From d61a1735e9d938de7da4fa4cd9aa1f61429ebc59 Mon Sep 17 00:00:00 2001
From: Zach Gotsch <orbipedis@gmail.com>
Date: Mon, 5 Oct 2020 12:07:14 -0700
Subject: [PATCH] ui/text example: Use a unit component to identify the target
 Text (#612)

---
 examples/ui/text.rs | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/examples/ui/text.rs b/examples/ui/text.rs
index ecd7f08135..5bce8a5970 100644
--- a/examples/ui/text.rs
+++ b/examples/ui/text.rs
@@ -13,8 +13,11 @@ fn main() {
         .run();
 }
 
-fn text_update_system(diagnostics: Res<Diagnostics>, mut query: Query<&mut Text>) {
-    for mut text in &mut query.iter() {
+// A unit struct to help identify the FPS UI component, since there may be many Text components
+struct FpsText;
+
+fn text_update_system(diagnostics: Res<Diagnostics>, mut query: Query<(&mut Text, &FpsText)>) {
+    for (mut text, _tag) in &mut query.iter() {
         if let Some(fps) = diagnostics.get(FrameTimeDiagnosticsPlugin::FPS) {
             if let Some(average) = fps.average() {
                 text.value = format!("FPS: {:.2}", average);
@@ -43,5 +46,6 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
                 },
             },
             ..Default::default()
-        });
+        })
+        .with(FpsText);
 }