state.scroll_event_received = true;
+                let axis = if state.modifiers.shift {
+                    wl_pointer::Axis::HorizontalScroll
+                } else {
+                    axis
+                };
                 let axis_modifier = match axis {
                     wl_pointer::Axis::VerticalScroll => state.vertical_modifier,
                     wl_pointer::Axis::HorizontalScroll => state.horizontal_modifier,
@@ -1555,6 +1565,11 @@ impl Dispatch<wl_pointer::WlPointer, ()> for WaylandClientStatePtr {
                 value120,
             } => {
                 state.scroll_event_received = true;
+                let axis = if state.modifiers.shift {
+                    wl_pointer::Axis::HorizontalScroll
+                } else {
+                    axis
+                };
                 let axis_modifier = match axis {
                     wl_pointer::Axis::VerticalScroll => state.vertical_modifier,
                     wl_pointer::Axis::HorizontalScroll => state.horizontal_modifier,
diff --git a/crates/gpui/src/platform/linux/x11/client.rs b/crates/gpui/src/platform/linux/x11/client.rs
index 39c0b0fd6d..27ee1c8ea4 100644
--- a/crates/gpui/src/platform/linux/x11/client.rs
+++ b/crates/gpui/src/platform/linux/x11/client.rs
@@ -817,10 +817,15 @@ impl X11Client {
 
                             if let Some(old_scroll) = old_scroll {
                                 let delta_scroll = old_scroll - new_scroll;
+                                let (x, y) = if !modifiers.shift {
+                                    (0.0, delta_scroll)
+                                } else {
+                                    (delta_scroll, 0.0)
+                                };
                                 window.handle_input(PlatformInput::ScrollWheel(
                                     crate::ScrollWheelEvent {
                                         position,
-                                        delta: ScrollDelta::Lines(Point::new(0.0, delta_scroll)),
+                                        delta: ScrollDelta::Lines(Point::new(x, y)),
                                         modifiers,
                                         touch_phase: TouchPhase::default(),
                                     },