Pass scrolltop in custom Lua function

docs/en/src/general-config.md

@@ -42,9 +42,16 @@ Set it to `true` if you want to hide all remaps in the help menu.
 
 Type: boolean
 
-#### xplr.config.general.vimlike_scrolling
+#### xplr.config.general.paginated_scrolling
 
-Set it to `true` if you want vim-like scrolling.
+Set it to `true` if you want paginated scrolling.
+
+Type: boolean
+
+#### xplr.config.general.scroll_padding
+
+Set the padding value to the scroll area.
+Only applicable when `xplr.config.general.paginated_scrolling = false`.
 
 Type: boolean
 

docs/en/src/layout.md

@@ -495,6 +495,7 @@ It contains the following information:
 
 - [layout_size][37]
 - [screen_size][37]
+- [scrolltop][57]
 - [app][38]
 
 ### Size
@@ -508,6 +509,12 @@ It contains the following information:
 
 Every field is of integer type.
 
+### scrolltop
+
+Type: integer
+
+The start index of the visible nodes in the table.
+
 ### app
 
 This is a lightweight version of the [Lua Context][39]. In this context, the
@@ -587,3 +594,4 @@ Hence, only the following fields are available.
 [54]: borders.md#border-type
 [55]: #customlayout
 [56]: sum-type.md
+[57]: #scrolltop

docs/en/src/upgrade-guide.md

@@ -132,6 +132,8 @@ compatibility.
     `xplr.config.general.paginated_scrolling = true` to revert back to the
     paginated scrolling.
   - Set `xplr.config.general.scroll_padding` to customize the scroll padding.
+  - The calculated `scrolltop` value will be passed as part of the
+    `Content Rendeder Argument` in `Dynamic` layout renderer functions.
 
 Thanks to @noahmayr for contributing to a major part of this release.
 

src/init.lua

@@ -96,8 +96,8 @@ xplr.config.general.hide_remaps_in_help_menu = false
 -- Type: boolean
 xplr.config.general.paginated_scrolling = false
 
--- Set the padding value to the scroll area. Only applicable when
--- `xplr.config.general.paginated_scrolling` is set to `false`.
+-- Set the padding value to the scroll area.
+-- Only applicable when `xplr.config.general.paginated_scrolling = false`.
 --
 -- Type: boolean
 xplr.config.general.scroll_padding = 5

src/ui.rs

@@ -84,6 +84,7 @@ pub struct ContentRendererArg {
     pub app: app::LuaContextLight,
     pub screen_size: Rect,
     pub layout_size: Rect,
+    pub scrolltop: u16,
 }
 
 #[derive(Debug, Clone, Default, Serialize, Deserialize, PartialEq, Eq)]
@@ -743,7 +744,7 @@ pub fn block<'a>(config: PanelUiConfig, default_title: String) -> Block<'a> {
 pub struct UI<'lua> {
     pub lua: &'lua Lua,
     pub screen_size: TuiRect,
-    pub scrolltop: usize,
+    pub scrolltop: u16,
 }
 
 impl<'lua> UI<'lua> {
@@ -764,8 +765,7 @@ impl UI<'_> {
         let config = panel_config.default.clone().extend(&panel_config.table);
         let app_config = app.config.clone();
         let header_height = app_config.general.table.header.height.unwrap_or(1);
-        let height: usize =
-            (layout_size.height.max(header_height + 2) - (header_height + 2)).into();
+        let height: usize = layout_size.height.saturating_sub(header_height + 2).into();
         let row_style = app_config.general.table.row.style.clone();
 
         let rows = app
@@ -773,16 +773,17 @@ impl UI<'_> {
             .as_ref()
             .map(|dir| {
                 // Scroll
+                let padding = app.config.general.scroll_padding;
                 if app.config.general.paginated_scrolling {
                     // Paginated scrolling
                     self.scrolltop = height * (dir.focus / height.max(1))
                 } else {
-                    // vim-like-scrolling
+                    // Vim-like-scrolling
                     self.scrolltop = match dir.focus.cmp(&self.scrolltop) {
                         Ordering::Greater => {
                             // Scrolling down
                             if dir.focus >= self.scrolltop + height {
-                                dir.focus - height + 1
+                                dir.focus.saturating_sub(height + 1)
                             } else {
                                 self.scrolltop
                             }
@@ -792,7 +793,6 @@ impl UI<'_> {
                     };
 
                     // Add padding if possible
-                    let padding = app.config.general.scroll_padding;
                     if padding != 0 {
                         if dir.focus < self.scrolltop + padding {
                             self.scrolltop = dir.focus.saturating_sub(padding);
@@ -1326,6 +1326,7 @@ impl UI<'_> {
             app: app.to_lua_ctx_light(),
             layout_size: layout_size.into(),
             screen_size: self.screen_size.into(),
+            scrolltop: self.scrolltop,
         };
 
         let panel: CustomPanel = lua::serialize(self.lua, &ctx)