Add a VERY experimental markdown viewer

egui_demo_lib/src/apps/demo/demo_windows.rs

@@ -13,17 +13,19 @@ struct Demos {
 impl Default for Demos {
     fn default() -> Self {
         let demos: Vec<Box<dyn super::Demo>> = vec![
-            Box::new(super::widget_gallery::WidgetGallery::default()),
-            Box::new(super::sliders::Sliders::default()),
-            Box::new(super::input_test::InputTest::default()),
-            Box::new(super::font_book::FontBook::default()),
-            Box::new(super::painting::Painting::default()),
             Box::new(super::dancing_strings::DancingStrings::default()),
             Box::new(super::drag_and_drop::DragAndDropDemo::default()),
-            Box::new(super::tests::Tests::default()),
-            Box::new(super::window_options::WindowOptions::default()),
+            Box::new(super::font_book::FontBook::default()),
+            Box::new(super::markdown_editor::MarkdownEditor::default()),
+            Box::new(super::painting::Painting::default()),
             Box::new(super::scrolling::Scrolling::default()),
+            Box::new(super::sliders::Sliders::default()),
+            Box::new(super::widget_gallery::WidgetGallery::default()),
+            Box::new(super::window_options::WindowOptions::default()),
+            // Tests:
             Box::new(super::layout_test::LayoutTest::default()),
+            Box::new(super::tests::IdTest::default()),
+            Box::new(super::input_test::InputTest::default()),
         ];
         Self {
             open: vec![false; demos.len()],

egui_demo_lib/src/apps/demo/layout_test.rs

@@ -29,7 +29,7 @@ impl Default for LayoutTest {
 
 impl super::Demo for LayoutTest {
     fn name(&self) -> &str {
-        "🖹 Layouts"
+        "🗺 Layout Test"
     }
 
     fn show(&mut self, ctx: &egui::CtxRef, open: &mut bool) {

egui_demo_lib/src/apps/demo/markdown_editor.rs

@@ -0,0 +1,66 @@
+use egui::*;
+
+#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
+#[derive(PartialEq)]
+pub struct MarkdownEditor {
+    markdown: String,
+}
+
+impl Default for MarkdownEditor {
+    fn default() -> Self {
+        Self {
+            markdown: r#"
+# Markdown editor
+Markdown support in egui is experimental, and *very* limited. There are:
+
+* bullet points
+  * with sub-points
+* `inline code`
+* *emphasis*
+* [hyperlinks](https://github.com/emilk/egui)
+
+---
+
+Also the separator
+
+                "#
+            .trim_start()
+            .to_owned(),
+        }
+    }
+}
+
+impl super::Demo for MarkdownEditor {
+    fn name(&self) -> &str {
+        "🖹 Markdown Editor"
+    }
+
+    fn show(&mut self, ctx: &egui::CtxRef, open: &mut bool) {
+        egui::Window::new(self.name()).open(open).show(ctx, |ui| {
+            use super::View;
+            self.ui(ui);
+        });
+    }
+}
+
+impl super::View for MarkdownEditor {
+    fn ui(&mut self, ui: &mut egui::Ui) {
+        ui.vertical_centered(|ui| {
+            egui::reset_button(ui, self);
+            ui.add(crate::__egui_github_link_file!());
+        });
+        ui.separator();
+        ui.columns(2, |columns| {
+            ScrollArea::auto_sized()
+                .id_source("source")
+                .show(&mut columns[0], |ui| {
+                    ui.text_edit_multiline(&mut self.markdown);
+                });
+            ScrollArea::auto_sized()
+                .id_source("rendered")
+                .show(&mut columns[1], |ui| {
+                    egui::experimental::markdown(ui, &self.markdown);
+                });
+        });
+    }
+}

egui_demo_lib/src/apps/demo/mod.rs

@@ -14,6 +14,7 @@ pub mod font_contents_emoji;
 pub mod font_contents_ubuntu;
 pub mod input_test;
 pub mod layout_test;
+pub mod markdown_editor;
 pub mod painting;
 pub mod scrolling;
 pub mod sliders;

egui_demo_lib/src/apps/demo/tests.rs

@@ -1,9 +1,9 @@
 #[derive(Default)]
-pub struct Tests {}
+pub struct IdTest {}
 
-impl super::Demo for Tests {
+impl super::Demo for IdTest {
     fn name(&self) -> &str {
-        "📋 Tests"
+        "📋 ID Test"
     }
 
     fn show(&mut self, ctx: &egui::CtxRef, open: &mut bool) {
@@ -14,7 +14,7 @@ impl super::Demo for Tests {
     }
 }
 
-impl super::View for Tests {
+impl super::View for IdTest {
     fn ui(&mut self, ui: &mut egui::Ui) {
         ui.heading("Name collision example");