scroll sensitivity

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Added the coroutines `Animator.wait_until_complete` and `pilot.wait_for_scheduled_animations` that allow waiting for all current and scheduled animations https://github.com/Textualize/textual/issues/1658
 - Added the method `Animator.is_being_animated` that checks if an attribute of an object is being animated or is scheduled for animation
+- Added App.scroll_sensitivity to adjust how many lines the scroll wheel moves the scroll position https://github.com/orgs/Textualize/projects/5?pane=issue&itemId=12998591
+- Added Shift+scroll wheel and ctrl+scroll wheen to scroll horizontally
 
 ### Changed
 

src/textual/app.py

@@ -369,6 +369,8 @@ class App(Generic[ReturnType], DOMNode):
         self.css_path = css_paths
         self._registry: WeakSet[DOMNode] = WeakSet()
 
+        self.scroll_sensitivity: float = 3
+
         self._installed_screens: WeakValueDictionary[
             str, Screen | Callable[[], Screen]
         ] = WeakValueDictionary()

src/textual/widget.py

@@ -1575,7 +1575,7 @@ class Widget(DOMNode):
 
         """
         return self.scroll_to(
-            x=self.scroll_target_x - 1,
+            x=self.scroll_target_x - self.app.scroll_sensitivity,
             animate=animate,
             speed=speed,
             duration=duration,
@@ -1607,7 +1607,7 @@ class Widget(DOMNode):
 
         """
         return self.scroll_to(
-            x=self.scroll_target_x + 1,
+            x=self.scroll_target_x + self.app.scroll_sensitivity,
             animate=animate,
             speed=speed,
             duration=duration,
@@ -1639,7 +1639,7 @@ class Widget(DOMNode):
 
         """
         return self.scroll_to(
-            y=self.scroll_target_y + 1,
+            y=self.scroll_target_y + self.app.scroll_sensitivity,
             animate=animate,
             speed=speed,
             duration=duration,
@@ -1671,7 +1671,7 @@ class Widget(DOMNode):
 
         """
         return self.scroll_to(
-            y=self.scroll_target_y - 1,
+            y=self.scroll_target_y - +self.app.scroll_sensitivity,
             animate=animate,
             speed=speed,
             duration=duration,
@@ -2478,15 +2478,25 @@ class Widget(DOMNode):
         if self._has_focus_within:
             self.app.update_styles(self)
 
-    def _on_mouse_scroll_down(self, event) -> None:
-        if self.allow_vertical_scroll:
-            if self.scroll_down(animate=False):
-                event.stop()
+    def _on_mouse_scroll_down(self, event: events.MouseScrollDown) -> None:
+        if event.ctrl or event.shift:
+            if self.allow_horizontal_scroll:
+                if self.scroll_right(animate=False):
+                    event.stop()
+        else:
+            if self.allow_vertical_scroll:
+                if self.scroll_down(animate=False):
+                    event.stop()
 
-    def _on_mouse_scroll_up(self, event) -> None:
-        if self.allow_vertical_scroll:
-            if self.scroll_up(animate=False):
-                event.stop()
+    def _on_mouse_scroll_up(self, event: events.MouseScrollUp) -> None:
+        if event.ctrl or event.shift:
+            if self.allow_horizontal_scroll:
+                if self.scroll_left(animate=False):
+                    event.stop()
+        else:
+            if self.allow_vertical_scroll:
+                if self.scroll_up(animate=False):
+                    event.stop()
 
     def _on_scroll_to(self, message: ScrollTo) -> None:
         if self._allow_scroll: