terminal: Add setting for scroll multiplier (#39463)

Closes #5130

Release Notes:

- Added setting option for scroll multiplier of the terminal

---------

Signed-off-by: Marco Mihai Condrache <52580954+marcocondrache@users.noreply.github.com>
Co-authored-by: MrSubidubi <finn@zed.dev>

assets/settings/default.json

@@ -1550,6 +1550,8 @@
     // Default: 10_000, maximum: 100_000 (all bigger values set will be treated as 100_000), 0 disables the scrolling.
     // Existing terminals will not pick up this change until they are recreated.
     "max_scroll_history_lines": 10000,
+    // The multiplier for scrolling speed in the terminal.
+    "scroll_multiplier": 1.0,
     // The minimum APCA perceptual contrast between foreground and background colors.
     // APCA (Accessible Perceptual Contrast Algorithm) is more accurate than WCAG 2.x,
     // especially for dark mode. Values range from 0 to 106.

crates/settings/src/settings_content/terminal.rs

@@ -116,6 +116,10 @@ pub struct TerminalSettingsContent {
     ///
     /// Default: 10_000
     pub max_scroll_history_lines: Option<usize>,
+    /// The multiplier for scrolling with the mouse wheel.
+    ///
+    /// Default: 1.0
+    pub scroll_multiplier: Option<f32>,
     /// Toolbar related settings
     pub toolbar: Option<TerminalToolbarContent>,
     /// Scrollbar-related settings

crates/settings/src/vscode_import.rs

@@ -737,6 +737,7 @@ impl VsCodeSettings {
             option_as_meta: self.read_bool("terminal.integrated.macOptionIsMeta"),
             project: self.project_terminal_settings_content(),
             scrollbar: None,
+            scroll_multiplier: None,
             toolbar: None,
         })
     }

crates/settings_ui/src/page_data.rs

@@ -5168,6 +5168,24 @@ pub(crate) fn settings_data(cx: &App) -> Vec<SettingsPage> {
                     metadata: None,
                     files: USER,
                 }),
+                SettingsPageItem::SettingItem(SettingItem {
+                    title: "Scroll Multiplier",
+                    description: "The multiplier for scrolling in the terminal with the mouse wheel",
+                    field: Box::new(SettingField {
+                        json_path: Some("terminal.scroll_multiplier"),
+                        pick: |settings_content| {
+                            settings_content.terminal.as_ref()?.scroll_multiplier.as_ref()
+                        },
+                        write: |settings_content, value| {
+                            settings_content
+                                .terminal
+                                .get_or_insert_default()
+                                .scroll_multiplier = value;
+                        },
+                    }),
+                    metadata: None,
+                    files: USER,
+                }),
                 SettingsPageItem::SectionHeader("Toolbar"),
                 SettingsPageItem::SettingItem(SettingItem {
                     title: "Breadcrumbs",

crates/terminal/src/terminal.rs

@@ -108,13 +108,6 @@ actions!(
     ]
 );
 
-///Scrolling is unbearably sluggish by default. Alacritty supports a configurable
-///Scroll multiplier that is set to 3 by default. This will be removed when I
-///Implement scroll bars.
-#[cfg(target_os = "macos")]
-const SCROLL_MULTIPLIER: f32 = 4.;
-#[cfg(not(target_os = "macos"))]
-const SCROLL_MULTIPLIER: f32 = 1.;
 const DEBUG_TERMINAL_WIDTH: Pixels = px(500.);
 const DEBUG_TERMINAL_HEIGHT: Pixels = px(30.);
 const DEBUG_CELL_WIDTH: Pixels = px(5.);
@@ -1890,10 +1883,11 @@ impl Terminal {
     }
 
     ///Scroll the terminal
-    pub fn scroll_wheel(&mut self, e: &ScrollWheelEvent) {
+    pub fn scroll_wheel(&mut self, e: &ScrollWheelEvent, scroll_multiplier: f32) {
         let mouse_mode = self.mouse_mode(e.shift);
+        let scroll_multiplier = if mouse_mode { 1. } else { scroll_multiplier };
 
-        if let Some(scroll_lines) = self.determine_scroll_lines(e, mouse_mode) {
+        if let Some(scroll_lines) = self.determine_scroll_lines(e, scroll_multiplier) {
             if mouse_mode {
                 let point = grid_point(
                     e.position - self.last_content.terminal_bounds.bounds.origin,
@@ -1926,8 +1920,11 @@ impl Terminal {
         self.word_from_position(window.mouse_position());
     }
 
-    fn determine_scroll_lines(&mut self, e: &ScrollWheelEvent, mouse_mode: bool) -> Option<i32> {
-        let scroll_multiplier = if mouse_mode { 1. } else { SCROLL_MULTIPLIER };
+    fn determine_scroll_lines(
+        &mut self,
+        e: &ScrollWheelEvent,
+        scroll_multiplier: f32,
+    ) -> Option<i32> {
         let line_height = self.last_content.terminal_bounds.line_height;
         match e.touch_phase {
             /* Reset scroll state on started */

crates/terminal/src/terminal_settings.rs

@@ -7,6 +7,7 @@ use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 
 pub use settings::AlternateScroll;
+
 use settings::{
     RegisterSetting, ShowScrollbar, TerminalBlink, TerminalDockPosition, TerminalLineHeight,
     VenvSettings, WorkingDirectory, merge_from::MergeFrom,
@@ -42,6 +43,7 @@ pub struct TerminalSettings {
     pub default_height: Pixels,
     pub detect_venv: VenvSettings,
     pub max_scroll_history_lines: Option<usize>,
+    pub scroll_multiplier: f32,
     pub toolbar: Toolbar,
     pub scrollbar: ScrollbarSettings,
     pub minimum_contrast: f32,
@@ -105,6 +107,7 @@ impl settings::Settings for TerminalSettings {
             default_width: px(user_content.default_width.unwrap()),
             default_height: px(user_content.default_height.unwrap()),
             detect_venv: project_content.detect_venv.unwrap(),
+            scroll_multiplier: user_content.scroll_multiplier.unwrap(),
             max_scroll_history_lines: user_content.max_scroll_history_lines,
             toolbar: Toolbar {
                 breadcrumbs: user_content.toolbar.unwrap().breadcrumbs.unwrap(),

crates/terminal_view/src/terminal_view.rs

@@ -519,7 +519,12 @@ impl TerminalView {
                 return;
             }
         }
-        self.terminal.update(cx, |term, _| term.scroll_wheel(event));
+        self.terminal.update(cx, |term, cx| {
+            term.scroll_wheel(
+                event,
+                TerminalSettings::get_global(cx).scroll_multiplier.max(0.01),
+            )
+        });
     }
 
     fn scroll_line_up(&mut self, _: &ScrollLineUp, _: &mut Window, cx: &mut Context<Self>) {

docs/src/configuring-zed.md

@@ -3586,6 +3586,7 @@ List of `integer` column numbers
     "option_as_meta": false,
     "button": true,
     "shell": "system",
+    "scroll_multiplier": 3.0,
     "toolbar": {
       "breadcrumbs": false
     },
@@ -3998,6 +3999,26 @@ Disable with:
 }
 ```
 
+### Terminal: Scroll Multiplier
+
+- Description: The multiplier for scrolling speed in the terminal when using mouse wheel or trackpad.
+- Setting: `scroll_multiplier`
+- Default: `1.0`
+
+**Options**
+
+Positive floating point values. Values less than or equal to 0 will be clamped to a minimum of 0.01.
+
+**Example**
+
+```json
+{
+  "terminal": {
+    "scroll_multiplier": 5.0
+  }
+}
+```
+
 ## Terminal: Toolbar
 
 - Description: Whether or not to show various elements in the terminal toolbar.