refactor easy_mark_viewer.rs: break it up into logical parts

egui/src/experimental/easy_mark_viewer.rs

@@ -3,74 +3,79 @@ use crate::*;
 
 /// Parse and display a VERY simple and small subset of Markdown.
 pub fn easy_mark(ui: &mut Ui, easy_mark: &str) {
+    easy_mark_it(ui, easy_mark::Parser::new(easy_mark))
+}
+
+pub fn easy_mark_it<'em>(ui: &mut Ui, items: impl Iterator<Item = easy_mark::Item<'em>>) {
     ui.horizontal_wrapped(|ui| {
-        let row_height = ui.fonts()[TextStyle::Body].row_height();
+        ui.spacing_mut().item_spacing = Vec2::zero();
-        let one_indent = row_height / 2.0;
+        for item in items {
-        let spacing = vec2(0.0, 2.0);
+            item_ui(ui, item);
-        let style = ui.style_mut();
-        style.spacing.interact_size.y = row_height;
-        style.spacing.item_spacing = spacing;
-
-        for item in easy_mark::Parser::new(easy_mark) {
-            match item {
-                easy_mark::Item::Newline => {
-                    // ui.label("\n"); // too much spacing (paragraph spacing)
-                    ui.allocate_exact_size(vec2(0.0, row_height), Sense::hover()); // make sure we take up some height
-                    ui.end_row();
-                }
-
-                easy_mark::Item::Text(style, text) => {
-                    ui.add(label_from_style(text, style));
-                }
-                easy_mark::Item::Hyperlink(style, text, url) => {
-                    let label = label_from_style(text, style);
-                    ui.add(Hyperlink::from_label_and_url(label, url));
-                }
-
-                easy_mark::Item::Separator => {
-                    ui.add(Separator::new().horizontal());
-                }
-                easy_mark::Item::Indentation(indent) => {
-                    let indent = indent as f32 * one_indent;
-                    ui.allocate_exact_size(vec2(indent, row_height), Sense::hover());
-                }
-                easy_mark::Item::QuoteIndent => {
-                    let rect = ui
-                        .allocate_exact_size(vec2(row_height, row_height), Sense::hover())
-                        .0;
-                    let rect = rect.expand2(spacing * 0.5);
-                    ui.painter().line_segment(
-                        [rect.center_top(), rect.center_bottom()],
-                        (1.0, ui.style().visuals.weak_text_color()),
-                    );
-                }
-                easy_mark::Item::BulletPoint => {
-                    ui.allocate_exact_size(vec2(one_indent, row_height), Sense::hover());
-                    bullet_point(ui, one_indent);
-                    ui.allocate_exact_size(vec2(one_indent, row_height), Sense::hover());
-                }
-                easy_mark::Item::NumberedPoint(number) => {
-                    let width = 3.0 * one_indent;
-                    numbered_point(ui, width, number);
-                    ui.allocate_exact_size(vec2(one_indent, row_height), Sense::hover());
-                }
-                easy_mark::Item::CodeBlock(_language, code) => {
-                    let where_to_put_background = ui.painter().add(Shape::Noop);
-                    let mut rect = ui.monospace(code).rect;
-                    rect = rect.expand(1.0); // looks better
-                    rect.max.x = ui.max_rect_finite().max.x;
-                    let code_bg_color = ui.style().visuals.code_bg_color;
-                    ui.painter().set(
-                        where_to_put_background,
-                        Shape::rect_filled(rect, 1.0, code_bg_color),
-                    );
-                }
-            };
         }
     });
 }
 
-fn label_from_style(text: &str, style: easy_mark::Style) -> Label {
+pub fn item_ui(ui: &mut Ui, item: easy_mark::Item<'_>) {
+    let row_height = ui.fonts()[TextStyle::Body].row_height();
+    let one_indent = row_height / 2.0;
+
+    match item {
+        easy_mark::Item::Newline => {
+            // ui.label("\n"); // too much spacing (paragraph spacing)
+            ui.allocate_exact_size(vec2(0.0, row_height), Sense::hover()); // make sure we take up some height
+            ui.end_row();
+        }
+
+        easy_mark::Item::Text(style, text) => {
+            ui.add(label_from_style(text, &style));
+        }
+        easy_mark::Item::Hyperlink(style, text, url) => {
+            let label = label_from_style(text, &style);
+            ui.add(Hyperlink::from_label_and_url(label, url));
+        }
+
+        easy_mark::Item::Separator => {
+            ui.add(Separator::new().horizontal());
+        }
+        easy_mark::Item::Indentation(indent) => {
+            let indent = indent as f32 * one_indent;
+            ui.allocate_exact_size(vec2(indent, row_height), Sense::hover());
+        }
+        easy_mark::Item::QuoteIndent => {
+            let rect = ui
+                .allocate_exact_size(vec2(2.0 * one_indent, row_height), Sense::hover())
+                .0;
+            let rect = rect.expand2(ui.style().spacing.item_spacing * 0.5);
+            ui.painter().line_segment(
+                [rect.center_top(), rect.center_bottom()],
+                (1.0, ui.style().visuals.weak_text_color()),
+            );
+        }
+        easy_mark::Item::BulletPoint => {
+            ui.allocate_exact_size(vec2(one_indent, row_height), Sense::hover());
+            bullet_point(ui, one_indent);
+            ui.allocate_exact_size(vec2(one_indent, row_height), Sense::hover());
+        }
+        easy_mark::Item::NumberedPoint(number) => {
+            let width = 3.0 * one_indent;
+            numbered_point(ui, width, number);
+            ui.allocate_exact_size(vec2(one_indent, row_height), Sense::hover());
+        }
+        easy_mark::Item::CodeBlock(_language, code) => {
+            let where_to_put_background = ui.painter().add(Shape::Noop);
+            let mut rect = ui.monospace(code).rect;
+            rect = rect.expand(1.0); // looks better
+            rect.max.x = ui.max_rect_finite().max.x;
+            let code_bg_color = ui.style().visuals.code_bg_color;
+            ui.painter().set(
+                where_to_put_background,
+                Shape::rect_filled(rect, 1.0, code_bg_color),
+            );
+        }
+    };
+}
+
+fn label_from_style(text: &str, style: &easy_mark::Style) -> Label {
     let easy_mark::Style {
         heading,
         quoted,
@@ -79,7 +84,7 @@ fn label_from_style(text: &str, style: easy_mark::Style) -> Label {
         underline,
         strikethrough,
         italics,
-    } = style;
+    } = *style;
 
     let mut label = Label::new(text);
     if heading {