Add ability to scroll popovers with vim (#12650)

Co-Authored-By: ahmadraheel@gmail.com



Release Notes:

- vim: allow scrolling the currently open information overlay using
`ctrl-{u,d,e,y}`etc. (#11883)

crates/editor/src/scroll/scroll_amount.rs

@@ -1,7 +1,8 @@
 use crate::Editor;
 use serde::Deserialize;
+use ui::{px, Pixels};
 
-#[derive(Clone, PartialEq, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Deserialize)]
 pub enum ScrollAmount {
     // Scroll N lines (positive is towards the end of the document)
     Line(f32),
@@ -25,4 +26,11 @@ impl ScrollAmount {
                 .unwrap_or(0.),
         }
     }
+
+    pub fn pixels(&self, line_height: Pixels, height: Pixels) -> Pixels {
+        match self {
+            ScrollAmount::Line(x) => px(line_height.0 * x),
+            ScrollAmount::Page(x) => px(height.0 * x),
+        }
+    }
 }