egui_extras: follow closure-based conventions for TableBody.heterogeneous_rows

egui_demo_lib/src/apps/demo/table_demo.rs

@@ -1,5 +1,5 @@
 use egui::TextStyle;
-use egui_extras::{Size, StripBuilder, TableBuilder, TableRow, TableRowBuilder};
+use egui_extras::{Size, StripBuilder, TableBuilder, TableRow};
 
 /// Shows off a table with dynamic layout
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
@@ -91,7 +91,7 @@ impl TableDemo {
                     });
                 });
             })
-            .body(|body| {
+            .body(|mut body| {
                 if !self.heterogeneous_rows {
                     body.rows(text_height, self.num_rows, |row_index, mut row| {
                         row.col(|ui| {
@@ -107,47 +107,27 @@ impl TableDemo {
                         });
                     });
                 } else {
-                    let row_builder = DemoRowBuilder {
+                    let rows = DemoRows::new(self.num_rows);
-                        row_count: self.num_rows,
+                    body.heterogeneous_rows(rows, DemoRows::populate_row);
-                    };
-                    body.heterogeneous_rows(row_builder);
                 }
             });
     }
 }
 
-struct DemoRowBuilder {
-    row_count: usize,
-}
-
 struct DemoRows {
     row_count: usize,
     current_row: usize,
 }
 
-impl Iterator for DemoRows {
+impl DemoRows {
-    type Item = f32;
+    fn new(row_count: usize) -> Self {
-
+        Self {
-    fn next(&mut self) -> Option<Self::Item> {
+            row_count,
-        if self.current_row < self.row_count {
+            current_row: 0,
-            let thick = self.current_row % 6 == 0;
-            self.current_row += 1;
-            Some(if thick { 30.0 } else { 18.0 })
-        } else {
-            None
         }
     }
-}
 
-impl TableRowBuilder for DemoRowBuilder {
+    fn populate_row(index: usize, mut row: TableRow<'_, '_>) {
-    fn row_heights(&self, _: &Vec<f32>) -> Box<dyn Iterator<Item = f32>> {
-        Box::new(DemoRows {
-            row_count: self.row_count,
-            current_row: 0,
-        })
-    }
-
-    fn populate_row(&self, index: usize, mut row: TableRow<'_, '_>) {
         let thick = index % 6 == 0;
         row.col(|ui| {
             ui.centered_and_justified(|ui| {
@@ -172,6 +152,20 @@ impl TableRowBuilder for DemoRowBuilder {
     }
 }
 
+impl Iterator for DemoRows {
+    type Item = f32;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.current_row < self.row_count {
+            let thick = self.current_row % 6 == 0;
+            self.current_row += 1;
+            Some(if thick { 30.0 } else { 18.0 })
+        } else {
+            None
+        }
+    }
+}
+
 fn clock_emoji(row_index: usize) -> String {
     char::from_u32(0x1f550 + row_index as u32 % 24)
         .unwrap()

egui_extras/src/table.rs

@@ -351,15 +351,16 @@ pub struct TableBody<'a> {
     end_y: f32,
 }
 
-pub trait TableRowBuilder {
-    fn row_heights(&self, widths: &Vec<f32>) -> Box<dyn Iterator<Item = f32> + '_>;
-    fn populate_row(&self, index: usize, row: TableRow<'_, '_>);
-}
-
 impl<'a> TableBody<'a> {
-    pub fn heterogeneous_rows(mut self, builder: impl TableRowBuilder) {
+    pub fn widths(&self) -> &Vec<f32> {
-        let mut heights = builder.row_heights(&self.widths);
+        &self.widths
+    }
 
+    pub fn heterogeneous_rows(
+        &mut self,
+        mut heights: impl Iterator<Item = f32>,
+        mut populate_row: impl FnMut(usize, TableRow<'_, '_>),
+    ) {
         let max_height = self.end_y - self.start_y;
         let delta = self.start_y - self.layout.current_y();
 
@@ -398,7 +399,7 @@ impl<'a> TableBody<'a> {
                     height: height,
                 };
                 self.row_nr += 1;
-                builder.populate_row(row_index, tr);
+                populate_row(row_index, tr);
                 row_index += 1;
                 current_height += height;
                 continue;