Add benchmark example for Iced's Row/Column widgets

examples/huge_nested_row_column.rs

@@ -0,0 +1,120 @@
+use iced::{
+    widget::{column, row},
+    Alignment, Element, Length, Sandbox, Settings,
+};
+use iced_native::Renderer;
+use iced_taffy::{grid, Grid};
+use rand::prelude::*;
+use rand_chacha::ChaCha8Rng;
+use std::iter;
+use taffy::prelude::*;
+
+mod common {
+    pub mod colors;
+    pub mod layout_timer;
+    pub mod rect;
+}
+use common::colors::*;
+use common::layout_timer::LayoutTimer;
+use common::rect::rect;
+
+pub fn main() -> iced::Result {
+    Example::run(Settings::default())
+}
+
+struct Example {
+    click_count: u32,
+}
+
+#[derive(Debug, Clone, Copy)]
+enum Message {
+    Increment,
+}
+
+/// A helper function to recursively construct a deep tree
+pub fn build_deep_row_column_tree<'a, R: Rng, M: 'a, Rend: Renderer + 'a>(
+    rng: &mut R,
+    node_count: &mut usize,
+    levels: usize,
+    nodes_per_level: usize,
+) -> Vec<Element<'a, M, Rend>> {
+    *node_count += nodes_per_level;
+
+    if levels == 1 {
+        // Build leaf nodes
+        return (0..nodes_per_level)
+            .map(|_| rect(20.0, random_color(rng)).into())
+            .collect();
+    } else {
+        // Add another layer to the tree
+        // Each child gets an equal amount of the remaining nodes
+        return (0..nodes_per_level)
+            .map(|_| {
+                let children =
+                    build_deep_row_column_tree(rng, node_count, levels - 1, nodes_per_level);
+                if levels % 2 == 0 {
+                    row(children)
+                        .width(Length::Shrink)
+                        .height(Length::Shrink)
+                        .align_items(Alignment::Fill)
+                        .into()
+                } else {
+                    column(children)
+                        .width(Length::Shrink)
+                        .height(Length::Shrink)
+                        .align_items(Alignment::Fill)
+                        .into()
+                }
+            })
+            .collect();
+    }
+}
+
+/// A tree with a higher depth for a more realistic scenario
+fn build_deep_row_column_hierarchy<'a, M: 'a, Rend: Renderer + 'a>(
+    levels: usize,
+    nodes_per_level: usize,
+) -> Element<'a, M, Rend> {
+    let mut node_count = 0;
+    let mut rng = ChaCha8Rng::seed_from_u64(12345);
+    let children = build_deep_row_column_tree(&mut rng, &mut node_count, levels, nodes_per_level);
+    println!("node_count: {}", node_count);
+
+    if (levels + 1) % 2 == 0 {
+        row(children)
+            .width(Length::Shrink)
+            .height(Length::Shrink)
+            .align_items(Alignment::Fill)
+            .into()
+    } else {
+        column(children)
+            .width(Length::Shrink)
+            .height(Length::Shrink)
+            .align_items(Alignment::Fill)
+            .into()
+    }
+}
+
+impl Sandbox for Example {
+    type Message = Message;
+
+    fn new() -> Self {
+        Example { click_count: 0 }
+    }
+
+    fn title(&self) -> String {
+        String::from("Custom widget - Iced")
+    }
+
+    fn update(&mut self, message: Message) {
+        match message {
+            Message::Increment => {
+                self.click_count += 1;
+            }
+        }
+    }
+
+    fn view(&self) -> Element<Message> {
+        LayoutTimer::new(build_deep_row_column_hierarchy(12, 2)).into()
+    }
+}