From 94479317b3b764d30f770b06736f193a67a57a54 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Thu, 20 May 2021 21:45:00 +0200
Subject: [PATCH] Add #[must_use] to container types: remind to call show()

---
 egui/src/containers/area.rs              | 1 +
 egui/src/containers/collapsing_header.rs | 1 +
 egui/src/containers/combo_box.rs         | 1 +
 egui/src/containers/frame.rs             | 1 +
 egui/src/containers/panel.rs             | 3 +++
 egui/src/containers/resize.rs            | 1 +
 egui/src/containers/scroll_area.rs       | 1 +
 egui/src/containers/window.rs            | 1 +
 egui/src/grid.rs                         | 1 +
 9 files changed, 11 insertions(+)

diff --git a/egui/src/containers/area.rs b/egui/src/containers/area.rs
index 194e75d2..9c10cc01 100644
--- a/egui/src/containers/area.rs
+++ b/egui/src/containers/area.rs
@@ -40,6 +40,7 @@ impl State {
 ///     .show(ctx, |ui| {
 ///         ui.label("Floating text!");
 ///     });
+#[must_use = "You should call .show()"]
 #[derive(Clone, Copy, Debug)]
 pub struct Area {
     pub(crate) id: Id,
diff --git a/egui/src/containers/collapsing_header.rs b/egui/src/containers/collapsing_header.rs
index 53657b27..0af5b04d 100644
--- a/egui/src/containers/collapsing_header.rs
+++ b/egui/src/containers/collapsing_header.rs
@@ -134,6 +134,7 @@ pub(crate) fn paint_icon(ui: &mut Ui, openness: f32, response: &Response) {
 /// // Short version:
 /// ui.collapsing("Heading", |ui| { ui.label("Contents"); });
 /// ```
+#[must_use = "You should call .show()"]
 pub struct CollapsingHeader {
     label: Label,
     default_open: bool,
diff --git a/egui/src/containers/combo_box.rs b/egui/src/containers/combo_box.rs
index 8f19ffcf..acc00c40 100644
--- a/egui/src/containers/combo_box.rs
+++ b/egui/src/containers/combo_box.rs
@@ -19,6 +19,7 @@ use epaint::Shape;
 ///     }
 /// );
 /// ```
+#[must_use = "You should call .show*"]
 pub struct ComboBox {
     id_source: Id,
     label: Option<Label>,
diff --git a/egui/src/containers/frame.rs b/egui/src/containers/frame.rs
index 00146109..36b272c6 100644
--- a/egui/src/containers/frame.rs
+++ b/egui/src/containers/frame.rs
@@ -5,6 +5,7 @@ use epaint::*;
 
 /// Color and margin of a rectangular background of a [`Ui`].
 #[derive(Clone, Copy, Debug, Default, PartialEq)]
+#[must_use = "You should call .show()"]
 pub struct Frame {
     /// On each side
     pub margin: Vec2,
diff --git a/egui/src/containers/panel.rs b/egui/src/containers/panel.rs
index e6cba26a..dd3a4bfc 100644
--- a/egui/src/containers/panel.rs
+++ b/egui/src/containers/panel.rs
@@ -23,6 +23,7 @@ use crate::*;
 ///    ui.label("Hello World!");
 /// });
 /// ```
+#[must_use = "You should call .show()"]
 pub struct SidePanel {
     id: Id,
     max_width: f32,
@@ -95,6 +96,7 @@ impl SidePanel {
 ///    ui.label("Hello World!");
 /// });
 /// ```
+#[must_use = "You should call .show()"]
 pub struct TopPanel {
     id: Id,
     max_height: Option<f32>,
@@ -171,6 +173,7 @@ impl TopPanel {
 ///    ui.label("Hello World!");
 /// });
 /// ```
+#[must_use = "You should call .show()"]
 #[derive(Default)]
 pub struct CentralPanel {
     frame: Option<Frame>,
diff --git a/egui/src/containers/resize.rs b/egui/src/containers/resize.rs
index df1f05d0..2450ad27 100644
--- a/egui/src/containers/resize.rs
+++ b/egui/src/containers/resize.rs
@@ -18,6 +18,7 @@ pub(crate) struct State {
 
 /// A region that can be resized by dragging the bottom right corner.
 #[derive(Clone, Copy, Debug)]
+#[must_use = "You should call .show()"]
 pub struct Resize {
     id: Option<Id>,
     id_source: Option<Id>,
diff --git a/egui/src/containers/scroll_area.rs b/egui/src/containers/scroll_area.rs
index 1e99e831..a54c402d 100644
--- a/egui/src/containers/scroll_area.rs
+++ b/egui/src/containers/scroll_area.rs
@@ -30,6 +30,7 @@ impl Default for State {
 // TODO: rename VScroll
 /// Add vertical scrolling to a contained [`Ui`].
 #[derive(Clone, Debug)]
+#[must_use = "You should call .show()"]
 pub struct ScrollArea {
     max_height: f32,
     always_show_scroll: bool,
diff --git a/egui/src/containers/window.rs b/egui/src/containers/window.rs
index 1da3d554..5501af7a 100644
--- a/egui/src/containers/window.rs
+++ b/egui/src/containers/window.rs
@@ -21,6 +21,7 @@ use super::*;
 /// egui::Window::new("My Window").show(ctx, |ui| {
 ///    ui.label("Hello World!");
 /// });
+#[must_use = "You should call .show()"]
 pub struct Window<'open> {
     title_label: Label,
     open: Option<&'open mut bool>,
diff --git a/egui/src/grid.rs b/egui/src/grid.rs
index b2c519e6..642e143b 100644
--- a/egui/src/grid.rs
+++ b/egui/src/grid.rs
@@ -246,6 +246,7 @@ impl GridLayout {
 ///     ui.end_row();
 /// });
 /// ```
+#[must_use = "You should call .show()"]
 pub struct Grid {
     id_source: Id,
     striped: bool,